U.S. patent application number 09/992813 was filed with the patent office on 2003-01-09 for method of synchronizing independently distributed software and database schema.
Invention is credited to Brodersen, Robert A., Chatterjee, Prashant, Coker, John L., Lim, Peter S..
Application Number | 20030009753 09/992813 |
Document ID | / |
Family ID | 21911513 |
Filed Date | 2003-01-09 |
United States Patent
Application |
20030009753 |
Kind Code |
A1 |
Brodersen, Robert A. ; et
al. |
January 9, 2003 |
Method of synchronizing independently distributed software and
database schema
Abstract
Upgrading a software application from one or more upgrade
package files in a server (1) to a client (21a, 21b, 21c).
According to this method a copy of the upgrade package files and an
upgrade database table are created on the server (1). A pointer is
created in the client's (21a, 21b, 21c) file on the server (1).
This pointer points to the upgrade package files on the server (1);
In invoking the upgrade the, the upgrade files are made active, and
the upgrade database table is scanned when a client (21a, 21b, 21c)
docks. This is to determine the status of an upgrade with respect
to the particular client (21a, 21b, 21c). The upgrade is copied to
the client (21a, 21b, 21c) if the client (21a, 21b, 21c) has not
received the upgrade. At this point the upgrade may be invoked at
the client (21a, 21b, 21c). Also disclosed is a program product
carrying code for the upgrade method.
Inventors: |
Brodersen, Robert A.;
(Redwood City, CA) ; Chatterjee, Prashant;
(Saratoga, CA) ; Coker, John L.; (Hillsborough,
CA) ; Lim, Peter S.; (Redwood City, CA) |
Correspondence
Address: |
COOLEY GODWARD LLP
ATTN: PATENT GROUP
11951 FREEDOM DRIVE, SUITE 1700
ONE FREEDOM SQUARE- RESTON TOWN CENTER
RESTON
VA
20190-5061
US
|
Family ID: |
21911513 |
Appl. No.: |
09/992813 |
Filed: |
November 27, 2001 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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09992813 |
Nov 27, 2001 |
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09375427 |
Aug 17, 1999 |
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6324693 |
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09375427 |
Aug 17, 1999 |
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PCT/US98/03572 |
Feb 24, 1998 |
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60040534 |
Feb 27, 1997 |
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Current U.S.
Class: |
717/172 ;
717/169 |
Current CPC
Class: |
Y10S 707/99953 20130101;
G06F 8/65 20130101; Y10S 707/99954 20130101 |
Class at
Publication: |
717/172 ;
717/169 |
International
Class: |
G06F 009/445 |
Claims
We claim:
1. A method of upgrading a software application from upgrade
package files in a server (1) to a client (21a, 21b, 21c)
comprising the steps of: a) creating a copy of the upgrade package
files on the server (1); b) creating an upgrade database table on
the server (1); b) creating a pointer in the client's (21a, 21b,
21c) file on the server (1) pointing to the upgrade package files
on the server (1); c) making the upgrade active; d) scanning the
upgrade database table when a client (21a, 21b, 21c) docks to
determine the status of an upgrade with respect to the client (21a,
21b, 21c); d) copying the upgrade to a client (21a, 21b, 21c) if
the client (21a, 21b, 21c) has not received the upgrade; and e)
invoking the upgrade at the client (21a, 21b, 21c).
2. The method of claim 1 comprising invoking the upgrade at the
beginning of a client (21a, 21b, 21c) session.
3. The method of claim 1 comprising invoking the upgrade at the end
of a client (21a, 21b, 21c) session.
4. The method of claim 1 comprising invoking the upgrade at the
client's (21a, 21b, 21c) option.
5. The method of claim 1 comprising invoking the upgrade at the
server's (1) option.
6. The method of claim 1 comprising creating a docking item file
type to scan the upgrade database table when the client (21a, 21b,
21c) docks to thereby determine the status of an upgrade with
respect to the client (21a, 21b, 21c).
7. An article of manufacture comprising a computer usable medium
having computer program code means embodied therein for causing
upgrading a software application from upgrade package files in a
server (1) to a client (21a, 21b, 21c), the computer readable
program means in said article of manufacture comprising: a)
computer readable program code means for causing a computer to
effect creating a copy of the upgrade package files on the server
(1); b) computer readable program code means for causing a computer
to effect creating an upgrade database table on the server (1); b)
computer readable program code means for causing a computer to
effect creating a pointer in the client's (21a, 21b, 21c) file on
the server (1) pointing to the upgrade package files on the server
(1); c) computer readable program code means for causing a computer
to effect making the upgrade active; d) computer readable program
code means for causing a computer to effect scanning the upgrade
database table when a client (21a, 21b, 21c) docks to determine the
status of an upgrade with respect to the client (21a, 21b, 21c); d)
computer readable program code means for causing a computer to
effect copying the upgrade to a client (21a, 21b, 21c) if the
client (21a, 21b, 21c) has not received the upgrade; and e)
computer readable program code means for causing a computer to
effect invoking the upgrade at the client (21a, 21b, 21c).
8. The article of manufacture of claim 7 further comprising
computer readable program code means for causing a computer to
effect invoking the upgrade at the beginning of a client (21a, 21b,
21c) session.
9. The article of manufacture of claim 7 further comprising
computer readable program code means for causing a computer to
effect invoking the upgrade at the end of a client (21a, 21b, 21c)
session.
10. The article of manufacture of claim 7 further comprising
computer readable program code means for causing a computer to
effect invoking the upgrade at the client's (21a, 21b, 21c)
option.
11. The article of manufacture of claim 7 further comprising
computer readable program code means for causing a computer to
effect invoking the upgrade at the server's (1) option.
12. The article of manufacture of claim 7 further comprising
computer readable program code means for causing a computer to
effect creating a docking item file type to scan the upgrade
database table when the client (21a, 21b, 21c) docks to thereby
determine the status of an upgrade with respect to the client (21a,
21b, 21c).
13. A program storage device readable by a machine, tangibly
embodying a program of instructions executable by a machine to
perform method steps for of upgrading a software application from
upgrade package files in a server (1) to a client (21a, 21b, 21c)
said method steps comprising: a) creating a copy of the upgrade
package files on the server (1); b) creating an upgrade database
table on the server (1); b) creating a pointer in the client's
(21a, 21b, 21c) file on the server (1) pointing to the upgrade
package files on the server (1); c) making the upgrade active; d)
scanning the upgrade database table when a client (21a, 21b, 21c)
docks to determine the status of an upgrade with respect to the
client (21a, 21b, 21c); d) copying the upgrade to a client (21a,
21b, 21c) if the client (21a, 21b, 21c) has not received the
upgrade; and e) invoking the upgrade at the client (21a, 21b,
21c).
14. The program storage device of claim 13 wherein said method
steps further comprise invoking the upgrade at the beginning of a
client (21a, 21b, 21c) session.
15. The program storage device of claim 13 wherein said method
steps further comprise invoking the upgrade at the end of a client
(21a, 21b, 21c) session.
16. The program storage device of claim 13 wherein said method
steps further comprise invoking the upgrade at the client's (21a,
21b, 21c) option.
17. The program storage device of claim 13 wherein said method
steps further comprise invoking the upgrade at the server's (1)
option.
18. The program storage device of claim 13 wherein said method
steps further comprise creating a docking item file type to scan
the upgrade database table when the client (21a, 21b, 21c) docks to
thereby determine the status of an upgrade with respect to the
client (21a, 21b, 21c).
Description
INTRODUCTION
[0001] I. Technical Field
[0002] This invention relates to a system and method for providing
updates to a network of partially replicated relational database
systems, and, more particularly, for providing an efficient means
for computing the visibility to a client on the network of a
transaction processed against the database.
[0003] II. Background
[0004] Relational databases are a commonly-employed data structure
for representing data in a business or other environment. A
relational database represents data in the form of a collection of
two-dimensional tables. Each table comprises a series of cells
arranged in rows and columns. Typically, a row in a table
represents a particular observation. A column represents either a
data field or a pointer to a row in another table.
[0005] For example, a database describing an organizational
structure may have one table to describe each position in the
organization, and another table to describe each employee in the
organization. The employee table may include information specific
to the employee, such as name, employee number, age, salary, etc.
The position table may include information specific to the
position, such as the position title ("salesman", "vice president",
etc.), a salary range, and the like. The tables may be related by,
for example, providing in each row of the employee table a pointer
to a particular row in the position table, coordinated so that, for
each row in the employee table, there is a pointer to the
particular row in the position table that describes that employee's
position. A relational database management system (RDBMS) supports
"joining" these tables in response to a query from a user, so that
the user making a query about, for example, a particular employee,
may be provided with a report of the selected employee, including
not only the information in the employee table, but also the
information in the related position table.
[0006] Relational databases may be much more complex than this
example, with several tables and a multiplicity of relations among
them.
[0007] With the widespread use of inexpensive portable computers,
it is advantageous to replicate a database onto a portable computer
for reference at locations remote from the central computer. The
replicated database may then be referenced by the user of the
portable computer, without requiring reference to the main
database, which may be maintained at a central location
inconvenient to the user of the portable computer. However, there
are a number of difficulties with the use of a replicated
database.
[0008] One disadvantage is that a full copy of the central database
may require more data storage than is desired or economical. For
example, a salesman working in the field may need to refer to the
database for information regarding sales opportunities in his sales
area, but have no need to refer to any information regarding sales
opportunities outside of his area. One possible approach to reduce
the amount of required data storage is to simply replicate only
that portion of the database that is needed by the user. However,
this approach does not recognize that the criteria to determine
which portions of the data are required is likely to vary over
time. For example, the salesman may have a new city added to his
territory. Under conventional approaches, the salesman would need
to re-replicate his local copy of the database, this time selecting
data including the added city. Such a practice is inconvenient,
subject to error, and time-consuming.
[0009] A further disadvantage to a replicated database is the
difficulties encountered in attempting to update data using the
replicated copy. A change made to the replicated database is not
made to the central database, leading to a discrepancy between the
information that is stored in the replicated copy of the database
and the information that is stored in the central database.
Although it is possible to journal modifications made to the
replicated copy and apply an identical modification to the central
database, one problem that this approach faces is the possibility
of colliding updates; that is, where a user of a replicated copy
makes a change to data that is also changed by a user of the
central copy or by the user of another replicated copy.
[0010] It is therefore desirable to provide a capability to
maintain one or more partially-replicated copies of a central
database, in such a way that the degree of replication may be
easily changed without requiring a refresh of the entire replicated
database, and that permits updates to be coordinated among users of
the central database and users of the partially replicated
databases.
SUMMARY OF THE INVENTION
[0011] The present invention is directed to a method of maintaining
a partially replicated database in such a way that updates made to
a central database, or to another partially replicated database,
are selectively propagated to the partially replicated database.
Updates are propagated to a partially replicated database if the
owner of the partially replicated database is deemed to have
visibility to the data being updated. Visibility is determined by
use of predetermined rules stored in a rules database. In one
aspect of the invention, the stored rules are assessed against data
content of various tables that make up a logical entity, known as a
docking object, that is being updated.
[0012] In another aspect of the invention, the stored rules are
assessed against data content of one or more docking objects that
are not necessarily updated, but that are related to a docking
object being updated. In one embodiment, the visibility attributes
of the related docking objects are recursively determined.
[0013] In yet another aspect of the invention, changes in
visibility are determined to enable the central computer to direct
the nodes to insert the docking object into its partially
replicated database. Such changes in visibility are determined so
as to enable the central computer to direct a node to remove a
docking object from its partially replicated database.
[0014] In a further aspect of the invention, the predetermined
rules are in declarative form and specify visibility of data based
upon structure of the data without reference to data content.
[0015] In still another aspect of the invention, the levels of the
database schema and the database access software are synchronized
to prevent an updated schema from being processed by a back-level
version of software.
[0016] A still further aspect of our invention is a method of
upgrading a software application from one or more upgrade package
files in a server (1) to a client (21a, 21b, 21c). According to
this method a copy of the upgrade package files and an upgrade
database table are created on the server (1). A pointer is created
in the client's (21a, 21b, 21c) file on the server (1). This
pointer points to the upgrade package files on the server (1). In
invoking the upgrade the, the upgrade files are made active, and
the upgrade database table is scanned when a client (21a, 21b, 21c)
docks. This is to determine the status of an upgrade with respect
to the particular client (21a, 21b, 21c). The upgrade is copied to
the client (21a, 21b, 21c) if the client (21a, 21b, 21c) has not
received the upgrade. At this point the upgrade may be invoked at
the client (21a, 21b, 21c).
[0017] A still further aspect of our invention is a program product
article of manufacture encompassing a computer usable medium with
computer program code embodied therein for causing the upgrading of
a software application from upgrade package files in a server (1)
to a client (21a, 21b, 21c). The computer readable program in the
program product article of manufacture contains computer readable
program code means for causing a computer to effect creating a copy
of the upgrade package files on the server (1), creating an upgrade
database table on the server (1); creating a pointer in the
client's (21a, 21b, 21c) file on the server (1) pointing to the
upgrade package files on the server (1), making the upgrade active,
scanning the upgrade database table when a client (21a, 21b, 21c)
docks to determine the status of an upgrade with respect to the
client (21a, 21b, 21c), copying the upgrade to a client (21a, 21b,
21c) if the client (21a, 21b, 21c) has not received the upgrade,
and invoking the upgrade at the client (21a, 21b, 21c).
[0018] A even further aspect of our invention is a program product
in the form of a program storage device readable by a machine,
tangibly embodying a program of instructions executable by a
machine to perform method steps for of upgrading a software
application from upgrade package files in a server (1) to a client
(21a, 21b, 21c) said method steps comprising creating a copy of the
upgrade package files on the server (1), creating an upgrade
database table on the server (1); creating a pointer in the
client's (21a, 21b, 21c) file on the server (1) pointing to the
upgrade package files on the server (1), making the upgrade active,
scanning the upgrade database table when a client (21a, 21b, 21c)
docks to determine the status of an upgrade with respect to the
client (21a, 21b, 21c), copying the upgrade to a client (21a, 21b,
21c) if the client (21a, 21b, 21c) has not received the upgrade,
and invoking the upgrade at the client (21a, 21b, 21c).
BRIEF DESCRIPTION OF THE DRAWINGS
[0019] FIG. 1 depicts an overview of the operation of one
embodiment of the present invention.
[0020] FIG. 2 depicts a database schema that shows the relationship
of the various components that make up a Docking Object.
[0021] FIG. 3 depicts steps performed by an update manager to
update a database.
[0022] FIG. 4 depicts steps performed by a Docking Manager to
transmit and/or receive one or more transaction logs.
[0023] FIG. 5 depicts the steps performed by a merge processor to
merge transaction log records into an existing database.
[0024] FIG. 6 depicts the steps performed by a log manager to
prepare a partial transaction log.
[0025] FIG. 7 depicts the steps performed by a visibility
calculator for calculating visibility for a docking object as
invoked by a log manager.
[0026] FIG. 8 depicts the steps performed to synchronize a
partially replicated database in response to a change in data
visibility.
DESCRIPTION OF SPECIFIC EMBODIMENTS
[0027] Overview
[0028] FIG. 1 depicts an overview of the operation of one
embodiment of the present invention. FIG. 1 depicts a central
computer system 1 and three remote computer systems (or "nodes")
21-a, 21-b, and 21-c. Each of nodes 21-a, 21-b and 21-c are
depicted in various states of communication with central computer
system 1, as will be more fully explained. Central computer system
1 includes a central database 3, a docking manager 5, a merge
processor 7 and a log manager 9. Central computer system 1
additionally optionally includes update manager 11 responsive to
user input 13.
[0029] Node 21-a is a remote computer system, such as a mobile
client such as a laptop computer. Node 21-a includes a partially
replicated remote database 23-a, update manager 31-a responsive to
user input 33-a, docking manager 25-a and merge manager 27-a. In
operation, update manager is responsive to user input 33-a to make
changes to remote database 23-a as directed by the operator of node
21-a. Updates made are recorded, or journaled, in node update log
35-a.
[0030] At some point at the convenience of the operator of node
21-a, node docking manager 35-a is activated, and enters into
communication with central docking manager 5. Update log 35-a is
taken as input by node docking manager 25-a, and provided to
central docking manager 5. Central docking manager 5 creates a
received node update log 19, which contains all the information
that had been recorded in update log 35-a. Optionally, partial log
17-a is taken as input by central docking manager 5 and provided to
node docking manager 25-a, as more fully described herein.
[0031] At some point in time, at the convenience of the operator of
central computer system 1, merge processor 7 is activated. Merge
processor 7 takes as input received node update log 19, and applies
the updates described therein to central database 3. In the process
of applying the updates from received node update log 19, merge
processor journals the updates applied to central update log 15.
Optionally, update manager 11, responsive to user input 12 makes
additional changed to central database 3 as directed by the
operator of central computer system 1. The updates made by update
manager 11 are additionally journaled in central update log 15.
[0032] At some point in time, at the convenience of the operator of
central computer system 1, log manager 9 is activated. Log manager
9 takes as input central update log 15 and produces as output a set
of partial logs 17-a, 17-b and 17-c according to visibility rules
as will be further described herein. Each of partial logs 17-a,
17-b and 17-c corresponds to one of nodes 21-a, 21-b and 21-c. When
a node docking manager such as node docking manager 25-a enters
into communication with central docking manager 5 and optionally
requests transmission of its corresponding partial log, central
docking manager 5 takes as input the appropriate partial log, such
as partial log 17-a, and presents it to node docking manager 25-a.
Node docking manager 25-a then replicates partial log 17-a as merge
log 37-a.
[0033] At some point in the future, at the convenience of the
operator of node 21-a, merge processor 27-a is activated. Merge
processor 27-a takes as input merge log 37-a, and applies the
updates described therein to partially replicated database
23-a.
[0034] In addition to node 21-a, FIG. 1 also depicts two additional
nodes 21-b and 21-c. Node 21-b is depicted in communication with
central computer 1. However, unlike node 21-a, the operator of node
21-b has requested only to send his updates to central computer
system 1, and has not requested to be presented with changes made
elsewhere to be made to his partially replicated database 23-b.
This may be, for example, if the operator has an urgent update that
must be made as soon as possible, but does not have the time to
receive updates from other nodes. Accordingly, FIG. 1 shows only
transmission of node update log 35-a from node docking manager 25-b
to central docking manager 5, and no transmission from central
docking manager 5 to node docking manager 25-b. Accordingly, the
merge manager for node 21-b is not activated and is not shown.
[0035] Likewise, node 21-c is depicted as not in communication with
central computer system 1. Accordingly, the docking manager for
node 21-c is not activated and is not shown.
[0036] By the cycle described above, updates made by each of nodes
21-a, 21-b and 21-c are presented to central computer system 1,
permitting central database 3 to be updated accordingly. In
addition, each of the updates made by each of the nodes 21-a, 21-b
and 21-c, as well as updates made on central computer system 1, are
routed back to each of nodes 21-a, 21-b, and 21-c, thereby keeping
each of partial databases 23-a, 23-b and 23-c in synchronization
with each other and with central database 3.
[0037] Database Structure
[0038] The synchronization of central database 3 with node
databases 23-a, 23-b and 23-c is performed using a construct called
a Docking Object. A Docking Object consists of Member Tables
(including one Primary Table), Visibility Rules, Visibility Events,
and related Docking Objects.
[0039] A Member Table is a table of the relational database that
makes up a docking object. When a docking object is propagated from
central database 3 to one of node databases 23-a, 23-b or 23-c, the
propagation takes the form of an insertion into each of the Member
Tables associated with the particular docking object. Similarly,
when a docking object is scheduled to be removed from a database,
that removal consists of deleting records from the member tables
associated with the docking object. For example, a docking object
that represents a sales opportunity may include tables that
represent the opportunity itself (e.g., named "S_OPTY"), the
product whose sale is represented by the opportunity (e.g., named
"S_OPTY_PROD"), the contact for the opportunity (e.g., named
"S_OPTY_CONTACT"), etc. Each of these tables is said to be a member
table of the "Opportunity Docking Object."
[0040] A Primary Table is a Member Table that controls whether a
particular instance of a Docking Object is visible to a particular
node. The Primary Table has a Primary Row-ID value that is used to
identify a row of the Primary Table being updated, deleted or
inserted. For example, the "Opportunity Docking Object" may have as
a primary table the table S_OPTY. The row-id of that table, i.e.,
S_OPTY.row_id, is the Primary Row-ID for the Opportunity Docking
Object.
[0041] A Visibility Rule is a criterion that determines whether a
particular instance of a Docking Object is "visible" to a
particular node 21. If a Docking Object is visible to a particular
node, that node will receive updates for data in the Docking
Object. Visibility Rules are of two types, depending on the field
RULE_TYPE. A Visibility Rule with a RULE TYPE of "R" is referred to
as an SQL Rule. An SQL Rule includes a set of Structured Query
Language (SQL) statements that is evaluated to determine if any
data meeting the criteria specified in the SQL statements exists in
the Docking Object. If so, the Docking Object is visible to the
node. A Visibility Rule with a RULE_TYPE of "O" is referred to as a
Docking Object Rule. A Docking Object Rule specifies another
Docking Object to be queried for visibility. If the specified
Docking Object is visible, then the Docking Object pointing to it
is also visible.
[0042] A Related Docking Object is a Docking Object that is
propagated or deleted when the Docking Object under consideration
is propagated or deleted. For example, an Opportunity Docking
Object may have related Docking Objects representing the sales
contacts, the organizations, the products to be sold, and the
activities needed to pursue the opportunity. When an Opportunity
Docking Object is propagated from Central Database 3 to one of node
databases 23, the related docking objects are also propagated.
[0043] FIG. 2 depicts a database schema that shows the relationship
of the various components that make up a Docking Object. The schema
is a meta-database, in that it does not describe the data being
accessed in the database. Rather, the schema is a separate database
that defines the structure of the database being accessed. That is,
it is a database comprising tables that describe the relationships
and data contexts of another database.
[0044] Each of the tables shown in FIG. 2 is a table in a
relational database, and as such is in row-column form. Many
columns represent fields that are common to all the illustrated
tables. Such fields include for example, a ROW_ID to identify a
particular row in the table, as well as fields to tack the date and
time that a row was created and last modified, and the identity of
the user who created or modified the row. In addition, each table
contains fields specific to that table, and which are described in
detail below.
[0045] Table S_DOBJ 61 describes the Docking Objects in an
application. Table S_DOBJ 61 includes the fields OBJ_NAME and
PRIMARY_TABLE_ID. Field OBJ_NAME defines the name of the Docking
Object being described. Field PRIMARY_TABLE_ID is used to identify
the primary table associated with this Docking Object.
[0046] Table S_DOBJ_INST 63 describes whether a particular instance
of a Docking Object, described by table S_DOBJ 61, is present on a
particular node's database. Table S_DOBJ_INST 63 includes the
fields NODE_ID, DOBJ_ID and PR_TBL_ROW_ID. Field NODE_ID points to
a particular node table 65. Field DOBJ_ID points to the Docking
Object to which the Docking Object instance applies. Field
PR_TBL_ROW_ID is used to select a particular row in the Primary
Table of the Docking Object. This value identifies the Docking
Object instance.
[0047] Table S_REL_DOBJ 67 describes the related Docking Objects of
a particular Docking Object, described by table S_DOBJ 61. Table
S_REL_DOBJ 67 includes the fields DOBJ_ID, REL_DOBJ_ID, and
SQL_STATEMENT. Field DOBJ_ID identifies the Docking Object that
owns a particular related Docking Object. Field REL_DOBJ_ID
identifies the related Docking Object that is owned by the Docking
Object identified by DOBJ_ID. Field SQL_STATEMENT is an SQL
statement that may be executed to obtain the Primary ID value of
the related Docking Object.
[0048] Table S_DOBJ_TBL 69 describes the member tables of a
particular Docking Object, described by table S_DOBJ 61. Table
S_DOBJ_TBL 69 includes the fields DOBJ_ID, TBL_ID, and
VIS_EVENT_FLG. Field DOBJ_ID identifies the Docking Object that
contains the member table described by the row. Field TBL_ID
identifies the particular table in the database that is the member
table described by the row. Field VIS_EVENT_FLG is a flag that
indicates whether a change to this Docking Object can result in a
visibility event. A value of "Y" indicates that a change can result
in a visibility event; a value of "N" indicates that it cannot.
[0049] Table S_DOBJ_VIS_RULE 71 contains the visibility rules
associated with a particular Docking Object. S_DOBJ_VIS_RULE 71
contains the fields DOBJ_ID, RULE SEQUENCE, RULE_TYPE,
SQL_STATEMENT and CHECK_DOBJ_ID. Field DOBJ_ID identifies the
Docking Object with which a particular visibility rule is
associated. Field RULE_SEQUENCE is a sequence number that indicates
the sequence, relative to other visibility rules in table
S_DOBJ_VIS_RULE 71, in which the particular visibility rule should
be run. RULE_TYPE specifies whether the particular visibility rule
is of type "R," indicating an SQL visibility rule or of type "O,"
indicating a Docking Object visibility rule.
[0050] If RULE_TYPE is equal to "R," field CHECK_DOBJ_ID is not
meaningful, and field SQL_STATEMENT contains an SQL statement that
is evaluated using the Primary ROW-ID of the primary table
associated with this Docking Object and a particular Node 21. If
the SQL statement returns any records, the Docking Object is deemed
to be visible to the Node 21 for which visibility is being
determined.
[0051] If RULE_TYPE is equal to "O," both field CHECK_DOBJ_ID and
field SQL_STATEMENT are meaningful. Field CHECK_DOBJ_ID specifies a
docking object whose visibility should be determined. If the
specified docking object is deemed to be visible, then the docking
object associated with the visibility rule is also visible. Field
SQL_STATEMENT contains a SQL statement that, when executed, returns
the Row-ID of the docking object identified by CHECK_DOBJ_ID that
corresponds to the docking object instance associated with the
visibility rule.
[0052] Table S_APP_TBL 73 is an Application Table that describes
all the tables used in a particular application. It is pointed to
by table S_DOBJ_TBL 69 for each member table in a docking object,
and by table S_DOBJ for the primary table in a docking object.
S_APP_TBL 73 points to table S_APP_COL 75, which is an Application
Column Table that describes the columns of data in a particular
application. S_APP_TBL 73 points to table S_APP_COL 75 directly
through a primary key and indirectly through such means as a
Foreign Key Column Table 81, User Key Column Table 83, and Column
Group Table 85. The relationship of an Application Table,
Application Column Table, Foreign Key Column Table, User Key Column
Table and Column Group Table are well known in the art and are not
further described.
[0053] Update Processing
[0054] FIG. 3 depicts steps performed by an update manager 31 such
as update manager 31-a, 31-b or 31-c in updating a database, such
as a node database 23-a, 23-b or 23-c, responsive to user input.
Execution of update manager 31 begins in step 101. In step 103, the
update manager 31 accepts from the user input 33 in the form of a
command requesting that the data in database 23 be altered. The
request may be in the form of a request to delete a row of a table,
to add a row to a table, or to change the value of a cell at a
particular column of a particular row in a table. In step 105,
using a well-known means, the update manager 31 applies the
requested update to database 23. In step 107, the update manager 31
creates a log record describing the update and writes it to update
log 35.
[0055] The contents of a log record describe the update made. Each
log record indicates the node identifier of the node making the
update, an identification of the table being updated, and an
identification of the type of update being made, i.e., an insertion
of a new row, a deletion of an existing row, or an update to an
existing row. For an insertion, the log record additionally
includes an identifier of the row being inserted, including its
primary key and the values of the other columns in the row. For a
deletion, the log record identifies the primary key of the row
being deleted. For an update, the log record identifies the primary
key of the row being updated, the column within the row being
updated, the old value of the cell at the addressed row and column,
and the new value of the cell.
[0056] After writing a log record in step 107, the update processor
exits for this update. The foregoing description of the update
processing preferably includes additional steps not material to the
present invention, for example, to assure authorization of the user
to make the update, to stage and commit the write to the database
to allow for rollback in the event of software or hardware failure,
and the like. These steps are well-known in the art and are not
described further.
[0057] An update manager 11 executing in central computer system I
operates in an analogous manner, except that it updates central
database 3 and writes its log records to central update log 11.
[0058] Docking Processing
[0059] FIG. 4 depicts steps performed by a Docking Manager 25 such
as Docking Manager 25-a, 25-b or 25-c to transmit and/or receive
one or more transaction logs. Docking Manager 25 is invoked by the
user of a remote node such as node 21-a, 21-b or 21-c, whereby the
user requests that the node dock with central computer 1 to upload
an update log such as update log 35-a to central computer 1, to
download a partial log such as partial log 17-a, or both. Execution
of Docking Manager 25 begins in step 121. In step 123, Docking
Manager 25 connects with central computer 1 under the control of
Central Docking Manager 5. This connection can be any connection
that enables data exchange. It is anticipated that the most common
form of a connection is a telephone line used in conjunction with a
modem, but other forms of data connection, such as a Local Area
Network or a TCP/IP connection may also be used. Step 125 checks to
see whether the user has requested that node update log 35-a be
uploaded to the Central Computer 1. If so, execution proceeds to
step 127. If not, step 127 is skipped and control is given to step
129. In step 127, Docking Manager 25 uploads its update log to
central computer 1. The upload may be accomplished with any known
file transfer means, such as XMODEM, ZMODEM, KERMIT, FTP, ASCII
transfer, or any other method of transmitting data. In step 129,
Docking Manager 25 checks to see whether the user has requested
that a partial log such as partial log 17-a be downloaded from
Central Computer 1. If so, execution proceeds to step 131. If not,
step 131 is skipped and control is given to step 133. In step 131,
Docking Manager 25 downloads its partial log from central computer
1. The download may be accomplished with any known file transfer
means, such as XMODEM, ZMODEM, KERMIT, FTP, ASCII transfer, or any
other method of transmitting data. In step 133, having completed
the requested data transfer, Docking Manager 25 exits.
[0060] Merge Processing
[0061] Merge processing is performed by a processor such as node
merge processor 27-a, 27-b, or 27-c, or central merge processor 7.
The merge process serves to update its associated database with a
transaction that has been entered by a user of a computer remote
from the computer where merge processing is being performed. Merge
processing is analogous to update processing and is similar in form
to update processing as previously disclosed with reference to FIG.
3, with three differences. First, the input to a merge processor is
not an update entered directly by a user, but rather is a log file
that is obtained from a computer remote from the computer where the
merge is executing. A second difference is that, as shown by in
FIG. 1, merge processing does not produce a log when performed at a
node. The function of a log on a node is to record a transaction
for propagation to Central Computer system 1 and thence to other
nodes as required. A transaction that is the subject of a merge in
a node has been communicated to Central Computer System 1, and
there is no need to re-communicate it.
[0062] A third difference is that merge processing must be capable
of detecting and resolving multiple conflicting transactions. For
example, assume that a field contains the value "Keith Palmer."
Assume further that a user at node 27-a enters a transaction to
update that field to "Carl Lake," and a user at node 27-b enters a
transaction to update the same field to "Greg Emerson." Without
collision detection, data among various nodes may become corrupt.
When the transaction for user 27-a is merged, the field is updated
from "Keith Palmer" to "Carl Lake." Without collision handling,
when the transaction for node 27-b is merged, the field would be
updated to "Greg Emerson," and the central database would then be
out of synch with the database of node 27-a. Furthermore, when
merge processing is performed on each of nodes 27-a and 27-b, each
node will update its database with the other's transactions,
leaving at least one node out of synch with the other node and with
central database.
[0063] Therefore, merge processing must also have a means of
detecting collisions and correcting them. In the above example, a
simple way to detect and correct a collision is to compare the
value in the database to the value that the merge log reflects as
being the previous value in the node database. If the two values do
not match, Merge processor 7 may reject the transaction and
generate a corrective transaction to be sent to the node from which
the conflicting transaction originated. In the above example, when
the transaction for node 27-b was presented to merge processor 7,
merge processor 7 would compare "Keith Palmer," the prior value of
the field as recorded by node 27-b to "Carl Lake," the present
value of the field as recorded in central database 3. Detecting the
mismatch, merge processor 7 may then generate a transaction to
change the value "Greg Emerson" to "Carl Lake," and write that
transaction to update log 15. In a subsequent docking operation,
that transaction would be routed back to node 27-b to bring its
database 23-b in synch with the other databases.
[0064] The above is one example of a collision and a resulting
corrective action. Other types of collisions include, for example,
an update to a row that has previously been deleted, inserting a
row that has previously been inserted, and the like. Merge
processing must detect and correct each of these collisions. This
may be performed using any of a number of well-known methods, and
is not discussed further.
[0065] FIG. 5 depicts the steps performed by merge processor such
as central merge processor 7. Although it depicts merge processor 7
writing to central database 3 and to transaction log 15, it is
equally representative of a node merge processor such as node merge
processor 27-a, 27-b or 27-c updating a node database 23-a, 23-b or
23-c. Merge processing begins at step 141. In step 143, merge
processor 7 finds the first unprocessed transaction on received log
19. In step 147, merge processor 7 selects a transaction from
received log 19. In step 149, merge processor 149 attempts to
update database 3 according to the transaction selected in step
147. In step 151, merge processor 7 determines whether the database
update of step 149 failed due to a collision. If so, merge
processor proceeds to step 153, which generates a corrective
transaction. Following the generation of the corrective
transaction, the merge processor returns to step 149 and again
attempts to update database 3. If no collision was detected in step
151, execution proceeds to step 157. In step 157, merge processing
checks to see if it is executing on central computer 1. If so, step
155 is executed to journal the transaction to log 15. In any case,
either if step 157 determines that the merge processing is being
performed on a node or after step 155, execution proceeds to step
159. Step 159 checks to see if any transactions remain to be
processed from log 19. If so, execution repeats from step 147,
where the next transaction is selected. If not, merge processing
exits in step 161.
[0066] Log Management
[0067] FIG. 6 depicts the steps to be performed by log manager 9 to
prepare a partial transaction log such as partial transaction log
17-a, 17-b, or 17-c. The procedure depicted in FIG. 6 is executed
for each node available to dock with central computer system 1. Log
manager 9 begins execution in step 171. In step 173, Log Manager 9
finds the first unprocessed transaction for the node whose partial
transaction log is being prepared. In step 175, log manager 9
selects a transaction for processing. In step 177, log manager 9
checks to see whether the selected transaction originated on the
same node for which processing is being performed. If so, there is
no need to route the transaction back to the node, and control
proceeds to step 179. Step 179 checks to see whether there are any
transactions remaining to be processed. If so, control is given
again to step 175. If not, control passes to step 189, which
records the last transaction that was processed for this node, and
then exits at step 191. If the transaction originates in other than
the same node as the node for which processing is being performed,
control is given to step 181. Step 181 calls a visibility
calculator to determine whether the selected transaction is visible
to the node being processed. The Visibility calculator routine is
described in detail further herein. In step 183, merge processor 9
checks to see whether the visibility calculator determined that the
transaction is visible. If it is not visible, control is passed to
step 179, which performs as disclosed above. If the transaction is
visible, control is passed to step 185. Step 185 writes a record
for this transaction to the partial transaction log for the node
being processed, for example, partial transaction log 17-a for node
21-a. In step 187, the log manager 9 records the last transaction
that was processed for this node, and then passes control to step
179, which determines whether to select additional transactions or
exit, as disclosed above.
[0068] Visibility Calculation
[0069] FIG. 7 depicts a flowchart describing the process a
visibility calculator for calculating visibility for a docking
object as invoked by step 181 of log manager 9. The visibility
calculator is called with the node-id of the node for which
visibility is being calculated, the docking object for which the
visibility is being calculated, and the row-id of the docking
object whose visibility id being calculated. The visibility
calculator uses this information, in conjunction with information
obtained from meta-data stored in the schema depicted in FIG. 2, to
determine whether a particular transaction that updates a
particular row of a particular docking object is visible to a
particular node.
[0070] The Visibility calculator begins execution at step 201. In
step 203, the visibility calculator makes a default finding that
the transaction is not visible. Therefore, unless the visibility
calculator determines that a transaction is visible, it will exit
with a finding of no visibility. In step 205, the visibility
calculator selects the first visibility rule associated with the
docking object. This is done by finding the table S_DOBJ_VIS_RULE
71 associated with the current Docking Object as pointed to by
table S_DOBJ 61. In step 205, the visibility calculator selects the
row of table S_DOBJ_VIS_RULE 71 with the lowest value for field
RULE_SEQUENCE.
[0071] In step 207, the Visibility Calculator checks the field
RULE_TYPE for a value of "R." The value of "R" indicates that the
rule is a SQL visibility rule. If so, the Visibility Calculator
proceeds to step 209. In step 209 the Visibility Calculator obtains
a SQL statement from field SQL_STATEMENT and executes it. An
example of such an SQL statement might be:
[0072] SELECT `X` FROM S_OPTY_EMP
[0073] WHERE OPTY_ID=:PrimaryRowId
[0074] AND EMP_ID=:NodeId;
[0075] This SQL statement causes a query to be made of application
table S_OPTY_EMP. The query selects any records meeting two
criteria. First, the records selected must have a field OPTY_ID,
which is a row id or key, equal to the Primary Row-ID of the
Docking Object whose visibility is being determined. Second, the
records selected must have a field EMP_ID, which may be for
example, an identifier of a particular employee, equal to the
NodeId of the node for whom visibility is being determined. In
ordinary language, this SQL statement will return records only if a
row is found in a table that matches employees to opportunities,
where the opportunity is equal to the one being updated, and the
employee to whom the opportunity is assigned is the operator of the
node.
[0076] This is a simplistic example, provided for maximum
comprehension. More complex SQL statements are possible. For
example, the rule:
[0077] SELECT `X` FROM
[0078] &Table_Owner.S_ACCT_POSTN ap
[0079] &Table_Owner.S_EMP_POSTN ep
[0080] WHERE ap.POSITION_ID=ep.POSITION_ID
[0081] AND ep.EMP_ID=:NodeId;
[0082] This rule queries the tables S_ACCT_POSTN (which relates a
particular account with a particular position in the organization
that is responsible for the account) and S_EMP_POSTN (which relates
what employee corresponds to a particular position). The condition
"ap.POSITION_ID =ep.POSITION_ID" requires finding a row in the
account-to-position table that has the same position as a row in
the employee-to-position table. The condition "ep.EMP_ID=:NodeId"
further requires that the selected row in the employee-to-position
table also have an Employee ID equal to the ID of the user of the
Node for which visibility is being determined. In ordinary
language, this condition allows visibility if the employee occupies
the position that has responsibility for the account in the docking
object being updated.
[0083] There is no particular limit to the complexity of the
conditions in the SQL statement used to evaluate visibility.
Particular implementations of SQL may impose limitations, and
resource considerations may make it desirable to use less complex
statements, but these limitations are not inherent in the
invention.
[0084] Step 211 evaluates whether the execution of SQL_STATEMENT in
step 209 returned any records. If records were returned, this
indicates that the Node for which visibility is being checked has
visibility to the docking object being processed. Accordingly, if
records are returned, the Visibility Calculator proceeds to step
213. In step 213, the transaction is marked visible. Because no
further rules need to be evaluated to determine visibility, the
visibility calculator proceeds to step 228. Step 228 synchronizes
the databases by determining whether the calculated visibility
requires the insertion or deletion of a docking object into a
particular node's partially replicated database. This may occur,
for example, if a node is determined to have visibility to a
docking object due to a change to a related docking object. For
example, an owner of a node may be assigned to a particular
activity that is related to a particular sales opportunity. As a
result, the node should be provided with a copy of the object
representing the sales opportunity.
[0085] FIG. 8 depicts the steps performed to synchronize a
partially replicated database in response to a change in data
visibility. Execution begins in step 241. In step 243, the
Visibility Calculator references the visibility just calculated for
a docking object. If the Docking Object is visible, execution
proceeds to step 245. Step 245 references the S_DOBJ_INST table, to
verify that a row exists for the Docking Object for the current
node. If a row exists, this indicates that the node in question
already has a copy of the referenced Docking Object, and the
routine proceeds to step 255, where it exits. If, however, no row
exists for the Docking Object at the node being processes, this
indicates that the node in question does not have a copy of the
Docking Object on its partially replicated database. The routine
then proceeds to step 247, where a transaction is generated to
direct the node to insert the Docking Object into its partially
replicated database.
[0086] If step 243 determines that the Docking Object is not
visible, execution proceeds to step 249. Step 249 references the S
DOBJ_INST table, to verify that no row exists for the Docking
Object for the current node. If step 243 determines that no row
exists in the S_DOBJ_INST table for the current docking object for
the current row, this indicates that the node in question does not
have a copy of the referenced Docking Object, and the routine
proceeds to step 255, where it exits. If, however, a row exists for
the Docking Object at the node being processed, this indicates that
the node in question does have a copy of the Docking Object on its
partially replicated database. The routine then proceeds to step
251, where a transaction is generated to direct the node to delete
the Docking Object from its partially replicated database.
[0087] Referring again to FIG. 7, following the data
synchronization routine of step 228, the Visibility Calculator
proceeds to step 229, where it exits. Referring to FIG. 6, as
previously described, the resulting finding of visibility is
available to be checked by the log manager in step 183 to determine
to write the transaction.
[0088] Referring again to FIG. 7, if step 211 determines that no
records were returned by the execution of the SQL statement in step
209, execution proceeds with step 215. Step 215 checks to see
whether there are any remaining visibility rules to be assessed. If
not, the visibility calculator proceeds to step 228 to synchronize
the database, and then to step 229, where it exits. In this case,
the default mark of no visibility that was set in step 203 remains
set. This value will also be used by the log manager as shown in
FIG. 6, step 183, to determine not to write the transaction.
[0089] Referring again to FIG. 7, if rules remain to be assessed,
control proceeds to step 217, which selects the next rule to be
processed. Control is then given again to step 207 to begin
processing the new rule.
[0090] The preceding text provided a description of the processing
or SQL visibility rule; that is, visibility rules of type "R." If
step 207 determines that the visibility rule is not of type "R,"
the visibility rule is of type "O." Type "O" indicates a
docking-object visibility rule. In such a case, the docking object
being processed will be considered to be visible if it is related
to a particular related docking object that is visible. If field
RULE_TYPE is not equal to "R," then. execution proceeds to step
221. Step 221 determines the related Docking Object whose
visibility must be determined to determine whether the current
docking object is visible. The related Docking Object identifier is
obtained from field CHECK_DOBJ_ID in table S_DOBJ_VIS_RULE 71. In
step 223, the Visibility Calculator determines which row in the
related Docking Object must be queried for visibility. In order to
determine this, the Visibility Calculator obtains a predetermined
SQL statement from the field SQL_STATEMENT and executes it. The SQL
statement is a query that select one or more rows of the Docking
Object that, for example, correspond to the docking object for
which the Visibility Calculator was invoked.
[0091] For example, assume that it is desired to indicate that a
record for a sales opportunity should be visible if the Node has
visibility to any sales quote made for that sales opportunity. This
may be accomplished using the following SQL statement:
[0092] SELECT"_ID" FROM
[0093] &Table_Owner.S_DOC_QUOTE
[0094] WHERE OPTY_ID=:Primary Rowld
[0095] This SQL statement accesses a table S_DOC_QUOTE that
contains all sales quotes. The WHERE clause specifies retrieval of
all rows where the Opportunity ID of the row is equal to the Row-ID
of the opportunity for which visibility is being calculated. The
Visibility manager retrieves the specified Row-Ids, thereby
identifying the rows of the S_DOC_QUOTE table whose visibility must
checked.
[0096] Having determined the a related docking object and the
row-ID of that related docking object upon whose visibility the
visibility of the current docking object depends, the Visibility
Calculator proceeds to step 225. In step 225, the Visibility
Calculator recursively invokes itself to determine visibility of
the related docking object. The recursively invoked Visibility
Calculator operates in the same manner as the Visibility Calculator
as called from the Log Manager 9, including the capability to
further recursively invoke itself. When the recursive call
concludes, it returns a visibility indicator for the related
Docking Object, and control proceeds to step 227. In step 227, the
Visibility calculator determines whether the related Docking Object
was determined to have been visible. If so, the Visibility
Calculator proceeds to step 213 to mark the originally current
Docking Object as visible, and then to step 228 to synchronize the
database and then to step 229 to exit. If the related Docking
Object was not determined to be visible, control proceeds to step
215 to determine whether additional visibility rules remain to be
assessed.
[0097] The Visibility Calculator, in conjunction with the Log
Manager is therefore able to determine what subset of update
transaction data is required to be routed to any particular node.
This operation serves to reduce the transmission of unneeded data
from the Central Computer 1 to the various nodes such as nodes
21-a, 21-b and 21-c that utilize partially replicated databases,
and to reduce the system resources such as disk space needed to
store, and the CPU time needed to process, what would otherwise be
required to maintain a fully replicated database on each remote
node.
[0098] The operation of the log manager 9 in conjunction with the
Visibility Calculator herein described will be apparent from
reference to the description and to the drawings. However, as a
further aid in the description of these facilities, a pseudocode
representation of these facilities is hereto attached as an
Appendix.
[0099] Software Distribution Integration with Remote Upgrade
[0100] The docking facility of the present invention also permits
the distribution of software upgrades and related database schema.
This provides an easy process to allow administrators to notify
remote users of the existence of software upgrades and to
distribute software upgrades to remote users. It provides an easy
process for remote users to receive notification of software
upgrades and to apply the software upgrade. It provides a means to
associate a software upgrade with a remote schema upgrade so that
the software upgrade is not applied before the remote schema
upgrade. It provides a means for a remote user to provide feedback
regarding a successful or unsuccessful completion of the software
upgrade to the administrator.
[0101] Typically, implementation of software upgrades is very
passive. The user does not actively receive information about the
availability of software that should be downloaded. Users are
required to download the file manually, and, once received, the
upgrade is installed using an installer package separate from the
software package being upgraded. It would be advantageous to
provide a means in the software package to publish the availability
of software for download to remote users so that the remote users
are informed of the need to download software and are prompted when
the download should occur, and provide for the dependency of a
software upgrade on an accompanying schema upgrade.
[0102] According to one embodiment of our invention there is
provided is a method of upgrading a software application from one
or more upgrade package files in a server (1) to a client (21a,
21b, 21c). According to this method a copy of the upgrade package
files and an upgrade database table are created on the server (1).
A pointer is created in the client's (21a, 21b, 21c) file on the
server (1). This pointer points to the upgrade package files on the
server (1); In invoking the upgrade the, the upgrade files are made
active, and the upgrade database table is scanned when a client
(21a, 21b, 21c) docks. This is to determine the status of an
upgrade with respect to the particular client (21a, 21b, 21c). The
upgrade is copied to the client (21a, 21b, 21c) if the client (21a,
21b, .sup.21c) has not received the upgrade. At this point the
upgrade may be invoked at the client (21a, 21b, 21c).
[0103] The upgrade can be invoked at any point during a docking
session, for example, at the beginning of a client (21a, 21b, 21c)
session., or, and most preferably, at the end of a client (21a,
21b, 21c) session. The upgrade can be invoked at the client user's
option, or at the server's option, that is, by forced downloading
as will be described hereinbelow.
[0104] One way of implementing the invention, as will be described
more fully hereinbelow, is to create a docking item file type to
scan the upgrade database table when the client (21a, 21b, 21c)
docks to thereby determine the status of an upgrade with respect to
the client (21a, 21b, 21c).
[0105] These various aspects of our invention may be implemented as
program products. That is, they may be implemented as a computer
usable medium with computer program code embodied therein for
causing the upgrading of a software application from upgrade
package files in a server (1) to a client (21a, 21b, 21c). The
computer readable program in the program product article of
manufacture contains computer readable program code means for
causing a computer to effect creating a copy of the upgrade package
files on the server (1), creating an upgrade database table on the
server (1); creating a pointer in the client's (21a, 21b, 21c) file
on the server (1) pointing to the upgrade package files on the
server (1), making the upgrade active, scanning the upgrade
database table when a client (21a, 21b, 21c) docks to determine the
status of an upgrade with respect to the client (21a, 21b, 21c),
copying the upgrade to a client (21a, 21b, 21c) if the client (21a,
21b, 21c) has not received the upgrade, and invoking the upgrade at
the client (21a, 21b, 21c).
[0106] Additionally, our invention may be implemented as a program
product in the form of a program storage device readable by a
machine, tangibly embodying a program of instructions executable by
a machine to perform method steps for of upgrading a software
application from upgrade package files in a server (1) to a client
(21a, 21b, 21c) said method steps comprising creating a copy of the
upgrade package files on the server (1), creating an upgrade
database table on the server (1); creating a pointer in the
client's (21a, 21b, 21c) file on the server (1) pointing to the
upgrade package files on the server (1), making the upgrade active,
scanning the upgrade database table when a client (21a, 21b, 21c)
docks to determine the status of an upgrade with respect to the
client (21a, 21b, 21c), copying the upgrade to a client (21a, 21b,
21c) if the client (21a, 21b, 21c) has not received the upgrade,
and invoking the upgrade at the client (21a, 21b, 21c).
[0107] The integrated update works as follows. At the end of a
normal docking session, the user is prompted with the information
regarding the availability of a software upgrade. The user has the
option to download the software upgrade or to defer and download
the software upgrade later. This can be overridden by the system
administrator, who has the ability to mark the file as a force
download. In such a case, the user is not prompted to download the
file; instead, the file is downloaded without input from the user.
The user is prompted using a message box that has the ability to
time out.
[0108] There are two classes of software upgrades: software that is
being distributed in conjunction with a schema upgrade and software
that is not associated with a schema upgrade. If the software is
associated with a schema upgrade, the software upgrade is not
applied until after the schema upgrade has been applied. The
applying of the schema upgrade invokes the software upgrade at the
end of the processing of the schema upgrade. If the software is not
associated with a schema upgrade, then after successfully
downloading the software upgrade files, the user will be prompted
to apply the upgrade now or to defer. The administrator will have
the ability to force the applying of the software upgrade
immediately upon completion of the docking session.
[0109] Once the user chooses to apply the software upgrade, the
installation component is invoked and the database application is
closed. The installation component then guides the user through the
necessary steps needed to apply the software.
[0110] The system administrator uses a dialog to specify the
association of files, messages and schema upgrades for an upgrade
package. The dialog includes a master section and a detail section.
The master section allows for the creation of a header record that
names the upgrade package and specifies some general attributes
regarding the upgrade. The detail section associates software
upgrade files, messages and schema upgrades.
[0111] The attributes of the master record include the name of the
upgrade package; the schema version of the database after the
upgrade is applied; a message supplied to users to view prior to
downloading the upgrade; a message to be displayed when the upgrade
is applied; a download attribute indicating how the file must be
downloaded, e.g., whether the file must be downloaded immediately
or whether it may be deferred by the user; an application attribute
indicating how the upgrade may be applied, e.g., whether the
upgrade must be applied immediately, may be deferred by the user,
or must be deferred pending a corresponding upgrade of a
corresponding schema or software upgrade; and a description.
[0112] The attributes of the detail record include a record type
indicating whether the file is a message, a software upgrade, etc.,
and the name of the file.
[0113] Upgrades are denoted by a record in an upgrade table in the
database. Once a record is created in the upgrade table and the
associated upgrade package is made active, Log Manager routes this
information using the previously described docking mechanisms to
remote users by creating an entry in the users' server.ts files.
This entry points to a global upgrade table of contents (TOC) file.
A single TOC file serves all docking users per application server
installation. The upgrade TOC file contains the detailed
information regarding the upgrade package. In this embodiment, only
one upgrade package is active at a given time.
[0114] When a user docks and retrieves the server.ts file, the
docking client scans the server.ts file for the existence of
upgrade entries. Depending upon the attributes of any upgrade
entries in the server.ts file, either the upgrade files be
downloaded immediately or a message is displayed to the user. The
user optionally has have the option either download the files
during the current docking session or defer download until a later
docking session.
[0115] Depending upon the attributes of the upgrade package, the
installation component may be invoked automatically or the user may
defer applying the upgrade. If the software upgrade is associated
with a schema upgrade, then after the schema upgrade has been
applied, the status of software upgrade files is checked to verify
that all files associated with the upgrade have been downloaded.
Any files not yet downloaded will be downloaded, making a
connection to the application server if necessary. The software
upgrade will then be invoked by the installation component.
[0116] The file types are represented by the field UTLTocFileType.
A file type of UTLTocFileTOCUpg indicates the Upgrade TOC file, and
a file type of UTLTocFileUpgrade indicates a file that is a
constituent part of an upgrade. Optionally, a file type of
UTLTocFileMessage indicates a file containing a message to be
displayed to the user.
[0117] The upgrade is represented to the user as a new dock item
type, named CSSDockUpg. The CSSDockUpg class is derived from the
CSSDockItem class.
[0118] When the user docks and is sending or receiving data from
the server, the CSSDockUpg dock item type is created. When
executed, this class examines the server.ts file for an entry type
of UTLTocFileTOCUpg. If found, either the message specified by the
entry pre-download message will be displayed to the user using a
time-out dialog box at the end of the docking session or the files
will be downloaded immediately depending on the attributes of the
entry type UTLTocFileTOCUpg.
[0119] Once the files are downloaded, the apply message from the
upgrade TOC file is displayed to the user at the end of the docking
session. Alternatively, the installation component is invoked by
the mobile client.
[0120] When the upgrade is applied, the installation component is
invoked. If the user defers application of the upgrade, then each
time the user issues docks to the headquarters server, the docking
client looks for the upgrade TOC file in the upgrade directory on
the client machine. If the file exists, the apply message is
displayed to the user.
[0121] After the upgrade files have been downloaded the upgrade TOC
file is stored locally on the client. This file will then be
examined after the schema upgrade process has completed.
[0122] The master copy of the upgrade package files is placed on
the file server. When a Log Manager process is processing a user
and encounters the transaction that makes the upgrade package
active, Log Manager copies these files to the local application
server upgrade directory if the files do not already exist. Log
Manager also creates the upgrade TOC file in this directory if the
TOC file does not already exist.
[0123] Once an upgrade package is marked as active, a record in the
docking transaction log is created. This record will cause the log
preprocessor to create the global upgrade TOC file. The contents of
the file are inserted into a text column of the upgrade package.
When the log router is executing for a particular user, this record
will cause the log router to create an entry in the user's
server.ts file, which that points to the global upgrade TOC file.
The log router also ensures that the global upgrade TOC file exists
in a predetermined directory. If the file exists, the log router
reads the text column of the upgrade package that contains the
contents of the TOC file and creates the global upgrade TOC file.
Alternatively, the log router may read the text column and create
an upgrade TOC file for each user. This would prevent more than one
log router executable from creating the global upgrade TOC
file.
[0124] In some cases, a schema upgrade will require a corresponding
software upgrade in order for the schema to function properly. This
may occur, for example, when the vendor supplies a new
software-schema pair. A customer cannot cause a software version
conflict with the ability for dbinit/data merge to apply the schema
changes. If schema upgrade that requires a corresponding software
upgrade is to be applied, the software upgrade must be applied
first, because it is the new software that provides support for the
schema upgrade.
[0125] An example of this scenario is when the vendor ships new
software and a new version of the database. The system
administrator packages the software and makes it available for
download by the user. The system administrator then applies the
database upgrade to the central database.
[0126] At some point, a remote user docks and is informed that the
central database has been updated, and that the user's docking
operation is limited to downloading changes to the database; that
is, the user is not permitted to upload transactions until his own
partially replicated database has been upgraded to match the
central database schema. The user then downloads the database
upgrade files corresponding to the upgrade installed on the central
database. The installation component is invoked (either by the
client-side software upon detecting the upgrade condition, or
expressly invoked by the user, depending on the upgrade file's
attributes). The installation component opens the database upgrade
files and contains a checksum value for the upgrade file set. The
checksum is compared against a value in the user's configuration
file that uniquely identifies the user's software level. If the
checksum value is different, then the client software does not have
the ability to apply the schema changes. The schema changes will be
deferred until the user separately upgrades his or her software
level.
[0127] A checksum may also be included in the DX files that
represent transactions. The data merge component verifies the
checksum associated with the transaction against the checksum in
the configuration file. If the checksums do not match, the
application of the DX file is deferred. This prevents a user from
inadvertently applying changes that cannot be supported by the
software.
CONCLUSION
[0128] Various modifications to these embodiments will be readily
apparent to those skilled in the art, and the generic principles
defined herein may be applied to other embodiments without the use
of inventive faculty. Thus, the present invention is not intended
to be limited to the embodiments shown herein, but is to be
accorded the widest scope consistent with the principles and novel
features disclosed herein.
[0129] All publications and patent applications mentioned in this
specification are herein incorporated by reference to the same
extent as if each individual publication or patent application was
specifically and individually indicated to be incorporated by
reference.
[0130] The invention now being fully described, it will be apparent
to one of ordinary skill in the art that many changes and
modifications can be made thereto without departing therefrom.
1APPENDIX Writing User Transaction Log File for a Given Laptop Node
This program will be called by a server-side process that processes
transaction log entries for all Laptop Nodes. For each Laptop Node,
the calling process building the UserTrxnLogFileName and calling
Program 1. Input Parameters .cndot. LaptopNodeId - node_id of the
destination laptop .cndot. UserTxnLogFileName - full path of the
file where txns will be written .cndot. MaxBatchTxns - number of
txns between commits and updates to the S_DOCK_STATUS table .cndot.
MaxTxns - number of txns to process in this session. Use this
parameter to limit processing. Main Algorithm - - Check parameters
IF (MaxTxns < 1 .parallel. MaxBatchTxns < 1) THEN Invalid
Parameter END IF - - Get last LOG_EXTRACT number for the Laptop
from S_DOCK_STATUS last_txn_commit_number =
UTLDStatGetLogNum(LaptopNodeId); - - Initialize Variables NumTxns =
0; - - Total number of txns processed NumBatchTxns = 0; - - Total
number of txns written in the current batch - - Read Docking Object
and Table definitions into memory structures StartDictApi ( ); - -
Open the User Log Txn file Open User Log Txn file - - Select and
process new txns in S_DOCK_TRANSACTION_LOG - - where
txn_commit_number > last_txn_commit_number FOR each new txn LOOP
- - Stop processing if reach MaxTxns IF NumTxns = MaxTxns THEN
break; END IF; - - Prevent circular txns. Do not send the txn back
to the originating laptop IF txn.OriginNodeId = LaptopNodeId THEN
Goto next transaction END IF; - - Process all other types of
transactions - - This is the visibility calculator! - - This
routine also processes implicit visibility events - - Later: Data
Merge can call this function to check whether a txn is - - still
visible when merging txns into a laptop or server database.
CheckVisibility (LaptopNodeId, LogRecordType, TableName,
TransRowId); IF txn is visible THEN - - Write transactions to
UserTxnLog file depending on the - - type of LogRecordType. Write
the txn to the user log file ++NumBatchTxns END IF; - - Finished
processing the txn - - Commit (if needed) IF NumBatchTxns =
MaxBatchTxns THEN - - Assume that separate process comes around and
deletes - - Txns in S_DOCK_TRANSACTION_LOG that have been processed
- - for all nodes. So, no need to delete the txns from the log.
Update last LOG_EXTRACT number for Laptop in S_DOCK_STATUS Commit;
NumBatchTxns = 0 END IF; ++NumTxns End Loop; /* Each transaction in
the Txn Log table */ - - Commit Update last LOG_EXTRACT number for
Laptop in S_DOCK_STATUS Commit; - - Close log file (if needed) IF
UserTxnLogFileP != NULL THEN Close File; END IF; StopDictApi ( );
Check Visibility Routines - - Check if a record in the txn log is
visible to a LaptopNodeId BOOL CheckVisibility (LaptopNodeId,
LogRecordType, TableName, TransRowId) { - - SQLStatements routed
based on the destination list IF LogRecordType in (`SQLStatement`)
THEN IF Laptop Node in destination list THEN return TRUE; END IF; -
- Shadow and Multi Record LogRecordTypes are routed to all nodes -
- No visibility events with these LogRecordTypes. ELSIF
LogRecordType in (`ShadowOperation`, `MultiRecordDelete`,
`MultiRecordUpdate`) THEN return TRUE; - - Simple Deletes need more
processing ELSIF LogRecordType in (--Simple Delete`) THEN IF
(table.visibility in (`Enterprise`, `Limited`)) THEN return TRUE;
END IF; - - Simple Inserts and Simple Updates need more processing
- - CheckTxnVisibility( ) also processes implicit visibility events
ELSIF LogRecordType in (`Simple Insert`, `Simple Update`) THEN IF
(table.visibility = `Enterprise`) THEN return TRUE; ELSIF
table.visibility = `Limited` THEN IF CheckTxnVisibility
(LaptopNodeId, Table, RowId) THEN return TRUE; END IF; END IF; END
IF; } - - Check if a record in the txn log is visible to a
LaptopNodeId static BOOL CheckTxnVisibility (LaptopNodeId, Table,
RowId) { BOOL bVisible = FALSE; Find the Table in the Dictionary;
IF Table not found THEN Error: Table not defined END IF; FOR all
docking objects that the table belongs to LOOP - - Generate SQL to
get PrimaryId values of the Docking Object GeneratePrimaryIdSQL
(Table, RowId, DockingObject); FOR each PrimaryId value retrieved
LOOP CheckObjectVisibility (LaptopNodeId, PrimaryTable,
PrimaryRowId) IF object is visible THEN - - Because
CheckObjectVisibility( ) also processes implicit - - visibility
events, we must loop through ALL docking objects - - even if we
already know that the Txn is visible. - - Exception: if the table
has VIS_event_FLG = `N` - - then we can return immediately. IF
Table.visibilityEventFLG = `N` THEN return TRUE; ELSE bVisible =
TRUE; END IF; END IF; END LOOP; END LOOP; return bVisible; } - -
Check if an instance of a docking object is visible to the laptop
user. - - Also processes implicit visibility events! BOOL
CheckObjectVisibility (LaptopNodeId, DockingObjectName,
PrimaryRowId) { FOR each visibility rule for the Docking Object
LOOP IF RuleType = RuleSQL THEN Run the select SQL statement using
PrimaryRowId; IF any rows returned THEN - - row is visible - -
Process an implicit Download Object DownloadObjectInstance
(LaptopNodeId, PrimaryTableName, PrimaryRowId); return TRUE; END
IF; ELSIF RuleType = CheckDockingObject THEN Run the ParameterSQL
using PrimaryRowId to get newPrimaryRowId FOR each record retrieved
by ParameterSQL LOOP - - RECURSIVE! CheckObjectVisibility
(LaptopNodeId, CheckDockingObjectName, newPrimaryRowId); IF rc =
TRUE THEN - - Process an implicit Download Object
DownloadObjectInstance (LaptopNodeId, PrimaryTableName,
PrimaryRowId); return TRUE; END IF; END LOOP; END IF; END LOOP; - -
Object is not visible. - - Process an implicit Remove Object
RemoveObjectInstance (LaptopNodeId, PrimaryTableName,
PrimaryRowId); return FALSE; } Generate SQL Statement to Get
PrimaryId - - Generate the SELECT SQL statement to get the
PrimaryId value of - - the docking object for the given MemberTable
- - - - SQL statement looks like: - - SELECT tp.<row_id> - -
FROM <table_owner>.<Table> t1, - -
<table_owner>.<- PKTable> t2, - - ... one or more
intermediate tables between the table - - and the PrimaryTable - -
<table_owner>.<- PKTable> tN - -
<table_owner>.<PrimaryTable> tp - - WHERE t1.ROW_ID =
:row_id /* row_id in transaction log */ - - /* join to PK table t2
*/ - - AND t1.<FKColumn> = t2.<PKColumn> - - AND <t1
FKCondition> - - /* any number of joins until reach the table
that joins - - to the PrimaryTable */ - - /* join from t2 to tN */
- - AND t2.<FKColumn> = tN.<PKColumn> - - AND <t2
FKCondition> - - /* join to the PrimaryTable */ - - AND
tN.<FKColumn> = tp.<PKColumn> - - AND <tN
FKCondition> - - Note that there may be one or more paths from
the Member Table - - to the Primary Table. We need to generate a
SQL select statement - - for each of the paths and UNION the
statements together. - - - - This function assumes that there are
no loops in the definition. - - - - These SQL statement do not
change for each Table in a Docking Object, - - so we can calculate
them one and store them in memory. - - struct { CHAR* selectList;
CHAR* fromClause; CHAR* whereClause; UINT numTables; /* also the
number of joint to reach the Primary Table */ } GenStmt;
GeneratePrimaryIdSQL (Table, DockingObject) { /* there may be more
than one SQL statement, so we have a dynamic array of SQL
statements. Each element in the array is a path from the Table to
the Primary Table*/ DynArrId GenStmtArr; GenStmt newGenStmt; CHAR*
sqlStmt; DynArrCreate (GenStmtArr); - - Create the first element
and initialize newGenStmt = malloc( ); newGenStmt.numTables = 1;
newGenStmt.selectList = "SELECT row_id"; newGenStmt.fromClause =
"FROM <Table> t1"; newGenStmt.whereClause = "WHERE t1.ROW_ID
= :row_id"; DynArrAppend (GenStmtArr, &newGenStmt); /*
Recursively follow FKs to the PrimaryTable */ Build the select,
from and where clause simultaneously */ AddPKTable (Table,
DockingObject, GenStmtArr, 0); - - Union all the paths together
numStmts = DynArrSize (GenStmtArr); FOR all elements in the array
LOOP tmpSqlStmt = GenStmtArr[j].selectList.- parallel.
GenStmtArr[j].fromClause .parallel. GenStmtArr[j].whereClause;
sqlStmt = sqlStmt .parallel. `UNION` .parallel. tmpSqlStmt; END
LOOP; DynArrDestroy (GenStmtArr); IF sqlStmt = NULL THEN Error: no
path from Table to Primary Table. END IF; } - - Recursively follow
all FKs to the Primary Table AddPKTable (Table, DockingObject,
GenStmt, InputStmtNum) { UINT numFKS = 0; UINT StmtNum; GenStmt
newGenStmt; FOR all FKs for the table LOOP IF PKTable is a Member
Table of the Docking Object THEN - - If there's more than one FK,
then there is more than one path - - out of the current table. - -
Copy the SQL stmt to a new DynArrElmt to create a new path IF
numFKs > 0 THEN - - Create a new element and copy from
GenStmt[InputStmtNum] newGenStmt = malloc( ); newGenStmt.numTables
= GenStmt[InputStmtNum].numTables; newGenStmt.selectList =
GenStmt[InputStmtNum].selectList; newGenStmt.fromClause =
GenStmt[InputStmtNum].fromClause; newGenStmt.whereClause =
GenStmt[InputStmtNum].whereClause; DynArrAppend (GenStmtArr,
&newGenStmt); StmtNum = DynArrSize (GenStmtArr); - - Put a
check here for infinite loops IF StmtNum == 20 THEN Error: Probably
got an Infinite loop? END IF; ELSE StmtNum = InputStmtNum; END IF;
- - Append the new PKTable to the fromClause and whereClause
GenStmt[StmtNum].fromCl- ause = GenStmt[StmtNum].fromClause
.parallel. ",.backslash.n <Table> t<numTables + 1>";
GenStmt[StmtNum].whereClau- se = GenStmt[StmtNum].whereclause
.parallel. "AND t<numTables>.<FKColumn> =
t<numTables + 1>.<PKColumn>" .parallel. "AND
<FKCondition for Table if any>"; ++GenStmt.numTables; - -
PKTable is the Primary Table then Done. IF PKTable = PrimaryTable
THEN RETURN; ELSE AddPKTable (PKTable, DockingObject, GenStmt,
StmtNum); END IF; - - Only count FKs to other member tables in the
same Docking Object ++numFKs; END IF; END LOOP; RETURN; } Process
Visibility Events - - Download an Object Instance to a Laptop - -
This function also downloads all Related Docking Object instances.
BOOL DownloadObjectInstance (LaptopNodeId, ObjectName,
PrimaryRowId) { - - Check if the object instance is already
downloaded to the laptop Find the object instance in the
S_DOBJ_INST table IF exists on laptop THEN return TRUE; END IF; - -
Register object instance in S_DOBJ_INST table - - Write Download
Object records to the Txn Log FOR each member table of the docking
object LOOP Generate SQL select statement to download records Write
each retrieved record to the User Txn Log file END LOOP; - -
Download records for Parent Object instances FOR each
RelatedDockingObject LOOP Run ParameterSQL to get newPrimaryId of
RelatedDockingObjects FOR each newPrimaryId retrieved LOOP - -
Check if the instance of the object is visible to the laptop user
CheckObjectVisibility (LaptopNodeId, ObjectName, PrimaryRowId) IF
visible THEN DownloadObjectInstance (LaptopNodeId,
RelatedDockingObject, newPrimaryRowId); END IF; END LOOP; END LOOP;
return TRUE; } - - Remove an Object Instance to a Laptop - - This
function also removes all Related Docking Object instances. BOOL
RemoveObjectInstance (LaptopNodeId, ObjectName, PrimaryRowId) { - -
Check if the object instance is already downloaded to the laptop
Find the object instance in the S_DOBJ_INST table IF does not exist
on laptop THEN return TRUE; END IF; - - Delete the object instance
from S_DOBJ_INST table - - Write Remove Object records to the Txn
Log FOR each member table of the docking object LOOP Generate SQL
select statement to get records to delete Write each retrieved
record to the User Txn Log file END LOOP; - - Remove for Parent
Object instances FOR each RelatedDockingObject LOOP Run
ParameterSQL to get newPrimaryId of RelatedDockingObjects FOR each
newPrimaryId retrieved LOOP - - Check if the instance of the object
is visible to the laptop user CheckObjectVisibility (LaptopNodeId,
ObjectName, PrimaryRowId) IF not visible THEN RemoveObjectInstance
(LaptopNodeId, RelatedDockingObject, newPrimaryRowId); END IF; END
LOOP; END LOOP; return TRUE; }
* * * * *