Browse Prior Art Database

Mechanism to Specify a Database CCSID for Database Manager

IP.com Disclosure Number: IPCOM000106177D
Original Publication Date: 1993-Oct-01
Included in the Prior Art Database: 2005-Mar-20
Document File: 6 page(s) / 289K

Publishing Venue

IBM

Related People

Obermann, D: AUTHOR [+2]

Abstract

A design and functional specification is presented which allows explicit declaration of the CCSID (or code page) of an OS/2* Database Manager database at the time of database creation.

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This is the abbreviated version, containing approximately 28% of the total text.

Mechanism to Specify a Database CCSID for Database Manager

      A design and functional specification is presented which allows
explicit declaration of the CCSID (or code page) of an OS/2* Database
Manager database at the time of database creation.

      When a database is created using the OS/2 Database Manager
(DBM), a code page is assigned to the database which can never be
changed, and which governs all subsequent character processing,
including: - high-level language precompilation - SQL grammar parsing
- index management - comparisons and collation - optimization of
SELECTs.  This is not an exhaustive list.  Consequently, the database
code page is very important to database operations.

      The OS/2 DBM provides the user no explicit means to specify the
database code page.  Rather, the database must be created by an
application running on the server, and the code page of the
application (ie., OS/2 process) that issues the CREATE DATABASE
command is assigned to the database.  This design is inadequate for
several reasons, including: - the design uses "code page" as the
encoding paradigm, a paradigm that does not apply to other operating
platforms such as UNIX** ("code sets") and Windows ("character sets")
- the creator of a database has only indirect control over the code
page assigned to a database - creation of a database from a client is
inhibited by the need to determine the application code page on the
client - porting the DBM to other operating platforms is made more
difficult by the need to determine the application code page on each
platform - it is impossible to create a database in a client code
page unless that code page is also supported on the database server.

      This last observation is perhaps the most troubling.  For
example, it is common to construct a database client-server network
where the database resides on a powerful workstation running OS/2,
while the clients use simpler environments such as DOS Windows.  In
such a configuration, the logical choice for the code page of the
database would be that which matches the encoding scheme of the
Windows client, as such a choice eliminates the need to perform
encoding conversions (suffering performance degradation and possible
data loss).  However, the OS/2 DBM cannot support this configuration,
because the CREATE DATABASE design prevents creation of an OS/2
database using a Windows encoding.

      This disclosure presents a design whereby the Database Manager
user can optionally specify the code page of a database at the time
of database creation.  It is shown that this solution eliminates
and/or reduces the severity of the problems just outlined.

      This invention builds upon a foundation consisting of the
design and function offered in the OS/2 Extended Services Database
Manager, first publicly available in March, 1992.  The proposal
modifies this foundation as necessary.

      When discussing details particular to a giv...