Administration: Planning

Range-clustered tables

A range-clustered table cannot be created in a database having more than one partition.

Catalog table space design

When creating a database, three table spaces are defined, including the SYSCATSPACE table space for the system catalog tables. The page size that becomes the default for all table spaces is set when the database is created. If a page size greater than 4096 or 4 K is chosen, the page size for the catalog tables is restricted to a row size that it would have if the catalog table space had a page size of 4 K. The default database page size is stored as an informational database configuration parameter called pagesize.

Supported territory codes and code pages

In Appendix B, "National language support (NLS)" in Administration Guide: Planning, the topic called "Supported territory codes and code pages" has tables for each territory. Two tables require updates:

China (PRC), territory identifier: CN

The code page for the Linux^(TM) GBK row in the "China (PRC), territory identifier: CN" table should be changed from 1383 to 1386.

That is, the row should now read:

1386     D-4     GBK     86     zh_CN.GBK     Linux

Japan, territory identifier: JP

The table for " Japan, territory identifier: JP" has been revised.

The following locale name should be removed:

954      D-1      eucJP   81       japanese      Solaris

Here is the revised table:

XA function supported by DB2 Universal Database

DB2 Universal Database^(TM) (UDB) supports the XA91 specification defined in X/Open CAE Specification Distributed Transaction Processing: The XA Specification, with the following exceptions:

• Asynchronous services

  The XA specification allows the interface to use asynchronous services, so that the result of a request can be checked at a later time. The database manager requires that the requests be invoked in synchronous mode.

• Registration

  The XA interface allows two ways to register an RM: static registration and dynamic registration. DB2^(R) UDB supports both dynamic and static registration. DB2 UDB provides two switches:

  • db2xa_switch for dynamic registration
  • db2xa_switch_static for static registration
• Association migration

  DB2 UDB does not support transaction migration between threads of control.

XA switch usage and location

As required by the XA interface, the database manager provides a db2xa_switch and a db2xa_switch_static external C variable of type xa_switch_t to return the XA switch structure to the TM. Other than the addresses of various XA functions, the following fields are returned:

Field

Value

name

The product name of the database manager. For example, DB2 UDB for AIX.

flags

For db2xa_switch TMREGISTER | TMNOMIGRATE is set

Explicitly states that DB2 UDB uses dynamic registration, and that the TM should not use association migration. Implicitly states that asynchronous operation is not supported.

For db2xa_switch_static TMNOMIGRATE is set

Explicitly states that DB2 UDB uses dynamic registration, and that the TM should not use association migration. Implicitly states that asynchronous operation is not supported.

version

Must be zero.

Using the DB2 Universal Database XA switch

The XA architecture requires that a Resource Manager (RM) provide a switch that gives the XA Transaction Manager (TM) access to the RM's xa_ routines. An RM switch uses a structure called xa_switch_t. The switch contains the RM's name, non-NULL pointers to the RM's XA entry points, a flag, and a version number.

Linux- and UNIX^(R)-based systems

The switch for DB2 Universal Database (UDB) can be obtained through either of the following two ways:

• Through one additional level of indirection. In a C program, this can be accomplished by defining the macro:

     #define db2xa_switch (*db2xa_switch)
     #define db2xa_switch_static (*db2xa_switch)

  prior to using db2xa_switch or db2xa_switch_static.
• By calling db2xacic or db2xacicst

  DB2 UDB provides these APIs, which return the address of the db2xa_switch or the db2xa_switch_static structure. This function is prototyped as:

     struct xa_switch_t * SQL_API_FN  db2xacic( )
     struct xa_switch_t * SQL_API_FN  db2xacicst( )

With either method, you must link your application with libdb2.

Windows NT

The pointer to the xa_switch structure, db2xa_switch, or db2xa_switch_static is exported as DLL data. This implies that a Windows NT^(R) application using this structure must reference it in one of three ways:

• Through one additional level of indirection. In a C program, this can be accomplished by defining the macro:

  #define db2xa_switch (*db2xa_switch)
  #define db2xa_switch_static (*db2xa_switch)

  prior to using db2xa_switch or db2xa_switch_static.
• If using the Microsoft^(R) Visual C++ compiler, db2xa_switch or db2xa_switch_static can be defined as:

  extern __declspec(dllimport) struct xa_switch_t db2xa_switch
  extern __declspec(dllimport) struct xa_switch_t db2xa_switch_static

• By calling db2xacic or db2xacicst

  DB2 UDB provides this API, which returns the address of the db2xa_switch or db2xa_switch_static structure. This function is prototyped as:

  struct xa_switch_t * SQL_API_FN  db2xacic( )
  struct xa_switch_t * SQL_API_FN  db2xacicst( )

With any of these methods, you must link your application with db2api.lib.

Example C Code

The following code illustrates the different ways in which the db2xa_switch or db2xa_switch_static can be accessed via a C program on any DB2 UDB platform. Be sure to link your application with the appropriate library.

   #include <stdio.h>
   #include <xa.h>

   struct xa_switch_t * SQL_API_FN  db2xacic( );

   #ifdef DECLSPEC_DEFN
   extern __declspec(dllimport) struct xa_switch_t db2xa_switch;
   #else
   #define db2xa_switch (*db2xa_switch)
   extern struct xa_switch_t db2xa_switch;
   #endif

main( )
   {
      struct xa_switch_t *foo;
      printf ( "%s \n", db2xa_switch.name );
      foo = db2xacic();
      printf ( "%s \n", foo->name );
      return ;
   }

Updated TPM and tp_mon_name values for xa_open string formats

The Internal settings column in the following table has been updated to reflect settings for the thread of control (TOC).

TOC is the entity to which all DB2 UDB XA connections are bound:

• When set to a value of T, all DB2 UDB XA connections formed under a particular OS thread are unique to that thread. Multiple threads cannot share DB2 UDB connections. Each OS thread has to form its own set of DB2 UDB XA connections.
• When set to a value of P, all DB2 UDB XA connections are unique to the OS Process and all XA connections can be shared between OS threads.

AXLIB=libEncServer (for Windows)
     =/usr/lpp/encina/lib/libEncServer
        (for Linux and UNIX systems)
HOLD_CURSOR=T
CHAIN_END=T
SUSPEND_CURSOR=F
TOC=T

AXLIB=libEncServer (for Windows)
     =/usr/lpp/encina/lib/libEncServer
        (for Linux and UNIX systems)
HOLD_CURSOR=F
CHAIN_END=T
SUSPEND_CURSOR=F
TOC=T

AXLIB=mqmax 
(for Windows)
     =/usr/mqm/lib/libmqmax_r.a 
(for AIX threaded applications)
     =/usr/mqm/lib/libmqmax.a 
(for AIX non-threaded applications)
     =/opt/mqm/lib/libmqmax.so 
(for Solaris)
     =/opt/mqm/lib/libmqmax_r.sl 
(for HP threaded applications)
     =/opt/mqm/lib/libmqmax.sl 
(for HP non-threaded applications)
     =/opt/mqm/lib/libmqmax_r.so 
(for Linux threaded applications)
     =/opt/mqm/lib/libmqmax.so 
(for Linux non-threaded applications)
HOLD_CURSOR=F
CHAIN_END=F
SUSPEND_CURSOR=F
TOC=P

AXLIB=somtrx1i (for Windows)
     =libsomtrx1
        (for Linux and UNIX systems)
HOLD_CURSOR=F
CHAIN_END=T
SUSPEND_CURSOR=F
TOC=T

AXLIB=ibmsfDB2
HOLD_CURSOR=F
CHAIN_END=T
SUSPEND_CURSOR=F
TOC=T

AXLIB=libtux
HOLD_CURSOR=F
CHAIN_END=F
SUSPEND_CURSOR=F
TOC=T

Activating conversion tables for code pages 923 and 924

The following table contains a list of all the code page conversion table files that are associated with code pages 923 and 924. Each file is of the form XXXXYYYY.cnv or ibmZZZZZ.ucs, where XXXXX is the source code page number and YYYY is the target code page number. The file ibmZZZZZ.ucs supports conversion between code page ZZZZZ and Unicode.

Conversion table files for euro-enabled code pages

The following tables list the conversion tables that have been enhanced to support the euro currency symbol. If you want to disable euro symbol support, download the conversion table file indicated in the column titled "Conversion table files".