Download PDF - IBM Redbooks
Download PDF - IBM Redbooks
Download PDF - IBM Redbooks
You also want an ePaper? Increase the reach of your titles
YUMPU automatically turns print PDFs into web optimized ePapers that Google loves.
3.3 SAP modifications to optimize the solution stack<br />
DB2 10 is a major release for the DB2 product itself, bringing many features with great benefit<br />
for the SAP solution. It is also an anchor point for several innovations, architectural cleanups,<br />
and performance improvements on the SAP side. As shown in this section, these<br />
improvements benefit current releases and releases already in maintenance for several<br />
years. They also lay the foundation for future optimizations.<br />
3.3.1 Full implicit layout<br />
Before DB2 10, you had to create databases and table spaces before creating tables in the<br />
database. The database service layer (DBSL) had to filter out and inspect the CREATE<br />
TABLE statements from the ABAP DDIC and perform necessary creation and cleanup steps<br />
transparently. This process included generating database and table space names, including<br />
namespace management and cleanup activities. Because of restrictions of the DDIC platform<br />
interface, part of this DDIC function had to be implemented in C within the DBSL.<br />
DB2 9 introduced implicit object creation to eliminate the need to perform those additional<br />
actions from within the application. SAP used this feature and by default creates all<br />
non-range-partitioned tables in PBG UTSs. However, certain table space attributes still could<br />
not be specified with the CREATE TABLE statement. Therefore, some objects had to be<br />
explicitly created.<br />
With DB2 10, these attributes, namely DSSIZE, Buffer Pool, and Member Cluster are online<br />
changeable. With DB2 10, all objects are created implicitly. Figure 3-2 shows how the table<br />
space naming conventions changed over the history of the SAP releases. The full implicit<br />
layout introduced with DB2 10 is available for the most current SAP releases and has been<br />
retrofitted to release 6.20. Therefore, all those releases share a common allocation and<br />
naming scheme with DB2 10.<br />
min. SAP<br />
release<br />
min. DB2<br />
version<br />
major<br />
changes<br />
Figure 3-2 SAP table layout history<br />
3.3.2 Hybrid database service layer<br />
multi-table<br />
tablespace<br />
single-table<br />
tablespace<br />
3.1I 5.1 SBTAB00.BTAB00 TABLE.TABLE<br />
4.5B 5.1 A012#123.#SAP A010#123.TABLE<br />
4.6x 6.1 A012X123.XSAP A010X123.TABLE<br />
6.20 7.1 LOBs A012X123.XSAP A010X123.TABLE<br />
6.40 8.1 Unicode A012X123.XSAP A010X123.TABLE<br />
7.10 9.1<br />
6.20 (!) 10.1<br />
implicit<br />
layout, UTS<br />
full implicit<br />
layout<br />
The DBSL is the database abstraction layer of the SAP kernel. It handles the connections to<br />
the database system and translates the ABAP Open SQL Syntax to the basic language of the<br />
underlying database system. It also contains various performance optimization features, such<br />
38 Running SAP Solutions with <strong>IBM</strong> DB2 10 for z/OS on the <strong>IBM</strong> zEnterprise System<br />
---<br />
DSNnnnnn.TABLE (*)<br />
DSNX1A2B.TABLE (**)<br />
stogroup<br />
DBTAB00, IBTAB00<br />
DTABLE, ITABLE<br />
SAPA0D<br />
SAPA0I<br />
PRDA0D<br />
PRDA0I<br />
PRDA0D<br />
PRDA0I<br />
PRDA0D<br />
PRDA0I<br />
SYSDEFLT<br />
--- DSNnnnnn.TABLE (*) SYSDEFLT
Change language