ABAP performance on cluster Table

[brian_zhu]

Recently i met a case of ABAP performance issue on cluster table.  i think blog is a good place to

share this topic.  Your comments are really appreciate.

Issue description and analysis

Database perspective:  SQL trace showed a table cluster  KOCLU:

the Full table scan on table cluster KOCLU is done , which is the reason of this exepensive SQL Statement.

but why DBI ignore the values of the primary key fields as these values are already provied in the ABAP Source code.

ABAP perspective

Cluster table KONV is only existing ABAP Dictionary and stored in the table cluster KOCLU on the database level.

KONV Primary key fields:         

MANDT
KNUMV
KPOSN
STUNR
ZAEHK

From the fields list above, the key field KNUMV was specified but not transfered to database side.

the reason behind this is the OR operation. After this is removed, the key fields were transfered to the

database side and the Index range scan was chosen instead of the full table scan.