A strategy for improving performance is to disable all
data definition operations while your applications are running.
You do this by using SQLUtil to set the DDL Enabled
parameter in the DBECon file to NO.
This is a simple matter if you do all data definition in a
development DBEnvironment. In such a case, you can disable
DDL in the production DBEnvironment only.
Disabling data definition
Allows ALLBASE/SQL to
retain sections in memory between
transactions. This means that an application program that
re-executes the same sections again and again does not require
ALLBASE/SQL to read the sections in from disk each time. This can
significantly improve performance.
 |
| |
|
 | NOTE:
ALLBASE/SQL can retain sections in memory between transactions.
However, if DDL is enabled, ALLBASE/SQL checks its system catalog
once per transaction to see if the cached section is still valid.
When DDL is disabled, ALLBASE/SQL does not have to check. Disabling
DDL still results in best performance. |
|
| |
|
Makes it impossible to perform
data definition and to lock system catalog pages exclusively.
Does not inhibit the revalidating of sections. If ALLBASE/SQL
encounters invalid sections, they will be revalidated as necessary.
Disables the following statements:
ADD DBEFILE ADD GROUP ADD TO GROUP
ALTER DBEFILE ALTER TABLE CREATE DBEFILE
CREATE DBEFILESET CREATE GROUP CREATE INDEX
CREATE TABLE CREATE VIEW DROP DBEFILE
DROP DBEFILESET DROP GROUP DROP INDEX
DROP TABLE DROP VIEW GRANT
REMOVE FROM GROUP REVOKE START DBE NEWLOG
TRANSFER OWNERSHIP UPDATE STATISTICS
|
Inhibiting DDL has little effect on performance
for applications that do not re-use the same sections.
