Creating Temporary Tables
For each temporary table you define, a base table structure and a number of its instances are created in the database as ordinary tables with ordinary table structures. The number of temporary table instances is determined by the value of the Temp Table Instances setting in PeopleTools Options added to the number of PeopleSoft Application Engine temporary tables. These temporary tables are used as work tables that hold transient data, and because they are real tables, they are permanent structures in the database, remaining until an explicit DROP TABLE command is executed against them.
The nature of a temporary table means that the amount of data that each temporary work table holds varies significantly after each use. Therefore, when RUNSTATS are executed against them, there is a good chance that the statistics captured may not apply and will negatively influence the DB2 optimizer access path selection the next time you use the temporary work table.
Each record of the type Temporary Table is defined as a VOLATILE table in DB2 (beginning with version 8). This definition takes advantage of the DB2 optimizer’s enhanced capability to formulate efficient index access paths for those tables that hold volatile data, without relying on current table statistics.
Example: VOLATILE Used in CREATE TABLE DDL
This example shows the VOLATILE parameter in the CREATE TABLE DDL for the base temp table and its instances.
CREATE TABLE FSDMOA.PS_AEEXT_TAO (PROCESS_INSTANCE DECIMAL(10) NOT NULL, AE_INT_1 SMALLINT NOT NULL, AE_APPLID CHAR(12) NOT NULL, AE_SECTION CHAR(8) NOT NULL, AE_STEP CHAR(8) NOT NULL) VOLATILE IN FSDMOA.PTAPPE;