Phase I determines whether new statistics are needed and enters this as a TODO flag in the control table
DBSTATC . Using SAPDBA internal rules, methods are entered in DBSTATC for creating or updating obsolete or non-existent statistics.Standard call
sapdba -checkopt PSAP% -method E
The
sapdba -checkopt PSAP% call uses the primary index to determine the size of all tables. checkopt only enters tables into DBSTATC that already have statistics.Syntax
sapdba
-u system/<password>
-checkopt <tablespace | tablespace list | table | <keyword>>
-method E | C
-option R<n (*1000)> | P<n>
-time <d>
-T -<h>
-force
SAPDBA Command Options
-u |
Database user / password |
-checkopt |
Database objects and key words for the operation |
-method |
Analysis method |
-option |
Option for the analysis method (only for the method E ) |
-time <d> |
Updates all statistics older than <d> days |
-T <h> |
Restricts the operation to <h> hours |
-force |
Resets the TODO flags in the control table DBSTATC regardless of the current situation |
Key Words
DBSTATC_TAB |
All tables entered in the control table DBSTATC |
SAPDBA chooses the correct analysis method and option and enters them into the control table
DBSTATC if the customer flag is not set. If the table is small the optimizer starts with the method C ; if the table grows it switches to the method E .The
checkopt logs are in the directory sapcheck/<timestamp>.opt .For more information, see:
CCMS Support for the Cost-Based Optimizer
SAPDBA Internal Rules for Determining Statistics for the CBO