This procedure enables you to change the table DBSTATC , used to control the update of cost-based optimizer (CBO) statistics for selected R/3 tables in the Informix database. SAP delivers the control table DBSTATC to you with several hundred pre-defined entries for R/3 Basis and Application tables that have special requirements for statistics updates. For all other tables (that is, for those not appearing in the control table), update statistics is performed with the default settings. If you make an entry in the control table DBSTATC , you are changing the default settings used for analyzing an R/3 table and updating its statistics.

You are ready to use CCMS. Refer to Getting Started in CCMS with Informix DBA.

1. Choose Tools ® CCMS ® DB Administration ® Cost based optimizer ® Configuration.

The system displays the control table DBSTATC , showing configuration information for tables that have special requirements for update statistics. The most important fields are as follows:

Important Fields in DBSTATC Table

Field	Value	Comment
DB object	<TABLE NAME>	The name of the table with special requirements for update statistics (must be entered in uppercase)
DB object type	01	Indicates "table" – this is the default setting
Use	O A	R/3 Basis table – this is the default setting Refers to a table from application monitor (see transaction ST07) – do not normally use (if you use this setting, extra statistics are collected for the application monitor when update statistics is executed using SAPDBA from the command line, which greatly increases run times.)
Active	A N U	Update statistics is performed for table, if necessary – this is the default setting Excludes table from update statistics – do not use unless SAP advises you to Forces update statistics on table for every run of update statistics – do not use unless SAP advises you to, as it increases run times
Accuracy	1 2	Forces update statistics HIGH for all index columns Update statistics HIGH for leading index columns, MEDIUM for other index columns – this is the default setting
TODO flag	X	Forces update statistics of the table the next time update statistics is run – do not normally use, as this might cause unnecessary alerts to be produced
History flag	X	Causes historical data to be collected
TODO chg. date		The date on which the entry in DBSTATC was last changed – do not use



Do not enter or change any fields other than the ones shown above. Other fields are either not relevant to Informix databases, or are maintained automatically by the system.

2. To see full details of an entry in the control table DBSTATC , choose the entry you want to see and then choose Detail.

The system displays all the fields for the entry you choose.

3. To add a new entry to the control table DBSTATC (that is, to configure the settings used for checking and updating statistics on an R/3 table), do the following:
1. If necessary, choose Change -> Display to switch to change mode.
2. Choose New entries.

The system displays a dialog box for you to specify the new entry.

3. Enter values as shown in the table in step 1. Use the default settings except for fields where you have good reason to use some other setting.
4. Save the entry.
4. To change an existing entry in the control table DBSTATC (that is, to re-configure the settings used for checking and updating statistics on an R/3 table already in the control table), do the following:
1. If necessary, choose Change ® Display to switch to change mode.
2. Choose the entry you want to change.
3. Choose Detail.

The system displays a dialog box for you to change the existing entry.

4. Enter values as shown in the table in step 1. Use the default settings except for fields where you have good reason to use some other setting.
5. Save the entry.
5. To delete an entry from the control table DBSTATC (that is, to use the default settings are used for checking and updating statistics on an R/3 table), do the following:



Do not delete the entries made by SAP in the control table DBSTATC if you use the application monitor, because the statistics required by the application monitor can then no longer be collected.

1. If necessary, choose Change ® Display to switch to change mode.
2. Choose the entry you want to delete.
3. Choose Delete.
4. Save the deletion.

The way the Informix optimizer updates statistics for tables with entries in the control table DBSTATC is changed. This takes effect the next time update statistics is run. Update statistics run from SAPDBA or CCMS (including from the DBA Planning Calendar) is affected by such changes.

Update Statistics in CCMS (Informix)

Checking and Updating Statistics for a Single Table in CCMS (Informix)

Update Statistics with SAPDBA