Runstats Index

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The Runstats Index Wizard gathers statistics on indexes. If no statistics are available, DB2 makes fixed default assumptions which may result in inefficiencies.

To ensure the effectiveness of the paths selected, you can run the wizard:

• After a table is loaded.
• After an index is physically created.
• After running Rebuild Index or Reorg Index without collecting statistics.

For more information, see Rebuild Index (DB2 z/OS) and Reorg Index (DB2 z/OS).

• Before running Reorg Index with the OFFPOSLIMIT, INDREFLIMIT, or LEAFDISTLIMIT options. For more information, see Reorg Index (DB2 z/OS).

Platform Availability

• DB2 z/OS

To Gather Statistics on an Index

1. On the Datasource Navigator/Explorer, expand the Tablespaces or Indexes node.

   DBArtisan displays objects of the selected type.

2. Right-click the target tablespace and select RunStats Index from the context menu.

   DBArtisan opens the RunStats Index Utility wizard.

3. Use the following table as a guide to understanding and modifying settings in the wizard:

Step	Settings and tasks
1	Select Index	If you initiated the RunStats Index operation against one or more indexes, the target indexes are initially displayed. To check additional Indexes, click the Add button.
	Add	Opens the Indexes Selector dialog.
	Delete	Deletes selected index.
	Set Properties	Opens the Set Correlation Option Dialog Box for the selected row.
2	Select tablespaces	If you initiated the RunStats Index operation against one or more tablespaces, the target tablespaces are initially displayed. To check additional tablespaces, click the Add button.
	Add	Opens the Object Selector Dialog Box.
	Delete	Deletes selected tablespace.
	Set Properties	Opens the Set Correlation Option Dialog Box for the selected row.
3	Access level while RUNSTATS is running	Lets you select an access level, either Readonly or Change.
	Do you want to output message to SYSPRINT?	Lets you specify to output message to SYSPRINT.
	Do you want to force aggregation or rollup processing to be done even though some parts do not contain data?	Lets you specify to process with forced aggregation, gathered into a mass, or rollup.
4	Update Statistics	Lets you update the catalog statistics.
	History Statistics	Lets you update the history statistics.

4. When ready, click Finish.

Set Correlation Option Dialog Box

The table below describes the options and functionality on the Set Correlation Option dialog:

Option	Description
KeyCard	Collects all of the distinct values in all of the 1 to n key column combinations for the specified indexes. n is the number of columns in the index.
Frequent Item	Lets you add items to the grid.
Add	Opens the Add Frequent Item Dialog Box

Add Frequent Item Dialog Box

The table below describes the options and functionality on the Add Frequent Item dialog:

Option	Description
Number of Columns	Lets you type the number of columns. Default is 1.
Count	Lets you type the count. Default is 10.