Upgrading explain tables

If you must maintain explain table information that you gathered in your Db2® copies from previous releases, upgrade your explain tables to Db2 version 11.5.

Before you begin

Ensure that you have DBADM authority. For additional authorization details, see Command Reference.

About this task

You can manually upgrade your explain tables after you upgrade your database, or you can re-create the explain tables and gather new information.

Procedure

To upgrade the explain tables, run the db2exmig command, as follows: 
db2exmig -d dbname -e explain_schema -u userid password
where:
  • dbname represents the database name. This parameter is required.
  • explain_schema represents the schema name of the explain tables that you are migrating. This parameter is required.
  • userid and password represent the current user's ID and password. These parameters are optional.

Results

The explain tables are upgraded. The db2exmig command renames the original explain tables, creates a new set of tables by using the EXPLAIN.DDL file, and copies the contents of the original explain tables to the new tables. Finally, the tool drops the original explain tables. The db2exmig command preserves any user-added columns in the explain tables.

What to do next

Use the db2expln command to see the access plan information in the upgraded explain tables.