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 XPU 

XPU is a database tool that you use to check the consistency of the volumes in a database instance and to update the statistics for the SQL Optimizer.

When the database instance is checked, all B* trees are analyzed. This is a very time-intensive process, since all pages need to be read.

XPU does not reorganize the database instance; it just analyzes its current state.

Prerequisites

·        Before the XPU checks are started, the database instance must be in the operational state ONLINE.

·        XUSER entries must exist, or the environment variable SQLOPT must be set as follows: SQLOPT="-d <database_name> -u <database_user>,<database_user_password>"

Syntax 

xpu -v|-s [-u] count

-v

Check consistency of the volumes

-s

Update statistics for the SQL Optimizer

-u

Only in combination with the option –s; all tables of the database are checked. If this option is not set, then only those tables are analyzed whose size has changed the most since the last check.

count

Maximum number of parallel tasks; 1 < count < 50

Example

Checking a database instance:

xpu –v 10

 

See also:

Background Knowledge, SQL Optimizer

Database Manager CLI, Updating the Optimizer Statistics with the Program XPU

 

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