Checking Physical Consistency in the DBA Planning Calendar (Info

Checking Physical Consistency in the DBA Planning Calendar (Informix)

Use

You can use the DBA Planning Calendar in the Computing Center Management System (CCMS) to schedule checks on the physical consistency of your Informix database. SAPDBA is called to perform the checks, which do not change database data and do not require storage space.

For more information about consistency checks, see Data Consistency with SAPDBA.

Prerequisites

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

You know how to use the DBA Planning Calendar. For more information, see:

DBA Planning Calendar for an overview

DBA Planning Calendar (Informix) for Informix-specific aspects

For more information about scheduling an action (for example, check physical consistency) in the DBA Planning Calendar, see Scheduling Actions in the DBA Planning Calendar.

In general, schedule consistency checks immediately before a database backup (ON-Bar) or archive (ON-Archive). This means that the backup or archive contains data checked for consistency.
If you use the ONCHECK methods (see table below), be aware that table locks might occur. Therefore, it is best to schedule the check when the database is not in productive use.

Procedure

Choose Tools ® CCMS ® DB Administration ® DBA Planning Calendar.

Choose the day when you want the physical consistency to be checked.

Choose Create action.

Select Physical Consistency Check.

Enter data as required in the fields Start Time, Period (weeks), and Calendar. For more information, see Scheduling Actions in the DBA Planning Calendar.

Choose Continue.

Select the type of check you want and enter data as required:

Type of check	Description
Unload to '/dev/null' checks	More thorough check method
for table	Checks a single named table
for dbspace	Checks a single named dbspace
for tables with 'BLOB' fields	Checks all tables with "blob" fields
for all tables of database	Checks all tables of the database, so can take a long time
ONCHECK	Less thorough check method – schedule when database not in productive use because of table locks
ONCHECK -cI	Checks the indexes of tables with "blob" fields
ONCHECK -CD	Checks the data of tables with "blob" fields

For more information, see Type and Frequency of Data Consistency Checks with SAPDBA (the same principles apply to checks performed in the DBA Planning Calendar).

"Blob" data is most likely to have consistency problems. Therefore, it is sensible to schedule checks on blob data more often than on other types of data.

Choose Continue to start the check.

Result

The check is now scheduled. It will be executed at the scheduled date and time. For more information about looking at the results, see Checking the Results of Actions in the DBA Planning Calendar and Using the DB Operations Monitor.

If there are problems with the consistency check, you can look at the log written by SAPDBA. Refer to Log for Data Consistency with SAPDBA.