Checking Tables with ‘Blob’ Fields Using ONCHECK -cD with SAPDBA
Checking Tables with ‘Blob’ Fields Using ONCHECK -cD with SAPDBA
Use
You can use SAPDBA to check the data consistency of the data in tables with "blob" fields in your Informix database. If there is any doubt, check the entire database for consistency since other tables might also be affected. This procedure checks tables without changing them and it does not require storage space.
To find out which kind of check to do and how often, see
How to Run Data Consistency Checks with SAPDBA. For more information on the Informix tool ONCHECK used in this procedure, see the Informix documentation.Prerequisites
Procedure
SAPDBA checks the tables for data consistency. As the processing runs, you see a message like the following for each table checked:
A014:
Checking table ‘a014’ (1/136)
Running ‘ONCHECK -cD’... (32 rows)
You can stop the check before it has finished by twice simultaneously pressing the keys
Ctrl C . This is useful if you have run out of time, for example, or the performance on your system is poor. You can then restart the action by choosing the same action again. However, you must use exactly the same parameters as the first time. Refer to Restarting Uncompleted Consistency Requests with SAPDBA.Result
The tables with blob fields are now checked for data consistency.
SAPDBA displays a message like the following when the check has successfully completed:
‘Consistency Check’ of selected tables detected no problems!!
SAPDBA displays an error message like the following when there are problems:
Unload to ‘/dev/null’ of one or more tables failed!!
Please check the log carefully.
For more information about how to find and check the log and output file from the check, see
Log for Data Consistency with SAPDBA.
You need to periodically clear up the
See also:
Informix documentation