Sybase IQ 12.4.0 installation instructions Spiqcheckdb

Running

sp_iqcheckdb

Value	Action
2	Runs CheckStorage. Checks for leaked blocks and corrupt
	database pages by walking all the block maps in the system and
	reading every database page. Runs about 50 times slower than
	option 1. Produces a report of findings. Does not reset the free list.
	This option is the same as the default option when -iqdroplksis
	passed to the server except that it runs in read-only mode.
3	Runs CheckAllocation Fix. Server must have been started with -
	iqdroplks switch. Checks for leaked blocks by walking all block
	maps in the system. Runs very fast (about 1 second per GB of
	data). Produces a report of findings. If no error is detected, resets
	database free list to calculated allocation map.
	Sybase recommends that you use this option to recover the
	database free list only when the default option cannot do so due to
	errors encountered during processing, and no backed up version is
	available to restore.

In order to recover leaked storage within a database, first start the server with the -iqdroplksswitch in the asiqsrv12 command.

Next, connect to your database and issue the command:

sp_iqcheckdb

The stored procedure reads all storage within the database. On successful completion, it updates the database free list to reflect the true storage allocation for the database. It then generates a report listing the working and actions it has performed.

If it finds an error, sp_iqcheckdb reports the name of the object and the type of error found. It does not update the free list if any errors are detected.

Because it reads the entire database, sp_iqcheckdb may take a long time to run. The length of time depends on the size of the database and the size of the machine it executes on. Typically, sp_iqcheckdb can process between 20GB and 100GB per hour.

The dbcc_option settings of 1 and 3 provide a fast way to check for leaked storage within the system. They do this by walking the various block maps, or object directories, that make up the database. The underlying database pages that make up the actual tables and indexes are not read. Therefore, successful completion of sp_iqcheckdb using option 1 or 3 does not guarantee absolutely that the database is not corrupt.

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