Suspending and resuming updates to databases

quiesce database hold allows you to block updates to one or more databases while you perform a disk unmirroring or external copy of each database device. Because no writes are performed during this time, the external copy (the secondary image) of the database is identical to the primary image. While the database is in the quiescent state, read-only queries to operations on the database are allowed. To resume updates to the database, issue quiesce database release when the external copy operation has completed. You can load the external copy of the database onto a secondary server, ensuring that you have a transactionally consistent copy of your primary image. You can issue quiesce database hold from one isql connection and then log in with another isql connection and issue quiesce database release.

The syntax for quiesce database is:

quiesce database tag_name hold database_name 
	[, database_name]
[for external dump]

or:

quiesce database tag_name release

where:

• tag_name – is a user-defined label for the list of databases to hold or release.

• database_name – is the name of a database for which you are suspending updates.

For example, to suspend updates to the pubs2 database, enter:

quiesce database pubs_tag hold pubs2

Adaptive Server writes messages similar to the following to the error log:

QUIESCE DATABASE command with tag pubs_tag is being executed by process 9.
Process 9 successfully executed QUIESCE DATABASE with HOLD option for tag pubs_tag. Processes trying to issue IO operation on the quiesced database(s) will be suspended until user executes Quiesce Database command with RELEASE option.

Any updates to the pubs2 database are delayed until the database is released, at which time the updates complete. To release the pubs2 database, enter:

quiesce database pubs_tag release

After releasing the database, you can bring up the secondary server with the -q parameter if you used the for external dump clause. Recovery makes the databases transactionally consistent, or you can wait to bring the database online and then apply the transaction log.