Garbage collection, manual

If automatic sweeping has been turned off, or only runs rarely because of the sweep interval setting, the DBA can manually force a sweep to be performed. The command to carry out this task is:

gfix -s[weep] [-i[gnore]] database_name

This command will force the garbage left over from old rolled-back transactions to be removed, reducing the database size and improving the performance of new transactions.

The -i[gnore] option may be supplied. This forces Firebird to ignore checksum errors on database pages. This is not a good idea and should rarely need to be used, however, if your database has suffered some problems it might be necessary to use it.

The following example shows a manual database sweep being implemented:

linux> gfix -sweep my_employee