Configuring enable housekeeper GC

You can configure the level for SAP ASE garbage collection.

Configure SAP ASE for garbage collection task using:
sp_configure "enable housekeeper GC", value
The valid values for the enable housekeeper GC configuration parameter are:
  • 0 – disables the housekeeper garbage collection task, but enables lazy garbage collection by the delete command. You must use reorg reclaim_space to deallocate empty pages. This is the cheapest option with the lowest performance impact, but it may cause performance problems if many empty pages accumulate. SAP recommends that you do not use this value.

  • 1 – enables lazy garbage collection, by both the housekeeper garbage collection task and the delete command. This is the default value. If more empty pages accumulate than your application allows, consider options 4 or 5. You can use the optdiag utility to obtain statistics of empty pages.

  • 2 – reserved for future use.

  • 3 – reserved for future use.

  • 4 – enables aggressive garbage collection for both the housekeeper garbage collection task and the delete command. This option is the most effective, but the delete command is the most expensive. This option is ideal if the deletes on your dataonly locked tables are in a batch.

  • 5 – enables aggressive garbage collection for the housekeeper, and lazy garbage collection by delete. This option is less expensive for deletes than option 4. This option is suitable when deletes are caused by concurrent transactions.

For example, enter:
sp_configure "enable housekeeper GC", 4