Leaf and range scan mode settings

If a table has more than one attached index, the B-tree scanner uses the leaf scan mode. If you want small indexes to be scanned by the leaf scan method, set the rangesize option of the BTSCANNER configuration parameter to 100.

If you decide to enable range scan mode when a single index exists in the partition, set rangesize option of the BTSCANNER configuration parameter to the minimum size that a partition must have to be scanned using this mode. Specify the size in kilobytes.

The following example specifies that:

• The server will start two B-tree scanner threads.
• The server will consider cleaning indexes in the hot list (a list of indexes that caused the server to do extra work) when 50000 deleted items are found in the index.
• Indexes with a partition size that is equal to or larger than 100 KB will be cleaned using the range scan mode.
• Indexes with a partition size of less than 100 KB will be cleaned using the leaf scan mode.
• Index compression is set at the medium (default) level

BTSCANNER num=2,threshold=50000,rangesize=100,compression=default