1.33 BITMAP_MERGE_AREA_SIZE
BITMAP_MERGE_AREA_SIZE
specifies the amount of memory Oracle uses to merge bitmaps retrieved from a range scan of the index.
Property | Description |
---|---|
Parameter type |
Integer |
Default value |
|
Modifiable |
No |
Modifiable in a PDB |
No |
Range of values |
Operating system-dependent |
Basic |
No |
Note:
Oracle does not recommend using the BITMAP_MERGE_AREA_SIZE
parameter unless the instance is configured with the shared server option. Oracle recommends that you enable automatic sizing of SQL working areas by setting PGA_AGGREGATE_TARGET
instead. BITMAP_MERGE_AREA_SIZE
is retained for backward compatibility.
BITMAP_MERGE_AREA_SIZE
is relevant only for systems containing bitmap indexes. A larger value usually improves performance, because the bitmap segments must be sorted before being merged into a single bitmap.
See Also:
Oracle Database SQL Tuning Guide for more information on using bitmap indexes for performance