| Property | Description |
|---|---|
|
Parameter type |
Integer |
|
Default value |
|
|
Modifiable |
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. It specifies the amount of memory Oracle uses to merge bitmaps retrieved from a range scan of the index. 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