- **Description**: Uses bitmap indexes to scan the heap more efficiently. - **Performance**: Efficient for large datasets with selective conditions. - **Factors**: Pages fetched, rows scanned, disk I/O cost. - **Cost**: `io_cost * pages fetched + cpu_tuple_cost * rows scanned` - ![[ex_bmp_heap.svg|200x200]] - **Operates on**: [[Math and Computation/Databases/Postgres/Structures/Index|Index]] [[Page]] - **Workloads**: - [[IO]] - [[DataFileRead]] - [[DataFilePrefetch]] - [[LWLock]] - [[BufferContent]] - [[SharedTidBitmap]] - [[IPC]] - [[ParallelBitmapScan]]