- **Description**: Scans a table using an index. - **Performance**: Depends on index and query selectivity. - **Factors**: Index size, disk I/O cost. - **Cost**: `index cost + cpu_index_tuple_cost * index entries scanned` - ![[ex_index_scan.svg|200x200]] - **Operates on**: [[Math and Computation/Databases/Postgres/Structures/Index|Index]]