tablescan
TableScan is a database query execution operation that reads every row from a table, typically in a sequential manner, without using an index to locate specific rows. It represents the most straightforward form of data retrieval and is often contrasted with index-based access methods, which target a subset of rows via a lookup structure.
Table scans are commonly chosen when the table is small, when there is no usable index for
Performance considerations center on data volume and I/O bandwidth. The cost of a table scan generally grows