Description: A table scan is a method of accessing all rows in a table to find the desired data. This approach involves traversing each row of the table, which can result in high performance costs, especially in large tables. During a table scan, the database management system (DBMS) examines each record, which can take significant time and resources. This method is commonly used when there are no available indexes to facilitate the search for specific data or when a large number of rows need to be accessed. Although table scanning can be inefficient, it is a fundamental technique in data retrieval and can be useful in situations where a complete analysis of the table is required. Additionally, table scanning may be the only viable option in certain scenarios, such as when performing aggregation operations or applying filters that affect most rows. In summary, while table scanning may be less efficient than other access methods, it remains an essential tool in database query techniques.
