Indexing helps to improve performance for databases query. And most of the DBA believe that rebuilding indexes also help to increase the performance and they are rebuilding indexes at a regular period of time. But most of the cases this is not true and very rare case index rebuild is required or helped on performance.
Category: Oracle Core
Sep 27 2020
How Oracle Database Processes DML Internally
Result set rows can be fetched either a row at a time or in groups. In the fetch stage, the database selects rows and, if requested by the query, orders the rows. Each successive fetch retrieves another row of the result until the last row has been fetched. DML-Operation. Insert a Record into a Table. …
Sep 26 2020
How Oracle Database Process Select Query Internally
This topic will describe how Oracle works internally with Index and Full Table Scan. Full Table Scan (No Index) when all blocks are available in Buffer Cache. Full Table Scan (No Index) when Blocks are not available in Buffer Cache. Select query Using index when get block from index and table segments. Select query Using …