Multithreaded DBMSs?

I was wondering what DBMSs actua开发者_如何转开发lly use multithreading in their query plans/executions?

Oracle supports this, as does SQL Server and DB2. I do not believe that MySQL or PostgeSQL support parallel queries though.

I believe most databases that support table partitioning will support querying each partition at the same time if the need arises rather than just pruning unneeded partitions. Oracle can do this. Teradata definitely does this.

MySQL only uses one thread per query (in the standard engines); this includes if the tables are partitioned.

The Multi-threading is used in dB @ many areas, for example at the Query Evaluation.

*) The Parallel Query execution is done with the help of Multi-threading for Optimizing the performance of the Query evaluation.

*) Parallelize the dB backup like creating a separate backup thread for each available tape drive will accomplish the dB server Back-up. (eg) Oracle Uses it.

*) Using the Table Reorganization - When the time goes the dB becomes bulky and the DBA will reorganize the tables in the intention of improve the performance of the dB.

---- In oracle the POSIX and C++ is used to achieve the multi-threading.----