Index management | Agent management

Tablespace management

If you want to use Database Managed Storage devices as containers for tablespaces, you should consider following factors to make sure to effectively manage DMS:

• How to perform file system caching

  File system caching is performed as follows:

  • For DMS device container tablespaces, the operating system does not cache pages in the file system cache.
  • For a DMS file container, the operating system might cache pages in the file system cache.

• How to buffer data read

  A database buffer pool can store the data read from disk casually. But considering that there is a limitation to the buffer pool space, some data pages might be deleted from the buffer pool before the application actually uses this page. In this case, you might be able to increase the size of the database buffer pool to achieve more buffered data, which eventually improves the performance of the database. But on the other hand, it consumes more memory at the same time, so that you should identify whether there is buffer memory that can be used for the database buffer pool.

• Using LOB or LONG data

  When an application retrieves either LOB or LONG data, the database manager does not cache the data in its buffers. Each time an application needs one of these pages, the database manager must retrieve it from disk. However, if LOB or LONG data is stored in SMS or DMS file containers, file system caching might provide buffering and, as a result, we can get better performance.