Tune configuration parameters for basic text searching
You can optimize the performance of basic text searches by tuning certain configuration parameters.
- AUTO_READAHEAD
- The AUTO_READAHEAD configuration parameter enables automatic read-ahead. Pages that are brought into the bufferpool cache during sequential scans of data records can improve the performance of a query when the server detects that the query is encountering I/O.
- BUFFERPOOL
- The BUFFERPOOL configuration parameter defines a buffer pool for pages that correspond to each unique page size that is used by your dbspaces. You can specify information about the buffer pool, including its size, the number of LRU queues in the buffer pool, the number of buffers in the buffer pool, and minimum and maximum percentages of modified pages in the LRU queues.
- RESIDENT
- The RESIDENT configuration parameter specifies whether the resident portion of shared memory remains resident in operating system physical memory. If your operating system supports forced residency, you can improve the performance of searches by specifying that the resident portion of shared memory is not swapped to disk. Set the RESIDENT configuration parameter to 1 (on).
- VPCLASS
- You can add the noage option to the VPCLASS configuration parameter setting for the BTS virtual processor. The noage option improves performance by disabling priority aging by the operating system. The BTS virtual processor that is created automatically does not include the noage option.
- PRELOAD_DLL_FILE
- You can add the BTS shared library, bts.bld,
to a PRELOAD_DLL_FILE configuration parameter setting to preload
the BTS shared library when the server starts instead of loading the
library the first time you run a BTS function or create a bts index.
For example, add the following line to your onconfig file:
PRELOAD_DLL_FILE $INFORMIXDIR/extend/bts.version/bts.bldThe version is the specific version number for the extension. Run the bts_release() function to find the correct version number. The version number of the BTS extension can change in any fix pack or release. After you upgrade, you must update the value of the PRELOAD_DLL_FILE configuration parameter if the version number of the BTS extension changed.
Important: Do not preload the bts_cl.bld file or the BTS extension does not operate properly.