solidDB® provides a simple SQL optimization feature that increases performance with specific types of single-table SQL queries. Performance improvements apply to SELECT, DELETE, and UPDATE statements. The feature does not apply to INSERT statements.
Simple SQL optimization is enabled/disabled with the SQL.SimpleSQLOpt parameter. By default, this feature is turned on and the SQL.SimpleSQLOpt parameter does not appear in the solid.ini file. To disable the feature, you must add the following lines to the solid.ini file:
[SQL] SimpleSQLOpt=No
Once you have added these lines to the file, you can always enable the feature by specifying SimpleSQLOpt=Yes or removing the parameter from the [SQL] section.
When simple SQL optimization is turned on, solidDB® automatically optimizes single-table SQL queries that meet the following conditions:
▪The statement accesses only a single table.
▪The statement does not contain a view, subquery, UNION, INTERSECT, or so on.
▪The statement does not use ROWNUM.
▪The statement does not use a solidDB® sequence object that is used to retrieve sequence numbers.
As with other optimization techniques, the simple SQL optimization feature speeds up most queries, but reduces performance for a few types of queries. If particular queries run more slowly when you are using simple SQL optimization, you can turn off the feature.