Re: Update statistics automatic ?

Pascale wrote: > > Hi everybody, > > I will have more information about update statistics > > On a online informix database 7.23, does statistics updated automatically ?? No the statistics and data distributions are not automatically maintained. You must keep them up-to-date by periodically doing the recommended series of UPDATE STATISTICS statements. See the release notes files for 7.2x or the PERFORMANCE GUIDE for 7.3 which contain the recommended series. As an alternative to learning this yourself you can get my utility dostats.ec from the IIUG Software Repository in the package utils2_ak which implements these recommendations with many configuration options. > or must I have to "isql" update statistics ?? > How optimiser is doing ?? > Can I select plain ?? Not in 7.23. Optimizer directives were implemented in 7.30 and later versions. You would need to upgrade the server to 7.30 or 7.31 or even to IDS.2000 (9.20) when it comes out next month. > For example, can I put directives to parser to told (as in oracle) for a > query : I want to parse my query with using index, or scan all rows > SELECT /*+ALL ROWS */ * FROM my_table > ^ > I > that is the directive !! Art S. Kagel