Re: substr or like
Date: Thu, 3 Jul 2008 09:44:45 -0700 (PDT)
> Run the built-in SQL trace facility on the two SQL statements or use
> auto-trace. Remember the effect that having some of the data buffered
> from a prior run will have on subsequent runs so if possible pre-load
> the data or take an average of the followup executions of the SQL to
> base you analysis on.
> Parse information is available via the trace. See Performance and
> Tuning manual for instructions on use.
> HTH -- Mark D Powell --
Thanks for your responses, i have launched the statistic script cause they re was not up todate and now, the two queries take the same time : 14 second.
All my tests are done many times and i take those when pre load is ok.
The most cost is a table full scan on the substr query which increase the time but without be more than with like operator query (using a index).
I will use a substr index and it will be better.
Chmanu Received on Thu Jul 03 2008 - 11:44:45 CDT