Hi,
When we run a report, we can see that it first analyses, then brings back data.
Sometimes it takes so much time in analysing the query. Why does this happen?
Even if it returns only limited number of rows say : 300, it takes quite a lot of time in analysing. Why is it so?
Thanks in advance.
botech (BOB member since 2006-08-10)
you can distinguish two phases when submitting an sql query :
The first “analyse by the motor” phase when the database engine will analyse your query
Then, the “Fetch” period where database bring you the corresponding results.
The first one can be very long even if the query only retrieve a few lines and it is very hard to estimate. Ask you dba guys about this question if you want more details
Regards
Bernard
bernard timbal 
(BOB member since 2003-05-26)
The query can take more time for analysis if it has sum, distinct or group by. Also if the report has many breaks.
Hope this helps 
pinku (BOB member since 2006-08-23)
Thanks a lot guys.
It was very helpful.
botech (BOB member since 2006-08-10)
(BOB member since 2002-06-20)