Re: Simple SQL Question

Franco Bruno Borghesi wrote:


Hi!

Sorry for being late with the answer, I was busy at one of our customer;)

> wouldn't it be easier using offset & limit?: you always select from the 
> table with an itemkey,location order by clause. You save the current 
> offset between requests, and for every request you re-execute the query 
> with a different offset.  Sure, but sometimes I have to query by name, and dont want to create  another query
component.

> If you still want to go with what you already have, you should keep the 
> lastItemKey and lastLocaltion values between requests, and your where 
> clause should be something like:
> WHERE (itemKey=:lastItemKey AND location>:lastLocation) OR 
> (itemKey>:lastItemKey)
  It works perfectly, but I have to consider the performance issue,  because if i use 'or' statement, postgres doesn't
useindex scan,  and I also have tables with 3 or more keys and 500.000 records , 
 
where  the performance of this method is poor.  Maybe I will end up using limit and offset in case of incremental
fetching,butif the table is modified between requests, it can behave  weird.  Is there a perfect solution to this?
 

Sorry for the english

Thank you again,

Andras Kutrovics