My complex saved procedure works instantly for many of DBs,

But it will require a lot more than 30 sec to complete them on DB X, maybe more but we did not find yet.

DB X does not possess the most data but our supporter 'delete' some data and re-place them lately.

I have remedied the table identity Index however it does not help.

I Quickly found whenever a light table 'Left Join' a sub query that will return the primary data, the execution becomes slow.

The sub query is fast and and if I place sub query to some temp hash table and left join the hash table, the totally fast!

Anybody understand what happened for this DB X, and also the solution ?

Thanks

I discovered it triggered by missing index, however i do not understand why now? I additionally concerned about the rate for placing a large amount data if set index on server.

Have statistics been up-to-date and indexes been reconstructed? Or disabled?

Especially after lots of card inserts, removes etc

Thanks

I discovered it triggered by missing index, however i do not understand why now? I additionally concerned about the rate for placing a large amount data if set index on server.