Subject RE: [firebird-support] Deletion of rows from multiple tables takes a lot of time around 30mins
Author Leyne, Sean
> Today one of our customer complained that removing clients from
> application is taking a lot of time around 30-40mins.  So I looked into their
> database whose DB size is around 340MB and found that our DBA has a called
> deletion triggers in main table. Triggers will delete all the client information
> from related tables that 6 tables. Also, I checked the child tables from any
> additional triggers  but there were none.
> Now, when I copied this database to my development environment deletion
> works fast takes around 5 mins. I also rechecked with their older databases
> also whose size is around 1GB. Found no slowness during deletion.
> The question arises why this deletion process is taking so much of time at
> customer environment ?

Let's start with:

- Is the server also a Windows domain controller?
- Have you compared performance of customer/your storage using Crystal Disk Mark?
- What FB engine (Classic, SuperServer) are you running?
- What FB version are you running?
- If SuperServer what is the db page cache size?
- What is the db page size?

> Another thing I noticed was that FBServer was consuming 25% CPU usage
> during deletion.

That would not be surprising.