I have a database in which there is a parent “Account” row that then has a 1-Many relationship with another table, and that table has a 1-Many relationship with another table. This goes on about 6 levels deep (with Account at the top). At the very bottom there could possibly be thousands (can even go beyond 100k) of rows. On each table there is a foreign key set to cascade on delete.
The issue is, that if I try to delete the very top row (an “Account”), it can take minutes, sometimes well over 10 minutes. Is there a faster way to delete all the rows (such as maybe going from the bottom up in individual delete statements) or is cascading pretty much it?
I am using MSSQL 2005 & MSSQL 2008 for the server, ans L2S to perform the delete, although i can use a T-SQL statement if it is faster.
Ive tried doing the delete from the SQL Management Studio too, and that takes just as long.
edit: we have tried re-indexing the database, with negligible difference, maybe a minute or two difference. I appreciate all your answers, it looks like i am going to have to start writing some code to do soft deletes!
A delete is a delete, and if you want to delete massive amounts of rows (100k), it will take a while.
If you do a soft delete (set a status to “D” for example) you can then run a job to actually delete the rows in batches of say 1,000 or so over time it may work better for you. The soft delete should update only the header row and would be very fast. You’d need to code your application to ignore these “D” status rows and their children though.
EDIT
To further @Kane’s comment. you could only do a soft delete, or you could do a soft delete followed by a batch process to do the actual deletes if you really want to. I’d just stick with the soft deletes if drive space is not an issue.