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I have a query that creates several temporary tables and then inserts data into them. From what I understand this is a potential cause of Table Spool. When I look at my execution plan the bulk of my processing is spent on Table Spool. Are there any good techniques for improving these types of performance problems? Would using a view or a CTE offer me any benefits over the temp tables?
I also noticed that when I mouse over each table spool the output list is from the same temporary table.
Well, with the information you gave I can tell only that: the query optimizer has chosen the best possible plan. It uses table spools to speed up execution. Alternatives that don’t use table spools would be even slower.
How about showing the query, the table(s) schema and cardinality, and the plan.
Update
I certainly understand if you cannot show us the query. But is really hard to guess why the spooling is preffered by the engine whithout knowing any specifics. I recommend you go over Craig Freedman’s blog, he is an engineer in the query optimizer team and has explained a lot of the inner workings of SQL 2005/2008 optimizer. Here are some entries I could quickly find that touch the topic of spooling in one form or another:
SQL customer support team also has an interesting blog at http://blogs.msdn.com/psssql/
And ‘sqltips’ (the relational engine’s team blog) has some tips, like Spool operators in query plan…