14,499 questions
Spools typically appears in two places of a plan. One where it is being written to, and one where it is read.
Keep in mind that the costs are estimates, and nothing you should pay that much attention to.
Execution plan for table spool
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sakuraime
2,346
Reputation points
Anyone saw any execution plan starting with a table spool ? and also it cost is grater than 100%
SQL Server | Other
3 answers
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Erland Sommarskog 121.8K Reputation points MVP Volunteer Moderator2021-07-05T21:56:53.623+00:00 -
CathyJi-MSFT 22,396 Reputation points Microsoft External Staff2021-07-06T06:22:31.203+00:00 Hi @sakuraime ,
Spool is a physical operator that shows up in the execution plan. Query optimizer uses spools when it thinks that it’s better to put data in the temp table rather than hitting a table again and again using seeks and scans.
Check if below blog could help you.
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sakuraime 2,346 Reputation points
2021-07-06T13:19:20.22+00:00 thanks and do you know why the cost is over 100%???
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CathyJi-MSFT 22,396 Reputation points Microsoft External Staff
2021-07-07T09:00:05.443+00:00 Hi @sakuraime ,
These are just estimated costs so you shouldn't place too much attention on them.
By the way, check if below blog could help you.
SQL Server Execution Plan shows cost of more than 100 percentage
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Tom Phillips 17,771 Reputation points2021-07-06T17:05:41.79+00:00 There are many reasons for the total to be >100% on the estimated plan. There was a problem in SSMS which caused this. However, it is still possible. Make sure you have the current version of SSMS installed.