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PaulHernandez-8067 asked PaulHernandez-8067 commented

Synapse dedicated SQL pool - 100% Cost in estimated plan for "Compute to Control Node"

Hi everyone,

I am trying to understand an estimated execution plan for a query running on an sql dedicated pool.

The cost is 100% allocated to the operation "Compute to Control Node".

What does it mean?

We are trying to determine if it worths to create a partition in a small table (only 200K rows) or not. I think compare the two plans could be an option but I cannot understand them and cannot find online documentation.

Could someone please provide some documentation links regarding execution plans on dedicated pools, or is this info currently not available?

BR.
Paul

azure-synapse-analytics
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Hi @PaulHernandez-8067,

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TomPhillips-1744 answered PaulHernandez-8067 commented

Can you post the XML query plan here https://www.brentozar.com/pastetheplan/.

In answer to your question, partitioning is generally not a query performance enhancement tool. With proper indexing, partitioning will not help query performance.

Partitioning a table that small, will not have any performance impact. Partitioning is really only useful for loading/unloading large amounts of data. For example, billions of rows per month, and you only want to keep a rolling 12 months of data in the table.

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Hi @TomPhillips-1744 ,

thanks for your reply.

Unfortunately the Bent Ozar tool is not working for me. It gives me the following error:
147326-image.png

I attached the two estimated plans in xml format.

Any help will be appreciated.

Best regards,
Paul147293-20211108-my-query-plan-1.xml147372-20211108-my-query-plan-2.xml


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