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Understanding and Using the PARALLEL & NO_PARALLEL Hint correctly

unknown-2973982Feb 20 2016 — edited Feb 21 2016

Hello All,

I hope this finds you all in good Spirits.

I am in the process of tuning this one bit of SQL that has several sub select queries inside of it and my task is to speed up the over all execution to completion time if possible.

One of the people that I am working looked at the explain plan and then suggested that I use the NO_PARALLEL Hint.

From what I understand, this hint simply overrides a PARALLEL specification in the table clause. In general, hints take precedence over table clauses.

If this is true, then I am confused on how using NO_PARALLEL hint, will actually help speed up the query.

It is very possible that some how I am missing what this hint actually does...

Can someone please break it down for me so I can understand how using the NO_PARALLEL hint could speed up a query?

Thanks,

Lady Allora.

This post has been answered by JustinCave on Feb 21 2016
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