Should I index staging tables?

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Should I index staging tables?

jungnaja

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December 14, 2008 at 5:55 pm

#202894

I have a few staging tables. They are highly active tables with a lot of inserts and deletes. Should I index them? The auto statistic is on.

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Jeff Moden SSC Guru Points: 1004414 More actions · Answer 1

Impossible to tell from what you've described.

--Jeff Moden

RBAR is pronounced "ree-bar" and is a "Modenism" for Row-By-Agonizing-Row.
First step towards the paradigm shift of writing Set Based code:
________Stop thinking about what you want to do to a ROW... think, instead, of what you want to do to a COLUMN.

Change is inevitable... Change for the better is not.

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Jeffrey Williams SSC Guru Points: 90305 More actions · Answer 2

Well, I guess the answer is: It depends :hehe:

Do you want to slow down your inserts/deletes? If so, then yeah - you probably want to add some indexes. Do you want to speed up your selects without slowing down your inserts/deletes - then, maybe, but probably not. And finally, do you want to speed up your deletes at the expense of your inserts? If so, then yeah - you can probably add some indexes that would help.

Most of the time, you don't index staging tables at all. Validation and verification of the data is done after loading the staging tables, just prior to loading into the production tables. And since you want to load the staging tables as fast as possible - you really don't want to add any indexes.

Jeffrey Williams
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Grant Fritchey SSC Guru Points: 398909 More actions · Answer 3

Are the inserts & deletes done all the time or in discrete batches? If the latter, you can leave indexes off until you need them and then add them. If it's constant, you'll have to weigh the cost/benefit as Jeffrey outlined.

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jungnaja SSC-Addicted Points: 422 More actions · Answer 4

Thank you everyone for the responses. There are jobs checking these staging tables every 15 minutes to get the data to insert into the fact tables. So the tables are constantly changing.