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Live Aggregate Projections and deletes/updates

  • September 12, 2014
  • 2 replies
  • 18 views

Emanuel_Pordes_1
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Hi,

We have fact tables which are mostly append-only (i.e. deletes/updates are very rare) and would like to make use of Live Aggregate Projections (LAP).

As I understand it, if we create a LAP anchored to that table and we wish to do a delete/update we would need to do the following to avoid having the delete statement fail:

1) drop LAP
2) delete/update
3) re-create LAP

I'm assuming that the following could be done without affecting any in-flight or subsequent queries against the fact table and LAP.

If so, then would it not make sense to be able to specify such behaviour when creating the LAP.
i.e. be able to choose between the following two options when the underlying anchor projections' data becomes stale

A) fallback to querying to the raw fact table (e.g. superprojection) until the LAP can be re-created in a consistent state

B) keep answering from the LAP with stale aggregates until the LAP can be re-created (as a tmp table) and swapped with the LAP once consistent

Would such a feature be feasible?

Thanks!


2 replies

Amin
  • New Participant
  • May 11, 2015

Hi,

 

Do you know if there will be any DELETE/UPDATE support for Live Aggregate Projections any time soon? As mentioned in above post, performing a) Drop LAP b) DELETE/UPDATE raw data, and c) Re-create LAP in the background is one option. There are also other options to update LAP partially based on the data affected by DELETE/UPDATE operation.

 

Thanks.


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  • Participating Frequently
  • May 13, 2015

The only way to update LAPs is the procedure you describe.