Live Aggregate Projections and deletes/updates
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
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!
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
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 consistentWould such a feature be feasible?
Thanks!
0
Comments
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.
The only way to update LAPs is the procedure you describe.