Re: Proposal to Enable/Disable Index using ALTER INDEX (with patch)

On Oct 16, 2024, at 6:01 PM, Shayon Mukherjee <shayonj@gmail.com> wrote:

I'll take some time to think this through and familiarize myself with the new systable_inplace_update_begin. In the meantime, aside from the in-place updates on pg_index, I would love to learn any first impressions or feedback on the patch folks may have.

My take away from whether or not an in-place update is needed on pg_index [1]

- It’s unclear to me why it’s needed. 

- I understand the xmin would get incremented when using CatalogTupleUpdate to update indisenabled.

- However, I haven’t been able to replicate any odd behavior locally or CI. 

- FWIW - REINDEX CONCURRENTLY (via index_swap),  index_constraint_create and few other places perform CatalogTupleUpdate to update the relevant attributes as well.

Based on the above summary and after my testing I would like to propose a v3 of the patch. The only difference between this and v1 [2] is that the update of pg_index row happens via CatalogTupleUpdate.

[1]  https://www.postgresql.org/message-id/20180618215635.m5vrnxdxhxytvmcm@alap3.anarazel.de

[2] https://www.postgresql.org/message-id/EF2313B8-A017-4869-9B7F-A24EDD8795DE%40gmail.com

Thank you for bearing with me on this :D

Shayon