[sgarland]

Nope. Performance and WAL bloat will both occur.

https://www.cybertec-postgresql.com/en/unexpected-downsides-...

[sroussey]

This is a great article, thank you!

[sroussey]

I wonder how this works out for MySQL. Any time I’ve used uuid there I’ve used my own version (more like v7 that is available now).

This makes a big difference for the primary key (clustered index for both MySQL and postgresql).

Does anyone have an analysis for MySQL secondary indexes like the above referenced one for PostgreSQL secondary indexes?

[sgarland]

MySQL stores the PK with every secondary index, and uses it to retrieve the requested rows (unless the query is covered by the index). I’d think for most queries, this would result in a similar slowdown.