On 12/18/21 22:27, Tom Lane wrote:
Tomas Vondra <tomas.von...@enterprisedb.com> writes:
Here's a PoC demonstrating this idea. I'm not convinced it's the right
way to deal with this - it surely seems more like a duct tape fix than a
clean solution. But it does the trick.
I was imagining something a whole lot simpler, like "don't try to
cache unused sequence numbers when wal_level > minimal". We've
accepted worse performance hits in that operating mode, and it'd
fix a number of user complaints we've seen about weird sequence
behavior on standbys.
What do you mean by "not caching unused sequence numbers"? Reducing
SEQ_LOG_VALS to 1, i.e. WAL-logging every sequence increment?
That'd work, but I wonder how significant the impact will be. It'd bet
it hurts the patch adding logical decoding of sequences quite a bit.
regards
--
Tomas Vondra
EnterpriseDB: http://www.enterprisedb.com
The Enterprise PostgreSQL Company
