On Thu, 2025-01-23 at 22:33 -0800, Gurjeet Singh wrote: > > > I am also wondering if having an autovacuum setting to control it would be > > > a good idea for a feature. > > > > I'm all for that. > > Please see attached an initial patch to disable truncation behaviour in > autovacuum. This patch retains the default behavior of autovacuum truncating > relations. The user is allowed to change the behaviour and disable relation > truncations system-wide by setting autovacuum_disable_vacuum_truncate = true. > Better parameter names welcome :-)
I hope it is possible to override the global setting with the "vacuum_truncate" option on an individual table. My suggestion for the parameter name is "autovacuum_disable_truncate". > One additional improvement I can think of is to emit a WARNING or NOTICE > message > that truncate operation is being skipped, perhaps only if the truncation > would've freed up space over a certain threshold. Interesting idea, but I think it is independent from this patch. > Perhaps there's value in letting this parameter be specified at database > level, > but I'm not able to think of a reason why someone would want to disable this > behaviour on just one database. So leaving the parameter context to be the > same > as most other autovacuum parameters: SIGHUP. I can imagine setting that on only a certain database. Different databases typically have different applications, which have different needs. Eventually, the patch should have documentation and regression tests. Yours, Laurenz Albe
