Thank you, Guillaume, Tom. In that case, querying pg_stat_user_tables on replica for last_vacuum, last_autovacuum, last_analyze, and last_autoanalyze columns makes no sense? Those specific columns are not transferred from the master? The same goes for n_* columns? Currently, on my replica, all those columns are null and 0, while on the master they have a value. Seems like only seq_scan, last_seq_scan, idx_scan, ... are fulfilled.
Also, data behind pg_stats (n_distinct, most_common_vals, most_common_freqs, etc) is replicated, right? It seems that we can query those just fine. On Fri, Jan 17, 2025 at 4:34 PM Guillaume Lelarge <guilla...@lelarge.info> wrote: > Hi, > > Le ven. 17 janv. 2025 à 15:38, Franjo Stipanovic <frit...@gmail.com> a > écrit : > >> Question regarding autovacuum settings in a PostgreSQL streaming >> replication setup. Specifically, I am curious about whether it is possible >> (and advisable) to have different values for the following settings on the >> master and replica databases: >> - autovacuum_vacuum_scale_factor >> - autovacuum_analyze_scale_factor >> >> Can the above settings be configured differently on the master and >> replica databases in a streaming replication setup? I just tested this on >> AWS RDS Postgres. >> > > They could but it doesn't matter. VACUUM and ANALYZE aren't executed on > replicas because they are write operations, and you can't write on replicas. > > >> How would those different settings interact with replication, for >> example, if I apply change on master, would it be replicated to replica and >> override my replica setting? >> > Changes on the postgresq.conf file aren't replicated, but ALTER TABLE ... > (SET autovacuum...) are. > >> I was expecting that this is not possible in streaming replication, only >> in logical replication. >> > > You're right, it's not possible. > > > -- > Guillaume. > -- best wishes, Franjo Stipanovic
