Should we enable pgsm_normalized_query or not? — Missing QAN examples on PMM 3.8.1

1

Hi team,

Following up on this earlier thread: No query examples in PMM QAN with pg_stat_monitor normalized queries enabled

We’re on PMM 3.8.1 monitoring PostgreSQL with pg_stat_monitor, and confirmed the same behavior: with pgsm_normalized_query = on, QAN’s Examples tab shows “Sorry, no examples found for this query” since the normalized query column only stores placeholders ($1, $2) and never the literal values.

This is tracked as PMM-13195, but we need to decide our config going forward, so a few questions:

  1. What’s Percona’s actual recommendation — should we run with pgsm_normalized_query = on or off in production? The install docs recommend on but that silently disables Examples, which seems like an important trade-off to flag.
  2. If we turn it off to get Examples back, are there known downsides beyond the Table/Plan behavior mentioned in the earlier thread — e.g. performance overhead of storing literal query text, memory/storage growth in pg_stat_monitor’s shared buffer, or security/PII exposure from capturing literal values?
  3. Is there a way to get both — normalized aggregation and example queries — short of waiting on pg_stat_monitor PR #350 (the stalled bind_variables column)?
  4. Any ETA or plan for PMM-13195, and would it help if we added our environment details/+1 to that ticket?

Environment:

  • PMM: 3.8.1
  • Database: PostgreSQL 17 version
  • Extension: pg_stat_monitor (via shared_preload_libraries)
  • Current: pgsm_normalized_query = on

Would really appreciate guidance on which setting to run with, since Examples are important for us to debug slow queries but we don’t want to break aggregation or hit hidden costs. Thanks!

2

Can someone help me on this issue?