Attached is v4, changing how GUCs are picked for inclusion on the query plans. Instead of picking the GUCs based on group and/or explicitly, a new GUC_EXPLAIN flag is used for that.
I went through GUCs defined in guc.c and marked those in QUERY_TUNING* groups accordingly, with the exception of default_statistics_target because that seems somewhat useless without showing the value used to actually analyze the table (and/or columns).
I've also included a couple of other GUCs, that I find to be relevant:
The one bit that needs fixing is escaping the GUC values when showing them in the plan. Looking at the other places that currently escape stuff, I see they only care about YAML/JSON/XML and leave the regular output unescaped. I was wondering if it's OK with the current format with all GUCs on a single line
QUERY PLAN --------------------------------------------------- Seq Scan on t (cost=0.00..54.63 rows=13 width=4) Filter: ('x''y'::text = (a)::text) GUCs: enable_nestloop = 'off', work_mem = '32MB' (3 rows)
but I suppose it is, because without the escaping a user can break whatever format we use. So I'll do the same thing, escaping just the structured formats (YAML et al).
The question however is whether someone has a better formatting idea?
regards
-- Tomas Vondra http://www.2ndQuadrant.com PostgreSQL Development, 24x7 Support, Remote DBA, Training & Services
