add pg_stat_statements plans#1315
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Add pg_stat_statements metrics: plans_total: Number of times planned plans_seconds_total: Total time spent in planning the statement It needs the PostgreSQL setting: pg_stat_statements.track_planning Signed-off-by: Julien Francoz <julien@les-tilleuls.coop>
| statStatementsPlansSecondsTotal = prometheus.NewDesc( | ||
| prometheus.BuildFQName(namespace, statStatementsSubsystem, "plans_seconds_total"), | ||
| "Total time spent in planning the statement, in seconds", | ||
| []string{"user", "datname", "queryid"}, |
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queryID looks like a label with unbounded cardinality. Could we drop it?
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I need it, for example to get the ratio of calls by plan and find queries which are badly used (for example prepare + bind inside a loop)
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This doesn't work well with Prometheus though 😅.
Maybe that could become an exemplar label in the histogram?
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I don’t understand the problem. It’s already the same in all the other metrics from pg_stat_statements.
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Apologies, I probably should have said this from the beginning. I'm not a maintainer for this repository! If the maintainers are ok with it, that's what counts
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What I meant by "this doesn't work well with Prometheus" is that a single query will have a single ID and generate a single timeseries; another query will get a different ID and therefore become a brand-new timeseries.
All those unique IDs will become an entry in Prometheus's Posting index (good blog in case you'd like to read more). A gigantic posting index will make PromQL queries slower and increase resource usage
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Add pg_stat_statements metrics:
plans_total: Number of times planned
plans_seconds_total: Total time spent in planning the statement
It needs the PostgreSQL setting: pg_stat_statements.track_planning