Re: Performance differential when 0 values present vs when 1 values present. Planner return 52k rows when 0 expected.

2022-04-25 Thread Tom Lane
Emil Iggland writes: > The query that is giving us issues is the following, channel 752433 has > NO values, 752431 has values. > (Channel 752433 only has valueseries 752434) > select * from datavalue > where dataview in ( select id from valueseries where channel = > %channel_idx%) > ORDER BY VA

Performance differential when 0 values present vs when 1 values present. Planner return 52k rows when 0 expected.

2022-04-25 Thread Emil Iggland
Dear mailing list We are investigating a strange performance issue with our database. Our use case is a sensor reading database where we have sensor location (called channels), parameter settings (called valueseries) and reading (called datavalues). Datavalues is partitioned per month. Like t