On Thu, Feb 27, 2020 at 02:35:18AM +0900, Yugo NAGATA wrote: > Hi, > > Attached is a patch for allowing auto_explain to log plans before > queries are executed. > > Currently, auto_explain logs plans only after query executions, > so if a query gets stuck its plan could not be logged. If we can > know plans of stuck queries, we may get some hints to resolve the > stuck. This is useful when you are testing and debugging your > application whose queries get stuck in some situations.
Indeed that could be useful. > This patch adds new option log_before_query to auto_explain. Maybe "log_before_execution" would be better? > Setting auto_explain.log_before_query option logs all plans before > queries are executed regardless of auto_explain.log_min_duration > unless this is set -1 to disable logging. If log_before_query is > enabled, only duration time is logged after query execution as in > the case of when both log_statement and log_min_duration_statement > are enabled. I'm not sure about this behavior. The final explain plan is needed at least if log_analyze, log_buffers or log_timing are enabled.
