pg_stat_activity - 如何查看正在运行的存储过程中的当前活动

Question

I have a postgres environment where stored procedures are used extensively and these procedures are complex and call other stored procedures.

When I query the pg_stat_activity table, I get a record that shows the procedure being called, but no indication is given on what sql statements are being called within the procedure.

eg. select myprocname($1,$2,$3,$4)

As a result, I am unable to isolate specific SQL statements which may be causing a performance issue. The RDS in question is an amazon RDS instance, so OS level access to the process is not available (as far as I have been able to determine).

I have searched for information on google on this subject without much luck to this point.

This question is not about the specific scenario as the code is proprietary and I can't discuss it directly, but on how to perform such tuning when the main source I am used to using is not providing enough detail.

Answer 1

There are two ways to see how long SQL statements inside functions take:

1. Enableauto_explain with auto_explain.log_nested_statements = on . That will allow you to see the duration and the execution plans of the SQL statements inside the function in the PostgreSQL log file.

2. Enable pg_stat_statements and set the parameter pg_stat_statements.track = all .

   Then pg_stat_statements will track information for the SQL statements inside a function. That way you can see which of your statements consume how much time in the database.