Re: EXPLAIN and FK references?

Ron <ronljohnsonjr@xxxxxxxxx> · Thu, 12 Jan 2023 01:33:56 -0600



    On 1/12/23 01:11, Tom Lane wrote:

    
      Ron <ronljohnsonjr@xxxxxxxxx> writes:

      
        On 1/12/23 00:07, Tom Lane wrote:

        
          No, not directly, but you could look at EXPLAIN ANALYZE to see which
of the RI triggers is eating the time.

        
        Good to know, but even deleting one day of data (90,000 rows using an index 
scan on the date field) takes forever.

      
      So delete a relatively small number of rows, and do it with
EXPLAIN *ANALYZE*.  Without ANALYZE, you aren't getting any
relevant data.
    
    
    Doing that when trying to delete one minute of data is
    exactly what was needed.  99.999% of the time was spent on a
    checking another table which didn't have a supporting index.

    
    Adding that index makes things run as expected.

    
    -- 

      Born in Arizona, moved to Babylonia.