Re: Accounting for between table correlation

On 1/15/21 10:49 AM, Alexander Stoddard wrote:

Please reply to list also.
Ccing list.

> 
>     So to be clear, the process imports the data, then you run a query and
>     it completes in x time, you then ANALYZE the same data and it runs in y
>     time. Is that correct?
> 
> The process imports data, ANALYZE is run and then queries run in x time.
> A subsequent ANALYZE, may or may not, change the time to y.
> x may be greater or less than y for any given pair of runs, and the 
> difference is vast. Two very different performance domains, due to the 
> plan, I believe. If I am correctly reading the EXPLAIN plans the row 
> estimates are always way off (and low), regardless of if a high or low 
> performing plan is actually chosen.

Well I'm going to say this is not going to get a useful answer without 
some concrete numbers. Too many variables involved to just start 
guessing at solutions.

> 
> Thank you,
> Alex


-- 
Adrian Klaver
adrian.klaver@aklaver.com