Re: Accounting for between table correlation

On 1/15/21 11:54 AM, Adrian Klaver wrote:
> 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.

Not sure if it would work for the vendor or not but:

https://explain.depesz.com/

offers an option to obfuscate EXPLAIN/ANALYZE output.

>
>>
>> Thank you,
>> Alex
>
>

--
Adrian Klaver
adrian(dot)klaver(at)aklaver(dot)com