Re: [PERFORM] Queries taking ages in PG 8.1, have been much faster in PG<=8.0

[Markus Wollny]

 

> -----Ursprüngliche Nachricht-----
> Von: Tom Lane [mailto:[EMAIL PROTECTED] 
> Gesendet: Montag, 5. Dezember 2005 15:33
> An: Markus Wollny
> Cc: pgsql-performance@postgresql.org
> Betreff: Re: AW: [PERFORM] Queries taking ages in PG 8.1, 
> have been much faster in PG<=8.0 
 
> Could we see the pg_stats row for answer.session_id in both 
> 8.0 and 8.1?

Here you are:

select null_frac
        , avg_width
        , n_distinct
        , most_common_vals
        , most_common_freqs
        , histogram_bounds
        , Correlation
from pg_stats
where schemaname = 'survey'
and tablename = 'answer'
and attname = 'session_id';

8.1:
null_frac               0
avg_width               4
n_distinct              33513
most_common_vals        
{1013854,1017890,1021551,1098817,764249,766938,776353,780954,782232,785985}
most_common_freqs       
{0.001,0.001,0.001,0.001,0.000666667,0.000666667,0.000666667,0.000666667,0.000666667,0.000666667}
histogram_bounds        
{757532,819803,874935,938170,1014421,1081507,1164659,1237281,1288267,1331016,1368939}
Correlation             -0.0736492

8.0.3:
null_frac               0
avg_width               4
n_distinct              29287
most_common_vals        
{765411,931762,983933,1180453,1181959,1229963,1280249,1288736,1314970,764901}
most_common_freqs       
{0.001,0.001,0.001,0.001,0.001,0.001,0.001,0.001,0.001,0.000666667}
histogram_bounds        
{757339,822949,875834,939085,1004782,1065251,1140682,1218336,1270024,1312170,1353082}
Correlation             -0.237136

Kind regards

   Markus

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