> -----Ursprüngliche Nachricht----- > Von: Tom Lane [mailto:tgl@xxxxxxxxxxxxx] > Gesendet: Montag, 5. Dezember 2005 15:33 > An: Markus Wollny > Cc: pgsql-performance@xxxxxxxxxxxxxx > 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
