"Guillaume Smet" <guillaume.smet@xxxxxxxxxxx> wrote > [root@bd root]# iostat 10 > > Device: tps Blk_read/s Blk_wrtn/s Blk_read Blk_wrtn > sda 7.20 0.00 92.00 0 920 > sda1 0.00 0.00 0.00 0 0 > sda2 6.40 0.00 78.40 0 784 > sda3 0.00 0.00 0.00 0 0 > sda4 0.00 0.00 0.00 0 0 > sda5 0.00 0.00 0.00 0 0 > sda6 0.80 0.00 13.60 0 136 > sdb 5.00 0.00 165.60 0 1656 > sdb1 5.00 0.00 165.60 0 1656 > > Nested Loop (cost=0.00..13.52 rows=2 width=1119) (actual > time=155.286..155.305 rows=1 loops=1) > -> Index Scan using pk_newslang on newslang nl (cost=0.00..3.87 rows=1 > width=1004) (actual time=44.575..44.579 rows=1 loops=1) > Index Cond: (((codelang)::text = 'FRA'::text) AND (3498704 = > numnews)) > -> Nested Loop Left Join (cost=0.00..9.61 rows=2 width=119) (actual > time=110.648..110.660 rows=1 loops=1) > -> Index Scan using pk_news on news n (cost=0.00..3.31 rows=2 > width=98) (actual time=0.169..0.174 rows=1 loops=1) > Index Cond: (numnews = 3498704) > -> Index Scan using pk_photo on photo p (cost=0.00..3.14 rows=1 > width=25) (actual time=110.451..110.454 rows=1 loops=1) > Index Cond: (p.numphoto = "outer".numphoto) > Total runtime: 155.514 ms > Someone is doing a massive *write* at this time, which makes your query *read* quite slow. Can you find out which process is doing write? Regards, Qingqing
