Hi everybody, An SQL execution is very slow. What can I do to makes it faster。 count_MCL -------- 3476534 count_MLC -------- 34442313 count_HLCC --------- 245119339 --------------------------------------------------------------------------------------------------------------------------------------------------- eki0601_pg=# explain analyze select * FROM MCL,MLC,HCC WHERE MCL.clid = MLC.clid AND MLC.lctid = HCC.lctid AND MCL.ctid = '01010002759' order by HCC.ccdate desc fetch first 10 row only ; QUERY PLAN ------------------------------------------------------------------------------------------------------------------------------------ ------------------------------------------------------------------------- Limit (cost=0.00..2119.09 rows=10 width=6294) (actual time=431697.682..433829.812 rows=10 loops=1) -> Nested Loop (cost=0.00..1764617853.95 rows=8327231 width=6294) (actual time=431697.679..433829.803 rows=10 loops=1) -> Nested Loop (cost=0.00..1453759062.80 rows=245081856 width=4710) (actual time=0.097..302838.488 rows=13615078 loops=1) -> Index Scan Backward using hlcc_20110322_idx on hcc (cost=0.00..27082303.79 rows=2 45081856 width=193) (actual time=0.020..18232.493 rows=13615078 loops=1) -> Index Scan using idx910300732140000 on MLC (cost=0.00..5.81 rows=1 width=4517) (actual time=0 .017..0.018 rows=1 loops=13615078) Index Cond: ((mlc.lctid)::text = (hcc.lctid)::text) -> Index Scan using mcl_tk14289_idx1 on MCL (cost=0.00..1.26 rows=1 width=1584) (actual time=0.009..0. 009 rows=0 loops=13615078) Index Cond: ((mcl.clid)::text = (mlc.clid)::text) Filter: ((mcl.ctid)::text = '01010002759'::text) Total runtime: 433830.691 ms (10 rows) --------------------------------------------------------------------------------------------------------------------------------------------------- -- Sent via pgsql-admin mailing list (pgsql-admin@xxxxxxxxxxxxxx) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-admin
