Hello, If you has index on id, then you can use SELECT id FROM tabulka ORDER BY id DESC LIMIT 1;
See 4.8. FAQ Regards Pavel Stehule On Wed, 11 Feb 2004, David Teran wrote: > Hi > > we have a table with about 4 million rows. One column has an int value, > there is a btree index on it. We tried to execute the following > statement and it is very slow on a dual G5 2GHZ with 4 GB of RAM. > > explain analyze select count(*) from job_property where int_value = 0; > > Aggregate (cost=144348.80..144348.80 rows=1 width=0) (actual > time=13536.852..13536.852 rows=1 loops=1) > -> Seq Scan on job_property (cost=0.00..144255.15 rows=37459 > width=0) (actual time=19.422..13511.653 rows=42115 loops=1) > Filter: (int_value = 0) > Total runtime: 13560.862 ms > > > > Is this more or less normal or can we optimize this a little bit? > FrontBase (which we compare currently) takes 2 seconds first time and > about 0.2 seconds on second+ queries. > > regards David > > > ---------------------------(end of broadcast)--------------------------- > TIP 6: Have you searched our list archives? > > http://archives.postgresql.org > ---------------------------(end of broadcast)--------------------------- TIP 4: Don't 'kill -9' the postmaster
