Re: [GENERAL] Seq Scan cost shown to be (cost=10000000000.00..10000000001.10)
> When one uses “enable_” settings to adjust planner behavior, PostgreSQL > just sets really high costs for the operations affected (like the one you > see). > > As SeqScan is the only possible way to execute your query, it is still > choosen. > I get it. Thanks! -- Amit Langote -- Sent via pgsql-general mailing list (pgsql-general@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-general
Re: [GENERAL] Seq Scan cost shown to be (cost=10000000000.00..10000000001.10)
>> Although, I suspect the (dropped index + enable_seqscan) causes this, >> is the cost shown in explain output some kind of default max or >> something like that for such abnormal cases? > > When you set enable_xxx=off, it not actually disables the xxx > operation, it sets the start cost to the high value (100). > Oh, okay, thanks! -- Amit Langote -- Sent via pgsql-general mailing list (pgsql-general@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-general
Re: [GENERAL] Seq Scan cost shown to be (cost=10000000000.00..10000000001.10)
2013/5/27 Amit Langote > Although, I suspect the (dropped index + enable_seqscan) causes this, > is the cost shown in explain output some kind of default max or > something like that for such abnormal cases? > When one uses “enable_” settings to adjust planner behavior, PostgreSQL just sets really high costs for the operations affected (like the one you see). As SeqScan is the only possible way to execute your query, it is still choosen. Somewhat related thread: http://www.postgresql.org/message-id/4d5b06ac.2020...@lelarge.info -- Victor Y. Yegorov
Re: [GENERAL] Seq Scan cost shown to be (cost=10000000000.00..10000000001.10)
On Mon, May 27, 2013 at 12:42 AM, Amit Langote wrote: > I set enable_seqscan=off and also accidentally dropped the only index [...] > Seq Scan on testdata (cost=100.00..101.10 rows=2 width=71) [...] > Although, I suspect the (dropped index + enable_seqscan) causes this, > is the cost shown in explain output some kind of default max or > something like that for such abnormal cases? When you set enable_xxx=off, it not actually disables the xxx operation, it sets the start cost to the high value (100). -- Kind regards, Sergey Konoplev PostgreSQL Consultant and DBA Profile: http://www.linkedin.com/in/grayhemp Phone: USA +1 (415) 867-9984, Russia +7 (901) 903-0499, +7 (988) 888-1979 Skype: gray-hemp Jabber: gray...@gmail.com -- Sent via pgsql-general mailing list (pgsql-general@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-general
