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From	Jayadevan M
Subject	Query planning
Date	October 31, 2014 10:46:12
Msg-id	CAFS1N4gp-nJz63SrwiRruRUSOw9nYu8nEoTcXO+Ozc5joDx7hg@mail.gmail.com Whole thread Raw
Responses	Re: Query planning
List	pgsql-general

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Hi all,

I am going through PostgreSQL documentation on how row estimation is done in PostgreSQL.
http://www.postgresql.org/docs/current/static/row-estimation-examples.html
There is a reference to cardinality (rel_cardinality) there. But that is an estimate of the number of rows in the table, right?

How many unique values are there in a column (cardinality), that is estimated while finding out selectivity?

Regards,

Jayadevan

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Date: 31 October 2014, 05:22:56
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Subject: Re: Planet Postgres

Query planning - Mailing list pgsql-general

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