Обсуждение: Postgre inner work question

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Postgre inner work question

От
Lucas Cotta
Дата:
Hi!

Does postgre execute the queries following a execution plan tree, where the leafs are table scans, and the nodes are joins?

I'm looking for a database where I can get a cardinality from a partial result of the execution... for example, print the cardinality of the results until the next join operator use this result...

Thanks!

Postgre inner work question

От
Lucas Cotta
Дата:
Hi!

Does postgre execute the queries following a execution plan tree, where the leafs are table scans, and the nodes are joins?

I'm looking for a database where I can get a cardinality from a partial result of the execution... for example, print the cardinality of the results until the next join operator use this result...

Thanks!

Re: Postgre inner work question

От
Adrian von Bidder
Дата:
On Tuesday 12 April 2011 01.02:35 Lucas Cotta wrote:
> Does postgre execute the queries following a execution plan tree, where
> the leafs are table scans, and the nodes are joins?

yes, see the "EXPLAIN" SQL command (EXPLAIN SELECT * FROM ....), it will
shwo this tree.

http://www.postgresql.org/docs/9.0/static/sql-explain.html

cheers
-- vbi

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