Postgre inner work question

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!

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
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