Re: [HACKERS] Equivalence Rules

2014-03-02 Thread Antonin Houska
There are 2 kinds of rules in this document: for joins and for set operations. As for joins, I think they are all about *inner* joins. Postgres (IMO) "implements" them by not doing anything special if query only contains inner joins. On the other hand, attention has to be paid if there's at least

[HACKERS] Equivalence Rules

2014-03-02 Thread Ali Piroozi
Hi My question is: Does PostgreSQL implements equivalence rules(from those are listed in email's attachment)? Which function or which part of source code(in PostgreSQL ) implements the equivalence rules? I think, this should be implemented in query optimization part of PostgreSQL, but which rule a

Re: [HACKERS] Equivalence Rules

2014-02-28 Thread Ali Piroozi
"where" means, which function or which part of source code. I want to use that(function or part of source code), to produce the equivalence (based on equivalence rules in attachment) Relational Algebra for a given SQL query(Relational Algebra).

Re: [HACKERS] Equivalence Rules

2014-02-28 Thread David Johnston
Ali Piroozi wrote > Hi > Which equivalence rule from those are listed in > email's attachment are implemented in postgresql? > where are them? What do you mean by "where"? The various JOINS and UNION/INTERSECT/DIFFERENCE are all defined capabilities. SQL is not purely relational in nature so som

[HACKERS] Equivalence Rules

2014-02-28 Thread Ali Piroozi
Hi Which equivalence rule from those are listed in email's attachment are implemented in postgresql? where are them? Thanks equivalenceRules.pdf Description: Adobe PDF document -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www