Turn off transitive joins
Hi all,
Is there some way by which I can tell postgresql to not to consider
transitive joins while considering join pairs.
I.e. Let's say a query has two join predicates one between A & B relations
and the other between B and C relations.
While constructing the DP to find the best join order, the Optimizer also
consider join between A & C, which can be thought of as a transitive join.
Is their some way to turn this off or tell postgresql to not to consider
these type of joins ?
Import Notes
Reply to msg id not found: CAPzqDmgSTR+r81bysEDex_-XDLCaW_PX6etMy_bppmbsgXQeYQ@mail.gmail.comReference msg id not found: CAPzqDmjBVcbo9b8dF4qTzhsaKZojErQ0tKr7wpJu+vvQC6aww@mail.gmail.comReference msg id not found: CAPzqDmi2HsKtHtv0QJGXXm54t4aYfYwAo5ZeQ6nmmCMxHh7dGA@mail.gmail.comReference msg id not found: CAPzqDmjAr7yDWe277kuuPZ4Z3jYqCTfYK9A-KjTR59b8hgdsA@mail.gmail.comReference msg id not found: CAPzqDmgSTR+r81bysEDex_-XDLCaW_PX6etMy_bppmbsgXQeYQ@mail.gmail.com
Gourav Kumar <gourav1905@gmail.com> writes:
Is there some way by which I can tell postgresql to not to consider
transitive joins while considering join pairs.
No ... and you have presented no reason whatever why we should consider
adding such a capability.
Maybe you should be trying to construct your join graph someplace
earlier, before the optimizer processes the join quals.
regards, tom lane
--
Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org)
To make changes to your subscription:
http://www.postgresql.org/mailpref/pgsql-hackers
I don't think there is any need to add any such capability in postgresql,
but I need it for my work.
I need the join qualifiers.
On 15-Oct-2017 1:37 AM, "Tom Lane" <tgl@sss.pgh.pa.us> wrote:
Show quoted text
Gourav Kumar <gourav1905@gmail.com> writes:
Is there some way by which I can tell postgresql to not to consider
transitive joins while considering join pairs.No ... and you have presented no reason whatever why we should consider
adding such a capability.Maybe you should be trying to construct your join graph someplace
earlier, before the optimizer processes the join quals.regards, tom lane