You can use "explain" for confirming differences. For inner joins, it would make the same plan.
2013/6/14 Igor Tatarinov <i...@decide.com>: > I would expect no difference because of predicate pushdown. > > igor > decide.com > > > On Thu, Jun 13, 2013 at 11:31 AM, Naga Vijay <nvti...@gmail.com> wrote: >> >> Sure, Will do >> >> >> On Thu, Jun 13, 2013 at 10:42 AM, Stephen Sprague <sprag...@gmail.com> >> wrote: >>> >>> Hi naja, >>> test those two versions (or three now) and report back to the group. :) >>> even if some smarty-pants thinks he knows the answer its always good to >>> confirm things are as they should be. >>> >>> >>> On Wed, Jun 12, 2013 at 11:54 PM, Sanjay Subramanian >>> <sanjay.subraman...@wizecommerce.com> wrote: >>>> >>>> Hi >>>> >>>> I would actually do it like this…so that the set on the left of JOIN >>>> becomes smaller >>>> >>>> SELECT a.item_id, a.create_dt >>>> FROM >>>> ( SELECT >>>> item_id, create_dt >>>> FROM >>>> A >>>> WHERE >>>> item_id = 'I001' >>>> AND >>>> category_name = 'C001' >>>> ) a >>>> JOIN >>>> b >>>> ON >>>> a.item_id = b.item_id >>>> ; >>>> >>>> >>>> From: Naga Vijay <nvti...@gmail.com> >>>> Reply-To: "user@hive.apache.org" <user@hive.apache.org> >>>> Date: Wednesday, June 12, 2013 9:17 PM >>>> To: "user@hive.apache.org" <user@hive.apache.org> >>>> Subject: Enhancing Query Join to speed up Query >>>> >>>> Hi, >>>> >>>> Which of the two query options is better? >>>> >>>> SELECT a.item_id, a.create_dt >>>> FROM a JOIN b >>>> ON (a.item_id = b.item_id) >>>> WHERE a.item_id = 'I001' >>>> AND a.category_name = 'C001'; >>>> >>>> - or - >>>> >>>> SELECT a.item_id, a.create_dt >>>> FROM a JOIN b >>>> ON (a.item_id = b.item_id AND a.item_id = 'I001') >>>> WHERE a.category_name = 'C001'; >>>> >>>> Thanks >>>> Naga >>>> >>>> CONFIDENTIALITY NOTICE >>>> ====================== >>>> This email message and any attachments are for the exclusive use of the >>>> intended recipient(s) and may contain confidential and privileged >>>> information. Any unauthorized review, use, disclosure or distribution is >>>> prohibited. If you are not the intended recipient, please contact the >>>> sender >>>> by reply email and destroy all copies of the original message along with >>>> any >>>> attachments, from your computer system. If you are the intended recipient, >>>> please be advised that the content of this message is subject to access, >>>> review and disclosure by the sender's Email System Administrator. >>> >>> >> >
