Re: [HACKERS] Use unique index for longer pathkeys.

2014-08-07 Thread Kyotaro HORIGUCHI
Hello, > > Although, yes, you're right, irrespective of the "common > > something", and even if the dropped index was i_t1_pkey_2, which > > is on t1(a, b), the result tuples are sorted as expected only by > > the pathkey (t.a = t1.a, t1.b). It is because both t and t1 are > > still unique so the

Re: [HACKERS] Use unique index for longer pathkeys.

2014-08-04 Thread Amit Kapila
On Mon, Aug 4, 2014 at 1:22 PM, Kyotaro HORIGUCHI < horiguchi.kyot...@lab.ntt.co.jp> wrote: > > Hello, > > > I think irrespective of that we can trim t1.c & t1.d as we have > > primary key (unique and non column) for t1.a, t1.b. Basically > > even if we don't use the primary key index, we can stil

Re: [HACKERS] Use unique index for longer pathkeys.

2014-08-04 Thread Kyotaro HORIGUCHI
Hello, > > > Now drop the i_t1_pkey_1 and check the query plan again. > > > > > > drop index i_t1_pkey_1; > > > explain (costs off, analyze off) select * from t,t1 where t.a=t1.a > order by > > > t1.a,t1.b,t1.c,t1.d; > > >QUERY PLAN > > > ---

Re: [HACKERS] Use unique index for longer pathkeys.

2014-07-29 Thread Amit Kapila
On Mon, Jul 28, 2014 at 3:17 PM, Kyotaro HORIGUCHI < horiguchi.kyot...@lab.ntt.co.jp> wrote: > > > Now drop the i_t1_pkey_1 and check the query plan again. > > > > drop index i_t1_pkey_1; > > explain (costs off, analyze off) select * from t,t1 where t.a=t1.a order by > > t1.a,t1.b,t1.c,t1.d; > >

Re: [HACKERS] Use unique index for longer pathkeys.

2014-07-28 Thread Kyotaro HORIGUCHI
Hello, > > > I think there is one more disadvantage in the way current patch is > > > done which is that you need to collect index path keys for all relations > > > irrespective of whether they will be of any use to eliminate useless > > > pathkeys from query_pathkeys. One trivial case that comes

Re: [HACKERS] Use unique index for longer pathkeys.

2014-07-26 Thread Amit Kapila
On Sat, Jul 26, 2014 at 11:53 AM, Amit Kapila wrote: > On Fri, Jul 25, 2014 at 12:48 PM, Kyotaro HORIGUCHI < horiguchi.kyot...@lab.ntt.co.jp> wrote: > > > I think there is one more disadvantage in the way current patch is > > > done which is that you need to collect index path keys for all relatio

Re: [HACKERS] Use unique index for longer pathkeys.

2014-07-25 Thread Amit Kapila
On Fri, Jul 25, 2014 at 12:48 PM, Kyotaro HORIGUCHI < horiguchi.kyot...@lab.ntt.co.jp> wrote: > > I think there is one more disadvantage in the way current patch is > > done which is that you need to collect index path keys for all relations > > irrespective of whether they will be of any use to el

Re: [HACKERS] Use unique index for longer pathkeys.

2014-07-25 Thread Kyotaro HORIGUCHI
Hello. I've been cooled off and convinced that this patch has become quite useless by itself. It improves almost only UNIONs with ORDER BY on tables that have unioform primary keys, and needs my another patch to work. I'll try to reintegrate this patch into my 'another patch' as mentioned below

Re: [HACKERS] Use unique index for longer pathkeys.

2014-07-24 Thread Amit Kapila
On Tue, Jul 22, 2014 at 2:49 PM, Kyotaro HORIGUCHI < horiguchi.kyot...@lab.ntt.co.jp> wrote: > > Sorry , previous version has bugs. It stamps over the stack and > crashesX( The attached is the bug fixed version, with no > substantial changes. > > > On Tue, Jul 15, 2014 at 2:17 PM, Kyotaro HORIGUCHI

Re: [HACKERS] Use unique index for longer pathkeys.

2014-07-24 Thread Robert Haas
On Tue, Jul 22, 2014 at 5:19 AM, Kyotaro HORIGUCHI wrote: > # By the way, this style of calling a person is quite common > # among Japanese since the first-name basis implies very close > # relationship or it frequently conveys offensive shade. But I'm > # not sure what should I call others who're

Re: [HACKERS] Use unique index for longer pathkeys.

2014-07-22 Thread Kyotaro HORIGUCHI
Sorry , previous version has bugs. It stamps over the stack and crashesX( The attached is the bug fixed version, with no substantial changes. > On Tue, Jul 15, 2014 at 2:17 PM, Kyotaro HORIGUCHI < > horiguchi.kyot...@lab.ntt.co.jp> wrote: > > > > Hi, the attached is the revised version. > > Thank

Re: [HACKERS] Use unique index for longer pathkeys.

2014-07-19 Thread Amit Kapila
On Tue, Jul 15, 2014 at 2:17 PM, Kyotaro HORIGUCHI < horiguchi.kyot...@lab.ntt.co.jp> wrote: > > Hi, the attached is the revised version. Thanks Horiguchi-San for the updated patch. Today while looking into updated patch, I was wondering why can't we eliminate useless keys in query_pathkeys when

Re: [HACKERS] Use unique index for longer pathkeys.

2014-07-15 Thread Kyotaro HORIGUCHI
Hi, the attached is the revised version. - defined allnotnull instead of full_ordered in RelOptInfo and changed to use it. - compare_pathkeys_ignoring_strategy() is now integrated into compare_pathkeys(). - index pathkeys caching in RelOptInfo added. (build_index_pathkeys() does) -

Re: [HACKERS] Use unique index for longer pathkeys.

2014-07-14 Thread Amit Kapila
On Mon, Jul 14, 2014 at 4:02 PM, Kyotaro HORIGUCHI < horiguchi.kyot...@lab.ntt.co.jp> wrote: > At Mon, 14 Jul 2014 11:01:52 +0530, Amit Kapila wrote in > > On Fri, Jun 13, 2014 at 1:11 PM, Kyotaro HORIGUCHI < > > horiguchi.kyot...@lab.ntt.co.jp> wrote: > > I am bit worried about the extra cycles

Re: [HACKERS] Use unique index for longer pathkeys.

2014-07-14 Thread Kyotaro HORIGUCHI
Thank you for reviewing, the revised patch will come later. At Mon, 14 Jul 2014 11:01:52 +0530, Amit Kapila wrote in > On Fri, Jun 13, 2014 at 1:11 PM, Kyotaro HORIGUCHI < > horiguchi.kyot...@lab.ntt.co.jp> wrote: > > > > Hello, This is the continuation from the last CF. > > > > This patch inte

Re: [HACKERS] Use unique index for longer pathkeys.

2014-07-13 Thread Amit Kapila
On Fri, Jun 13, 2014 at 1:11 PM, Kyotaro HORIGUCHI < horiguchi.kyot...@lab.ntt.co.jp> wrote: > > Hello, This is the continuation from the last CF. > > This patch intends to make PG to use index for longer pathkeys > than index columns when, > > - The index is a unique index. > - All index columns

Re: [HACKERS] Use unique index for longer pathkeys.

2014-07-10 Thread Kyotaro HORIGUCHI
Thank you for taking a look on this patch. > I took a quick look at this patch, more or less because nobody else did. > > > Duing last CF, I proposed to match long pathkeys against index columns > > during creating index paths. This worked fine but also it is difficult > > to make sure that all s

Re: [HACKERS] Use unique index for longer pathkeys.

2014-07-07 Thread Abhijit Menon-Sen
Hi. I took a quick look at this patch, more or less because nobody else did. > Duing last CF, I proposed to match long pathkeys against index columns > during creating index paths. This worked fine but also it is difficult > to make sure that all side-effects are eliminated. Finally Tom Lane > su