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Re: [PATCH] Generic type subscription - Mailing list pgsql-hackers

From Artur Zakirov
Subject Re: [PATCH] Generic type subscription
Date
Msg-id CAKNkYnz_WWkzzxyFx934N=Ep47CAFju-Rk-sGeZo0ui8QdrGmw@mail.gmail.com
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In response to Re: [PATCH] Generic type subscription  (Dmitry Dolgov <9erthalion6@gmail.com>)
Responses Re: [PATCH] Generic type subscription
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Hello,

Do you have an updated version of the patch?

2016-10-18 20:41 GMT+03:00 Dmitry Dolgov <9erthalion6@gmail.com>:

> The term "subscription" is confusing me

Yes, you're right. "container" is too general I think, so I renamed everything
to "subscripting".

There is another occurrences of "subscription" including file names. Please fix them.

Also I've sent a personal email, that we have performance degradation of SELECT queries:

create table test (
    a int2[],
    b int4[][][]);

With patch:

=> insert into test (a[1:5], b[1:1][1:2][1:2])
      select '{1,2,3,4,5}', '{{{0,0},{1,2}}}'
      from generate_series(1,100000);
Time: 936,285 ms

=> UPDATE test SET a[0] = '2';
Time: 1605,406 ms (00:01,605)

=> UPDATE test SET b[1:1][1:1][1:2] = '{113, 117}';
Time: 1603,076 ms (00:01,603)

=> explain analyze select a[1], b[1][1][1] from test;
                                                 QUERY PLAN                                                  
-------------------------------------------------------------------------------------------------------------
 Seq Scan on test  (cost=0.00..3858.00 rows=100000 width=6) (actual time=0.035..241.280 rows=100000 loops=1)
 Planning time: 0.087 ms
 Execution time: 246.916 ms
(3 rows)

And without patch:

=> insert into test (a[1:5], b[1:1][1:2][1:2])
      select '{1,2,3,4,5}', '{{{0,0},{1,2}}}'
      from generate_series(1,100000);
Time: 971,677 ms

=> UPDATE test SET a[0] = '2';
Time: 1508,262 ms (00:01,508)

=> UPDATE test SET b[1:1][1:1][1:2] = '{113, 117}';
Time: 1473,459 ms (00:01,473)

=> explain analyze select a[1], b[1][1][1] from test;
                                                 QUERY PLAN                                                 
------------------------------------------------------------------------------------------------------------
 Seq Scan on test  (cost=0.00..5286.00 rows=100000 width=6) (actual time=0.024..98.475 rows=100000 loops=1)
 Planning time: 0.081 ms
 Execution time: 105.055 ms
(3 rows)

-- 
Artur Zakirov
Postgres Professional: http://www.postgrespro.com
Russian Postgres Company

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