Re: effect of JIT tuple deform?
| От | Pavel Stehule |
|---|---|
| Тема | Re: effect of JIT tuple deform? |
| Дата | |
| Msg-id | CAFj8pRBqyqqczRK3wrp2VJQMtY_RspgseLkvChk7C5MsNb7CoQ@mail.gmail.com обсуждение исходный текст |
| Ответ на | effect of JIT tuple deform? (Pavel Stehule <pavel.stehule@gmail.com>) |
| Ответы |
Re: effect of JIT tuple deform?
(Dmitry Dolgov <9erthalion6@gmail.com>)
|
| Список | pgsql-hackers |
2018-06-23 8:35 GMT+02:00 Pavel Stehule <pavel.stehule@gmail.com>:
HiI try to measure effect of JIT tuple deform and I don't see any possible effect.Is it this feature active in master branch?Is possible to see this feature in EXPLAIN ANALYZE?
Unfortunately I got slowdown
0. shared buffers = 1GB
1. create table with 50 int columns
2. insert into this table 4M rows
postgres=# \dt+ wt
List of relations
+--------+------+-------+-------+--------+-------------+
| Schema | Name | Type | Owner | Size | Description |
+--------+------+-------+-------+--------+-------------+
| public | wt | table | pavel | 893 MB | |
+--------+------+-------+-------+--------+-------------+
(1 row)
List of relations
+--------+------+-------+-------+--------+-------------+
| Schema | Name | Type | Owner | Size | Description |
+--------+------+-------+-------+--------+-------------+
| public | wt | table | pavel | 893 MB | |
+--------+------+-------+-------+--------+-------------+
(1 row)
default setting
postgres=# explain analyze select sum(c45) from wt;
+------------------------------------------------------------------------------------------------------------------------------------------+
| QUERY PLAN |
+------------------------------------------------------------------------------------------------------------------------------------------+
| Finalize Aggregate (cost=136120.69..136120.70 rows=1 width=8) (actual time=879.547..879.547 rows=1 loops=1) |
| -> Gather (cost=136120.47..136120.68 rows=2 width=8) (actual time=879.514..879.538 rows=3 loops=1) |
| Workers Planned: 2 |
| Workers Launched: 2 |
| -> Partial Aggregate (cost=135120.47..135120.48 rows=1 width=8) (actual time=850.283..850.284 rows=1 loops=3) |
| -> Parallel Seq Scan on wt (cost=0.00..130953.77 rows=1666678 width=4) (actual time=0.071..223.338 rows=1333347 loops=3) |
| Planning Time: 0.158 ms |
| JIT: |
| Functions: 6 |
| Generation Time: 4.267 ms |
| Inlining: false |
| Inlining Time: 0.000 ms |
| Optimization: false |
| Optimization Time: 2.472 ms |
| Emission Time: 15.929 ms |
| Execution Time: 899.496 ms |
+------------------------------------------------------------------------------------------------------------------------------------------+
(16 rows)
postgres=# set jit_tuple_deforming to off;
SET
postgres=# explain analyze select sum(c45) from wt;
+------------------------------------------------------------------------------------------------------------------------------------------+
| QUERY PLAN |
+------------------------------------------------------------------------------------------------------------------------------------------+
| Finalize Aggregate (cost=136120.69..136120.70 rows=1 width=8) (actual time=743.667..743.667 rows=1 loops=1) |
| -> Gather (cost=136120.47..136120.68 rows=2 width=8) (actual time=743.654..743.657 rows=3 loops=1) |
| Workers Planned: 2 |
| Workers Launched: 2 |
| -> Partial Aggregate (cost=135120.47..135120.48 rows=1 width=8) (actual time=715.532..715.533 rows=1 loops=3) |
| -> Parallel Seq Scan on wt (cost=0.00..130953.77 rows=1666678 width=4) (actual time=0.067..216.245 rows=1333347 loops=3) |
| Planning Time: 0.157 ms |
| JIT: |
| Functions: 4 |
| Generation Time: 1.989 ms |
| Inlining: false |
| Inlining Time: 0.000 ms |
| Optimization: false |
| Optimization Time: 0.449 ms |
| Emission Time: 7.254 ms |
| Execution Time: 761.549 ms |
+------------------------------------------------------------------------------------------------------------------------------------------+
(16 rows)
+------------------------------------------------------------------------------------------------------------------------------------------+
| QUERY PLAN |
+------------------------------------------------------------------------------------------------------------------------------------------+
| Finalize Aggregate (cost=136120.69..136120.70 rows=1 width=8) (actual time=879.547..879.547 rows=1 loops=1) |
| -> Gather (cost=136120.47..136120.68 rows=2 width=8) (actual time=879.514..879.538 rows=3 loops=1) |
| Workers Planned: 2 |
| Workers Launched: 2 |
| -> Partial Aggregate (cost=135120.47..135120.48 rows=1 width=8) (actual time=850.283..850.284 rows=1 loops=3) |
| -> Parallel Seq Scan on wt (cost=0.00..130953.77 rows=1666678 width=4) (actual time=0.071..223.338 rows=1333347 loops=3) |
| Planning Time: 0.158 ms |
| JIT: |
| Functions: 6 |
| Generation Time: 4.267 ms |
| Inlining: false |
| Inlining Time: 0.000 ms |
| Optimization: false |
| Optimization Time: 2.472 ms |
| Emission Time: 15.929 ms |
| Execution Time: 899.496 ms |
+------------------------------------------------------------------------------------------------------------------------------------------+
(16 rows)
postgres=# set jit_tuple_deforming to off;
SET
postgres=# explain analyze select sum(c45) from wt;
+------------------------------------------------------------------------------------------------------------------------------------------+
| QUERY PLAN |
+------------------------------------------------------------------------------------------------------------------------------------------+
| Finalize Aggregate (cost=136120.69..136120.70 rows=1 width=8) (actual time=743.667..743.667 rows=1 loops=1) |
| -> Gather (cost=136120.47..136120.68 rows=2 width=8) (actual time=743.654..743.657 rows=3 loops=1) |
| Workers Planned: 2 |
| Workers Launched: 2 |
| -> Partial Aggregate (cost=135120.47..135120.48 rows=1 width=8) (actual time=715.532..715.533 rows=1 loops=3) |
| -> Parallel Seq Scan on wt (cost=0.00..130953.77 rows=1666678 width=4) (actual time=0.067..216.245 rows=1333347 loops=3) |
| Planning Time: 0.157 ms |
| JIT: |
| Functions: 4 |
| Generation Time: 1.989 ms |
| Inlining: false |
| Inlining Time: 0.000 ms |
| Optimization: false |
| Optimization Time: 0.449 ms |
| Emission Time: 7.254 ms |
| Execution Time: 761.549 ms |
+------------------------------------------------------------------------------------------------------------------------------------------+
(16 rows)
When jit_tuple_deforming is enabled, the query is slower about 100ms, looks like performance regression
RegardsPavel
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