3、建立表testmem，分别在使用和不适用pgfincore情况下进行select, update, delete的操作，并对比执行时间，在这里为了更好的去作比较，建立三张表testmem1，testmem2，testmem3，分别进行三种操作进行对比。并插入相同的数据。
[postgres@localhost bin]$ ./psql
psql (9.4.5)
Type "help" for help.
postgres=# \d
No relations found.
postgres=# create table testmem1(t1 int, t2 text, t3 text, t4 bigint, t5 text, t6 text, t7 varchar, t8 char(22), t9 numeric);CREATE TABLE
postgres=# create table testmem2(t1 int, t2 text, t3 text, t4 bigint, t5 text, t6 text, t7 varchar, t8 char(22), t9 numeric);
CREATE TABLE
postgres=# create table testmem3(t1 int, t2 text, t3 text, t4 bigint, t5 text, t6 text, t7 varchar, t8 char(22), t9 numeric);
CREATE TABLE
postgres=# insert into testmem1 select generate_series(1,999999), 'wangshuo'||generate_series(1,999999)::text||random()::text, generate_series(1,999999)::text||'sure',generate_series(1,999999), random()::text,random()::text,random()::text,'liuyuanyuan', generate_series(1,999999);
INSERT 0 999999
postgres=# select pg_relation_size('testmem1')/1024/1024||'MB';
?column?
----------
166MB
(1 row)
postgres=# insert into testmem2 select generate_series(1,999999), 'wangshuo'||generate_series(1,999999)::text||random()::text, generate_series(1,999999)::text||'sure',generate_series(1,999999), random()::text,random()::text,random()::text,'liuyuanyuan', generate_series(1,999999);
INSERT 0 999999
postgres=# insert into testmem3 select generate_series(1,999999), 'wangshuo'||generate_series(1,999999)::text||random()::text, generate_series(1,999999)::text||'sure',generate_series(1,999999), random()::text,random()::text,random()::text,'liuyuanyuan', generate_series(1,999999);
INSERT 0 999999
postgres=# select pg_relation_size('testmem2')/1024/1024||'MB'; ?column?
----------
166MB
(1 row)
postgres=# select pg_relation_size('testmem3')/1024/1024||'MB';
?column?
----------
166MB
(1 row)
postgres=#
三种操作性能对比：
postgres=# select * from testmem1 where t1 < 789432 and t1 > 1208;
t1 | t2 | t3 | t4 | t5
| t6 | t7 | t8
| t9
--------+------------------------------------+------------+--------+------------
----------+----------------------+----------------------+-----------------------
-+--------
1209 | wangshuo12090.964191045146435 | 1209sure | 1209 | 0.075409890
152514 | 0.468206159770489 | 0.692714618053287 | liuyuanyuan
| 1209
1210 | wangshuo12100.652063825167716 | 1210sure | 1210 | 0.026932121
720165 | 0.802233531605452 | 0.706556385848671 | liuyuanyuan
| 1210
1211 | wangshuo12110.724962076637894 | 1211sure | 1211 | 0.732285636
477172 | 0.816857317462564 | 0.868489125277847 | liuyuanyuan
| 1211
1212 | wangshuo12120.0478062951005995 | 1212sure | 1212 | 0.190716865
006834 | 0.898683389648795 | 0.537546805106103 | liuyuanyuan
| 1212
1213 | wangshuo12130.582098880317062 | 1213sure | 1213 | 0.161297460
086644 | 0.395338968373835 | 0.684920639265329 | liuyuanyuan
| 1213
1214 | wangshuo12140.53120110463351 | 1214sure | 1214 | 0.253457680
810243 | 0.428548218682408 | 0.671272001229227 | liuyuanyuan
postgres=# update testmem2 set t7 = random()::text where t1 < 789432 and t1 > 1208;
UPDATE 788223
postgres=# delete from testmem3 where t1 < 789432 and t1 > 1208;
DELETE 788223
使用pgfincore前：通过查询表pg_stat_statments查看三种操作时间：
?