postgresql 最近优化的SQL集合案例、（不写过程了只记录案例，PG优化器问题还是不少）
案例1：
-- 原SQL + 执行计划：
explain analyze SELECT
G.PID,
G.FLOW_ID,
G.STATUS,
G.ID,
AAAAAA.INFO_ID,
G.CREATE_UNAME,
AAAAAA.FLOW_TIME,
G.CREATE_DEPTNAME,
G.BT,
G.MODULE_NAME,
G.MODULE_ID,
G.WH,
AAAAAA.PRIVATE_SN,
G.HANDLE_USERS,
G.JJCD,
G.JJCD_TEXT,
G.MJ,
G.MJ_TEXT
FROM
AAAAAA
INNER
JOIN
BBBBBBB G ON G.ID = AAAAAA.INFO_ID
WHERE
AAAAAA.FLOW_STATUS = '1'
AND AAAAAA.IS_FLOW = '1'
AND AAAAAA.USER_ID = '210322182658hbwJJvwlxItCjUQ8PeM'
AND G.ROWSTATE >- 1
AND G.MODULE_ID IN('1906261422364oh1kT8fYFKA3iaZcfT')
ORDER BY
AAAAAA.FLOW_TIME DESC LIMIT 30; QUERY PLAN ---------------------------------------------------------------------------------------------------------------------------------------------------------------------------
--
Limit (cost=0.99..41702.40 rows=30 width=484) (actual time=31582.593..31582.593 rows=0 loops=1)
-> Nested Loop (cost=0.99..5127883.64 rows=3689 width=484) (actual time=31582.592..31582.592 rows=0 loops=1)
-> Index Scan Backward using idx_AAAAAA_FLOW_TIME on AAAAAA (cost=0.43..2668871.97 rows=1142813 width=41) (actual time=0.024..17088.849 rows=1132689 loops=1
)
Filter: ((FLOW_STATUS = '1'::NUMERIC) AND (IS_FLOW = '1'::NUMERIC) AND (USER_ID = '210322182658hbwJJvwlxItCjUQ8PeM'::CHARACTER VARYING))
Rows Removed by Filter: 12796824
-> Index Scan using BBBBBBB_PKEY on BBBBBBB G (cost=0.56..2.14 rows=1 width=443) (actual time=0.013..0.013 rows=0 loops=1132689)
Index Cond: (ID = AAAAAA.INFO_ID)
Filter: ((ROWSTATE > '-1'::NUMERIC) AND (MODULE_ID = '1906261422364oh1kT8fYFKA3iaZcfT'::CHARACTER VARYING))
Rows Removed by Filter: 1
Planning time: 4.969 ms
Execution time: 31582.652 ms
(11 rows)
-- 索引优化 + 改写 SQL：
create index idx_AAAAAA_n1 on AAAAAA(INFO_ID,USER_ID);
create index idx_BBBBBBB_n1 on BBBBBBB(MODULE_ID,ROWSTATE); explain analyze SELECT
G.PID,
G.FLOW_ID,
G.STATUS,
G.ID,
AAAAAA.INFO_ID,
G.CREATE_UNAME,
AAAAAA.FLOW_TIME,
G.CREATE_DEPTNAME,
G.BT,
G.MODULE_NAME,
G.MODULE_ID,
G.WH,
AAAAAA.PRIVATE_SN,
G.HANDLE_USERS,
G.JJCD,
G.JJCD_TEXT,
G.MJ,
G.MJ_TEXT
FROM
AAAAAA
INNER
JOIN
BBBBBBB G ON G.ID = AAAAAA.INFO_ID
WHERE
AAAAAA.FLOW_STATUS = '1'
AND AAAAAA.IS_FLOW = '1'
AND AAAAAA.USER_ID = '210322182658hbwJJvwlxItCjUQ8PeM'
AND G.ROWSTATE >- 1
AND G.MODULE_ID IN('1906261422364oh1kT8fYFKA3iaZcfT')
AND ROWNUM > 0
ORDER BY
AAAAAA.FLOW_TIME DESC LIMIT 30; QUERY PLAN
-------------------------------------------------------------------------------------------------------------------------------------------------------------------
Limit (cost=601220.27..601220.28 rows=1 width=484) (actual time=150.256..150.256 rows=0 loops=1)
-> Sort (cost=601220.27..601220.28 rows=0 width=484) (actual time=150.254..150.254 rows=0 loops=1)
Sort Key: AAAAAA.FLOW_TIME DESC
Sort Method: quicksort Memory: 25kB
-> Count (cost=1.12..601220.26 rows=0 width=484) (actual time=150.249..150.249 rows=0 loops=1)
Stop Keys: (ROWNUM > 0)
-> Nested Loop (cost=1.12..601183.37 rows=3689 width=484) (actual time=150.248..150.248 rows=0 loops=1)
-> Index Scan using BBBBBBB_module_id on BBBBBBB G (cost=0.56..18096.56 rows=15946 width=443) (actual time=0.032..10.329 rows=8285 loops=1)
Index Cond: (MODULE_ID = '1906261422364oh1kT8fYFKA3iaZcfT'::CHARACTER VARYING)
Filter: (ROWSTATE > '-1'::NUMERIC)
Rows Removed by Filter: 1
-> Index Scan using idx_AAAAAA_n1 on AAAAAA (cost=0.56..36.48 rows=9 width=41) (actual time=0.017..0.017 rows=0 loops=8285)
Index Cond: ((INFO_ID = G.ID) AND (USER_ID = '210322182658hbwJJvwlxItCjUQ8PeM'::CHARACTER VARYING))
Filter: ((FLOW_STATUS = '1'::NUMERIC) AND (IS_FLOW = '1'::NUMERIC))
Planning time: 0.800 ms
Execution time: 150.329 ms
(16 rows)
这个案例 SQL开发写得有问题（ G.MODULE_ID IN('1906261422364oh1kT8fYFKA3iaZcfT') + LIMIT 30 ）点到为止不多说，而且 pg 优化器傻乎乎的，不会当成一个整体来执行，就一直往死里推。
案例2：
-- 原SQL + 执行计划 ： SELECT C.NBYJ AS CONTENT,
a.swdw_name || '(' || a.CREATE_uname || ')' AS UNAME,
TO_CHAR(c.ngrq, 'yyyy-mm-dd hh24:mi:ss') AS PDATE
FROM CCCCCCCC a
INNER JOIN EEEED d ON d.source_id = a.id AND d.module_id = '190626104707D1FgtbFlPHupVSUtLVK'
INNER JOIN EEEED e ON e.source_id = d.id AND e.module_id = '1906281143542BS15J0F45WqfUr9fMV'
INNER JOIN CCCCCCCC f ON f.source_id = e.id
INNER JOIN EEEED c ON c.source_id = f.id AND c.module_id = '1906281143542BS15J0F45WqfUr9fMV'
WHERE a.feedback_status = 1
AND C.ROWSTATE = 1
AND a.REMOTE_ID = '230620100133zXjW7irYYxRuUbIX4dN'
ORDER BY C.ngrq; QUERY PLAN ---------------------------------------------------------------------------------------------------------------------------------------------------------------------------
------
Sort (cost=546497.75..546497.75 rows=1 width=202) (actual time=47022.684..47022.684 rows=0 loops=1)
Sort Key: c.NGRQ
Sort Method: quicksort Memory: 25kB
-> Nested Loop (cost=398361.23..546497.74 rows=1 width=202) (actual time=47022.659..47022.659 rows=0 loops=1)
-> Nested Loop (cost=398360.80..539445.12 rows=5777 width=170) (actual time=32142.716..39565.986 rows=49597 loops=1)
-> Hash Join (cost=398360.37..511828.98 rows=6700 width=170) (actual time=32090.140..32437.179 rows=49662 loops=1)
Hash Cond: (c.SOURCE_ID = f.ID)
-> Index Scan using EEEED_MODULE_ID on EEEED c (cost=0.43..107101.65 rows=100105 width=170) (actual time=43.693..273.107 rows=100733 loops=1)
Index Cond: (MODULE_ID = '1906281143542BS15J0F45WqfUr9fMV'::CHARACTER VARYING)
Filter: (ROWSTATE = '1'::NUMERIC)
Rows Removed by Filter: 136
-> Hash (cost=396116.32..396116.32 rows=96530 width=64) (actual time=32046.152..32046.152 rows=49350 loops=1)
Buckets: 131072 Batches: 2 Memory Usage: 3343kB
-> Hash Join (cost=109182.84..396116.32 rows=96530 width=64) (actual time=17722.308..32017.501 rows=49350 loops=1)
Hash Cond: (f.SOURCE_ID = e.ID)
-> Seq Scan on CCCCCCCC f (cost=0.00..251072.86 rows=1340086 width=64) (actual time=40.837..13732.995 rows=1340086 loops=1)
-> Hash (cost=106850.85..106850.85 rows=100319 width=64) (actual time=17640.822..17640.822 rows=100869 loops=1)
Buckets: 131072 Batches: 2 Memory Usage: 5730kB
-> Index Scan using EEEED_MODULE_ID on EEEED e (cost=0.43..106850.85 rows=100319 width=64) (actual time=0.040..17575.199 rows=100869 loo
ps=1)
Index Cond: (MODULE_ID = '1906281143542BS15J0F45WqfUr9fMV'::CHARACTER VARYING)
-> Index Scan using EEEED_PKEY on EEEED d (cost=0.43..4.11 rows=1 width=64) (actual time=0.142..0.143 rows=1 loops=49662)
Index Cond: (ID = e.SOURCE_ID)
Filter: (MODULE_ID = '190626104707D1FgtbFlPHupVSUtLVK'::CHARACTER VARYING)
-> Index Scan using CCCCCCCC_PKEY on CCCCCCCC a (cost=0.43..1.21 rows=1 width=97) (actual time=0.150..0.150 rows=0 loops=49597)
Index Cond: (ID = d.SOURCE_ID)
Filter: ((FEEDBACK_STATUS = '1'::NUMERIC) AND (REMOTE_ID = '230620100133zXjW7irYYxRuUbIX4dN'::CHARACTER VARYING))
Rows Removed by Filter: 1
Planning time: 1044.045 ms
Execution time: 47023.095 ms
(29 rows)
-- 索引优化：
create index idx_EEEED_source_MODULE_ID on EEEED(source_id,module_id);
create index idx_CCCCCCCC_REMOTE_ID_FEEDBACK_STATUS on CCCCCCCC(REMOTE_ID,FEEDBACK_STATUS); QUERY PLAN
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
Sort (cost=256118.02..256118.02 rows=1 width=202) (actual time=0.079..0.079 rows=0 loops=1)
Sort Key: c.NGRQ
Sort Method: quicksort Memory: 25kB
-> Nested Loop (cost=18.99..256118.01 rows=1 width=202) (actual time=0.073..0.073 rows=0 loops=1)
-> Hash Join (cost=18.44..256116.63 rows=1 width=97) (actual time=0.073..0.073 rows=0 loops=1)
Hash Cond: (f.SOURCE_ID = e.ID)
-> Seq Scan on CCCCCCCC f (cost=0.00..251072.86 rows=1340086 width=64) (actual time=0.011..0.011 rows=1 loops=1)
-> Hash (cost=18.42..18.42 rows=1 width=97) (actual time=0.055..0.055 rows=0 loops=1)
Buckets: 1024 Batches: 1 Memory Usage: 8kB
-> Nested Loop (cost=1.53..18.42 rows=1 width=97) (actual time=0.055..0.055 rows=0 loops=1)
-> Nested Loop (cost=0.98..17.03 rows=1 width=97) (actual time=0.055..0.055 rows=0 loops=1)
-> Index Scan using idx_CCCCCCCC_REMOTE_ID_FEEDBACK_STATUS on CCCCCCCC a (cost=0.43..8.45 rows=1 width=97) (actual time=0.054..0.054 rows=0 loops=1)
Index Cond: ((REMOTE_ID = '230620100133zXjW7irYYxRuUbIX4dN'::CHARACTER VARYING) AND (FEEDBACK_STATUS = '1'::NUMERIC))
-> Index Scan using idx_EEEED_source_MODULE_ID on EEEED d (cost=0.55..8.57 rows=1 width=64) (never executed)
Index Cond: ((SOURCE_ID = a.ID) AND (MODULE_ID = '190626104707D1FgtbFlPHupVSUtLVK'::CHARACTER VARYING))
-> Index Scan using idx_EEEED_source_MODULE_ID on EEEED e (cost=0.55..1.38 rows=1 width=64) (never executed)
Index Cond: ((SOURCE_ID = d.ID) AND (MODULE_ID = '1906281143542BS15J0F45WqfUr9fMV'::CHARACTER VARYING))
-> Index Scan using idx_EEEED_source_MODULE_ID on EEEED c (cost=0.55..1.36 rows=1 width=170) (never executed)
Index Cond: ((SOURCE_ID = f.ID) AND (MODULE_ID = '1906281143542BS15J0F45WqfUr9fMV'::CHARACTER VARYING))
Filter: (ROWSTATE = '1'::NUMERIC)
Planning time: 2.936 ms
Execution time: 0.464 ms
(22 rows)
案例3：
-- 原SQL + 执行计划：
SELECT QWQWQW.ID,
QWQWQW.PID,
QWQWQW.PNID,
QWQWQW.WF_ID,
QWQWQW.WFNODE_ID,
QWQWQW.INFO_ID,
QWQWQW.WHOHANDLE,
QWQWQW.ACTNAME,
QWQWQW.MODULE_NAME,
QWQWQW.MODULE_ID,
QWQWQW.SEND_DEPTNAME,
QWQWQW.BT,
QWQWQW.RDATE,
QWQWQW.STATUS,
QWQWQW.READED_USERS,
QWQWQW.BACKREASON,
QWQWQW.PRE_OPINION,
QWQWQW.DEADLINE_ALERT,
QWQWQW.DEADLINE_WARNING,
QWQWQW.DEADLINE,
QWQWQW.GATHER_STATUS,
QWQWQW.URGENT,
QWQWQW.URGENT_TEXT,
QWQWQW.MJ,
QWQWQW.MJ_TEXT,
QWQWQW.FUZHU_WH,
QWQWQW.WH,
QWQWQW.FID,
QWQWQW.IS_CB,
QWQWQW.IS_CB_TEXT,
QWQWQW.RETURN_UNAME,
QWQWQW.RETRIEVE_TIME,
QWQWQW.DUSER_NAME,
QWQWQW.USER_ID,
QWQWQW.DUSER_ID,
QWQWQW.PRE_ACTNAME,
QWQWQW.NGR_ORGNAME,
FAV.ID AS FAVORITE_ID,
GPGPGP.NODE_TYPE,
(CASE WHEN QWQWQW.RETRIEVE_TIME IS NULL THEN QWQWQW.RDATE ELSE QWQWQW.RETRIEVE_TIME END) AS EDATE
FROM QWQWQW AS QWQWQW LEFT JOIN GPGPGP AS GPGPGP
ON QWQWQW.PNID = GPGPGP.ID LEFT JOIN GFGFGF AS FAV ON FAV.INFO_ID = QWQWQW.INFO_ID AND FAV.USER_ID = '210317113214OEl81T3fQMT6DQ0F8sf'
WHERE 1 = 1
AND QWQWQW.MODULE_ID NOT IN (
'1907042057531ABn7slgK0TQOnwpxny'
, '1906281143542BS15J0F45WqfUr9fMV'
, '190628151722nLv7zPl7NrbAJVisHve'
, '190708203559JjBokUI83kSH02Aco8s')
AND QWQWQW.IS_HB = - 1
AND QWQWQW.STATUS <> 4
AND QWQWQW.STATUS
> - 1
AND (((QWQWQW.MUSER_ID = '210317113214OEl81T3fQMT6DQ0F8sf') OR (QWQWQW.MUSER_ID IN
('180622194528xx5u4YOE67fPJCTD5YG'
, '190709174122R6zTDgKJyxfUI390t1r'
, '1907311655404iY1WvOrLVCuOaxppjr') AND (QWQWQW.DEPT_ID = '210317113214LlXqda7uwjMfaVwCwl7')) ))
AND QWQWQW.GATHER_STATUS IN (0
, 9)
ORDER BY QWQWQW.URGENT DESC, QWQWQW.STATUS, EDATE DESC
LIMIT 18; QUERY PLAN --------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
--------------------------------------------------------------------------------------------------------------------------------------------------------------
Limit (cost=207246.23..207246.27 rows=18 width=1320) (actual time=367907.141..367907.150 rows=18 loops=1)
-> Sort (cost=207246.23..207286.19 rows=15987 width=1320) (actual time=367907.141..367907.145 rows=18 loops=1)
Sort Key: QWQWQW.URGENT DESC, QWQWQW.STATUS, (CASE WHEN (QWQWQW.RETRIEVE_TIME IS NULL) THEN QWQWQW.RDATE ELSE QWQWQW.RETRIEVE_TIME END) DESC
Sort Method: top-N heapsort Memory: 35kB
-> Hash Left Join (cost=753.63..206832.97 rows=15987 width=1320) (actual time=272.135..367820.571 rows=16411 loops=1)
Hash Cond: (QWQWQW.INFO_ID = FAV.INFO_ID)
-> Nested Loop Left Join (cost=724.02..206543.54 rows=15987 width=1280) (actual time=176.826..367641.032 rows=16411 loops=1)
-> Bitmap Heap Scan on QWQWQW (cost=723.45..73747.21 rows=15987 width=1276) (actual time=73.983..58593.100 rows=16411 loops=1)
Recheck Cond: ((MUSER_ID = '210317113214OEl81T3fQMT6DQ0F8sf'::CHARACTER VARYING) OR (MUSER_ID = ANY ('{180622194528xx5u4YOE67fPJCTD5YG,190709174122R6zTDgKJyxfUI390t1r,1907311655404iY1WvOrLVCuOaxppjr}'::CHARACT
ER VARYING[])))
Filter: ((STATUS <> '4'::NUMERIC) AND (STATUS > '-1'::NUMERIC) AND (GATHER_STATUS = ANY ('{0,9}'::NUMERIC[])) AND (IS_HB = '-1'::NUMERIC) AND (MODULE_ID <> ALL ('{1907042057531ABn7slgK0TQOnwpxny,1906281143542B
S15J0F45WqfUr9fMV,190628151722nLv7zPl7NrbAJVisHve,190708203559JjBokUI83kSH02Aco8s}'::CHARACTER VARYING[])) AND ((MUSER_ID = '210317113214OEl81T3fQMT6DQ0F8sf'::CHARACTER VARYING) OR ((MUSER_ID = ANY ('{180622194528xx5u4YOE67fPJCTD5YG,190
709174122R6zTDgKJyxfUI390t1r,1907311655404iY1WvOrLVCuOaxppjr}'::CHARACTER VARYING[])) AND (DEPT_ID = '210317113214LlXqda7uwjMfaVwCwl7'::CHARACTER VARYING))))
Heap Blocks: exact=15711
-> BitmapOr (cost=723.45..723.45 rows=22032 width=0) (actual time=65.729..65.729 rows=0 loops=1)
-> Bitmap Index Scan on g_index_MUSER_ID1 (cost=0.00..575.22 rows=17955 width=0) (actual time=65.652..65.652 rows=16411 loops=1)
Index Cond: (MUSER_ID = '210317113214OEl81T3fQMT6DQ0F8sf'::CHARACTER VARYING)
-> Bitmap Index Scan on g_index_MUSER_ID1 (cost=0.00..140.24 rows=4077 width=0) (actual time=0.074..0.074 rows=0 loops=1)
Index Cond: (MUSER_ID = ANY ('{180622194528xx5u4YOE67fPJCTD5YG,190709174122R6zTDgKJyxfUI390t1r,1907311655404iY1WvOrLVCuOaxppjr}'::CHARACTER VARYING[]))
-> Index Scan using GPGPGP_PKEY on GPGPGP (cost=0.56..8.30 rows=1 width=36) (actual time=18.821..18.826 rows=1 loops=16411)
Index Cond: (QWQWQW.PNID = ID)
-> Hash (cost=29.48..29.48 rows=11 width=63) (actual time=95.285..95.285 rows=1 loops=1)
Buckets: 1024 Batches: 1 Memory Usage: 9kB
-> Index Scan using GFGFGF_user_id on GFGFGF FAV (cost=0.41..29.48 rows=11 width=63) (actual time=95.272..95.274 rows=1 loops=1)
Index Cond: (USER_ID = '210317113214OEl81T3fQMT6DQ0F8sf'::CHARACTER VARYING)
Planning time: 1411.150 ms
Execution time: 367907.348 ms
(24 rows)
-- 改写优化： SELECT QWQWQW.ID,
QWQWQW.PID,
QWQWQW.PNID,
QWQWQW.WF_ID,
QWQWQW.WFNODE_ID,
QWQWQW.INFO_ID,
QWQWQW.WHOHANDLE,
QWQWQW.ACTNAME,
QWQWQW.MODULE_NAME,
QWQWQW.MODULE_ID,
QWQWQW.SEND_DEPTNAME,
QWQWQW.BT,
QWQWQW.RDATE,
QWQWQW.STATUS,
QWQWQW.READED_USERS,
QWQWQW.BACKREASON,
QWQWQW.PRE_OPINION,
QWQWQW.DEADLINE_ALERT,
QWQWQW.DEADLINE_WARNING,
QWQWQW.DEADLINE,
QWQWQW.GATHER_STATUS,
QWQWQW.URGENT,
QWQWQW.URGENT_TEXT,
QWQWQW.MJ,
QWQWQW.MJ_TEXT,
QWQWQW.FUZHU_WH,
QWQWQW.WH,
QWQWQW.FID,
QWQWQW.IS_CB,
QWQWQW.IS_CB_TEXT,
QWQWQW.RETURN_UNAME,
QWQWQW.RETRIEVE_TIME,
QWQWQW.DUSER_NAME,
QWQWQW.USER_ID,
QWQWQW.DUSER_ID,
QWQWQW.PRE_ACTNAME,
QWQWQW.NGR_ORGNAME,
FAV.ID AS FAVORITE_ID,
GPGPGP.NODE_TYPE,
(CASE WHEN QWQWQW.RETRIEVE_TIME IS NULL THEN QWQWQW.RDATE ELSE QWQWQW.RETRIEVE_TIME END) AS EDATE
FROM QWQWQW AS QWQWQW LEFT JOIN GPGPGP AS GPGPGP
ON QWQWQW.PNID = GPGPGP.ID LEFT JOIN GFGFGF AS FAV ON FAV.INFO_ID = QWQWQW.INFO_ID AND FAV.USER_ID = '210317113214OEl81T3fQMT6DQ0F8sf'
WHERE 1 = 1
AND QWQWQW.MODULE_ID NOT IN (
'1907042057531ABn7slgK0TQOnwpxny'
, '1906281143542BS15J0F45WqfUr9fMV'
, '190628151722nLv7zPl7NrbAJVisHve'
, '190708203559JjBokUI83kSH02Aco8s')
AND QWQWQW.IS_HB = - 1
AND QWQWQW.STATUS <> 4
AND QWQWQW.STATUS
> - 1
AND ((
(QWQWQW.MUSER_ID = '210317113214OEl81T3fQMT6DQ0F8sf' ) OR (QWQWQW.MUSER_ID IN ('180622194528xx5u4YOE67fPJCTD5YG', '190709174122R6zTDgKJyxfUI390t1r', '1907311655404iY1WvOrLVCuOaxppjr') AND (QWQWQW.DEPT_ID = '210317113214LlXqda7uwjMfaVwCwl7') )
))
AND QWQWQW.GATHER_STATUS IN (0, 9)
ORDER BY QWQWQW.URGENT DESC, QWQWQW.STATUS, --EDATE DESC
LIMIT 18; QUERY PLAN --------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
--------------------------------------------------------------------------------------------------------------------------------------------------------
Limit (cost=0.98..809.31 rows=18 width=1320) (actual time=0.194..9.936 rows=18 loops=1)
-> Nested Loop Left Join (cost=0.98..717932.30 rows=15987 width=1320) (actual time=0.193..9.934 rows=18 loops=1)
Join Filter: (FAV.INFO_ID = QWQWQW.INFO_ID)
Rows Removed by Join Filter: 18
-> Nested Loop Left Join (cost=0.56..715264.94 rows=15987 width=1280) (actual time=0.166..9.886 rows=18 loops=1)
-> Seq Scan on QWQWQW (cost=0.00..582468.61 rows=15987 width=1276) (actual time=0.129..9.388 rows=18 loops=1)
Filter: ((STATUS <> '4'::NUMERIC) AND (STATUS > '-1'::NUMERIC) AND (GATHER_STATUS = ANY ('{0,9}'::NUMERIC[])) AND (IS_HB = '-1'::NUMERIC) AND (MODULE_ID <> ALL ('{1907042057531ABn7slgK0TQOnwpxny,1906281143542BS15J0F
45WqfUr9fMV,190628151722nLv7zPl7NrbAJVisHve,190708203559JjBokUI83kSH02Aco8s}'::CHARACTER VARYING[])) AND ((MUSER_ID = '210317113214OEl81T3fQMT6DQ0F8sf'::CHARACTER VARYING) OR ((MUSER_ID = ANY ('{180622194528xx5u4YOE67fPJCTD5YG,190709174
122R6zTDgKJyxfUI390t1r,1907311655404iY1WvOrLVCuOaxppjr}'::CHARACTER VARYING[])) AND (DEPT_ID = '210317113214LlXqda7uwjMfaVwCwl7'::CHARACTER VARYING))))
Rows Removed by Filter: 2903
-> Index Scan using GPGPGP_PKEY on GPGPGP (cost=0.56..8.30 rows=1 width=36) (actual time=0.026..0.026 rows=1 loops=18)
Index Cond: (QWQWQW.PNID = ID)
-> Materialize (cost=0.41..29.53 rows=11 width=63) (actual time=0.001..0.001 rows=1 loops=18)
-> Index Scan using GFGFGF_user_id on GFGFGF FAV (cost=0.41..29.48 rows=11 width=63) (actual time=0.021..0.022 rows=1 loops=1)
Index Cond: (USER_ID = '210317113214OEl81T3fQMT6DQ0F8sf'::CHARACTER VARYING)
Planning time: 6.222 ms
Execution time: 10.051 ms
(15 rows)
案例4：
-- 原SQL + 执行计划： SELECT COUNT(1) count
FROM QWQWQW AS QWQWQW
WHERE 1 = 1
AND QWQWQW.MODULE_ID NOT IN ('1907042057531ABn7slgK0TQOnwpxny'
, '1906281143542BS15J0F45WqfUr9fMV'
, '190628151722nLv7zPl7NrbAJVisHve'
, '190708203559JjBokUI83kSH02Aco8s')
AND QWQWQW.IS_HB = - 1
AND QWQWQW.STATUS <> 4
AND QWQWQW.STATUS
> - 1
AND (((QWQWQW.MUSER_ID = '210317154535TLbxcuA5czpmtp1Txl6')
OR (QWQWQW.MUSER_ID IN ('180622194528xx5u4YOE67fPJCTD5YG'
, '180622194639xbqoCeWkSgDpLoDnde8'
, '1907311655404iY1WvOrLVCuOaxppjr')
AND (QWQWQW.DEPT_ID = '210317154535unv1iMCGYYbl2isvYRJ'))))
AND QWQWQW.GATHER_STATUS IN (0
, 9); QUERY PLAN --------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
------------------------------------------------
Aggregate (cost=430753.32..430753.33 rows=1 width=8) (actual time=74224.814..74224.814 rows=1 loops=1)
-> Bitmap Heap Scan on QWQWQW (cost=8427.15..430181.10 rows=228888 width=0) (actual time=151.721..74199.376 rows=37946 loops=1)
Recheck Cond: ((MUSER_ID = '210317154535TLbxcuA5czpmtp1Txl6'::CHARACTER VARYING) OR (MUSER_ID = ANY ('{180622194528xx5u4YOE67fPJCTD5YG,180622194639xbqoCeWkSgDpLoDnde8,190731165540
4iY1WvOrLVCuOaxppjr}'::CHARACTER VARYING[])))
Rows Removed by Index Recheck: 372210
Filter: ((STATUS <> '4'::NUMERIC) AND (STATUS > '-1'::NUMERIC) AND (GATHER_STATUS = ANY ('{0,9}'::NUMERIC[])) AND (IS_HB = '-1'::NUMERIC) AND (MODULE_ID <> ALL ('{1907042057531ABn
7slgK0TQOnwpxny,1906281143542BS15J0F45WqfUr9fMV,190628151722nLv7zPl7NrbAJVisHve,190708203559JjBokUI83kSH02Aco8s}'::CHARACTER VARYING[])) AND ((MUSER_ID = '210317154535TLbxcuA5czpmtp1Txl6':
:CHARACTER VARYING) OR ((MUSER_ID = ANY ('{180622194528xx5u4YOE67fPJCTD5YG,180622194639xbqoCeWkSgDpLoDnde8,1907311655404iY1WvOrLVCuOaxppjr}'::CHARACTER VARYING[])) AND (DEPT_ID = '21031715
4535unv1iMCGYYbl2isvYRJ'::CHARACTER VARYING))))
Rows Removed by Filter: 215433
Heap Blocks: exact=73741 lossy=67166
-> BitmapOr (cost=8427.15..8427.15 rows=261132 width=0) (actual time=128.894..128.894 rows=0 loops=1)
-> Bitmap Index Scan on g_index_MUSER_ID1 (cost=0.00..8172.47 rows=257055 width=0) (actual time=128.823..128.823 rows=253379 loops=1)
Index Cond: (MUSER_ID = '210317154535TLbxcuA5czpmtp1Txl6'::CHARACTER VARYING)
-> Bitmap Index Scan on g_index_MUSER_ID1 (cost=0.00..140.24 rows=4077 width=0) (actual time=0.070..0.070 rows=0 loops=1)
Index Cond: (MUSER_ID = ANY ('{180622194528xx5u4YOE67fPJCTD5YG,180622194639xbqoCeWkSgDpLoDnde8,1907311655404iY1WvOrLVCuOaxppjr}'::CHARACTER VARYING[]))
Planning time: 0.965 ms
Execution time: 74224.913 ms
(14 rows)
-- 改写优化：
SELECT COUNT(1) AS count
FROM (
SELECT QWQWQW.ctid
FROM QWQWQW
WHERE QWQWQW.MODULE_ID NOT IN ('1907042057531ABn7slgK0TQOnwpxny', '1906281143542BS15J0F45WqfUr9fMV', '190628151722nLv7zPl7NrbAJVisHve', '190708203559JjBokUI83kSH02Aco8s')
AND QWQWQW.IS_HB = - 1
AND QWQWQW.STATUS <> 4
AND QWQWQW.STATUS > - 1
AND QWQWQW.MUSER_ID = '210317154535TLbxcuA5czpmtp1Txl6'
AND QWQWQW.GATHER_STATUS IN (0, 9) UNION SELECT QWQWQW.ctid
FROM QWQWQW
WHERE QWQWQW.MODULE_ID NOT IN ('1907042057531ABn7slgK0TQOnwpxny', '1906281143542BS15J0F45WqfUr9fMV', '190628151722nLv7zPl7NrbAJVisHve', '190708203559JjBokUI83kSH02Aco8s')
AND QWQWQW.IS_HB = - 1
AND QWQWQW.STATUS <> 4
AND QWQWQW.STATUS > - 1
AND QWQWQW.MUSER_ID IN ('180622194528xx5u4YOE67fPJCTD5YG', '180622194639xbqoCeWkSgDpLoDnde8', '1907311655404iY1WvOrLVCuOaxppjr')
AND QWQWQW.DEPT_ID = '210317154535unv1iMCGYYbl2isvYRJ'
AND QWQWQW.GATHER_STATUS IN (0, 9)
) AS x; QUERY PLAN --------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
-------------------------------------
Aggregate (cost=467680.88..467680.89 rows=1 width=8) (actual time=879.326..879.326 rows=1 loops=1)
-> Unique (cost=463674.92..464819.48 rows=228912 width=6) (actual time=865.739..875.807 rows=37946 loops=1)
-> Sort (cost=463674.92..464247.20 rows=228912 width=6) (actual time=865.737..869.383 rows=37946 loops=1)
Sort Key: QWQWQW.CTID
Sort Method: quicksort Memory: 3315kB
-> Append (cost=8229.62..443296.67 rows=228912 width=6) (actual time=133.174..858.615 rows=37946 loops=1)
-> Bitmap Heap Scan on QWQWQW (cost=8229.62..425632.41 rows=228605 width=6) (actual time=133.173..855.894 rows=37946 loops=1)
Recheck Cond: (MUSER_ID = '210317154535TLbxcuA5czpmtp1Txl6'::CHARACTER VARYING)
Rows Removed by Index Recheck: 372210
Filter: ((STATUS <> '4'::NUMERIC) AND (STATUS > '-1'::NUMERIC) AND (GATHER_STATUS = ANY ('{0,9}'::NUMERIC[])) AND (IS_HB = '-1'::NUMERIC) AND (MODULE_ID <> ALL (
'{1907042057531ABn7slgK0TQOnwpxny,1906281143542BS15J0F45WqfUr9fMV,190628151722nLv7zPl7NrbAJVisHve,190708203559JjBokUI83kSH02Aco8s}'::CHARACTER VARYING[])))
Rows Removed by Filter: 215433
Heap Blocks: exact=73741 lossy=67166
-> Bitmap Index Scan on g_index_MUSER_ID1 (cost=0.00..8172.47 rows=257055 width=0) (actual time=112.570..112.570 rows=253379 loops=1)
Index Cond: (MUSER_ID = '210317154535TLbxcuA5czpmtp1Txl6'::CHARACTER VARYING)
-> Bitmap Heap Scan on QWQWQW QWQWQW_1 (cost=140.32..15375.15 rows=307 width=6) (actual time=0.061..0.061 rows=0 loops=1)
Recheck Cond: (MUSER_ID = ANY ('{180622194528xx5u4YOE67fPJCTD5YG,180622194639xbqoCeWkSgDpLoDnde8,1907311655404iY1WvOrLVCuOaxppjr}'::CHARACTER VARYING[]))
Filter: ((STATUS <> '4'::NUMERIC) AND (STATUS > '-1'::NUMERIC) AND (GATHER_STATUS = ANY ('{0,9}'::NUMERIC[])) AND (IS_HB = '-1'::NUMERIC) AND (DEPT_ID = '2103171
54535unv1iMCGYYbl2isvYRJ'::CHARACTER VARYING) AND (MODULE_ID <> ALL ('{1907042057531ABn7slgK0TQOnwpxny,1906281143542BS15J0F45WqfUr9fMV,190628151722nLv7zPl7NrbAJVisHve,190708203559JjBokUI83
kSH02Aco8s}'::CHARACTER VARYING[])))
-> Bitmap Index Scan on g_index_MUSER_ID1 (cost=0.00..140.24 rows=4077 width=0) (actual time=0.061..0.061 rows=0 loops=1)
Index Cond: (MUSER_ID = ANY ('{180622194528xx5u4YOE67fPJCTD5YG,180622194639xbqoCeWkSgDpLoDnde8,1907311655404iY1WvOrLVCuOaxppjr}'::CHARACTER VARYING[]))
Planning time: 0.495 ms
Execution time: 879.423 ms
(21 rows)
PG优化器有时候给我的感觉就像个傻子似的，统计信息，直方图就像摆设，稍微有个弯就转不过去，但是总体算法，性能还是不错，比MySQL真的强太多。
还是ORACLE 的CBO牛逼点。
postgresql 最近优化的SQL集合案例、（不写过程了只记录案例，PG优化器问题还是不少）的更多相关文章
- 最有效地优化 Microsoft SQL Server 的性能
为了最有效地优化 Microsoft SQL Server 的性能,您必须明确当情况不断变化时,性能将在哪些方面得到最大程度的改进,并集中分析这些方面.否则,在这些问题上您可能花费大量的时间和精力 ...
- 数据库性能优化之SQL语句优化
一.问题的提出 在应用系统开发初期,由于开发数据库数据比较少,对于查询SQL语句,复杂视图的编写等是体会不出SQL语句各种写法的性能优劣,但是如果将应用系统提交实际应用后,随着数据库中数据的增加,系统 ...
- 整理：sql语句优化之SQL Server
. 增加服务器CPU个数;但是必须明白并行处理串行处理更需要资源例如内存.使用并行还是串行程是MsSQL自动评估选择的.单个任务分解成多个任务,就可 以在处理器上运行.例如耽搁查询的排序.连接.扫描和 ...
- Oracle12c中SQL优化（SQL TUNING）新特性之SQL计划指令
SQL计划指令是Oracle12c中自适应查询优化的功能之一.SQL计划指令就像“额外的提醒” ,用以提醒优化器你先前选择了的计划并不是最优的,典型的是因为错误的势评估.错误的势评估往往是由统计信息缺 ...
- [转]数据库性能优化之SQL语句优化1
一.问题的提出 在应用系统开发初期,由于开发数据库数据比较少,对于查询SQL语句,复杂视图的的编写等体会不出SQL语句各种写法的性能优劣,但是如果将应用系统提交实际应用后,随着数据库中数据的增加,系统 ...
- 数据库优化之SQL语句优化-记录
1. 操作符优化 (a) IN 操作符 从Oracle执行的步骤来分析用IN的SQL与不用IN的SQL有以下区别: ORACLE试图将其转换成多个表的连接,如果转换不成功则先执行IN里面的子查询,再查 ...
- 数据库性能优化之SQL语句优化（下）
(1) 选择最有效率的表名顺序(只在基于规则的优化器中有效): ORACLE 的解析器按照从右到左的顺序处理FROM子句中的表名,FROM子句中写在最后的表(基础表 driving table)将被最 ...
- 浅谈mysql配置优化和sql语句优化【转】
做优化,我在这里引用淘宝系统分析师蒋江伟的一句话:只有勇于承担,才能让人有勇气,有承担自己的错误的勇气.有承担错误的勇气,就有去做事得勇气.无论做什么事,只要是对的,就要去做,勇敢去做.出了错误,承担 ...
- SQL学习笔记之项目中常用的19条MySQL优化
在写文章之前,首先感谢 飞友科技 陆老师提供的文档.. 声明一下:下面的优化方案都是基于 “ Mysql-索引-BTree类型 ” 的 0x00 EXPLAIN 做MySQL优化,我们要善用 EXPL ...
- 数据库性能优化之SQL语句优化1
一.问题的提出 在 应用系统开发初期,由于开发数据库数据比较少,对于查询SQL语句,复杂视图的的编写等体会不出SQL语句各种写法的性能优劣,但是如果将应用系统提交实 际应用后,随着数据库中数据的增加, ...
随机推荐
- 智能制造之路—从0开始打造一套轻量级MOM平台之基础平台搭建（Linux部署）
一.前言 前面我们选定了Admin.net来搭建我们的MOM快速开发平台,本章主要描述.NET6平台的Linux部署,以及记录搭建过程中坑. 本次搭建我们选择某云的轻量应用服务器,系统选择CentOS ...
- mysql注释的方法
单行注释:"#", "--", 多行注释:/**/ 参考链接:https://www.cnblogs.com/JiangLe/articles/6897403. ...
- ABC295 D题 题解
题意简述 给定一个长度不超过\(\;5\times 10^5\;\)的,仅有数字构成的字符串,问存在多少段子串,使得子串内字符重新排序后,前半段与后半段相同? 做法分析 重组后前后两部分相同,其实也就 ...
- CentOS7更新OpenSSH
前言 整个过程不要断开ssh链接,如有必要可使用telnet远程操作. 系统版本:centos 7.9 OpenSSL版本:1.0.2k -> 1.1.1q OpenSSH版本:7.4p1 -& ...
- Hugging News #0814: Llama 2 学习资源大汇总 🦙
每一周,我们的同事都会向社区的成员们发布一些关于 Hugging Face 相关的更新,包括我们的产品和平台更新.社区活动.学习资源和内容更新.开源库和模型更新等,我们将其称之为「Hugging Ne ...
- ES集群&kibana安装
一.elasticsearch介绍 Elasticsearch 是个开源分布式搜索引擎,它的特点有:分布式,零配置,自动发现,索引自动分片,索引副本机制,restful 风格接口,多数据源,自动搜索负 ...
- 【LaTeX】语法（更新中）
目录 长度 空行 空格 超链接 数学公式 段落中(隐式) 单独成段(显式) 居中,左对齐,右对齐 居中 左对齐 右对齐 参考文献配置 TODO 参考资料 中文支持参考环境配置中的 内容,在这里不做重复 ...
- 接口未配置在app.json文件中
微信小程序发布 提示 接口未配置在app.json文件中 狗血 昨天更新 就在app.json中添加 解决问题 "requiredPrivateInfos":[ "ge ...
- 《Python魔法大冒险》 001 序章：少年小鱼的不平凡一天
在一个普通的城市里,生活着一个名叫小鱼的少年.他是一名初中生,但在班级里,他的学习成绩总是垫底.同学们经常取笑他,有时甚至戏称他为"倒数王". 放学后,小鱼一个人走在回家的路上,他 ...
- 触动精灵生成的APK文件如何加固保护
触动精灵是一款模拟手机触摸.按键操作的软件,通过制作脚本,可以让触动精灵代替双手,自动执行一系列触摸.按键操作, 深受一些极客开发者喜爱. 触动精灵生成的APK文件自带了一些基础的加密,可以保护APK ...