my query is simple but 10 seconds long to respond. please check and help me to improve that
SELECT
COUNT(test.code) AS sumid
FROM
test
WHERE
test.state = '03' AND test.type = '0'
AND test.year = '2020'
AND test.active IN (1 , 2)
AND test.status IN (1 , 4)
AND test.marhale = 0
LIMIT 1
explain that show:
id select_type table partitions type possible_keys key key_len ref rows filtered Extra
1 SIMPLE test index_merge type,year,marhale,state,status,active year,state,marhale,type 2,6,2,1 20354 27.24 Using intersect(year,state,marhale,type); Using where
this table is my important table in big database and we have many reports for all of the columns of that this causes us index many of fields.
this show create table of test :
CREATE TABLE `tashilat` (
`id` int(11) NOT NULL AUTO_INCREMENT,
`eid` varchar(10) COLLATE utf8_persian_ci NOT NULL,
`hcode` char(15) COLLATE utf8_persian_ci NOT NULL,
`code` char(16) COLLATE utf8_persian_ci NOT NULL,
`listcode` varchar(12) COLLATE utf8_persian_ci DEFAULT NULL,
`year` smallint(4) NOT NULL DEFAULT '1392',
`ddate` varchar(20) COLLATE utf8_persian_ci DEFAULT NULL,
`type` tinyint(4) NOT NULL,
`type_level` tinyint(4) NOT NULL,
`baseprice` varchar(10) COLLATE utf8_persian_ci NOT NULL,
`prices` varchar(10) COLLATE utf8_persian_ci NOT NULL,
`marhale` smallint(3) NOT NULL,
`maxmarhale` smallint(3) NOT NULL DEFAULT '0',
`paystatus` tinyint(1) NOT NULL DEFAULT '0',
`marhale_level` smallint(3) NOT NULL DEFAULT '0',
`pdate` varchar(20) COLLATE utf8_persian_ci DEFAULT NULL,
`paymethod` smallint(6) DEFAULT NULL,
`state` char(2) COLLATE utf8_persian_ci NOT NULL,
`bank` varchar(10) COLLATE utf8_persian_ci NOT NULL,
`branch` varchar(10) COLLATE utf8_persian_ci NOT NULL,
`tdate` varchar(20) COLLATE utf8_persian_ci DEFAULT NULL,
`daccept` tinyint(1) NOT NULL DEFAULT '1',
`dcode` varchar(32) COLLATE utf8_persian_ci DEFAULT NULL,
`mtime` varchar(10) COLLATE utf8_persian_ci DEFAULT NULL,
`mshkdate` varchar(20) COLLATE utf8_persian_ci DEFAULT NULL,
`ghtime` varchar(10) COLLATE utf8_persian_ci DEFAULT NULL,
`gh` varchar(10) COLLATE utf8_persian_ci DEFAULT NULL,
`submitted` tinyint(1) NOT NULL DEFAULT '0',
`submittedtype` int(11) DEFAULT NULL,
`submitteddate` varchar(20) COLLATE utf8_persian_ci DEFAULT NULL,
`ztype` varchar(2) COLLATE utf8_persian_ci DEFAULT NULL,
`bdate` varchar(20) COLLATE utf8_persian_ci DEFAULT NULL,
`pcode` varchar(20) COLLATE utf8_persian_ci DEFAULT NULL,
`lastp` tinyint(4) DEFAULT '0',
`tozihat` text COLLATE utf8_persian_ci,
`ncode` varchar(32) COLLATE utf8_persian_ci DEFAULT NULL,
`ndate` varchar(32) COLLATE utf8_persian_ci DEFAULT NULL,
`ccode` varchar(32) COLLATE utf8_persian_ci DEFAULT NULL,
`cdate` varchar(12) COLLATE utf8_persian_ci DEFAULT NULL,
`bcode` varchar(20) COLLATE utf8_persian_ci DEFAULT NULL,
`bdate` varchar(20) COLLATE utf8_persian_ci DEFAULT NULL,
`secindicator` varchar(100) COLLATE utf8_persian_ci DEFAULT NULL,
`hesab` varchar(20) COLLATE utf8_persian_ci DEFAULT NULL,
`stage` varchar(3) COLLATE utf8_persian_ci DEFAULT NULL,
`loantopic` varchar(50) COLLATE utf8_persian_ci DEFAULT NULL,
`baz` tinyint(1) DEFAULT NULL,
`accept` tinyint(4) NOT NULL DEFAULT '1',
`user` varchar(32) COLLATE utf8_persian_ci NOT NULL,
`sdate` varchar(32) COLLATE utf8_persian_ci NOT NULL,
`status` tinyint(1) NOT NULL DEFAULT '1',
`activetype` tinyint(4) NOT NULL DEFAULT '0',
`status_fact` int(11) DEFAULT NULL,
`status_date` varchar(25) COLLATE utf8_persian_ci DEFAULT NULL,
`active` tinyint(1) NOT NULL,
PRIMARY KEY (`id`),
KEY `tashilat_idx_bank` (`bank`),
KEY `tashilat_idx_shobe` (`branch`),
KEY `submitted` (`submitted`) USING BTREE,
KEY `listcode` (`listcode`),
KEY `mshkdate` (`mshkdate`),
KEY `eid` (`eid`),
KEY `baseprice` (`baseprice`),
KEY `code` (`code`),
KEY `hcode` (`hcode`),
KEY `marhale_level` (`marhale_level`),
KEY `type` (`type`),
KEY `year` (`year`),
KEY `marhale` (`marhale`),
KEY `maxmarhale` (`maxmarhale`),
KEY `state` (`state`),
KEY `status` (`status`),
KEY `active` (`active`),
FULLTEXT KEY `sdate` (`sdate`),
FULLTEXT KEY `ndate` (`ndate`),
FULLTEXT KEY `cdate` (`cdate`)
) ENGINE=InnoDB AUTO_INCREMENT=11293550 DEFAULT CHARSET=utf8 COLLATE=utf8_persian_ci
my query run in 11 seconds. with count(*) or with count(test.code) or without limit 1 not diffrence
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perfiomance questionws need more information please see dba.meta.stackexchange.com/questions/3034/…nbk– nbk2021年04月26日 10:58:25 +00:00Commented Apr 26, 2021 at 10:58
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Create one composite index instead of separate ones.Akina– Akina2021年04月26日 11:00:09 +00:00Commented Apr 26, 2021 at 11:00
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"my query run in 11 seconds. with count(*) or with count(test.code) or without limit 1 not difference" -- The suggestions were more about SQL coding; they rarely impact performance.Rick James– Rick James2021年04月27日 15:36:58 +00:00Commented Apr 27, 2021 at 15:36
1 Answer 1
"intersect" tells me that you have a bunch of 1-column indexes, when you should have an 'composite' index with all those columns. In particular:
INDEX(state, type, year, marhale, -- any order is OK
status, active) -- later; in either order
That is, start with all the columns that are tested with =
.
Another issue is with COUNT(test.code)
. That means "count how many rows have code IS NOT NULL
". If you really want "count the number of rows", then say simply COUNT(*)
.
If you want to test NULLness, then tack code
onto the end of my recommended index. That way, it will be a "covering" index, which adds another performance boost. (If you go with COUNT(*)
, tacking code
on the end is harmless but not helpful.)
If you want to discuss further, please provide SHOW CREATE TABLE
.
One more thing. If you add my composite index, Drop the index for the first column (probably DROP INDEX 'state'
).
The LIMIT 1
is useless since SELECT COUNT(..) FROM ..
will always give exactly 1 row. (It is also harmless.)
More
FULLTEXT
indexing is intended for lengthy text strings, not dates.
DATE
, DATETIME
, or TIMESTAMP
should be used for dates/times. VARCHAR
makes it difficult to compare dates.
11 "date" columns -- This seems strange. Maybe "date" does not mean "date"?
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thank you. your answer is below because too long as a comment:aynaz– aynaz2021年04月27日 04:37:57 +00:00Commented Apr 27, 2021 at 4:37
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@aynaz - I see nothing "below"; to what do you refer?Rick James– Rick James2021年04月27日 04:43:04 +00:00Commented Apr 27, 2021 at 4:43
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sorry, I have edited my question. please see again thataynaz– aynaz2021年04月27日 05:07:38 +00:00Commented Apr 27, 2021 at 5:07
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Adding the composite index should help performance a lot. If it does not, please provide a new
EXPLAIN
so we can check whether it is actually being used. Meanwhile, I added a few tips on the schema.Rick James– Rick James2021年04月27日 15:38:39 +00:00Commented Apr 27, 2021 at 15:38 -
added composite index and was very helpful. I hope it wasn't negative effect in other situationsaynaz– aynaz2021年04月27日 20:30:21 +00:00Commented Apr 27, 2021 at 20:30