MySQLサーバーを再起動するまでクエリが実行されないのはなぜですか？
MySQLがクエリを実行しないのはなぜですか？なぜフリーズするのでしょうか？それは単にそこに座って何もしません。 Show processlistは、MySQLをあきらめて再起動するのにかかる時間だけ「データを送信」した結果を示します。その後、クエリはほんの一瞬で実行されます。ログはエラーを生成しません。 Explainは、結合テーブルとそれらが一致するキーを示します。
actとclsは、L_IDと通常のs_IDでプライマリにインデックス付けされます
クエリを実行する前にMySQLを再起動しない限り、クエリを実行しようとするとMySQLがフリーズします。ここの誰かが、なぜそれをどうするのか、もっと良いのかについて私にアイデアを与えてくれることを願っています。
XAMPPを実行しているローカルホストと、次のようなデータをローカルで処理するクエリがあります。
INSERT INTO table
SELECT
act.P_ID,
act.L_ID,
act.L_Price,
act.A,
act.C,
round(((count(*) / sum(1/(cls.S_Price / cls.Sq))* act.Sq)+avg(cls.S_Price))/2) AS abc,
STDDEV((cls.S_Price / cls.Sq))/avg((cls.S_Price / cls.Sq)) AS std_dev,
count(*) as `samp`,
GROUP_CONCAT(DISTINCT cls.L_ID) as comps,
@datenow as `Timestamp`,
'1' AS B_score
FROM
act_table AS act
JOIN cls_table AS cls ON cls.S_ID = act.S_ID
AND cls.R = "val"
AND cls.S = "val"
AND cls.Sq BETWEEN act.Sq *.2 AND act.Sq * 1.8
AND cls.YB BETWEEN act.YB - 10 AND act.Year_Built + 12
AND cls.pv = act.pv
AND cls.PP = act.PP
AND cls.Bd = act.Bd
AND cls.th = act.th
AND cls.C_D > now()-interval 3 month
AND act.s_ID !=""
GROUP BY
act.P_ID
HAVING `samp` > 1
AND std_dev <= .1;
一度実行できます。再度実行する必要がある場合は、XAMPPでMySQLサーバーを再起動する必要があります。 clsテーブルには約40,000のレコードがあり、actには約7,000のレコードがあります。 MySQLを再起動した後、0.674秒で実行されます。
グラフィカルデータベース管理ソフトウェアであるNavicatからクエリを実行します。
エンジンInnoDBステータスを表示する
次の結果が得られます。
=====================================
2016-01-20 07:49:30 2aa0 INNODB MONITOR OUTPUT
=====================================
Per second averages calculated from the last 25 seconds
-----------------
BACKGROUND THREAD
-----------------
srv_master_thread loops: 1893 srv_active, 0 srv_shutdown, 225772 srv_idle
srv_master_thread log flush and writes: 227665
----------
SEMAPHORES
----------
OS WAIT ARRAY INFO: reservation count 52114
OS WAIT ARRAY INFO: signal count 95463
Mutex spin waits 264459, rounds 1248653, OS waits 21862
RW-shared spins 93765, rounds 1229580, OS waits 21549
RW-excl spins 93314, rounds 612670, OS waits 7456
Spin rounds per wait: 4.72 mutex, 13.11 RW-shared, 6.57 RW-excl
------------
TRANSACTIONS
------------
Trx id counter 15954141
Purge done for trx's n:o < 15954137 undo n:o < 0 state: running but idle
History list length 588
LIST OF TRANSACTIONS FOR EACH SESSION:
---TRANSACTION 0, not started
MySQL thread id 163, OS thread handle 0x2aa0, query id 7705288 optimus-PC 10.10.102.114 jemima init
SHOW ENGINE InnoDB STATUS
---TRANSACTION 15954140, ACTIVE 5 sec fetching rows
mysql tables in use 6, locked 6
392 lock struct(s), heap size 27512, 27219 row lock(s)
MySQL thread id 161, OS thread handle 0x2ef4, query id 7705282 optimus-PC 10.10.102.114 jemima Sending data
INSERT INTO table
SELECT
act.P_ID,
act.L_ID,
act.L_Price,
act.A,
act.C,
round(((count(*) / sum(1/(cls.S_Price / cls.Sq))* act.Sq)+avg(cls.S_Price))/2) AS abc,
STDDEV((cls.S_Price / cls.Sq))/avg((cls.S_Price / cls.Sq)) AS std_dev,
count(*) as `samp`,
GROUP_CONCAT(DISTINCT cls.L_ID) as comps,
@datenow as `Timestamp`,
'1' AS B_score
FROM
act_table AS act
JOIN cls_table AS cls ON cls.S_ID = act.S_ID
AND cls.R = "val"
AND cls.S = "val"
AND cls.Sq BETWEEN act.Sq *.2 AND act.Sq * 1.8
AND cls.YB BETWEEN act.YB - 10 AND act.Year_Built + 12
AND cls.pv = act.pv
AND cls.PP = act.PP
AND cls.Bd = act.Bd
AND cls.th = act.th
AND cls.C_D > now()-interval 3 month
AND act.s_ID !=""
GROUP BY
act.P_ID
HAVING `samp` > 1
AND std_dev <= .1;
--------
FILE I/O
--------
I/O thread 0 state: wait Windows aio (insert buffer thread)
I/O thread 1 state: wait Windows aio (log thread)
I/O thread 2 state: wait Windows aio (read thread)
I/O thread 3 state: wait Windows aio (read thread)
I/O thread 4 state: wait Windows aio (read thread)
I/O thread 5 state: wait Windows aio (read thread)
I/O thread 6 state: wait Windows aio (write thread)
I/O thread 7 state: wait Windows aio (write thread)
I/O thread 8 state: wait Windows aio (write thread)
I/O thread 9 state: wait Windows aio (write thread)
Pending normal aio reads: 0 [0, 0, 0, 0] , aio writes: 0 [0, 0, 0, 0] ,
ibuf aio reads: 0, log i/o's: 0, sync i/o's: 0
Pending flushes (fsync) log: 0; buffer pool: 0
2810151 OS file reads, 733114 OS file writes, 63302 OS fsyncs
54.08 reads/s, 16384 avg bytes/read, 13.32 writes/s, 1.76 fsyncs/s
-------------------------------------
INSERT BUFFER AND ADAPTIVE HASH INDEX
-------------------------------------
Ibuf: size 1, free list len 7149, seg size 7151, 7251 merges
merged operations:
insert 122683, delete mark 1668046, delete 28597
discarded operations:
insert 0, delete mark 0, delete 0
Hash table size 2212699, node heap has 881 buffer(s)
309907.24 hash searches/s, 5169.03 non-hash searches/s
---
LOG
---
Log sequence number 3963944279169
Log flushed up to 3963944279169
Pages flushed up to 3963944279169
Last checkpoint at 3963944279169
0 pending log writes, 0 pending chkp writes
21912 log i/o's done, 0.68 log i/o's/second
----------------------
BUFFER POOL AND MEMORY
----------------------
Total memory allocated 544210944; in additional pool allocated 0
Dictionary memory allocated 1038260
Buffer pool size 32768
Free buffers 1024
Database pages 30862
Old database pages 11372
Modified db pages 0
Pending reads 0
Pending writes: LRU 0, flush list 0, single page 0
Pages made young 1155251, not young 48421006
32.20 youngs/s, 7462.94 non-youngs/s
Pages read 2798392, created 408832, written 667825
54.08 reads/s, 0.64 creates/s, 12.20 writes/s
Buffer pool hit rate 1000 / 1000, young-making rate 0 / 1000 not 7 / 1000
Pages read ahead 33.28/s, evicted without access 0.00/s, Random read ahead 0.00/s
LRU len: 30862, unzip_LRU len: 0
I/O sum[746]:cur[0], unzip sum[0]:cur[0]
--------------
ROW OPERATIONS
--------------
0 queries inside InnoDB, 0 queries in queue
0 read views open inside InnoDB
Main thread id 3936, state: sleeping
Number of rows inserted 4309763, updated 8216503, deleted 12560, read 4268362560
42.60 inserts/s, 0.00 updates/s, 0.00 deletes/s, 321801.25 reads/s
----------------------------
END OF INNODB MONITOR OUTPUT
============================
_
@datenow_をCURRENT_DATE()に置き換えます。コンポジット
INDEX(R, S, C_D)をclsに追加します。「再起動」しないでください-ログを見てください。 _
SHOW PROCESSLIST_を見てください。 _SHOW ENGINE InnoDB STATUS_を見てください。