MySQL慢查詢日誌分析工具mysqldumpslow
mysqldumpslow是mysql內建的一種慢查詢日誌分析工具,顧名思義,就是查詢那些出那些查詢慢的SQL語句,由此分析出SQL查詢效率慢的原因。
通常來說,mysqldumpslow分組查詢的結果是相似的,它在展示統計結果時,可以將數字和字串分別抽象成“N”和“S”。當然也可以用-a 和 -n選項可以用來修改這些抽象的行為。
mysqldumpslow查詢命令
mysqldumpslow [options] [log_file]
mysqldumpslow選擇性參數(options),如下:
-a : 不將數字抽象成N,字串抽象成S。
樣本:
mysql%mysqldumpslow /home/mysql/logs/slow_query.log
Reading mysql slow query log from /home/mysql/logs/slow_query.log
Count: 1 Time=0.00s (0s) Lock=0.00s (0s) Rows=0.0 (0), FAVDBA[FAVDBA]@[10.1.45.51]
# Schema: Last_errno: N Killed: N
# Query_time: N.N Lock_time: N.N Rows_sent: N Rows_examined: N Rows_affected: N
# Bytes_sent: N
SET timestamp=N;
SELECT EVENT_NAME, EVENT_SCHEMA, EVENT_DEFINITION FROM INFORMATION_SCHEMA.EVENTS
mysql%mysqldumpslow -a /home/mysql/logs/slow_query.log
Reading mysql slow query log from /home/mysql/logs/slow_query.log
Count: 1 Time=0.00s (0s) Lock=0.00s (0s) Rows=0.0 (0), FAVDBA[FAVDBA]@[10.1.45.51]
# Schema: Last_errno: 0 Killed: 0
# Query_time: 0.004095 Lock_time: 0.002907 Rows_sent: 0 Rows_examined: 0 Rows_affected: 0
# Bytes_sent: 140
SET timestamp=1451270206;
SELECT EVENT_NAME, EVENT_SCHEMA, EVENT_DEFINITION FROM INFORMATION_SCHEMA.EVENTS
-n N : 將數字抽象顯示成至少指定的位元
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