JJON's StorY205 MySQL EXPLAIN ANALYZE 출처 : https://dev.mysql.com/doc/refman/8.0/en/explain.html MySQL :: MySQL 8.0 Reference Manual :: 13.8.2 EXPLAIN Syntax {EXPLAIN | DESCRIBE | DESC} tbl_name [col_name | wild] {EXPLAIN | DESCRIBE | DESC} [explain_type] {explainable_stmt | FOR CONNECTION connection_id} {EXPLAIN | DESCRIBE | DESC} ANALYZE select_statement explain_type: { FORMAT = format_name } format_name: { T dev.mysql.com MySQL 8... 2019. 10. 2. MySQL Hash Join Optimization 출처 : https://dev.mysql.com/doc/refman/8.0/en/hash-joins.html MySQL :: MySQL 8.0 Reference Manual :: 8.2.1.4 Hash Join Optimization 8.2.1.4 Hash Join Optimization Beginning with MySQL 8.0.18, MySQL employs a hash join for any query for which each join has an equi-join condition and uses no indexes, such as this one: SELECT * FROM t1 JOIN t2 ON t1.c1=t2.c1; A hash join is usually faster dev.mysql... 2019. 10. 2. MySQL 시퀀스(AUTO_INCREMENT) 조회 및 초기화 int(11) auto increment 최대 4294967295 이후에는 errorunsigned BIGINT 최대 18446744073709551615 까지 사용 가능 -- 테이블의 상태 확인show table status where name='T_HADOOP_LATEST_METRICS';+-------------------------+--------+---------+------------+-------+----------------+-------------+-----------------+--------------+-----------+----------------+---------------------+-------------+------------+-----------------+-------.. 2018. 9. 18. 벌크 insert 빠르게 하는 방법 기본적으로 100만개의 레코드를 벌크 인서트 할 때 아래 방법을 사용 합니다. declare TYPE tbl_ins IS TABLE OF LARGE_TBL%ROWTYPE index by binary_integer; w_ins tbl_ins; begin for i in 1 .. 1000000 loop w_ins(i).id := i; w_ins(i).value := 'foobar'; end loop; forall i in 1 .. 1000000 insert into large_tbl values w_ins(i); commit; end; / PL/SQL procedure successfully completed. Elapsed: 00:00:01.26 call count cpu elapsed disk query.. 2018. 3. 21. 이전 1 ··· 7 8 9 10 11 12 13 ··· 52 다음