oracle 学习笔记
发布时间:2020-12-12 14:08:28 所属栏目:百科 来源:网络整理
导读:先放张体系图,侵删 表准备 create table t as select * from all_objects; 索引测试 create index idx_object_id on t(object_id); 查询 select * from t where object_id = 29 执行计划查看:cost 2 第二次查询,查询这条指令的hash值会存在共享区,数据会
先放张体系图,侵删 表准备create table t as select * from all_objects;
索引测试create index idx_object_id on t(object_id);
查询select * from t where object_id = 29
执行计划查看:cost 2 添加HINT ,强制走全表扫描 select /*+full(t)*/ * from t where object_id = 29;
执行计划查看:cost 287 查询SQL执行次数SELECT t.sql_text,t.sql_id,t.parse_calls,t.executions from v$sql t where sql_text like '%insert into T values%' ORDER BY t.executions desc
创建表空间create tablespace TBS_LJB_A datafile 'F:oracle_dataTBS_LJB_A_01.DBF' size 1M autoextend ON uniform size 64K
在指定表空间创建表create table t_a(id int) tablespace TBS_LJB_A
插入测试数据insert into t_a select rownum from dual connect by level<=10000000 (编辑:李大同) 【声明】本站内容均来自网络,其相关言论仅代表作者个人观点,不代表本站立场。若无意侵犯到您的权利,请及时与联系站长删除相关内容! |