SELECT /*+INDEX(BSEMPMS SEX_INDEX) USE SEX_INDEX BECAUSE THERE ARE FEWMALE BSEMPMS */ FROM BSEMPMS WHERE SEX='M'; 9. /*+INDEX_ASC(TABLE INDEX_NAME)*/ 表明对表选择索引升序的扫描方法. 例如: SELECT /*+INDEX_ASC(BSEMPMS PK_BSEMPMS) */ FROM BSEMPMS WHERE DPT_NO='SCOTT'; 10. /*...
SQL> insert into test.testindex values('1',1); 已创建 1 行。 SQL> commit; 提交完成。 SQL> analyze table test.testindex compute statistics for all indexes; 表已分析。 SQL> set autotrace on; SQL> select /*+RULE */* FROM test.testindex where a='1';(使用基于rule的优化器,数据类型匹...
SQL> create index ind_cola on test.testindex(a); 索引已创建。 SQL> insert into test.testindex values('1',1); 已创建 1 行。 SQL> commit; 提交完成。 SQL> analyze table test.testindex compute statistics for all indexes; 表已分析。 SQL> set autotrace on; SQL> select /*+RULE */* ...
resumable_timeout--waittime(inseconds)forRESUMABLE(Default7200)date_cache--size(inentries)ofdate conversioncache(Default1000)no_index_errors--abort load on any indexerrors(DefaultFALSE)partition_memory--direct path partition memory limit to startspilling(kb)(Default0)table--Tableforexpress mode load...
在PL/SQL Developer软件中可以查看表的索引。 2、SQL语句的执行计划 利用PL/SQL Developer软件可以查看SQL语句详细的执行计划。 3、SQL语句的执行步骤 SQL语句的执行顺序是从未级节点往根级节点看的,上图中的SQL语句执行的顺序如下: INDEX RANGE SCAN->TABLE ACCESS BY INDEX ROWID->SELECT STATEMENT,GOAL=ALL_ROWS...
If you'd like to run these comparisons yourself, use this LiveSQL script. That covers one of the biggest differences in index types. Here are some other common index types.Function-based IndexesImage Pixabay These are simply indexes where one or more of the columns have a function applied ...
index_name可以不必写,Oracle会根据统计值选一个索引。 如果索引名或表名写错了,那这个hint就会被忽略。 如果指定对象是视图,需要按此方法指定。/*+hint view.table ...*/,其中table是view中的表。 一个很常见的错误时,在使用提示的时候最易犯的错误是与表的别名有关。正确的规则是,当在提示中使用表时,只要...
Fast data access: How to create and use indexes in Oracle Database Ensure data quality: Keys, Constraints and Referential Integrity Does your database pass the ACID test? Transactions, Concurrency and Consistency Code data logic in the database server: create a PL/SQL stored procedure Unde...
SQL> CREATE TABLE t1206_1 (c1 NUMBER,c2 NUMBER); CREATE INDEX idx_c1 ON t1206 (c1); Table created. SQL> CREATE INDEX idx_c1 ON t1206_1 (c1); Index created. SELECT c1 FROM t1206_1 WHERE c1 < 10; 查看执行计划: 执行计划就出来了,走的是index range scan ...
SQL>DROPINDEXPK_TAB_TEST;DROPINDEXPK_TAB_TEST*ERRORat line1:ORA-02429:cannot drop index usedforenforcementofunique/primary key 解决方法: 删除对应的约束就会自动删除该索引。而不是直接去删除该索引! 代码语言:javascript 代码运行次数:0 运行