FIRST_ROWSThe FIRST_ROWS hint explicitly chooses the cost-based approach to optimize a statement block with a goal of best response time (minimum resource usage to return first row). In newer Oracle version you should give a parameter with this hint: FIRST_ROWS(n) means that the optimizer w...
2、/*+ INDEX(TABLE INDEX_NAME) */ 表明对表选择索引的扫描方法. SELECT /*+INDEX(BSEMPMS SEX_INDEX) */ * FROM BSEMPMS WHERE SEX='M'; 3、/*+ INDEX_ASC(TABLE INDEX_NAME)*/ 表明对表选择索引升序的扫描方法. SELECT /*+INDEX_ASC(BSEMPMS PK_BSEMPMS) */ * FROM BSEMPMS WHERE DPT_NO='...
You can force the optimizer to use an index by using several techniques. You can use anINDEXhint (there are several of these, as explained later) to tell the optimizer to use a specific index or even any index the optimizer finds best. You can also adjust the initialization par...
Use released version of rake [#2065 #2066] Add /*+ OPTIMIZER_FEATURES_ENABLE('11.2.0.2') */ hint to address slow SCHEMA queries [#2055, #2068] build_subselect does not have ordering [#2070] Remove visit_Arel_Nodes_NotIn and visit_Arel_Nodes_In visitors [#2075, #2077] NOT IN clause...
1)具体的(Specific) 2)可测的(Measurable) 3)可实现的(Achievable) OWI方法论总结起来就是三点: 1)自顶向下,抓主要矛盾 2)选择可获得最大收益的事件入手 3)目标达到后见好就收 第二章:基本调优工具 一、性能调优工具 1)Dynamic performance views--动态性能视图 ...
Performance hint. getAction() - Method in class oracle.jdbc.xa.OracleMultiPhaseArgs getActiveSize() - Method in class oracle.jdbc.pool.OracleOCIConnectionPool Return the number of active or busy connections in the connection pool Note that the count cannot be guaranteed on any invoking subse...
3) hint是下面介绍的具体提示之一,如果包含多个提示,则每个提示之间需要用一个或多个空格隔开。 4) text 是其它说明hint的注释性文本 5)使用表别名。如果在查询中指定了表别名,那么提示必须也使用表别名。例如:select /*+ index(e,dept_idx) */ * from emp e; ...
ORA-17066Access layer specific implementation needed访问层需要具体实施。 ORA-17067Invalid Oracle URL specified指定了无效的 URL。 ORA-17068Invalid argument(s) in call调用中的无效参数。 ORA-17069Use explicit XA call使用明确的 XA 调用。 ORA-17070Data size bigger than max size for this type数据大小超...
Specify mydatastore as the datastore preference in the parameter clause of the CREATE INDEX statement. 2.2 Creating Preferences To create a datastore, lexer, filter, classifier, wordlist, or storage preference, use the CTX_DDL.CREATE_PREFERENCE procedure and specify one of the types described ...
Operating system releases, such as UNIX and Windows, often provide readme documents specific to that operating system. Additional Readme files may also exist. This Readme file is provided in lieu of system bulletins or similar publications. ...