函数索引(Function-based indexes)只有在where条件使用了与索引中相同的基于相同列的函数时才起作用。duzz$scott@orcl>set autotrace on duzz$scott@orcl>create table t1 as select * from dept; Table created. Elapsed: 00:00:00.01 duzz$scott@orcl>create index loc_idx on t1(upper(loc)); Index crea...
In this tutorial, you will learn how to use the Oracle function-based index to speed up queries that consist of functions.
Function-based index 可以很巧妙地帮助我们实现“不一般”的unique index, 但是如果没有注意function-based index对于该index对应的function的要求,很有可能会触发ORA-01802这个错误。 本文尝试去阐述这个错误是如何触发的,以及如果去解决。 OK, let’s get down to business. 记得Tom大叔的力作《Oracle编程艺术》中提...
second argument– value for which to search third argument– (optional) starting index This function returns either the ordinal position of a list element that matches a given value or -1 (the given value is not in the list). Example 1 The following expression returns 1. <indexOf> <list>...
Oracle技术之基于自定义函数的Function-Based索引创建 ,在oralce中给自建函数创建索引,结果不成功。source:CreateIndexIDX_T_SP_TWOTYPESTAT_0_fOnT_SP_TWOTYPESTAT_0(f_dateadd(yearmonth,12,2));err:thefunctionisnotdeterministic.我们看一下这是为什么?随便一个测试可
在Oracle中创建函数 句法 CREATE [OR REPLACE] FUNCTION function_name [ (parameter [, parameter]) ] RETURN return_datatype IS | AS [declaration_section] BEGIN executable_section [EXCEPTION exception_section] END [function_name]; 在创建过程或函数之前, 必须先定义一些参数。这些参数是 ...
Function-Based Normal索引(基于函数的普通索引)是Oracle数据库中一种特殊的索引类型,它允许用户根据列上的函数或表达式的结果来创建索引。这种索引类型不同于传统的基于单列或多列的索引,因为它不直接对表中的列值进行索引,而是对列值经过特定函数处理后的结果进行索引。 2. 阐述Function-Based Normal索引的作用和优...
Because 'DECODE(status, 'C', null, status)' has been set in the Function-Based Index 'T1_STATUS_FN', you, certainly, create the virtual column 'virtual_status' with 'DECODE(status, 'C', null, status)' and Oracle will show this error: 'ORA-54015: Duplicate column expression was speci...
Oracle Database Exadata Express Cloud Service - Version N/A and later: ORA-10631 When Trying To Shrink A Table That Has A Function-based Index.
Package Class Tree Deprecated Index HelpOracle Fusion Middleware Java API Reference for Oracle SOA Suite XPath Extension Function 12c Release 2 (12.2.1.4.0) E95682-01Prev Next Frames No Frames All Classes C G I O T C call(IXPathContext, List) - Method in interface oracle.fabric.common...