通过执行计划,我们看到ORACLE为了能够比较两个不同数据类型(字段A与B之间的比较),强制在字段A上加了一个数据类型转换函数,在ORACLE内部,运算从WHERE a=b转换为WHERETO_DATE(a)=b, 这也是为什么执行计划中出现INTERNAL_FUNCTION的原因-从实际的“二进制”执行计划生成可读性的执行计划的代码无法将内部操作码转换为相...
其实官方文档对INTERNAL_FUNCTION的介绍非常少,最常见的理解,INTERNAL_FUNCTION这种特殊函数用于执行隐式数据类型转换(implicit datatype conversion),可能来自官方文档https://docs.oracle.com/cd/E11882_01/server.112/e25523/part_avail.htm#sthref141。但是这个说法,事实上仅仅部分正确,而不是全部的事实。事实上,OR...
当前标签:INTERNAL_FUNCTIONORACLE数据库中执行计划出现INTERNAL_FUNCTION一定是隐式转换吗?潇湘隐者 2019-12-10 14:06 阅读: 3185 评论: 0 推荐: 1About 个人简介:网名潇湘隐者/潇湘剑客、英文名Kerry,兴趣广泛,广泛涉猎,个性随意。执意做一名会写代码的DBA,混迹于IT行业 个人微信公众号: 「DBA闲思杂想录」 ...
Sometimes,the columns are decrypted as a result and decrypt functions (appears as INTERNAL_FUNCTION in the execution plan) are applied on them, which can lead to poor approximations of column selectivity, leading to improper plans. This happens mostly when the encrypted columns are using SALT to ...
SQL> ALTER SYSTEM SET ENCRYPTION KEY AUTHENTICATED BY "oracle"; System altered. SQL> conn maclean/maclean Connected. SQL> create table enctab (t1 int encrypt); Table created. SQL> select * from enctab; no rows selected Execution Plan ...
{// 这里要验证 reply 来自可信的源requests[requestID].callback(response);}}contract OracleUser{Oracle constant oracle=Oracle(0x1234567);// 已知的合约functionbuySomething(){oracle.query("USD",this.oracleResponse);}functionoracleResponse(bytes response)public{require(msg.sender==address(oracle));// ...
Loadable Function Reference Type Conversion in Expression Evaluation Operators Flow Control Functions Numeric Functions and Operators Date and Time Functions String Functions and Operators Full-Text Search Functions Cast Functions and Operators XML Functions Bit Functions and Operators Encryption...
This document is meant to assist both Customers and Oracle Support Analysts in handling situations and Service Requests in which the problem is related to the usage of the undocumented function WMSYS.WM_CONCAT. Solution Sign In To view full details, sign in with your My Oracle Support account...
Built-In Function and Operator Reference Loadable Function Reference Type Conversion in Expression Evaluation Operators Flow Control Functions Numeric Functions and Operators Date and Time Functions String Functions and Operators Full-Text Search Functions Cast Functions and Operators XML Functio...
(disclaimer: I can’t look at the sourcecode, which means I look at the oracle executable with normal, modern tools. This also means that there’s a of stuff that I don’t see, for example if functionality has been added inside an existing function, then that’s totally invisible to ...