Note the use of the Oracle undocumented “materialize” hint in the “WITH clause”. The Oracle materialize hint is used to ensure that the Oracle cost-based optimizer materializes the temporary tables that are created inside the “WITH” clause. This is not necessary in Oracle10g, but it he...
The SQL WITH clause was introduced by Oracle in the Oracle 9i release 2 database. The SQL WITH clause allows you to give a sub-query block a name (a process also called sub-query refactoring), which can be referenced in several places within the main SQL query. The name assigned to th...
最近学习Oracle，所以在Vm中配置一个win10的虚拟机来安装Oracle 11g，平时实验报告使用在虚拟机中使用SqlP...
Example: Creating Joins with the ON clause in Oracle In this example, the employee_id column in the emplolyees table and department_id in departments table are joined using the ON clause. Wherever a employee_id in the EMPLOYEES table equals a department ID in the DEPARTMENTS table, the row...
To keep it simple, the following example only references the aggregations once, where the SQL “WITHclause” is normally used when an aggregation is referenced multiple times in a query. We can also use the SQL-99 “WITHclause” instead of temporary tables. TheOracleSQL “WITHclause” will ...
Note the use of the Oracle undocumented "materialize" hint in the "WITH clause". The Oracle materialize hint is used to ensure that the Oracle cost-based optimizer materializes the temporarytables that are created inside the "WITH" clause. This is not necessary in Oracle10g, but it helps en...
Oracle With Clause 本文参考网址:http://psoug.org/reference/with.html http://www.oracle-base.com/articles/misc/with-clause.php http://gennick.com/with.html---Understanding the WITH Claus 参考文档下载地址:http://ishare.iask.sina.com.cn/f/21674385.html TheWITH...
• Also useful for recursive queries (SQL-99, but not Oracle SQL) To keep it simple, the following example only references the aggregations once, where the SQL "WITH clause" is normally used when an aggregation is referenced multiple times in a query. ...
See alsoCreating a Global Temporary Table in Oracle Query 3 select * from emp where dept_no =5; The above query will not use the index as the where clause does not select the column which has an index Query 4 select * from emp where substr(emp_name,1,4) =’XYZW’; ...
Example 4: Using unnest with a non-path expression This is an example where the unnesting expression is not a path expression, and as a result, the UNNEST clause cannot be used. For example, a user may have multiple phone numbers in the same area code. To determine the num...