1、 打开熟悉的查看工具:PL/SQL Developer。 在PL/SQL Developer中写好一段SQL代码后,按F5,PL/SQL Developer会自动打开执行计划窗口,显示该SQL的执行计划。 2、 查看总COST,获得资源耗费的总体印象 一般而言,执行计划第一行所对应的COST(即成本耗费)值,反应了运行这段SQL的总体估计成本,单看这个总成本没有实际...
建立这个表的脚本是:rdbms\admin)ultxplan.sql。 SQL> connect sys/sys@colm2 as sysdba; SQL> @rdbms\admin\utlxplan.sql; SQL> create public synonym plan_table for plan_table;--建立同义词 SQL> grant all on plan_table to public;--授权所有用户 要在数据库中建立一个角色plustrace,用sys用户运行...
CREATE[ORREPLACE]TYPEnested_table_typeISTABLEOFelement_datatype [NOTNULL];Code language:SQL (Structured Query Language)(sql) If you want to drop a type, use the followingDROP TYPEstatement: DROPTYPEtype_name [FORCE];Code language:SQL (Structured Query Language)(sql) ...
PL/SQL Nested Table Using Initialized Values To get started using a Nested Table, create a code block that declares a nested table type and instantiates a nested table of this created type (Lines 2 & 4). This code iterates through a FOR Loop 3 times to show that the Nested Table has ...
1foreach rowin(select*fromT1wherename='David') loop2for(select*fromT2whereT2.id=outer.id) loop3Ifmatchthenpass the rowontothenextstep4Ifno matchthendiscard the row5endloop6endloop 具体来说, 如果上述 sql 语句执行循环嵌套连接的话, 那么实际的执行过程应该如下所示: ...
Ref: 1.Page 357, Oracle PL/SQL Programming FIFTH EDITION, Steven Feuerstein with Bill Pribyl, O'REILLY 2.http://www.itpub.net/viewthread.php?tid=640129
OraclePLSQL之嵌套表（NestedTable）OraclePLSQL 之嵌套表（NestedTable ）Test Code:Connected to Oracle Database 11g Enterprise Edition Release color_model_colors_tab 6 / Table created SQL> SQL> BEGIN 2 INSERT INTO color_models 3 VALUES ('RGB', color_tab_t ('RED','GREEN','BLUE'));4 ...
NONE FREQUENCY HEIGHT BALANCED QUALIFIED_COL_NAME VARCHAR2(4000) 修飾列名 関連項目: 「DBA_NESTED_TABLE_COLS」 「USER_NESTED_TABLE_COLS」 DBMS_STATSパッケージの詳細は、『Oracle Database PL/SQLパッケージおよびタイプ・リファレンス』を参照してください。 前...
PL/SQL procedure successfully completed. 谓词: Access: 表示这个谓词条件的值将会影响数据的访问路劲(全表扫描还是索引)。 Filter:表示谓词条件的值不会影响数据的访问路劲,只起过滤的作用。 在下文中,select * from t2, t1 where t2.id=t1.id and t2.id=2; ...
If the tree isn't expected to change often, a properly normalized hierarchy of attribute tables can be created in the initial design of a system, leading to simpler, more portable SQL statements; specifically ones that don't require an arbitrary number of runtime, programmatically created or de...