Oracle Database generates an internal SQL statement, which in turn generates a recursive call. In short, recursive calls are basically SQL performed on behalf of your SQL. So, if you had to parse the query, for example, you might have had to run some other queries to get ...
Explain with examples what is meant by lossy decomposition and how this problem can be avoided in DBMS. a. What is a collision? b. Explain three ways of handling collisions (a program is not needed; a clear brief explanation will suffice). ...
Explain with examples what is meant by lossy decomposition and how this problem can be avoided in DBMS. Why are pointers necessary in any programming language? What will happen with following code: a. Will print the numbers from 1 to infinite, b. Nothing will happen, c. Will show an error...
SQL>select*fromtable(dbms_xplan.display); 1.3 使用PL/SQL Developer,Navicat, Toad等客户端工具 常见的客户端工具如PL/SQL Developer,Navicat, Toad都支持查看解释计划。 Navicat [SQL]DELETEPLAN_TABLE[SQL]EXPLAINPLANFORSELECT*FROMEMP[SQL]SELECTLPAD('',LEVEL-1)||OPERATION||'('||OPTIONS||')'"Operatio...
The example in Figure 5 displays the basic execution plan and includes information on any predicates as well as the Optimizer Cost column. SELECT plan_table_output FROM TABLE(DBMS_XPLAN.DISPLAY('plan_table',null,'basic +predicate +cost')); Figure 5: Customized BASIC plan output with selected...
SQL>SELECT plan_table_output FROM TABLE(DBMS_XPLAN.DISPLAY('PLAN_TABLE')); 示例: SQL>EXPLAIN PLAN FOR SELECT * FROM DAVE; 已解释。 SQL>SELECT plan_table_output FROM TABLE(DBMS_XPLAN.DISPLAY('PLAN_TABLE')); 或者: SQL>select * from table(dbms_xplan.display); ...
SQL> SELECT plan_table_output FROM TABLE(DBMS_XPLAN.DISPLAY('PLAN_TABLE')); 或者: SQL> select * from table(dbms_xplan.display); PLAN_TABLE_OUTPUT --- Plan hash value: 3458767806 --- | Id | Operation | Name | Rows | Bytes | Cost (%CPU)| Time ...
Explain an SQL query and store the obtained execution plan in the test table. /* Create a table named test. */ obclient> CREATE TABLE test (statement_id VARCHAR(30), plan_id INT, gmt_create TIMESTAMP, remarks VARCHAR(4000), operator VARCHAR(255), options VARCHAR(255), object_node VARC...
baseline_ref_cursor DBMS_SQLTUNE.SQLSET_CURSOR; BEGIN -- create sql_plan_baseline for sql using plan from AWR DBMS_SQLTUNE.CREATE_SQLSET(:ss_name); open baseline_ref_cursor for select VALUE(p) from table(DBMS_SQLTUNE.SELECT_WORKLOAD_REPOSITORY(:b_snap_id, :e_snap_id, ...
SQL>SELECT plan_table_output FROM TABLE(DBMS_XPLAN.DISPLAY('PLAN_TABLE')); 示例: SQL>EXPLAIN PLAN FOR SELECT * FROM DAVE; 已解释。 SQL>SELECT plan_table_output FROM TABLE(DBMS_XPLAN.DISPLAY('PLAN_TABLE')); 或者: SQL>select * from table(dbms_xplan.display); ...