SQL> exec DBMS_STATS.GATHER_TABLE_STATS('HR', 'EMPLOYEES', method_opt=>'FOR COLUMNS SIZE 254 JOB_ID'); With a histogram on JOB_ID in place the optimizer estimates the correct number of rows will be returned from the sales table as seen in Figure 10. Figure 10: Correct cardinality ...
the execution plan is available for the entered statement and the explain plan button is selected in the query window. The logged in user also needs the necessary privileges, see the sections below for more information about privileges. If you wish not to get the plan by default every time a...
the execution plan is available for the entered statement and the explain plan button is selected in the query window. The logged in user also needs the necessary privileges, see the sections below for more information about privileges. If you wish not to get the plan by default every time a...
A plan table name if you are using a table different than PLAN_TABLE A statement ID if you have set a statement ID with the EXPLAIN PLAN A format option that determines the level of detail: BASIC, SERIAL, and TYPICAL, ALL, Some examples of the use of DBMS_XPLAN to display PLAN_TA...
Briefly explain the purpose of the loop, or iteration, structure. Then provide an original example algorithm with the loop structure. Why is a bitmap index used in data warehousing? How does cloud storage work? Do you always need to get the largest amount of RAM possible? Why or why not...
What is the advantage of using parallel processing instead of serial processing? What are stdin, stdout, and stderr, and how would a programmer use them? Think about a real-life process or activity that exemplifies loose coupling, and explain it. Describe how the process or activi...
• Object Databases:These days OOP concepts have also been introduced indatabasesystems to develop a newDBMSnamed object databases. These databases store the data directly in the form of objects. However, these databases are not as popular as the traditional RDBMS. ...
<font>SELECT PLAN_TABLE_OUTPUT FROM TABLE(DBMS_XPLAN.DISPLAY());</font> Auto DOP The note structure displaying why Auto DOP did not work (with the exception noted above on IO Calibrate) is like this: Automatic degree of parallelism is disabled: <reason> ...
When SQL trace is enabled for a database session, the Oracle server process handling that session writes detailed information about all database calls and operations to a trace file. Special database events may be set in order to cause Oracle to write even more specific information—such as ...
SQL> exec DBMS_STATS.GATHER_TABLE_STATS('HR', 'EMPLOYEES', method_opt=>'FOR COLUMNS SIZE 254 JOB_ID'); With a histogram on JOB_ID in place the optimizer estimates the correct number of rows will be returned from the sales table as seen in Figure 10. Figure 10: Correct cardinality ...