AWR report analysis in depth-part 2

AWR report analysis in depth-part 2   This document is continuation of AWR report analysis in depth step by step which will provide you an idea to understand AWR report more quickly. Please refer to first part:- AWR report analysis in depth-part 1 H.SQL Ordered by Elapsed Time in AWR REPORT For A:- For B:-Continue reading AWR report analysis in depth-part 2

AWR report analysis in depth-part 1

1.Let me  create a test case : I will take different OS statistics and run time statistics to compare with AWR report generated after execution. Case A.About test case in lower CPU:- I will create a table first create table t (id number, sometext varchar2(50),my_date date) tablespace data; Now I will create a simple procedureContinue reading AWR report analysis in depth-part 1

Comparison between exadata and non-exadata executions test case

First we need to load data SQL> alter session set tracefile_identifier=’ABC’; Session altered. Elapsed: 00:00:00.01 SQL> alter system set events ‘10046 trace name context forever, level 12′; System altered. Elapsed: 00:00:00.18 SQL> create table t1(c1 number,c2 char(2000)); Table created. Elapsed: 00:00:00.03 SQL> set autotrace on; SQL> set autotrace traceonly; SQL> insert into t1 select rownum,’A’Continue reading Comparison between exadata and non-exadata executions test case

Logical IO vs Physical IO vs Consistent gets oracle

Logical IO vs Physical IO vs Consistent gets I have created 1 GB table T1.   Let me check how many blocks are there in the table after I have analyzed it.   SQL> select BLOCKS from user_tables where table_name=’T1′;    BLOCKS ———-    139153   Autotrace report Let me clean buffer cache and check the autoContinue reading Logical IO vs Physical IO vs Consistent gets oracle

Backup and recovery Interview questions

Sarat 1) What are pre-checks you do before doing point in time recovery? 2) There is no previous level zero backup available, Can we take a Level 1 backup? 3) My database have 500+ datafiles, In that I lost 89 files. How you will identify which files to recover? 4) Can you explain what areContinue reading Backup and recovery Interview questions

RMAN interview questions

Heman Sahi 1. Your RMAN backup triggered, you deleted snapshot controlfile at backend, what will happen to your running backup ? 2. what happens internally when we issue ‘ RESYNC CATELOG’ for recovery catelog ? 3. You enabled Block change tracking and then immediately performed level 1 backup, will BCT be used ? 4. YourContinue reading RMAN interview questions

Oracle 12c gather statistics oracle deep dive

I referred some reference from my favorite Tim Hall blog (ORACLE_BASE) A.Basic of optimizer statistics: – The optimizer cost model relies on statistics collected about the objects involved in a query, and the database and host where the query runs. Statistics are critical to the optimizer’s ability to pick the best execution plan for aContinue reading Oracle 12c gather statistics oracle deep dive

Redo,Undo,Control file interview questions

Thanks Akhil Mohan. Debasis Maity: 1.Why controlfile and redolog file multiplexed? Control file : A control file is a small binary file that records the physical structure of the database and includes: The database name. Names and locations of associated datafiles and online redo log files. The timestamp of the database creation. The current logContinue reading Redo,Undo,Control file interview questions