Category Archives: Oracle Database

An Oracle database is a collection of data treated as a unit. The purpose of a database is to store and retrieve related information. A database server is the key to solving the problems of information management.Many companies has implemented their data in Oracle. Most of them are mission critical. So Oracle database concept need to be very clear to manage these mission critical things. At the same time Oracle database needs to deliver high performance also. A database server also prevents unauthorized access and provides efficient solutions for failure recovery.

Below section I have tried to present all the important features in Oracle Database management

Optimizer Mode

Last updated on November 23rd, 2015 at 03:34 pmSet in the Init.Ora Can be changed via ALTER SESSION CHOOSE, FIRST_ROWS, ALL_ROWS = cost based optimization RULE = rule based optimization Optimizer_Mode = Rule Original optimizer developed by prior to 7 Applications prior to 11i must run as RULE to be supported Documentation has warned of its removal uses strict rules for determining the execution path … Continue reading Optimizer Mode »

What is Oracle Database Lite 10g

Last updated on September 15th, 2016 at 05:30 amOracle Database Lite 10g extends the power of grid computing to a mobile workforce with a complete, integrated, secure database for building, deploying, and managing mobile applications for a broad range of mobile devices. Oracle Database Lite 10g enables persistent access to critical information and applications without requiring continuous connectivity to back-end enterprise systems. As a result, … Continue reading What is Oracle Database Lite 10g »

Oracle DBA: Hanganalyze and system state dump

Last updated on August 31st, 2016 at 01:11 pmMany times Oracle database get hangs due to locks or latching issue and Nobody can login to the system. It becomes critical and  And Usually we do shutdown abort to immediately resolve the issue. But  it is good to take system state dump/hanganalyze  at 1 min interval to analyze the locking or latching  issue afterwards before doing … Continue reading Oracle DBA: Hanganalyze and system state dump »

how to perform relink in Oracle

Last updated on August 31st, 2016 at 01:30 pmSometimes Oracle components may start giving strange issues like coredump  or the Operating system is patched, In these cases it is always recommended to try oracle relink to resolve the issues.A Oracle relink is also necessary whenever you install a new release or a patchset or when there is a patch or upgrade to the OS environment. Oracle … Continue reading how to perform relink in Oracle »

Oracle DBA: How to schedule jobs in Oracle Database

Last updated on August 31st, 2016 at 05:09 pmWe often wants to run pre-defined jobs at different schedule. Oracle database provides dba_jobs/dbms_scheduler (Oracle Database job scheduler) for the scheduling of pre-defined jobs. Information about DBA_JOBS ( Till 9i) Query to see the jobs running through dba_jobs select /*+ rule */ * from dba_jobs_running; or select /*+ ordered */ * from dba_jobs_running; Common Reason why jobs don’t execute … Continue reading Oracle DBA: How to schedule jobs in Oracle Database »

11g Alert log new features

Last updated on November 28th, 2015 at 11:58 am11g Alert log new features Beginning with Release 11g of Oracle Database, the alert log is written as both an XML-formatted file and as a text file, as in earlier releases.Both these log files are stored inside the ADR home.The ADR root directory is known as ADR BASE.The Automatic Diagnostic Repository (ADR) is a directory structure that … Continue reading 11g Alert log new features »

How to recreate redo log files

Last updated on September 15th, 2016 at 05:30 amWe often get situation where we need to increase the size of the redo log files as log switches are very frequent.Increasing the redo log files sizes decreases the log switches and  improves the performance of the database.There is no resize command for redo log files, it has to be recreated inorder to increase or decrease the … Continue reading How to recreate redo log files »

Top 5 ASM queries every DBA should know

Last updated on August 24th, 2016 at 06:48 pmASM is being used as storage environment in various organization.Here are Top 5 ASM queries every DBA  should know QUERY TO FIND THE FILES IN USE BY AN ASM INSTANCE col full_path format a50 col full_alias_path format a50 SELECT concat(‘+’||gname, sys_connect_by_path(aname, ‘/’)) full_alias_path FROM (SELECT gname, a.parent_index pindex, aname, a.reference_index rindex FROM v$asm_alias a, v$asm_diskgroup g … Continue reading Top 5 ASM queries every DBA should know »

Oracle DBA:RMAN basetables

Last updated on August 31st, 2016 at 05:12 pmRMAN is a powerful tool for taking backup .It maintains all the backup related informations oin Rman basetables in Rman catalog.We are listing all  tables and views are which  are vgenerated in the catalog database. Use the DESCRIBE command for each table or view to display column information.We have given some explanation for each table so that … Continue reading Oracle DBA:RMAN basetables »

Oracle Advanced Queuing

Last updated on November 23rd, 2015 at 01:28 pmOracle Advanced Queuing provides message queuing as an integrated part of the Oracle Server, thereby creating a message-enabled database. Oracle uses the following components to deliver AQ fuctionality: Message A message is the smallest unit of information inserted into and retrieved from a queue. It contains user data (payload) in the form of an object type, and … Continue reading Oracle Advanced Queuing »

Oracle Parallel Query Option

Last updated on September 14th, 2016 at 09:19 pmWhat Parallel Query Option can perform 1.To speed up access to data by using multiple processes 2.To maximise machine resource usage in query processing 3.To reduce elapsed time by increasing resource usage Operations That Can Run with Parallel Query Option 1.Parallel 2. Full table scans  or table move 3.Fast full index scans 4.Create index or rebuild index 5.Create table … Continue reading Oracle Parallel Query Option »