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

How ASM Failure Groups and CSS provides high availability

Last updated on August 27th, 2016 at 04:56 amASM Failure Groups and Redundancy 1)For systems that do not use external redundancy, ASM provides its own internal redundancy mechanism and additional high availability by way of failure groups 2) It is also collection of disk and is considered as subset of disk group. 3)Disk group redundancy can be Normal – It is Two-way mirroring requiring at … Continue reading How ASM Failure Groups and CSS provides high availability »

How to create Oracle view

Last updated on November 29th, 2016 at 10:52 amWhat is Oracle  view? -A view is a representation of data from one or more tables or views. -A view is a named and validated SQL query which is stored in the Oracle data dictionary. –Views do not contain any data – it is just a stored query in the database that can be executed when called. All the data it … Continue reading How to create Oracle view »

ASM : Lesson 3 ASM Diskgroups

ASM DiskgroupsOnce the disks are discovered, a diskgroup can be created that will encapsulate one or more of these disks. It is collection of disks that can managed as logical unit.A diskgroup, which is the highest-level data structure in ASM, is comparable to a LVM’s volume group. The creation of a diskgroup involves the validation of the disks to be added. These disks must have … Continue reading ASM : Lesson 3 ASM Diskgroups »

ASM : Lesson -2 How to prepare the ASM disks

Last updated on August 19th, 2016 at 06:11 pmASM Disks The first task in building the ASM infrastructure is to discover and associate (adding) ASM disks under ASM management. This step is best done with the coordination of Storage and Systems administrators. The Storage administrator will identify a set of disks and create the appropriate LUNs from the storage array and finally present them to … Continue reading ASM : Lesson -2 How to prepare the ASM disks »

How to find session details in Oracle database

Many times DBA need to look at the session details for analysis. The details includes sql_id, stats ,locking ,wait events.Here I am giving few queries on How to find session details in Oracle database   To find session Information col sid format 9999 col pid format 9999 col serial# format 99999 col process format a8 heading “unixPID” col spid format a8 heading “unixPID” col username format … Continue reading How to find session details in Oracle database »

Oracle Wait Events That Everyone Should Know part-II

Last updated on July 28th, 2016 at 05:58 pmThis is part II in series of Oracle Wait Events That Everyone Should Know control file sequential read The process is waiting for blocks to be read from a control file. This happens generally making a backup of the controlfiles sharing information (between instances) from the controlfile reading other blocks from the controlfiles reading the header block … Continue reading Oracle Wait Events That Everyone Should Know part-II »

Oracle ASH(Active Session History) Useful queries

Last updated on August 27th, 2016 at 05:07 amActive Session History (ASH) was introduced in Oracle 10g. It samples the activity of each active database session every second. The data is held in a buffer in memory in the database.The design goal is to keep about an hour (your mileage will vary). If a session is not active it will not be sampled. The in-memory … Continue reading Oracle ASH(Active Session History) Useful queries »

Oracle database tutorial:RAC

oracle RAC

In this section of Oracle Database Tutorial:RAC we will talk about RAC(Real application clusters) CONCEPTS AND FUNCTIONAL OVERVIEW RAC is the ability to have two or more instances connect to the same database. These instances reside on separate servers, thereby allowing each instance to make full use of the processing ability of each server. As these instances are accessing the same database they need to … Continue reading Oracle database tutorial:RAC »

100 Basics oracle dba questions and answers

Last updated on November 6th, 2016 at 09:13 amI am presenting here the 100 Basics oracle dba questions and answers. I hope you like it Question 1 You issue the following statement from SQL*Plus: startup mount. Where does Oracle obtain values for starting the instance? A. From the default settings for the tablespace B. From your init.ora file or spfile C. From Oracle default values … Continue reading 100 Basics oracle dba questions and answers »

Oracle Indexes and types of indexes in oracle with example

types of indexes in oracle with example

Last updated on September 17th, 2016 at 06:37 pmWe will be discussing Oracle indexes/types of indexes in oracle with example  in this post. I will through light on all the option on how to create index in oracle.I would also be discussing  how to check index size in oracle. I hope you will like this post. I will be looking forward for  feedback on this … Continue reading Oracle Indexes and types of indexes in oracle with example »

Top Useful scripts for Oracle Database for Monitoring purpose

Last updated on August 19th, 2016 at 06:40 pmWe often need to monitor the database session for performance reason.Here are Top Useful Scripts  for Oracle  Database for monitoring purpose Script to find the sid of the session you are logged in as select distinct(sid) from v$mystat;   Script to see all active session select username,osuser,sid,serial#, program,sql_hash_value,module from v$session where username is not null and status … Continue reading Top Useful scripts for Oracle Database for Monitoring purpose »

how to create table in oracle

Last updated on April 22nd, 2017 at 09:15 amThis article talks how to create table in Oracle. Oracle is the most RDBMS used everywhere for system Table of content What is Oracle database Table Creation of table in oracle SYNTAX FOR ORACLE CREATE TABLE statement Privilege required to create table Other characteristics associated with table How to modify the oracle database table Creation of table … Continue reading how to create table in oracle »