Search This Blog

Oracle DBA (12c/19c) Articles and Scripts

This blog is intended to share my knowledge on Oracle various scripts that I use as an Oracle DBA

Oracle DBA Checklist

Get link
Facebook
X
Pinterest
Email
Other Apps

- November 06, 2021

Get link
Facebook
X
Pinterest
Email
Other Apps

Comments

Register Archive log file manually in standby Database

- December 30, 2020

Some time, the archive logs are not shipping to standby location due to network issue. There may be several archive logs are waiting in standby location for one archive log file. For instance, Archive log sequence # 100 is not shipped to standby location. But other archive logs(sequence#101 to sequence#200) were shipped to standby and it is waiting to ship the sequence# 100. In this scenario, DBA can copy the archive log file and register manually. Once manually registered, the sequence#101 to sequence#200 will apply automatically on standby database. Step 1 Let us assume, the archive log file devdb12_1_283_801988635.arc is not shipped to standby due to some reason. Copy the archive log file devdb12_1_283_801988635.arc manually from primary to standby archive destination location. Step 2 Run the below command in standby database. ALTER DATABASE REGISTER LOGFILE '/dbArch/oradata/devdb12/ devdb12_1_283_801988635.arc'; Step 3 Verify th...

Step by Step: How to troubleshoot a slow running query in Oracle

- September 17, 2019

This is a day to day task of a DBA. Someone from application team comes to our desk and simply says a query is running slow. We may question him on many things but ultimately a DBA has to tune the query at the end. This is also very popular and known question for the DBA's who are attending interviews. This question is simply asked again and again. I have also been asked this question multiple times. After a pause, interviewer simply asks...so suppose a user comes and reports that his query is running slow, what will be your approach to tune this. There is no absolute or concrete answer to this question because there might be multiple way to tune a slow running query. Everyone can have a different approach. So here is my approach: Very first thing we have to find which type of query is running slow. Whether it is SELECT query of DML statements(insert, update, delete and merge). So first we will see how to tune a SELECT query Step 1 – Find the SQL_ID of the ...

OCR & OLR in RAC

- April 28, 2020

OCR (Oracle Cluster Registry) & OLR (Oracle Local Registry) In this section, I am going to cover the details about OCR (Oracle Cluster Registry) and OLR (Oracle Local Registry). Let's go into the topic!!! OCR (Oracle Cluster Registry) OCR will have all the cluster information. If the OCR is loss, the entire cluster will be affected. OCR is the central repository which stores the metadata, configuration, status of the clusterware resources.OCR is used to maintain application resources and availability.It also stores configuration information for CRS daemons and clusterware managed applications. Below are the information stored in the OCR. Node membership information ex: which nodes are the part of the cluster Software active version Server pools Status/Configuration for the cluster resources such as RAC databases, listeners, instances and services ASM instance and disk groups CRS application resource profiles such as VIP addresses etc.. Database services characteri...