AWS Solutions Architect – Associate Certification
Hi All, I am glad to announce that I have completed AWS Solutions Architect – Associate Level certification This is a completely new world with lots of opportunities to learn new things. Below is the...
View ArticleBook on Oracle 12c New features
A Book on Oracle 12c New features for administrators Hi All, It’s our pleasure to announce the availability of our first book – OCP 12c upgrade 1Z0-060 Exam Guide The book covers...
View ArticleAdaptive Cursor Sharing
Adaptive cursor sharing was introduced by Oracle in 11g release 1 as a way to generate best plan for a SQL in all situation. Prior to adaptive cursor sharing, optimizer used to generate a single plan...
View ArticleOracle 12c Learning Series: Automatic Table Recovery Using RMAN
Table recovery was possible in earlier release as well. Until previous release, if we wanted to recover a table, we had following options Database point in time recovery (DBPITR) Tablespace point in...
View ArticleMonitoring transaction recovery
Sometimes we end up in a situation where our long running transaction is not completing and we are also not sure how much further time it’s going to take. This happened with one of our DBA where they...
View ArticleOracle 12c Learning Series: In-database Archiving and Temporal Validity
One of the major challenge faced by an Oracle DBA is – how to effectively deal with historical data? Today, if we consider database tables for an enterprise, data in the table goes back several years...
View ArticleFixing SQL plans on ADG using SQL Profiles
With Active Dataguard setup, many of the read only applications runs on ADG and sometime the SQLs that are used by these applications runs into bad plans. ADG being a read only database, its not...
View ArticleUsing UDev to configure ASM disks
This is a small article on using UDev on RHEL 7. I have a virtual box with RHEL 7 and I am configuring ASM diskgroups. Before we configure ASM diskgroups, we need to have disks/partitions available at...
View ArticleOracle 12c Learning Series: Automatic Data Optimization – ADO
I am starting Oracle 12c learning series, where I am planning to publish multiple articles on Oracle 12c new features. I hope these articles will be helpful to DBAs aspiring for OCP 12c certification...
View ArticlePreviewing Backup Restore
Introduction: This is a short article on RMAN where we can check if our backups are really intact and can help us in critical situation when we have to restore and recover the database. We have a...
View ArticleLibrary Cache: Mutex X – Bug 20879889 – Fixed in 11.2.0.4
I recently encountered a bug related to MView log causing very high library cache: mutex x wait events. I will brief about the debugging steps I tried and fix for the same. Few things to note before I...
View ArticleMutex: What do we know ?
In my previous article on Latches, I mentioned various things related to latches including different types and their behavior. In this article I will describe similar things about mutexes. Mutex are...
View ArticleLatches: What do we know ?
Latches are low level serialization mechanism which protects memory areas inside SGA. They are light wait and less sophesticated than enqueues and can be acquired and released very quickly. Latch...
View ArticleBrief about Workload Management in Oracle RAC
This is a brief article about workload management in RAC. I tried to cover different components of workload management in RAC and how they are configured at client side or server side. I haven’t gone...
View ArticleHow many checkpoints in Oracle database ?
This Question came to my mind when I was discussing “direct path reads” with DBA candidates. I was surprised that many DBAs were not aware of object level checkpoint that happens while doing direct...
View ArticleCoverting MySQL database character set to UTF8
Recently I was engaged to convert the character set for few MySQL databases from latin1 to UTF8 collation utf8_general_ci. This article describes the approach taken for doing the same. First I will...
View ArticleCassandra 2.0 Architecture
In this article, I will cover various key structures that makes up Cassandra. We will also see what structure resides in memory and what resides on disk. In next article, I will give an overview of...
View ArticleAffect of object Statistics on SQL Execution statistics
This is a small article to demonstrate why correct statistics are important and how they affect execution statistics of same plan. In the past we learned that changing table statistics or index...
View ArticleTracing Single SQL in Oracle
Many times, while doing SQL tuning, we want to trace (event 10046) single SQL in database. Instead of going for module level tracing or session level using DBMS_MONITOR, we can simply use below alter...
View Articledirect path read behavior in Oracle 11.2
Prior to 11g, whenever optimizer goes for full table scan, Oracle used to show “db file scattered read” as wait event. But starting from 11g, a full table scan can show (depending on certain...
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