Oracle Multitenant: Impact of a Pluggable Database (PDB) Failure
Introduction Today I would be discussing the impact of a pluggable database failure (particularly media failure) on the other pluggable databases and the parent container database. In this article...
View ArticleOracle Database: Timezone mismatch between Local and Remote Connections
Today, I have come across an interesting issue. One of the application that I support, was complaining about timezone mismatch in the database between the local and remote connections. Basically, when...
View ArticleOracle Database 12c: You can acess the actual runtime query
While browsing through Oracle Docs, encountered with yet another new feature that Oracle has introduced in the 12c release. Starting from 12c, we can now get to know the actual query that is being...
View ArticleOracle Database: Finding Trace Event Codes to help in debugging
We often need to set different level of tracing for debugging database issues. However, it is not realistic for a DBA to remember the list of all the tracing event codes that can be set for debugging...
View ArticleOracle Database 12c: Move Datafile Online
Prior to Oracle Database 12c, moving a datafile was always a OFFLINE task. There were different approach to move a datafile. However, there was always a downtime associated with the datafile move...
View ArticleRMAN Block Media Recovery: Lets have a deeper look
As a DBA, we know there are situations where the database blocks get corrupted and we have different methods available to fix the corrupted blocks. In today’s article, I would be discussing the...
View ArticleDBVERIFY: Do we really need a USERID ?
DBVERIFY (dbv) is the Database Verification utility that can be used to perform a physical data structure integrity check. dbv can be used against ONLINE or OFFLINE datfiles as well as backup files....
View ArticleOracle RAC: GRID_HOME is occupied by crfclust.bdb
Recently, I have come across an issue in 11gR2 RAC, where the GI file system GRID_HOME was mostly consumed by a single file called crfclust.bdb This single file itself was about 30 GB of size....
View ArticleScript to Introduce Manual Block Corruption in Oracle Database
A block corruption in a database is a rare and unwanted situation. However, for testing corruption recovery scenario a DBA needs to have a actual corruption at the block level. I have written a wrapper...
View ArticleOracle Database 12c (12.1): Datapump Export and Pluggable databases
As a DBA, we all are familiar with the Datapump (EXPDP/IMPDP) utility for exporting and importing database objects in and across databases. However, with the introduction of Oracle Database 12c and...
View ArticleOracle database 12c (12.1) : Password file mystery
I was trying to implement password file authentication for my Oracle 12c database. However, seems like Oracle database was not recognizing the password file at all. As shown below, I had created a...
View ArticleThe unusual case of recreating Oracle (central) Inventory
It could be a rare situation, where your Oracle RDBMS inventory is corrupted or lost and you don’t have a copy of the inventory to restore it. As a standard process, we usually keep backup of the...
View ArticleInterpreting Free Space in ASM Diskgroup
The Perception: I had the perception that the FREE_MB returned from querying the V$ASM_DISKGROUP is the actual amount of free space available under a particular ASM diskgroup. Till date, I was using...
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Why Datapump Import (IMPDP) is not ignoring Index Statistics?
In today’s article, I would discuss a scenario where I was trying to speed up a Datapump import job by excluding the collection of table and index statistics during the import process. I was using...
View ArticleONLINE statistics collection in Oracle Database 12c : Part 1
In my last article “Why Datapump Import (IMPDP) is not ignoring Index Statistics?”, we have seen how the database feature of gathering ONLINE statistics for INDEX prevented IMPDP to exclude the...
View ArticleCreating an index?? Do you know what’s gonna be its size ??
We, as a DBA often create indexes in Oracle Databases. We come to know about the Index size once it is being actually created. However, did you know that there is a simplest way to determine the size...
View ArticleOracle: The myth, reality and the curious case of count(*)
Today’s article is all about the popular count(*) method of checking cardinality and is dedicated to novice Oracle DBAs like me. We use count(*) almost everyday at some point to check the number of...
View ArticleCreating Oracle Database Link with EZCONNECT (Easy Connect)
EZCONNECT (Easy Connect) is there for a long time. However, learned something new today about it; that it can be used to create database links. Hence, thought a post on it would be helpful for others...
View ArticleMigrate Oracle database using Transportable Tablespace
I have been working with Oracle Databases since last 6 years. However, surprisingly I never had the opportunity to use the Transportable Tablespace option of migrating data from one Oracle database to...
View ArticleArchive dest is exhausted? Well, there is a alternative : Oracle
Issues that we face Ideally in a production Oracle database, we enable the archivelog mode for the ONLINE redo logs to be archived during log switches. We must also periodically backup and clean up the...
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