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Alejandro Vargas' Blog

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Moving Databases from ASM to ZFS on Exadata

Exadata is the best database machine available to run every Oracle database workload. But many times, within Exadata proliferate a large number of test and...

Exadata is the best database machine available to run every Oracle database workload. But many times, within Exadata proliferate a large number of test and development databases, that do not require the special features available with Exadata, the Storage cells and ASM. One possibility is to move these large and less demanding databases to a storage layer that is also less expensive, ZFS is a perfect match, can be connected to Exadata, available to RAC databases, and...

How to replace old Exadata storage cells with the new X7-2 storage cells, without downtime

Lately I had to help various customers to replace their old storage cells with the new X7-2 ones. There are huge benefits in doing this, the X7 has 25.5TB of...

Lately I had to help various customers to replace their old storage cells with the new X7-2 ones. There are huge benefits in doing this, the X7 has 25.5TB of flash, 12 x 10TB disks and 192 GB of DDR4 Memory.                       The question my customers asked the most was: Can we do the migration from our old storage to the new X7 without downtime and without risk? The answer was: YES! For doing this I've prepared and implemented a procedure that cover step by step how to...

Exadata Parameter _AUTO_MANAGE_EXADATA_DISKS

Exadata auto disk management is controlled by the parameter _AUTO_MANAGE_EXADATA_DISKS. The default value for this parameter is TRUE.When...

Exadata auto disk management is controlled by the parameter _AUTO_MANAGE_EXADATA_DISKS. The default value for this parameter is TRUE.When _AUTO_MANAGE_EXADATA_DISKS is enabled, Exadata automate the following disk operations:If a griddisk becomes unavailable/available, ASM will OFFLINE/ONLINE it.If a physicaldisk fails or its status change to predictive failure, for all griddisks built on it ASM will DROP FORCE the failed ones and DROP the ones with predictive failures.If a...

Data Guard for Manual Failover, Step by Step

about:blankIn this post I'm showing the steps used to implement a manual failover scenario. My customer did not want to enable fast start failover but to leave...

about:blankIn this post I'm showing the steps used to implement a manual failover scenario. My customer did not want to enable fast start failover but to leave the decision to failover in case of a major crash to the management team.In the example I'm providing here I did configure flashback database with a one hour retention time so that the OS team can have this time to solve any issues on the primary, if they succeed to solve the problem in this time then the old primary...

Impact of Truncate or Drop Table When Flashback Database is Enabled

Recently I was working on a VLDB on the implementation of a disaster recovery environment configured with data guard physical standby and fast start...

Recently I was working on a VLDB on the implementation of a disaster recovery environment configured with data guard physical standby and fast start failover.One of the questions that come up was about the overhead of truncating and dropping tables. There are daily jobs on the database that truncate extremely large partitions, and as note 565535.1 explain, we knew there is an overhead for these operations.But the information on the note was not clear enough, with the...

Oracle Database 11g Underground Advice for Database Administrators, by April C. Sims

Recently I have received a request to review the book "Oracle Database 11g Underground Advice for Database Administrators" by April C. SimsI was happy to have...

Recently I have received a request to review the book "Oracle Database 11g Underground Advice for Database Administrators" by April C. SimsI was happy to have the opportunity to know some details about the author, she is an active contributor to the Oracle DBA community, through her blog "Oracle High Availability" .The book is a serious and interesting work, I think it provides a good study and reference guide for DBA's that want to understand and implement highly available...

How To Manually Open The Standby Database When The Primary Is Lost

This post explains how to manually convert the Physical Standby into the Primary database, when the Primary is not available anymore. The procedure is very...

This post explains how to manually convert the Physical Standby into the Primary database, when the Primary is not available anymore. The procedure is very simple, still is convenient to have it available so that in the stress situation of a production crash we can implement it without problems.Personally I prefer to work harder at the implementation stage and build an infrastructure strong enough to be configured using DG Broker, Observer and Fast Start Failover.Step by Step...