Infrastructure at your Service

Category Archives: Database Administration & Monitoring

David Barbarin

Windows Failover Cluster : Introduction to paxos tag

By | Database Administration & Monitoring, Operation systems | No Comments

A couple of days ago, I was in charge to install a new SQL Server AlwaysOn and availability group with one of my colleague Nathan Courtine. During the installation, we talked about testing a disaster recovery scenario where we have to restart the Windows Failover cluster in forced quorum mode. Restarting a WSFC in such mode implies some internal stuff especially for the cluster database data synchronization between nodes. The WSFC uses internally the paxos…

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Oracle Team

Extended clusters and asm_preferred_read_failure_groups

By | Database Administration & Monitoring | One Comment

By Franck Pachot . When you have 2 sites that are not too far you can build an extended cluster. You have one node on each site. And you can also use ASM normal redundancy to store data on each site (each diskgroup has a failure group for each site). Writes are multiplexed, so the latency between the two sites increases the write time. By default, reads can be done from one or the other…

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Oracle Team

DB_FLASHBACK_RETENTION_TARGET may hang your database

By | Database Administration & Monitoring | 3 Comments

By Franck Pachot . DB_FLASHBACK_RETENTION_TARGET is set to keep enough flashback logs to be able to flashback database within the specified retention window. But it’s supposed to be a target only, meaning that on space pressure some files can be deleted. But be careful, there are cases where they are not and then the database hangs until you set a lower retention.

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Oracle Team

SYS password on Oracle Cloud Service managed database

By | Database Administration & Monitoring | 2 Comments

By Franck Pachot . When you create a DBaaS on the Oracle Cloud services you have to provide an administration password in the database configuration form. You do not need a password to connect to the VM. You use SSH key for it: on creation you provide the public key that will allow you to connect as the oracle user or the opc user (which can ‘sudo su’). But for the database you need to…

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Daniel Westermann

A near zero downtime, near zero impact major release upgrade using Oracle GoldenGate

By | Database Administration & Monitoring | No Comments

In this post I’d like to share what we did for a customer who had the following requirements: Use Oracle GoldenGate Upgrade an Oracle 10.2.0.4 database running on Solaris 10 SPARC to Oracle 12.1.0.2 running on Exadata Keep the downtime as small as possible Minimize the impact on the production database as much as possible I will not describe why GoldenGate was the product of choice nor will I describe how we verified that Golgengate…

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Stéphane Haby

SQL Server 2016: new tools management strategy

By | Business Intelligence, Database Administration & Monitoring, Database management | No Comments

A lot of customer’s feedbacks are about difficulties to find easily SQL Server tools. Now, it is easier… A unified web page for SQL Server Tools The first good news is that Microsoft unified and gathered these tools for SQL Server on a single web page: https://msdn.microsoft.com/en-us/library/mt238365.aspx As DBA, this page is absolutely to be marked in your browser. The two major tools, SQL Server Management Studio (SSMS) and SQL Server Data Tool (SSDT), are…

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Daniel Westermann

A look at PostgreSQL 9.6 – psql gexec

By | Database Administration & Monitoring | No Comments

This little, but powerful, enhancement that it made it in PostgreSQL 9.6 is probably nothing a application can benefit of. But it can be huge saving for people doing maintenance operations on a PostgreSQL instance. It is the addition of the “gexec” meta command to psql. If you want to read where this comes from and how it evolved you can read the mail thread on hackers.

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