Infrastructure at your Service

Category Archives: Database Administration & Monitoring

Daniel Westermann

Be careful when putting the Oracle ADR on xfs, or better 4K sector format drives

By | Database Administration & Monitoring | No Comments

Today, after we did a fresh setup of a Grid Infrastructure cluster (12.1.0.2.170814) we faced two issues reported in the alert.log of the ASM instances (in fact you would see the same for the alert logs of any instance in that configuration but we did not had any other instance up and running at that time): This: ORA-00700: soft internal error, arguments: [dbgrfrbf_1], [/disk00/app/grid/diag/asm/+asm/+ASM2/metadata/INC_METER_SUMMARY.ams], [0], [4], [], [], [], [], [], [], [], [] ORA-27072:…

 
Read More
Franck Pachot

Bequeath connect to PDB: set container in logon trigger?

By | Database Administration & Monitoring, Oracle | No Comments

There are little changes when you go to multitenant architecture and one of them is that you must connect with a service name. You cannot connect directly to a PDB with a beaqueath (aka local) connection. This post is about a workaround you may have in mind: create a common user and set a logon trigger to ‘set container’. I do not recommend it and you should really connect with a service. Here is an…

 
Read More
Franck Pachot

Get trace file from server to client

By | Database Administration & Monitoring | No Comments

The old way to get a user dump trace file, for sql_trace (10046), Optimizer compilation trace (10053), lock trace (10704), Optimizer execution trace (10507),… is to go to the server trace directory. But if you don’t have access to the server (as in the ☁) the modern (12cR2) way is to select from V$DIAG_TRACE_FILE_CONTENTS. Before everybody is on 12.2 I’m sharing here a sqlplus script that I use for a long time to get the…

 
Read More
Mouhamadou Diaw

Replicating specific tables in PostgreSQL 10 Beta with mimeo

By | Database Administration & Monitoring | No Comments

In this blog I am going to test the extension mimeo with PostgreSQL 10 beta. Mimeo is a replication extension for copying specific tables in one of several specialized ways from any number of source databases to a destination database where mimeo is installed. In our configuration we are going to replicate data on a same server but between 2 clusters running on different ports. But it’s same for different servers. The pg_hba.conf should be…

 
Read More
William Sescu

OUD 11.1.2.3 – How to recover a lost entry in a replicated OUD environment

By | Database Administration & Monitoring | No Comments

By accident, it could happen that someone dropped an OUD entry in your replicated environment and of course, the entry is deleted on all replicas as well. And besides that, you got no logical ldif export of your OUD. Not a good situation, but if you have a done regular backups, there is a way out without resetting the whole OUD environment to an old timestamp. The idea is, to create a second empty OUD…

 
Read More
David Barbarin

SQL Server on Linux: Introduction to DBFS experimental tool

By | Database Administration & Monitoring, SQL Server | 2 Comments

A couple of months ago, Microsoft announced two additional command line tools for SQL Server that are mssql-scripter and DBFS. The latter has drawn my attention because it exposes live data from SQL Server DMVs as virtual files in a virtual directory on Linux operating system. Microsoft has probably taken another positive step in the SQL Server’s adoption on Linux. Indeed, in a Linux world, we may get Kernel’s performance and configuration data either directly…

 
Read More
William Sescu

MariaDB – How to migrate quickly MySQL to MariaDB over different hosts with mydumper/myloader and ncat

By | Database Administration & Monitoring | No Comments

A lot of possibilities exist to migrate MySQL to MariaDB. In this blog I would like to show a scenario where I migrate MySQL 5.7.19 with a lot of databases to MariaDB 10.2.7, which is on a different host. The tools I am using are mydumper/myloader and ncat. Please be aware that mydumper does not come out of the box. It has to be installed beforehand, like explained in my previous blog: https://blog.dbi-services.com/mariadb-speed-up-your-logical-mariadb-backups-with-mydumper/ The same…

 
Read More
William Sescu

MariaDB – Speed up your logical MariaDB backups with mydumper

By | Database Administration & Monitoring | No Comments

Per default, MariaDB is shipped with a utility called mysqldump for logical backups. For more information, please take a look at the following link. https://mariadb.com/kb/en/mariadb/mysqldump/ The mysqldump has advantages, e.g. it is easy to use and it is shipped with the standard MariaDB installation.  So, no additional installation is needed. However, it has also some disadvantages. E.g. it is single threaded and it is  writing to one big file, even with the latest version which…

 
Read More
Daniel Westermann

Developer GUI tools for PostgreSQL

By | Database Administration & Monitoring | No Comments

There was a recent thread on the PostgreSQL general mailing list asking for GUI tools for PostgreSQL. This is question we get asked often at customers so I though it might be good idea to summarize some of them in a blog post. When you know other tools than the ones listed here which look promising, let me know so I can add them. There is a list of tools in the PostgreSQL Wiki as…

 
Read More
Daniel Westermann

A wonderful PostgreSQL feature: default privileges

By | Database Administration & Monitoring | No Comments

Imagine this scenario (which is not so uncommon): You have a lot of objects in a user schema and you want to grant another user access to that tables. You can easily do this by granting select on the tables to the user and you’re fine. Really? Maybe now, but what will happen when the user which owns the objects creates new objects? Then you will need to grant those to the second user as…

 
Read More