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Database

Everything our consultants learn while running databases for customers: Oracle, PostgreSQL, SQL Server, MySQL, MariaDB, MongoDB and Delphix. Expect hands-on posts about installation, day-to-day administration, backup and recovery, performance tuning, replication and upgrades.

ROLLBACK TO SAVEPOINT;

By Franck Pachot . I love databases and, rather than trying to compare and rank them, I like to understand their difference. Sometimes, you make a mistake and encounter an error. Let’s take the following example: create table DEMO (n int); begin transaction; insert into DEMO values (0); select n “after insert” from DEMO; update DEMO set n=1/n; select n… 

EDB PEM – Monitor your Postgres cluster

In my last post, I explained, how to setup a HA Postgres Cluster using EDB Postgres Advanced Server and Failover Manager. As a next step, we want to install the EDB Postgres Enterprise Manager to monitor what we setup before. Introduction There are, of course, many good tools to monitor your Postgres Cluster, but in case you run your Postgres… 

Setup a two node Postgres HA Cluster using EDB Advanced Server and EFM

Some time ago I had a customer looking for a two node PostgreSQL Master/Replica solution. As we need Oracle compatibility in a later step, we decided to go with the EnterpriseDB tools. This article should give you an introduction on how to setup the environment. Prerequisites There are just some few things, that you need to prepare. You need (at… 

SQL Server Tips: Path of the default trace file is null

In addition of my precedent blog about this subject “SQL Server Tips: Default trace enabled but no file is active…”, I add a new case where the default path of the trace file was empty. The first step was to verify if the default trace is enabled with the command: SELECT * FROM sys.configurations WHERE name=’default trace enable’ It is… 

Adding PostgreSQL extensions without being super user?

Usually, when you need to install a PostgreSQL extension you do this as superuser (or at least I am doing it like this). The downside of that is, of course, that a super user must be available once a new extension is required or that all the extensions are installed by default (e.g. in template1). Recently the question popped up… 

Make Oracle database simple again!

Introduction Let’s have a look at how to make Oracle database as simple as it was before. Oracle database is a great piece of software, yes it’s quite expensive, but it’s still the reference and most of the companies can find a configuration that fits their needs according to a budget. Another complain about Oracle is the complexity: nothing is… 

One day training @ Microsoft Azure Cloud Workshop

Today, with my colleague Christophe, we follow the Microsoft Azure Training Day: Data and Analytics @ Microsoft Zürich (Wallisellen to be exact). After a presentation of SQL Server 2019, we begin with the First Lab about SQL Server 2019 and new features and we going through intelligent query processing, Data Discovery and Classification for personally identifiable information (PII) and General… 

SQL Server Tips: Orphan database user but not so orphan…

Beginning of this year, it is good to clean up orphan users in SQL Server databases. Even if this practice must be done regularly throughout the year of course. 😉 During my cleaning day, a new case appears that I never had before and enjoy to share it with you. To find orphan database-users, I use this query: SELECT *FROM… 

PostgreSQL 13: parallel vacuum for indexes

Because of its implementation of MVCC PostgreSQL needs a way to cleanup old/dead rows and this is the responsibility of vacuum. Up to PostgreSQL 12 this is done table per table and index per index. There are a lot of parameters to fine tune auto vacuum but none of those allowed vacuum to run in parallel against a relation. The… 

Dbvisit 9: Adding datafiles and or tempfiles

By Mouhamadou Diaw One question I was asking is if the standby_file_management parameter is relevant in a Dbvisit environment with Oracle Standard Edition. I did some tests and I show here what I did. We suppose that the Dbvisit is already set and that the replication is fine 1 2 3 4 5 6 7 8 9 10 11 12… 

Deploying your own PostgreSQL image on Nutanix Era

Some days ago we had a very good training on Nutanix. Nutanix is a Hyper-converged infrastructure and that means that all is software driven and the system can be deployed on many hardware configurations. I will not go into the details of the system itself but rather look at one component/module which is called Era. Era promises to simplify database…