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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.

SQL Server 2019 availability group R/W connection redirection, routing mesh and load balancing

SQL Server 2019 availability group feature will provide secondary to primary replica read/write connection redirection. I wrote about it in a previous blog post here. It consists in redirecting client application connections to the primary replica regardless of the target server specified in the connections string. That’s pretty interesting in some scenarios as read scale-out or specific multi-subnet configurations where… 

ORA-01000 and agent13c

Recently I received errors messages from OEM13c saying too many cursors were opened in a database: instance_throughput:ORA-01000: maximum open cursors exceeded My database had currently this open_cursors value: SQL> show parameter open_cursors NAME TYPE VALUE ———————————— ———– —————————— open_cursors integer 300 I decided to increase its value to 800: SQL> alter system set open_cursors=800; System altered. But a few minutes… 

Microsoft Inspire Partner Event 2019 / Day 3

dbi services at Microsoft Inspire Conference Core Note Satya Nadella – Day 3 The day started with the Core Note from Satya Nadella. Being alone at the conference allowed me to find one of the very last well-located seat to have a nice view of the Event 😉. I never saw a key note from Satya and I must admit… 

Microsoft Inspire Partner Event 2019 / Day 2

dbi services at Microsoft Inspire Conference SQL Server 2019 is in “public preview” stage, live from Microsoft Inspire 2019 – Day 2 Anshul Rampal (SQL Server product marketing team) and Rony Chatterjee (SQL Server Core team / Product Manager) presented the new SQL Server 2019 features in a 20-minutes session. SQL Server is 25 years old! Its new version –… 

Microsoft Inspire Partner Event 2019 / Day 1

dbi services at Microsoft Inspire Conference Summary of my first participation – Day 1 After 20 years in the business of IT Infrastructure, time has come to open my mind 😉 and Microsoft Inspire is the perfect opportunity. It is a partner conference that has quite a different approach compared to other software editors I worked for (e.g. Oracle). Indeed,… 

Migrating your users from md5 to scram authentication in PostgreSQL

One of the new features in PostgreSQL 10 was the introduction of stronger password authentication based on SCRAM-SHA-256. How can you migrate your existing users that currently use md5 authentication to the new method without any interruption? Actually that is quite easy, as you will see in a few moments, but there is one important point to consider: Not every… 

Huawei Dorado 6000 V3 benchmark

I had the opportunity to test the new Dorada 6000 V3 All-Flash storage system. See what the all-new Dorado 6000 V3 All-Flash Storage system is capable as storage for your database system. Before you read This is a series of different blog posts: In the first blog post, I talk about “What you should measure on your database storage and… 

Storage performance benchmarking with FIO

Learn how to do storage performance benchmarks for your database system with the open source tool FIO. Before you read This is a series of different blog posts: In the first blog post, I talk about “What you should measure on your database storage and why”. The second blog post will talk about “How to do database storage performance benchmark… 

What you should measure on your database storage and why

How can you do a good capacity and performance management for your databases, when you do not know, what your storage system is capable of, and what you need? In this article, we are discussing a way to test a storage system from an Oracle database point of view. Before you read This is a series of different blog posts:… 

Converting columns from one data type to another in PostgreSQL

Usually you should use the data type that best fits the representation of your data in a relational database. But how many times did you see applications that store dates or numbers as text or dates as integers? This is not so uncommon as you might think and fixing that could be quite a challenge as you need to cast… 

Telling the PostgreSQL optimizer more about your functions

When you reference/call functions in PostgreSQL the optimizer does not really know much about the cost nor the amount of rows that a function returns. This is not really surprising as it is hard to predict what the functions is doing and how many rows will be returned for a given set of input parameters. What you might not know…