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Pronouncing Database Terms

It is the business of educated people to speak so that no-one may be able to tell in what county their childhood was passed. -- A. Burrell, A Handbook for Teachers in Public Elementary School, 1891

The terms that reveal where a person (mis)spent a DBMS-related childhood are "char", "data", "GIF", "gigabyte", "GUI", "JSON", "query", "schema", "tuple", "_", "`", and "«".

CHAR

(1) Like "Care" because it's short for "Character" (so hard C and most folks say "Character" that way)?
(2) Like "Car" because it's short for "Character" (so hard C and a few folks in the British Isles say it that way and perhaps all other English words ending in consonant + "ar" are pronounced that way)?
(3) Like "Char" (the English word for a type of trout)?
C/C++ programmers say (3), for example Bjarne Stroustrup of C++ fame says that's …

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Galera Cache (gcache) is finally recoverable on restart

This post describes how to recover Galera Cache (or gcache) on restart.

Recently Codership introduced (with Galera 3.19) a very important and long awaited feature. Now users can recover Galera cache on restart.

Need

If you gracefully shutdown cluster nodes one after another, with some lag time between nodes, then the last node to shutdown holds the latest data. Next time you restart the cluster, the last node shutdown will be the first one to boot. Any followup nodes that join the cluster after the first node will demand an SST.

Why SST, when these nodes already have data and only few write-sets are missing? The DONOR node caches missing write-sets in Galera cache, but on restart this cache is wiped clean and restarted fresh. So the DONOR node …

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Using the InnoDB Buffer Pool Pre-Load Feature in MySQL 5.7

In this blog post, I’ll discuss how to use the InnoDB buffer pool pre-load feature in MySQL 5.7

Starting MySQL 5.6, you can configure MySQL to save the contents of your InnoDB buffer pool and load it on startup. Starting in MySQL 5.7, this is the default behavior. Without any special effort, MySQL saves and restores a portion of buffer pool in the default configuration. We made a similar feature available in Percona Server 5.5 – so the concept has been around for quite a while.

Frankly, time has reduced the need for this feature. Five years ago, we would typically store databases on spinning disks. These disks often took quite a long time to warm up with normal database workloads, which could lead to …

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Patching in the Cloud

As a developer at another company (not Oracle), I once worked the support phone lines as the philosophy of the company was that developers should be familiar with real customers and their applications. I recall one call on a particular morning:  a customer was crying because she had upgraded her database. The upgrade had destroyed her data. And, she had no backup. Her research data had been created for her PhD thesis. Sadly, she could not complete her degree since her work had been destroyed.

This true story has always reminded me of how deadly an upgrade can be.

Fortunately, the Oracle MySQL Cloud Service (MySQLCS) software has made the upgrade process more robust. With the MySQLCS software, you can test drive your upgrade process with your application. By spinning up a MySQLCS cloud instance you can:

  • Pre-check the new MySQL version to make sure system requirements such as disk space are adequate before the …
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How to build a stable MySQL Replication environment

While straight-forward to deploy, a production-ready and hence stable MySQL Replication setup requires a bit of planning and preparation. What does a solid replication configuration look like? What do you do when a topology is broken, and replication will not restart? How do you ensure performance? Or perform schema changes?

If you'd like to learn how to build a stable environment with MySQL replication, this webinar is for you. From OS and DB configuration checklists to schema changes and disaster recovery, you’ll have the information needed.

Join us next Tuesday as Krzysztof Książek, Senior Support Engineer at Severalnines, shares his top 9 tips on how to best build a production-ready MySQL Replication environment.

Top 9 Tips for building a stable MySQL Replication environment

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Making MySQL Better for Operations

In the MySQL team, one of our focuses over the last few releases has been improving the usability of the MySQL Server for operations teams.  The results can be seen in a number of areas:

  • Our continued investment in Performance Schema.  

Moving with SQL Server to Linux? Move from SQL Server to MySQL as well!

Over the recent years, there has been a large number of individuals as well as organizations who are ditching the Windows platform for Linux platform, and this number will continue to grow as more developments in Linux are experienced. Linux has for long been the leader in Web servers as most of the web servers run on Linux, and this could be one of the reasons why the high migration is being experienced.

Big News In Databases

There's bee a lot of big news in 2016, also when it comes to databases. Let's have a look at the really BIG news.

MySQL and MariaDB Become Modern

For a long time, MySQL and MariaDB were mostly limited to the functionality of SQL-92. Now, both of them have decided to move forward by supporting the WITH and OVER clauses in their next major release (MySQL 8.0, MariaDB 10.2). The MariaDB beta release already supports both features while the current MySQL “lab release” only currently supports the WITH clause.

Parallel Execution in PostgreSQL 9.6

Commercial databases have been able to do it for decades, …

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Upstart Basics for Automatic Restarts of MaxScale After Crash

Historically I do not care much about MariaDB's MaxScale, at least since I know how to build it from source when needed. But, as a support engineer who work at MariaDB, sometimes I have to deal with problems related to MaxScale, and this week it happened so that I had to explain what to do to implement automatic restarts of MaxScale "daemon" in case of crashes on RHEL 6.x.

In the process I had found out that two of my most often used Linux distributions, CentOS 6.x and Ubuntu 14.04, actually use Upstart, so good old System V's init tricks and scripts work there only partially and only because somebody cared to integrate them into this "new" …

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MySQL 8.0.0 first impressions: been running for 60 days

While headlines likes this are really silly I thought it might be worth sharing some experience with 8.0.0 on a few servers I use. I tend to test new versions of MySQL first as a slave. That is easy as it requires little work: make a copy of a working 5.7 slave, upgrade the server … Continue reading MySQL 8.0.0 first impressions: been running for 60 days

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