The recently released TokuDB brings many features. One of those features is support for XA Transactions. InnoDB already has support for XA Transactions.

XA Transactions are transactions which span multiple databases and or applications. XA Transactions use 2-phase commit, which is also the same method which MySQL Cluster uses.

Internal XA Transactions are used to keep the binary log and InnoDB in sync.

Demo 1: XA Transaction on 1 node:

mysql55-tokudb6> XA START 'demo01';
Query OK, 0 rows affected (0.00 sec)

mysql55-tokudb6> INSERT INTO xatest(name) VALUES('demo01');
Query OK, 1 row affected (0.01 sec)

mysql55-tokudb6> SELECT * FROM xatest;
+----+--------+
| id | name   |
+----+--------+
|  3 | demo01 |
+----+--------+
1 row in set (0.00 sec)

mysql55-tokudb6> XA END 'demo01';
Query OK, 0 rows affected (0.00 sec) …

Log Buffer Editions are marching along, and this Log Buffer #268 is once again all about Oracle, MySQL, and SQLServer plus some peeks at some of other glittering database technologies like PostgreSQL and DB2. Sit back and enjoy. Oracle: Martin has produced another scenario based blog post about Shrinking Tables to Aid Full Scans. What [...]

Since the famous conjecture by Eric Brewer and proof by Nancy Lynch et al., CAP has given the world countless learned discussions about distributed systems and many a well-funded start-up.  Yet who truly understands what CAP means?  Even a cursory survey of the blogosphere shows profound disagreement about the meaning of terms like CP, AP, and CA in real systems.  Those who disagree on CAP include some of the most illustrious personages of the database community.

We can therefore state with some confidence that CAP is confusing. Yet this observation itself raises deeper questions.  Is CAP merely confusing?  Or is it the case that as with other initially accepted but now doubtful ideas like the Copernican …

This is a cross-post from the MySQL Performance Blog. I thought it would be interesting to users of PostgreSQL, Redis, Memcached, and $system-of-interest as well.

For about the past year I’ve been formulating a series of tools and practices that can provide deep insight into system performance simply by looking at TCP packet headers, and when they arrive and depart from a system. This works for MySQL as well as a lot of other types of systems, because it doesn’t require any of the contents of the packet. Thus, it works without knowledge of what the server and client are conversing about. Packet headers contain only information that’s usually regarded as non-sensitive (IP address, port, TCP flags, etc), so it’s also very easy to get access to this data even in highly secure environments.

I’ve …

What's in a datatype then? A MySQL SMALLINT? A C int? An Oracle BLOB? One thing is for sure, they are not very well standardized, not even within the same environment, and much less so across them. And what does it means, really? When should I use a BLOB, when a BINARY VARCHAR and when to use a long long?

A datatype defines many attributes:

• What data I can store in it: Only numbers? Printable alaphanumeric characters? Unicode? Binary data? An object?
• What I can do with a value of that particular type and how does it behave? Can I concatenate two values? Add them (that is NOT the same as concatenate! The same operator (+) may be used, but it's not the same thing!)? Save it to a file?
• How is it stored and represented in technical terms. And this can be argued, a C int doesn't define how it is stored on disk, but a MySQL INT does! And a BLOB is a type that is largely there just because it …

Continuent is increasing its presence in Europe to offer our solutions and services for the open source database business sector in the region. VNC is Continuent's new partner in Germany, Austria and Switzerland (DACH). Read the entire press release here.Continuent and VNC are hosting a live webcast demonstrating advanced MySQL and PostgreSQL replication and clustering with Continuent Tungsten

Selena and I gave a talk on the various issues of running databases “in the cloud” at the recent linux.conf.au in Ballarat. Video is up, embedded below:

Zahlreiche Unternehmen verlassen sich auf MySQL und PostgreSQL für die Datenverwaltung. Aber was passiert, wenn die Datenbank abstürzt oder eine Wartung benötigt? Wie können Sie sicherstellen, dass Ihre Datenbank Höchstleistung bringt mit minimalem Arbeitsaufwand für den Administrator und maximaler Auslastung der vorhandenen Hardware? Erfahren Sie, wie VNC und Continuent Tungsten Enterprise

If you are interested in NoSQL databases (or maybe not) perhaps you have seen the anonymous "warning" about using MongoDB.   It concludes with the following pious request:

  Please take this warning seriously.

Now there are a lot of great resources about data management on the web but the aforementioned rant is not one of them.  If you plan to write technical articles and have people take them seriously, here are a few tips.

1. Sign your name.  Readers are more impressed when they see you are not afraid to stand behind your words. 
2. Explain what problem you were trying to solve.  Otherwise uncharitable readers might think you just started pumping information into a new database without thinking about possible consequences and now want to blame somebody …

I just finished reading a couple of interesting, and somewhat related, blog posts which I think are worth sharing (apologies to anyone who has already seen them). One is from Jelastic and the other is from Michal Hrušecký.

I’ve written about MariaDB and the Jelastic cloud before (see MariaDB now available as a hosted database via Jelastic cloud platform). Now Jelastic has published statistics on the relative popularity of the various databases they offer. The good news is MariaDB is currently the database of choice for 14% of their customers. The bad news is that we’re in fourth place behind their other three database choices (MySQL, …