Today, the current issue of iX has published my article on transactions in MySQL. It’s a comprehensive and brief introduction to the topic. The text is written in German. To obtain it, you buy iX at a kiosk or in a fiew weeks online in the virtual kiosk.
Category Databases
XML Features in PostgreSQL
Christian has some info on XML and XPath features in PostgreSQL, provided via UDF. Yes, I would also love to see something similar in MySQL!
With the XSLTkit project, we provide some XSLTs that allow transoformation of XSD to e.g. SQL CREATE TABLE statements. We also plan to do the same with XUpdate to SQL ALTER TABLE transformation. This way, you can use XSLTkit to emulate a XML database on top of a RDBMS or LDAP.
LinuxTag 2003: Kaj on MySQL and SAP DB
Just attended Kaj Arnö’s talk MySQL, SAP and the Enterprise. Kay explained the development process of merging SAP DB and MySQL. For the mediate future, a proxy will be integrated in the SAP DB client, which allows MySQL users to manage SAP DB via the MySQL clients like mysql, mysqldump, mysqlimport. In the long run, functionality will be added to MySQL that covers the functionality already provided by SAP DB (e.g. stored procedures, triggers, standardized error behaviour, …). At the end of this process, the “MySQL Enterprise” edition (this is not the official, but the working name) will incorporate the best from both worlds: MySQL robustness, ease of use, and SAP DB enterprise functionality.
It’s also good news that all the nice DB management GUIs available for SAP DB will then also work with MySQL.
UPDATE: MySQL has branded SAP DB MaxDB
MySQL: INSERT … SELECT with Same Table
The latest release MySQL 4.0.14 introduced a neat new feature:
[snip]
Enabled `INSERT’ from `SELECT’ when the table into which the records are inserted is also a table listed in the `SELECT’.
[/snip]
This means you can now issue a statement like
INSERT INTO table ( field ) SELECT field FROM table WHERE field = “data”;
which copies all records meeting the specified criteria to the same table.
The MySQL manual only states the behaviour previous to 4.0.14:
[snip]
The target table of the INSERT statement cannot appear in the FROM clause of the SELECT part of the query. (The problem is that the SELECT possibly would find records that were inserted earlier during the same run. When using subquery clauses, the situation could easily be very confusing.)
[/snip]
German Website on PostgreSQL
Conni Boenigk and Ralf Burger have set up a German Website on PostgreSQL.
Prevayler OO DB
From the Prevayler Web site [1]:
“Prevayler is the most reliable Free Software Prevalence layer we are capable of providing for Java.”
“With Prevalence we are finally free to create true object servers and use objects the way they were intended all along.
We are able to use any algorithm, data-structure and query language we please. We are no longer constrained to the ones provided by database and application servers which must run on disk data-blocks.
We believe the whole OO community is finally free to recover from the atrophy caused by database and application server restraints. We no longer have to distort and maim our object models to satisfy their limitations.
We no longer have DBAs imposing us database layout restrictions. We have freed them to do something more useful.
We have set fire to the table-models on our walls. We have deleted our database creation scripts. We no longer have to keep them updated.
We no longer have to license, install, configure and maintain a database and application server every single time we want to develop, demonstrate or deploy our systems for any of our clients. Give us a Java VM and we are good to go.”
via Reto Bachmann-Gmuer, private email
GIS Demo code available
The code and data for demonstrating MySQL 4.1’s new OpenGIS (geographic data) functionality is now available for download [1]. This demo has been demonstrated by Bar at the MySQL Users Conference [2].
[1] gd.tar.gz
[2] GIS session
Linux-Magazin Publishes MySQL Con Report
The German Linux Magazin published Sandro’s report from the first MySQL User Conference, which is also available online [1].
[1] http://www.linux-magazin.de/Artikel/ausgabe/2003/06/mysql/mysql.html
myxml User Defined Functions
Brian Aker from Slashdot announced [1] his new myxml User Defined Functions (UDF) for MySQL in the MySQL general mailinglist.
[1] http://marc.theaimsgroup.com/?l=mysql&m=104993600306514&w=2
Session at MySQL Conference, April 12
CEO Sandro Zic will talk about “MySQL in Peer-to-Peer Content Networks” at the MySQL Users Conference 2003 in San Jose/USA. The preliminary schedule of the conference is now online. Sandro will introduce CONESYS and have a close look at how MySQL handles high volumes of aggregated data.
Sandro Groganz 