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Extracting User SQL Queries from a MySQL Server

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Joe Kottke from FeedBurner in his MySQL Conference presentation today FeedBurner: Scalable Web Applications Using MySQL and Java mentioned a novel way of extracting SQL Select Statements from a MySQL Server.

The obvious MySQL ways include SHOW [FULL] PROCESSLIST, the Slow Query Log, and the General Query Log. In 5.1 you also use the INFORMATION_SCHEMA.PROCESSLIST.

Anyway, Joe mentioned he does a strings on tcpdump to extract the queries, and there was no need to restart the server (this point interested me). So, not letting a challenge go, having never used tcpdump.

Well, here’s how.


tcpdump -w mysqldump.txt -i lo

NOTE: You must log output to file with -w to get the full packets and not just headers.

In a seperate session.


$ mysql -uroot -p mysql -h `hostname`
mysql> select * from user;
mysql> exit
# I did a ctrl-C in the other terminal (not sure if necessary)
$ strings tcpdump.txt
select * from user
mysql
user
user

NOTE: localhost wasn’t valid, it had to be the hostname of the server. Of course you could access the server from a different client.

Of course there may be other or better ways, but it worked for me and was rather cool.

Perhaps this is a good reason to use SSL?

MySQL Migration Toolkit Extensions

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Just to add some more features of the MySQL Migration Toolkit from the MySQL Conference presentation MySQL Migration Toolkit by Mike Zinner from MySQL AB.

You can extend and modify the funcionality of the Migration toolkit with the supplied Eclipse Java project. I’ll need to download the code to write some more detailed notes, but here were a few points from Mike.

Classes are in the com.mysql.grt.modules Package Space
The main configurable classes are nameed Migration????..java and ReverseEngineer???.java with ???? being for the different Database Products

Within the Eclipse project, you can incoporate other languages. For example, ReveserEngineerMySQL Jdbc.java for example has a callGrtFunction to code written in C. This I’m assuming will allow you to incoporate all the other languages of the GRT such as Python, Lua. (I’m still impressed you can actually do this, a mini project for another day to pull this apart.

A question from the audience was about Oracle User Defined data types. MigrationOracle.java for example can easily be extended to cater for the migration of user defined data types to a suitable valid MySQL alternative.

References
MySQL Migration Toolkit – Provides details, screenshots and Flash Tutorials for SQL Server, Oracle and Access Migrations.

The MySQL Migration Toolkit

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A Wednesday afternoon presentation at the MySQL Conference was MySQL Migration Toolkit by Mike Zinner from MySQL AB.

In summary, the Migration Toolkit currently provides the following feature set.

  • Wizard like interface
  • Plug-in architecture
  • Migration of Oracle/MS SQL Server/MS Access/Generic JDBC Data Sources. 2006 support for Sybase and DB2.
  • Provides user support to expand to other databases
  • Customisable the produced wizard scripts at any step
  • Completely Scriptable (the wizard interface can produce command line replay scripts) -allows re-running, re-scheduling
  • Binaries include an Eclipse Java Project to enable easy extension of the Migration Toolkit.

The product is built on the Generic Runtime Environment (GRT) which is used in other MySQL GUI Products. The GRT is a thin C Layer that allows you to easily add modules written in other languages (e.g. C/C++, Java, Lua, Python etc).

The following are the steps of the Migration process.

  • Source/Target
  • Object selection
  • Object Mapping
  • Manual Editing
  • Schema Creation
  • Data Mapping
  • Bulk Transfer
  • Summary

Some more relevent points on some of the individual steps.

Source/Target

  • Screen caters for source specific requirements (e.g. SID for Oracle)

Object selection

  • Choose the different Schema Objects, including tables, views. Can limit by type, or individual objects
  • For Oracle additional objects include Schemas, Routines and Sequences

Object Mapping

  • Define Methods for mapping of schema objects
  • Includes Language types (e.g. latin1), multilanguage (utf8), or a user defined
  • For Tables you can choose the purpose which includes data consistency, statistical data. These rules will include determining best storage engine, intepreting auto increment columns.

Manual Editing

  • You Can drill down in great detail to define the object mapping, down to a column level
  • Provides a migrated objects review, including warnings (for example views need to be manually checked, or sequence not migrated)

Schema Creation

  • Can create objects in real-time or create a SQL script for later executation
  • You can review the generate SQL code that will be used in real-time and perform further manual refinement (e.g. converting to specific SMALLINT,INT,MEDIUMINT refinement)
  • Will show any warnings, and allow for manual correction

Data Mapping

  • Can create data in a real-time to a MySQL database
  • Create Insert Statements (normal data and blob data) (optimized multi-row insert with byte limits)
  • No facility at present for flat file creation/loading via LOAD INFILE

Bulk Transfer
Summary

  • A migration report which can be saved to disk.
  • Create a Migration script for the complete process. (which is a generated lua script)

I can see the possibility for the following enhancements.

  • Consider ENUM fields by analysing data (columns char < 20) and offer as data type
  • Consider determining AUTO_INCREMENT columns

References
MySQL Migration Toolkit – Provides details, screenshots and Flash Tutorials for SQL Server, Oracle and Access Migrations.

Hacking MySQL Source (in a good way)

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HackFest B: Creating a New SHOW Command by Brian Aker at the MySQL Users Conference

Brian stepped through the steps for those attending to modify and deploy new functionality in the mysql server. Cool. The end result I would consider for an experienced developer as relatively easy (after avoiding the pitfalls).

NOTE: I wasn’t able to complete this successfully during the session, but I’ve posted this, so hopefully the input and review of others can help in overcoming the current issues. See Outstanding Issues throughout my notes.

Our goal: Produce a new command SHOW CONFERENCE;

The following commands were performed on CentOS 4.2. There may be some differences with different Linux Distros.

Prepare a current Source Code Tree


su -
useradd mysqldev
su - mysqldev
wget http://downloads.mysql.com/snapshots/mysql-5.1/mysql-5.1.10-beta-nightly-20060426.tar.gz
# NOTE: You should check the snapshots page for latest versions http://downloads.mysql.com/snapshots.php
tar xvfz mysql-5.1.10-beta-nightly-20060413.tar.gz
cd mysql-5.1.10-beta-nightly-20060413
# compile script will depend on H/W and requirements
./BUILD/compile-pentium-debug --prefix=/home/mysqldev
make install
scripts/mysql_install_db --datadir=/home/mysqldev/data
sql/mysqld --basedir=/home/mysqldev --datadir=/home/mysqldev/data &

NOTE: This can take a while, so it’s a good opportunity to leave this and come back at a later time. The –prefix allows you to install into the new users directory ensuring that you can test without affecting any currently installed mysql installations on your machine.

The BUILD directory contains many different compilations for platforms and variants. This version contains 41 specific scripts. For the purpose of our new SHOW command, we are going to run in debug mode for any necessary debugging.

Outstanding Issues

  • I was surprised a make install didn’t configure the bin/mysqld and scripts/mysql_install_db as you would get in a binary distribution. There is probably additional commands necessary for this, but for the purpose of development it works.
  • I run multiple versions of MySQL on my machine, and I had some conflict with my /etc/my.cnf file, so I just removed it for the purpose of this test. There needs to be a cleaner way to ensure this isn’t used, and also to compartmentalise/isolate different source trees.

Confirm Installation

I ran this in a seperate terminal window.

su - mysqldev
bin/mysql -e "SELECT VERSION()"
+------------------------------------+
| VERSION()                          |
+------------------------------------+
| 5.1.10-beta-nightly-20060413-debug |
+------------------------------------+

This gives us a suitable source baseline.

Implementing a new SHOW Command

The easiest means of developing a new SHOW command is to base this on an existing command. We are going to base this new SHOW command on the SHOW AUTHORS command.

We are going to be looking at the following files.

  1. lex.h
  2. sql_yacc.yy
  3. sql_lex.h
  4. sql_parse.cc
  5. mysql_priv.h
  6. sql_show.cc

All these files are found under the sql directory in the source tree.

lex.h

131:     { "CONFERENCE",       SYM(CONFERENCE_SYM)},

sql_yacc.yy

 202:  %token  CONFERENCE_SYM
...
8267:       | CONFERENCE_SYM
8268:         {
8269:           LEX *lex=Lex;
8270:           lex->sql_command= SQLCOM_SHOW_CONFERENCE;
8271:         }
...
9366:       | CONFERENCE_SYM        {}

sql_lex.h

112:   SQLCOM_SHOW_CONFERENCE,

sql_parse.cc

3515:   case SQLCOM_SHOW_CONFERENCE:
3516:     res= mysqld_show_conference(thd);
3517:     break;

mysql_priv.h

915: bool mysqld_show_conference(THD *thd);

sql_show.cc

229: bool mysqld_show_conference(THD *thd)
230: {
231:   List<item> field_list;
232:   Protocol *protocol= thd->protocol;
233:   DBUG_ENTER("mysqld_show_conference");
234:
235:   field_list.push_back(new Item_empty_string("Name",100));
236:
237:   if (protocol->send_fields(&field_list,
238:                             Protocol::SEND_NUM_ROWS | Protocol::SEND_EOF))
239:     DBUG_RETURN(TRUE);
240:
241:   protocol->prepare_for_resend();
242:   protocol->store("Welcome to the MySQL User Conference 2006", system_charset_info);
243:   if (protocol->write())
244:     DBUG_RETURN(TRUE);
245:   send_eof(thd);
246:   DBUG_RETURN(FALSE);
247: }


cd ..
./BUILD/compile-pentium-debug --prefix=/home/mysqldev
...
gmake[3]: *** Waiting for unfinished jobs....
/bin/chmod +x mysql-test-run-t
/bin/mv mysql-test-run-t mysql-test-run
gmake[3]: Leaving directory `/home/mysqldev/mysql-5.1.10-beta-nightly-20060413/mysql-test'
gmake[2]: *** [all-recursive] Error 1
gmake[2]: Leaving directory `/home/mysqldev/mysql-5.1.10-beta-nightly-20060413/mysql-test'
gmake[1]: *** [all-recursive] Error 1
gmake[1]: Leaving directory `/home/mysqldev/mysql-5.1.10-beta-nightly-20060413'
gmake: *** [all] Error 2

Outstanding Issues

  • I’m sure there must be a more effecient means of compiling changes, this process effectively cleaned and started again.
  • I had a build failure which didn’t seem to make any sense.

At this point I wasn’t able to continue, but here are notes I took of next steps.

make install
gdb mysqld
run --gdb --debug

In another terminal session.

su - mysqldev
bin/mysql
mysql> SHOW CONFERENCE;

I’m keen to see it work in my own environment and documented for others to try.

Brian moved on to creating a INFORMATION_SCHEMA query but we ran out of time to complete this. I’ve got some notes to document as a later date.

PBXT – The MySQL Community Transactional Storage Engine

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In having a discussion with Paul McCullagh (the creator of PBXT transactional storage engine) and Taneli Otala MySQL AB CTO after the keynote presentation at the MySQL User Conference, Taneli made the following comment (paraphrased and reproduced with permission).

“I talk about PBXT in discussions shamelessly. The development of PBXT was excellent timing in the MySQL community landscape”.

It was an excellent commendation that MySQL AB management considered so highly the contributions from the community. As mentioned in the opening keynote, MySQL with the Storage Engine API with MySQL 5.1 has great potential to expand what options are available to user of MySQL.

Good work Paul. I like many others wish you the best in your continued development and contribution.

Improvements in SHOW STATUS

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It just dawned on me as this topic was mentioned in a MySQL Conference presentation yesterday in a manual process. So my thought is, why can’t the following functionality be added to the MySQL server.

My request for two new extensions to the SHOW STATUS command.

SAVE STATUS – This enables the current SHOW STATUS to be saved (or more specifically cached), you can only keep one copy per server instance.

DIFF STATUS – This shows the difference between the current SHOW STATUS and the last saved show status from the SAVE STATUS command.

This would quickly, easily and interactively via a mysql prompt enable a DBA to see the state of change in a more condensed form. The syntax may need to cater for Session/Global scope, and of course would need to be appropiately named, my examples is just an idea.

Of course you can write an easy script that does the same, and provide a diff, but why not include it directly?

Could not have said Agile better myself

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I’ve just attended Scott Ambler’s presentation on Agile Database Techniques: Data Doesn’t Have to be a Four-Letter Word Anymore at the MySQL Users Conference.

There is so much content on the topic, it’s impossible to present so much information in a short 45 minute session. I can speak with authority in regards to the same problem of condensing so much content given this issue with my own presentation MySQL for Oracle Developers.

I ask this question. Why is common sense considered such a radical approach? I state this because Agile Methodology approaches in so many ways are common sense, but “traditionalists” (and I use this term for several groups of existing IT dinosours), see change and continual improvement approaches as potentially evil, while they are constantly just trying to stay afloat daily with bloated, inefficient and overly complex legacy systems (I had to throw in several daggers at the same time, couldn’t resist).

This presentation echoed both a lot of my experiences and part of my writings and current projects. I have been a database modeller for over 16 years, and I have worked with Extreme Programming Agile Methodology for now over 6 years. Here are some abstract and unstructured bullet points from the presentation and some of my own comments intermingled. (Unfortunately due to other discussions I missed the initial 15 mins, however given the content and my own professional standings I can only fully understand what the initial content was).

  • Agile Modeling Driven Development AMDD
  • Agile Data Modelling
  • Iteration o (zero) should consist of an Initial Domain Model to provide scope and visibility of the bigger picture, but only a higher level view. Any extended time spent is wasted time.
  • Why use this approach to data modelling? To handle change efficiently.
  • There is a clear lack of tools and techniques in Automated Testing and Code Coverage concepts specifically for Data. See my thoughts on this at the links at the end of this entry.
  • Incremental software development enables a production rollout after every iteration
  • There is movement to a Data Modelling Standard based on the UML Notation
  • Transitioning approach to schema changes. Interesting concept, not necessary in a new project with Test Code Coverage, but essential for Legacy systems for a low risk approach using small steps.
  • Stop talking about data quality and actually doing something about it. Bad data, or more specifically must have migrated data, that breaks all the integrity in a new system has been the bain of my experiences in large data migration projects.
  • Generalising Specialists

Scott threw in a lot of Agile terms, and for most people in the audience I observed that quite a few of these terms were indeed foreign. I could easily see the potential for a Talk on Introduction to Agile – Applying to MySQL Projects.

One term I didn’t hear was YAGNI – You Ain’t Gonna Need It. This is an essential XP principle which in some ways sums up the common sense approach to software development. Don’t even thing about it until it’s made it’s way to the top of the customer requirements for the current interation.

I’ll also be getting the book “Refactoring Databases – Evolutionary Database Design” that was mentioned, I’m keen to read in depth more of the principles I so much promote myself. Sometimes I feel quite isolated in this area of Data Modelling colliding with Agile Methods.

I’ve written previously content that both re-inforces a number of points of this presentation and also complements Scott’s presentation in a number of ways. These include Unit Testing A Database and Database Modelling within an XP Methodology.

I recall this quote from a tee-shirt once owned, and I think is valid for certain IT professionals that continue to cling to traditional approaches in data modelling. Perhaps I should put it on an Agile slogan shirt for myself. Evolve or Die

In closing, I’ve been wanting to write a paper for quite some time titled “Better Productivity and Quality. An Agile Approach” to share my experiences. I’ve haven’t been able to put my thoughts down, having two other major writings in progress at present, but this presentation has only renewed my vigor.

Opening Conference Keynote

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Mike writes a good summary of the MySQL Conference opening keynote State of the Dolphin: Interview with Kaj, Monty and David of MySQL.

I’d like to add just two comments.

Firstly, it was great to see community awards to Giuseppe, Roland, Marcus and Rasmus. Well done!

Second, it was a great thing to see on the slides a reference to Paul’s PBXT Transactional Storage Engine. A MySQL storage engine from the community. I’ve had a chance to meet Paul and have a number of great discussions with him. I wish him all the best, and I’m happy to contribute what I can to see his engine make it into the MySQL product in the future.

Bootstraping

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Tuesday’s Keynote speaking from the MySQL Users Conference including a presentation from Greg Gianforte of RightNow Technologies on “Bootstrapping: Starting an Open Source Business With Almost No Money!” Read More.

Taking directly from Greg’s presentation, here are some key points for bootstraping that meant something to me.

  • Sales is Job #1
  • Don’t spend Beyond Your Means
  • There Is Always Another Way
  • What is Your Noble Purpose?

Some great points. In summary, not having funds should not be an excuse, find another way . You just need to think creatively. I agree completely, thinking creatively is something I do well. Immerse yourself – talk to lots of people, develop a one page description, get it out to as many people as possible, talk to people, ask for an order. Of course sales is #1, but for me personally, and also within the essense of the presentation – Honesty. His passion about helping people to get started has also lead to publishing a book for bootstrappers (in paperback to save money).

One of the key goals is to “Help our clients to better serve our customers”. Greg was also correct in the need to correct the loss of ethics in the IT and software industry, something I fight for back at home.

A number of these points provided great relevence given I’ve worked for two failed Internet startups.

The closing quiz raised some great questions. Here they are. (Hopefully now reproducible in the Open Source community, oops too late now!)

  • #1 What should you do first?
  • #2 You have an idea. What next?
  • #3 You have a good product, What next?
  • #4 You find a prospect. What next?
  • #5 Your product does not do everything a prospect wants. Should you?
  • #6. A major publication calls saying they are writing a big article about your products and wants you to buy an ad in the same issue of their magzine. You should?
  • #7 You are still gettting started and Dun & Bradstreet is asking for company info and detailed financial data. Should you:
  • #8 A major prospect says they want to fly to visit you, but you are still working out of your house. Should you:
  • #9 You are the only person working full time in the business and you are aksed how many employees you have. Tell them:
  • #10 You’ve just made your first sale and generated your first montly profit. You should.

I’ll save the expense by not giving any answers, but my favourite answer was for #9.

Greg started the presentation with the right words for me. Love Mountains, Love Skiing, check out our Careers. Anybody that knows me, knows that my plan for this year, it to be in the Northen Hemisphere for Winter, working for an organisation that is close to the snow, enabling me to go skiing. I just may have check it out.

My First BoF – MySQL GUI's

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Last night, I attended Mike Zinner’s presentation of MySQL GUI’s, most specifically MySQL Workbench. In summary I was very impressed with the current work, and the future potential. I’ve been waiting for now about a year to get access to full strength MySQL Workbench (it has been available for some time, but still in early development), having previously used DB Designer for MySQL Data Modelling. One of the limitations is finding a quality tool that runs under Linux. Well MySQL workbench will satisfy this and far more in the future.

A quick summary of some of the glossy features.

  • Reverse Engineering of schemas from multiple input sources including MySQL, Oracle, MS SQL Server.
  • Synchronisation with a MySQL Database.
  • Quick Re-Synchronisation.
  • Full GUI tools and features for creating and maintaining database objects including tables, primary keys, foreign keys, views.
  • Fully customisable styles via XML and <svg> functionality
  • Intitutive point, click and drag functionality for database objects (primary keys for example)
  • An interactive shell for the GRT.

The Best Feature

The introduction of the GRT Shell, an interactive shell will provide near unlimited potential.

From the shell you can do everything you can do via the GUI, and you can do it multiple languages including Lua, Python, C/C++ Java and in future Ruby, as well as the potential of many more. The potential of Scripts and Plugins is limitless. Mike demonstated a number of simple examples, so I’ll be very keen now to review and contribute to this functionality now that I’ve seen it in action. MySQL is working actively for community contribution with the recent introduction of the MySQL Forge.

Some of the discussion was the future direction of technology. Presently, there is some limitation of reuse in the end user GUI. A rich GUI is provided, but is platform specific, providing a different look and feel in Linux, Mac OS and Windows. One of the options, and definitely of interest is the consideration of using Java as a standard GUI language.

One of the requests was for more feedback, greater community input and contribution. I agree there needs to be better means here, one of my suggestions was perhaps an interactive Feedback model built into beta products, actively prompting users to provide feedback to MySQL. This would also enable MySQL to gain greater insite into the users of the GUI products.

In summary, excellent work Mike, with a team of just 4 that supports and develops all the MySQL GUI products.

Here is an overview diagram of the MySQL Workbench.

Save the Falcon!

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While many people will be blogging about the conference sessions and MySQL features, functionality and sessions, I thought it would be important to raise awareness of the creativity of developers often lost during the product lifecycle.

I met at the Speakers Function last night Jim Starkey, the founder of Netfrastructure, Inc, a company aquired by MySQL recently. At the conference was the official launch of a new transactional storage engine to be included in the MySQL 5.1 release is codenamed “Falcon”.

Too often, the flare and creativity of products, and also the initial history is lost when it reaches the marketing department of an organisation. In this case, after talking with Jim, we decided it was important to ensure the name “Falcon” remains. Why should the name conform to something generic, and quick frankly boring. So please join me.

Save The Falcon!

My MySQL Conference happenings

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Everybody has been writing lately of their likes of sessions and events for the MySQL User Conference, time for my 2 cents worth, with a twist.

I’ll be leaving early tomorrow at 7am (Friday my time), that’s Thursday 2pm Conference time. A taxi, two trains, two planes, and some 21 hours later, I’ll be at San Jose. In time to get a car and head to Davis California, a small town, where I have lived previously. After some catchup, I’m off to Lake Tahoe, (all up about 3 hrs from San Jose), for some R & R, and a weekend of Skiing, starting at Heavenly. No snow in the last few days, but 4 feet in the past week, and a bumper season to date. (The added benefit is it’s much cooler, I’m not a warm weather person, and my current home in Brisbane Australia is just too warm for my liking)

A lazy Sunday afternoon drive back, and ready for the MySQL User Conference starting on Monday. My presentation is nearer to the end on Thursday, so I’ll have plenty of time to soak in what’s on offer. Too much on the MySQL front to mention, performance and new features including clustering highlights, but also keen to hear Tim O’Reilly as I’m become more interested in Web 2.0, where it is and where it’s going. I see this philosophy of Services rather then Products, and highly user driven in features, functionality and content, in line with some of my principles and strong thoughts of Extreme Programming and Agile Development Methodologies.

I’ve also had positive comments and feedback from a number of MySQL colleagues of the past months, so it will be great to expand not only my intellect from the conference content, but my circle of new friends from the MySQL community. (And places in the world to visit in the future)

Installing MySQL 5 via rpm

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I don’t think I’ve ever installed MySQL via .rpm I have always installed via .tar.gz primarilarly because I’m an /opt system administrator from my old UNIX days. so my first experience installing on my CentOS 4.2 (aka RHEL 4).


$ rpm -Uvh MySQL-server-standard-5.0.19-0.rhel4.i386.rpm
warning: MySQL-server-standard-5.0.19-0.rhel4.i386.rpm: V3 DSA signature: NOKEY, key ID 5072e1f5
error: Failed dependencies:
perl(DBI) is needed by MySQL-server-standard-5.0.19-0.rhel4.i386
Suggested resolutions:
perl-DBI-1.40-8.i386.rpm
$ rpm --import /usr/share/doc/centos-release-4/RPM-GPG-KEY
$ yum install perl-DBI-1.40-8
$ rpm -Uvh MySQL-server-standard-5.0.19-0.rhel4.i386.rpm
warning: MySQL-server-standard-5.0.19-0.rhel4.i386.rpm: V3 DSA signature: NOKEY, key ID 5072e1f5
Preparing... ########################################### [100%]
1:MySQL-server-standard ########################################### [100%]
PLEASE REMEMBER TO SET A PASSWORD FOR THE MySQL root USER !
To do so, start the server, then issue the following commands:
/usr/bin/mysqladmin -u root password 'new-password'
/usr/bin/mysqladmin -u root -h lamda.arabx password 'new-password'
See the manual for more instructions.
Please report any problems with the /usr/bin/mysqlbug script!
The latest information about MySQL is available on the web at

http://www.mysql.com

Support MySQL by buying support/licenses at https://order.mysql.com
Starting MySQL...................................[FAILED]

Failed!!! What the!!!!

So turn to my good friend Morgan for help. I'd already done a little google research, but it took Morgan about 15 secs to know the problem, and know he had already experienced this with other clients.

Some References:
https://bugzilla.redhat.com/bugzilla/show_bug.cgi?id=167551
http://fedora.redhat.com/docs/selinux-faq-fc3/index.html#id2825880
http://confluence.atlassian.com/display/DISC/Prerequisites+and+installation+on+Fedora+or+RHEL+Linux
http://bugs.mysql.com/bug.php?id=12676

Some Analysis:

$ system-config-securitylevel
# shows that I have SELinux enabled.
$ /usr/sbin/selinuxenabled && echo "yes"
$ restorecon -R -v /var/lib

Ok, its working now. But wait there is no mysql command? Again, I'm .tar.gz user, had to realise the client is a seperate RPM.

rpm -ivh MySQL-client-standard-5.0.19-0.rhel4.i386.rpm

Well my first .rpm experience was, well eventful none the same.

More on Oracle Procedures Functionality (Part 2)

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As mentioned in my earlier post Emulating Oracle Output Functionality, I’ll be speaking at the MySQL Users Conference on the topic of MySQL for Oracle Developers. Here is the second in a series of points regarding current MySQL Stored Procedures and Functions functionality.

  • 3. Named Parameters
  • 4. Procedure Overloading

3. Named Parameters

Parameters passed to Procedures under normal operations can be considered positional parameters. For each parameter, a calling statement is required to pass the same number of parameters and in the same order. Named parameters allows the user to pass parmeters in the order of their choosing, and also not pass all parameters.

For Example, consider the following Oracle Stored Procedure definition.

  EXAMPLE_PROCEDURE(num IN NUMBER DEFAULT 0,
                    dte IN DATE DEFAULT SYSDATE,
                    str IN VARCHAR2 DEFAULT NULL,
                    str2 IN VARCHAR2 DEFAULT NULL);

This can be called in several ways, here are few examples.

  EXAMPLE_PROCEDURE();
  EXAMPLE_PROCEDURE(9,  '01-MAR-2006', 'Hello World', NULL);
  EXAMPLE_PROCEDURE(dte => '01-MAR-2006');
  EXAMPLE_PROCEDURE(dte => '01-MAR-2006', str2 => 'Hello World');

The key to being able to use named parameters, is the addition of the DEFAULT syntax in the variable definition.

Giuseppe Maxia has many MySQL stored procedures, and I applaud his initiate with The MySQL General Purpose Stored Routines Library. Included here is an implementation of handling named parameters. I can’t say I’ve used it personally, however I did browse the code (another Open Source benefit).

4. Procedure Overloading

Oracle provides the capability like Java, which allows for multiple procedures to have the same name, but have a different set of parameter arguments.

Oracle provides the ability to overload a Procedure call with the same number of arguments and varying datatypes, for example, going with the earlier DBMS_OUTPUT.PUT_LINE analogy, Oracle has the following specification.

  DBMS_OUTPUT.PUT_LINE (item IN NUMBER);
  DBMS_OUTPUT.PUT_LINE (item IN VARCHAR2);
  DBMS_OUTPUT.PUT_LINE (item IN DATE);

Likewise, it possible to have procedures with different numbers and types of arguments.

  EXAMPLE_PROCEDURE(num IN NUMBER);
  EXAMPLE_PROCEDURE(num IN NUMBER, str IN VARCHAR2);
  EXAMPLE_PROCEDURE(num IN NUMBER, dte IN DATE);
  EXAMPLE_PROCEDURE(num IN NUMBER, dte IN DATE, str IN VARCHAR2, str2 IN VARCHAR2);
etc.

Notes

As MySQL growth continues and developers take up placing greater business logic in the database with Stored Procedures, there may be merit to consider these points. On the flip side, 10 years ago, business logic was placed in the database for many reasons including the extent of capable client programming languages, a Client/Server architecture and of course tight coupling with Oracles GUI products. One could argue a justification as to how much business logic is stored in the database, and how much is managed within an application. Given the advent of the Web, and multiple applications and clients assessing coporate data, it’s logical to place essential logic as close to the source of the data as possible, and the introduction of Stored Procedures in MySQL 5 released last year provided the capacity to consider this.

At this time, I would err on the conservative side with the use of Stored Procedures. The type of application, requirements and signficantly the age of the product (being a new product or existing legacy product) all affect the outcome. As mentioned, Giuseppe feels strongly regarding named parameters, and has provided a workaround. The benefit with Open Source is this FREEDOM clearly exists when the community contributes. This can only benefit MySQL in areas such as Stored Procedures.

Myself, only a few days ago over the weekend, I took an Java Open Source product, that lacked the capacity to support the calling of Stored Procedures via JDBC, developed it myself and then submitted my work back to the Apache community. I was even more happy when it was accepted unaltered, committed and in the nightly build for the next day. Read More. I’m now working on the next contribution to the same project, providing JDBC Transaction Support. While this may seem a sidetrack, I’m actually specifically using this product in testing and usability of MySQL, so ultimately everybody wins.

Correction to earlier MySQL Statement

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I stand corrected on my earlier post Emulating Oracle Output Functionality (which I’ve updated) when I made a reference to MySQL catching up. That was not what I was implying, that MySQL had to catchup to Oracle. I was indeed making reference that MySQL is a 10 year old product, Oracle almost 30, and with a far greater historical R&D budget, MySQL as an organisation has for lack of a better term, entered the race at a later time. One could also argue it’s not a race, I’m just using this analogy.

For those that might have thought this in reading my earlier article, I’d encourage you to re-read my updated introduction for my clarification and correction.

The comment was made to me, “Oracle is very good at being Oracle” which is totally correct, and the “MySQL’s market now overlaps that of Oracle, and so there is competition.” Indeed Oracle, as a leader in the RDBMS industry has directed development in functionality and features.

We (being the MySQL product and Open Source) are indeed in competition (with other RDBMS products, both commercial and open source) , and will always be, however those that know me would also know that differing products serve to provide differing features and functionality in enterprise solutions. Some have strengths over others, and also weaknesses.

I am a strong advocate of larger enterprises currently using Oracle to embrace both Oracle and MySQL within an organisation for the benefit of serving differing purposes. I do not believe they are mutually exclusive. I believe there needs to be a looser coupling in the emerging marketplace. Of course, if a new company was starting tomorrow, and wanted to use Oracle, I would question the requirements as MySQL will serve the needs for most practical enterprise solutions. Had that question been asked 5 years ago, it would depend signficantly on the requirements, 10 years ago it would not have been a consideration.

A Basic MySQL Developer Installation

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Given a new Linux Installation, the following is my recommendation for installation of MySQL for a experienced software developer giving flexibility in a development environment.

1. Under normal circumstances, most distros include MySQL either in a default server installation or on the distribution CD’s. You should first ensure MySQL is not installed.

2. All products can be downloaded from the MySQL Downloads page.

3. Download MySQL 5.1 Beta – Linux (non RPM, Intel C/C++ compiled, glibc-2.3), this product is close to production release and stable. This also includes both Server and Client as well as provides flexibility in installation location and multiple installations.

3. Download MySQL Administrator 1.1.6.

4. Download MySQL Query Browser 1.1.18.

5. Download MySQL 5.1 Manual

Installation

su -
groupadd mysql
useradd -g mysql mysql
cd /opt
tar xvfz mysql-5.1.7-beta-linux-i686-icc-glibc23.tar.gz
ln -s mysql-5.1.7-beta-linux-i686-icc-glibc23 mysql
tar xvfz mysql-administrator-1.1.6-linux-i386.tar.gz
tar xvfz mysql-query-browser-1.1.18-linux-i386.tar.gz
tar xvfz refman-5.1-en.html-chapter.tar.gz
mv html-chapter mysql-manual-5.1
cd mysql
echo "[mysqld]
user=mysql
basedir=/opt/mysql
datadir=/opt/mysql/data
port=3306" > my.cnf
scripts/mysql_install_db
cd /opt
chown -R root /opt/mysql
chown -R mysql /opt/mysql/data
chgrp -R mysql /opt/mysql
chown -R root /opt/mysql/bin
cd /opt/mysql
./bin/mysqld_safe &
./bin/mysqladmin -u root password 'new-password'
./bin/mysqladmin -u root -h `hostname` -pnew-password password 'new-password'
./bin/mysqladmin -pnew-password shutdown
echo "PATH=/opt/mysql/bin:/opt/mysql-administrator/bin:/opt/mysql-query-browser/bin:$PATH; export PATH" > /etc/profile.d/mysql.sh
. /etc/profile.d/mysql.sh   # Just for this session
cp support-files/mysql.server /etc/rc.d/init.d
chkconfig mysql.server on

Operation

The MySQL server will start automatically on System boot

To run the MySQL Client

mysql -uroot -pnew-password mysql

To run the MySQL Administrator

mysql-administrator

To run the MySQL Query Browser

mysql-query-browser

Now that I remember all this, perhaps RPM’s are the way to go, I just don’t like the structure in deployed files.

What should I install?

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I was asked a simple question today by a collegue who is an experiened Java Developer and Oracle user and had just installed SUSE on his personal laptop, to align closer with his work environment. What MySQL should I install, the MySQL web site has this and this and this?

Simple question, but the answer isn’t as simple, especially when MySQL now has a number of different products encompassing client functionality in addition to the MySQL server.

Oracle got it right with the latest edition Oracle 10g Express Edition (XE). A simple one rpm install that includes the Oracle Server, Oracle client, a Web Based Administrator, Query Tool and Application Development tool. I guess as we are all experienced, the simple question isn’t something we have a some notes on handy, hence the purpose of my entry A Basic MySQL Developer Installation. NOTE: This is for a developer environment, installation would be simplier using RPM’s for a compatible Distro.

On that note, It would be good for MySQL to provide a more complete installation of it’s suite of products rather then letting 3rd parties package it all together. Problem is there are so many possible combinations, what do you do.

Data Modelling

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I’m a data modeller. I specialise in this, and for a number of years on large projects I’ve been able to focus on this single task within the System Development Life Cycle of software development for several months at a time. Unfortunately what depresses me the most, is I can’t get a full time position in what I’m an expert in. It’s not a specialised skill that an organisation can use on a full-time basis, unless it’s a large organisation, and quite frankly, Brisbane isn’t a market that can support the diversity of large organisations. (caveat, large organisations that are proactive in software development, not just large organisations that have significant IT requirements, but do not work proactively). This is why I can also do Software Development, Database Administration, and even System Administration. Again, I’m not good enough to fill one of these positions in a larger organisation as an expert, but I can generally hold my own, usually even with surpising results. (Side note, even this week, I was providing a possible solution and tool for system adminstration across a large organisation, and it was 5 mins work. Something the paid full-time system administrators were not providing????)

I only started looking at Domas Mituzas wordpress: friendly look at query log. I didn’t have to read far to see where it was going, and well I quite quickly turned off, sorry Domas, I’m sure your concluding points were valid. This is my point, and it has been echoed in our local MySQL users group as well, the lack of appropiate database design in open source projects. There are several contributors, but one I put down to the “Hobbist and the Professional Syndrome”. A topic for further discussion, but in summary here are the bullet points from a slide in a presentation I prepared.

Hobbist

  • Downloadable software and examples
  • Online tutorials
  • Books like Learn in 24 hours/For Dummies

Professional

  • Formal Qualifications
  • Grounding in sound programming practices
  • Understanding of SDLC principles
  • Worked in team environment

Middle Ground Developer

  • Time to skill verses output productivity
  • Depends on environment and requirements

And on a final note, I guess why doing some raving. I find it criminal that organisations encourage at times a level of incompetence by promoting people that develop bad code into positions where they can continue to ensure that bad code stays, and further business decisions only engrain an organisation down the continued wrong path. There is already enough poor software developers out there that give the industry a bad name, but the good ones are few and far between.

What do we do, how can we solve this problem? I don’t think it can be solved now in the Open Source community. Adopting an Agile Development methodology such as Extreme Programming (XP) for example, it a very good start in organisations, something I’ve been working with now, or working with the principles for 6 years.

PS: Modelling is actually spelt both Modeling and Modelling (2 l’s) across the various English derivitives. Just incase somebody wanted to make comment.

Contributing to JMeter

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As part of my using JMeter for the purpose of testing a new Transactional storage engine PBXT for MySQL, I’ve been investigating the best approach for handling transactions. Read more about earlier decisions at my earlier post Testing a new MySQL Transactional Storage Engine.

I found that the JMeter JDBC Sampler only supports SELECT and UPDATE Statements, and not calls to stored procedures. This is just one approach I’m considering taking.

Well, I guess it’s time to contribute code to an Apache Project. I’ve modified code and logged bugs before for Tomcat, but this will be my first attempt of modify code and submit.

A summary of what I did (really for my own short term memory):

Now I just have to wait to see if it’s accepted. Regardless, it works for me. And that’s Open Source. FREEDOM

svn checkout http://svn.apache.org/repos/asf/jakarta/jmeter/trunk/ jmeter

$ svn diff JDBCSampler.java > JDBCSampler.java.patch
$ cat  JDBCSampler.java.patch
Index: JDBCSampler.java
===================================================================
--- JDBCSampler.java    (revision 388876)
+++ JDBCSampler.java    (working copy)
@@ -23,6 +23,7 @@
 import java.sql.ResultSetMetaData;
 import java.sql.SQLException;
 import java.sql.Statement;
+import java.sql.CallableStatement;

 import org.apache.avalon.excalibur.datasource.DataSourceComponent;
 import org.apache.jmeter.samplers.Entry;
@@ -45,6 +46,8 @@

        public static final String QUERY = "query";
        public static final String SELECT = "Select Statement";
+       public static final String UPDATE = "Update Statement";
+       public static final String STATEMENT = "Call Statement";

        public String query = "";

@@ -69,6 +72,7 @@
                log.debug("DataSourceComponent: " + pool);
                Connection conn = null;
                Statement stmt = null;
+               CallableStatement cs = null;

                try {

@@ -88,14 +92,19 @@
                                        Data data = getDataFromResultSet(rs);
                                        res.setResponseData(data.toString().getBytes());
                                } finally {
-                                       if (rs != null) {
-                                               try {
-                                                       rs.close();
-                                               } catch (SQLException exc) {
-                                                       log.warn("Error closing ResultSet", exc);
-                                               }
-                                       }
+                                       close(rs);
                                }
+                       // execute stored procedure
+                       } else if (STATEMENT.equals(getQueryType())) {
+                               try {
+                                       cs = conn.prepareCall(getQuery());
+                                       cs.execute();
+                                       String results = "Executed";
+                                       res.setResponseData(results.getBytes());
+                               } finally {
+                                       close(cs);
+                               }
+                       // Insert/Update/Delete statement
                        } else {
                                stmt.execute(getQuery());
                                int updateCount = stmt.getUpdateCount();
@@ -112,20 +121,8 @@
                        res.setResponseMessage(ex.toString());
                        res.setSuccessful(false);
                } finally {
-                       if (stmt != null) {
-                               try {
-                                       stmt.close();
-                               } catch (SQLException ex) {
-                                       log.warn("Error closing statement", ex);
-                               }
-                       }
-                       if (conn != null) {
-                               try {
-                                       conn.close();
-                               } catch (SQLException ex) {
-                                       log.warn("Error closing connection", ex);
-                               }
-                       }
+                       close(stmt);
+                       close(conn);
                }

                res.sampleEnd();
@@ -164,6 +161,38 @@
                return data;
        }

+       public static void close(Connection c) {
+               try {
+                       if (c != null) c.close();
+               } catch (SQLException e) {
+                       log.warn("Error closing Connection", e);
+               }
+       }
+
+       public static void close(Statement s) {
+               try {
+                       if (s != null) s.close();
+               } catch (SQLException e) {
+                       log.warn("Error closing Statement", e);
+               }
+       }
+
+       public static void close(CallableStatement cs) {
+               try {
+                       if (cs != null) cs.close();
+               } catch (SQLException e) {
+                       log.warn("Error closing CallableStatement", e);
+               }
+       }
+
+       public static void close(ResultSet rs) {
+               try {
+                       if (rs != null) rs.close();
+               } catch (SQLException e) {
+                       log.warn("Error closing ResultSet", e);
+               }
+       }
+
        public String getQuery() {
                return query;
        }


$ svn diff JDBCSamplerBeanInfo.java > JDBCSamplerBeanInfo.java.patch
$ cat JDBCSamplerBeanInfo.java.patch
Index: JDBCSamplerBeanInfo.java
===================================================================
--- JDBCSamplerBeanInfo.java    (revision 388876)
+++ JDBCSamplerBeanInfo.java    (working copy)
@@ -50,7 +50,7 @@
                p.setValue(NOT_UNDEFINED, Boolean.TRUE);
                p.setValue(DEFAULT, JDBCSampler.SELECT);
                p.setValue(NOT_OTHER,Boolean.TRUE);
-               p.setValue(TAGS,new String[]{JDBCSampler.SELECT,"Update Statement"});
+               p.setValue(TAGS,new String[]{JDBCSampler.SELECT,JDBCSampler.UPDATE,JDBCSampler.STATEMENT});

                p = property("query");
                p.setValue(NOT_UNDEFINED, Boolean.TRUE);

Update

Good to know somebody read my post, and responded positively. The quickest way for patches is to log a Bugzilla request. Seemed somebody already had, so it was easy for me to just to contribute to Bug #38682

Emulating Oracle Output Functionality

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Updated 28-mar-2006
There really is no way to do a comparision by numbers in features and functionality when it comes to Oracle and MySQL in the area of Stored Procedures and Triggers. Oracle does provide a far greater and extensive features list, however having more only means it has more.

We all know this, MySQL is a growing evolving database product, having just celebrated it’s tenth anniversary, Oracle on the other hand, will next year be 30, and has had significant funding in R&D being up until recently the second largest software company world wide. However, being open source, MySQL has the advantages of being lean and mean, providing only functionality users actually want and use, and has the community and organisation that is focussed clearly on providing new and improved functionality that users need.

I’ll have a lot more to speak about on this topic at my MySQL User Conference presentation MySQL for Oracle Developers next month, however in the preceeding weeks I thought I’d open some discussion and debate on various features, particularly in the area of Stored Procedures.

Here are some initial points, I’d like to talk about today. The purpose of this discussion is to highlight the difference between these two products, and possibilly other RDBMS products. While a RDBMS offers a feature, I am not stating that MySQL should necessarily also have this feature, however as part of comparing products in these articles, I am comparing existing Oracle Functionality to MySQL, so it will generally involve the description of functionality that is not presently comparable.

  1. Package Space
  2. Provider Supplied Procedures

1. Package Space

MySQL provides for Stored Procedures and Functions only the definition of individual procedures and functions. There is no way to group them into logical groupings.

Oracle provides the functionality of Package Space. Groups of procedures and functions can be defined within a package. Consider it like a wrapper of a group of procedures and functions. The package definition consists of 2 parts, the header section, which defines the scope of the procedures and functions, and the body which defines the actual procedures and functions. An added advantage of this that within Oracle you can protect your package body code (making it unavailable for view). I’ll discuss this more at a later time.

I’d like to see MySQL consider a package syntax particularly as businesses start to work more extensively with stored procedures and functions in larger enterprise applications. UPDATE: As stated by Roland in the comments, you can register your support for this functionality at MySQL under Bug #11696.

Within MySQL you can emulate package name, at least in syntax. You can use a dot ‘.’ within a procedure name, unlike this restriction for tables. The down side is the call must be quoted. I’ll discuss this more next.

2. Provider Supplied Procedures

Oracle provides an extensive list of supplied procedures and functions, defined in many packages. One of the earliest you learn in Oracle development is DBMS_OUTPUT.PUT_LINE. As the name indicates, this allows your to output a line of information. This is a common means of debugging output. Andrew Gilfrin post on Debugging Stored Procedures in MySQL raises this point, and an interesting solution using a debugging table. While this functionality works, one of my goals is to provide compability functions so that any migration of code could be simplified. Here is a much simplier solution.

$ more dbms_output.put_line.mysql
DELIMITER //
DROP PROCEDURE `dbms_output.put_line`
//
CREATE PROCEDURE `dbms_output.put_line` (output  VARCHAR(255))
BEGIN
  SELECT output;
END;
//
DELIMITER ;

A MySQL Usage:

mysql> CALL `dbms_output.put_line` ('hello world');

A comparision Oracle Usage:

SQL> SET SERVER OUTPUT ON
SQL> BEGIN
SQL> DBMS_OUTPUT.PUT_LINE ('hello world');
SQL> END;

This is as close the syntax can be. With MySQL you require the CALL and the backqoutes (`). Both things that can be easily added in an automated way.

References:
DBMS_OUTPUT Note: this is a public web version of the Version 8i manual online. Oracle provides online documentation, but you require a login (which is free) to the Oracle Technology Network.

Oracle8i Supplied Packages Reference. Again this is dated information, being an older version, but gives you an indication. For reference Oracle 7 released in 1993 first provided Package/Procedure/Function functionality.

Other

On a side note, I’d really like to see a IF EXISTS syntax for DROP PROCEDURE. IF EXISTS is an excellent MySQL extension. Oracle for stored procedures has the CREATE OR REPLACE syntax.

Just how many articles are at Planet MySQL?

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I was trying to find an old article at Planet MySQL. One about a MySQL UDF to write to /var/log/messages. No luck.

Anyway, there is no search option on the site, and the latest addition of 10 entries per page makes it difficult to review pages. The RSS feed doesn’t give me a full option.

Anyway, it led me to look back in time to just how many articles are listed on Planet MySQL, and read some old stuff. I only came across it after I stumbled across the Brisbane MySQL Users Group back in Sep 2005.

Anyway the count was 2146. I’d like to see a stat on the home page of how many articles, and perhaps how many, last day, last week, last month.

MySQL Forge

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I was reading Zack Urlocker’s MySQL Workbench Beta article and was keen to look at the Extensible architecture. Not much detail yet in the Figure Stylesheets, Scripts and Plugins, which will be good when it’s there, however it lead me to another secret.

The MySQL Forge. This was mentioned at the Brisbane MySQL Users Group Meeting with Brian Aker in January. There isn’t much content at present, but there is a Call for Content.

I don’t recall anybody blogging about it, or maybe I just missed it. Giuseppe Maxia should get his MySQL General Purpose Stored Routines Library up there. On that thought, I’ve been looking for a post several months ago, about a UDF that wrote to the system log /var/log/messages. Does anybody remember this?

Another dissappointing MySQL article

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Another slightly disappointing article regarding MySQL, this one from a printed magazine. Below are my comments to the editor of Linux Format. The Dear Editor is an email link should others wish to make any comments. (Previous article comments What makes your blood boil?, Review of Database Magazine Article – “The Usual Suspects”)

Dear Editor,

I’ve recently subscribed to LXF, and have generally been very happy with the content in past months. I’m disappointed in your recent LXF77 article “Harness a database” Pg 57. Being a strong MySQL supporter, your article includes a number of practices which are less then ideal, and especially for the newly initiated, overly complicated when simplier alternatives exist.

I am happy to see that you had the current version 5.0.18. However in 7 years of using MySQL I’ve never had to compile from source, a binary has always been available, yet in your article you take the compile from source approach. While you may have done this to appease all possible readers of all POSIX variants, the binary for at least Linux could have been included.

In addition, much like your earlier article for Samba where you make reference to “most distros include this”, indeed MySQL is also included in most popular Linux distros.

You could have also made reference to the MySQL downloads area website. Infact, the MySQL 5.0 download area provides some 70+ dedicated distro versions for optimal usage. The site also states “For maximum stability and performance, we recommend that you use the binaries we provide.”

The second point that I do believe is completely unnecessary, and not recommended by MySQL, is the manual creation of user security. MySQL provides the CREATE USER command to achieve this. In your article, you would execute CREATE USER lxf@localhost IDENTIFIED BY ‘orangutan'; rather then an INSERT INTO user and a FLUSH PRIVILEGES.

Throughout your article you make no reference to the MySQL website, perhaps this is a policy, however it’s always ideal to have online references. At worst, a link to say www.linuxformat.co.uk/products/mysql (or appropiate) that provides links to the product information, in this case MySQL. This will allow you to undertake your necessary advertising, as well as track traffic.

I’m also sure, that contacting the MySQL Community Relations Manager for review of any MySQL content in future would be openly accepted, I’m even happy to review MySQL content in your magazine.

Atomicity, Consistency, Isolation, and Durability = ACID

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ACID is the key transaction processing feature for a RDBMS. Without this, the integrity of the database cannot be guaranteed.

In Summary.

Atomicity is an all-or-none proposition.
Consistency guarantees that a transaction never leaves your database in a half-finished state.
Isolation keeps transactions separated from each other until they’re finished.
Durability guarantees that the database will keep track of pending changes in such a way that the server can recover from an abnormal termination.

A clearer definition from the Wikipedia.

  • Atomicity refers to the ability of the DBMS to guarantee that either all of the tasks of a transaction are performed or none of them are. The transfer of funds can be completed or it can fail for a multitude of reasons, but atomicity guarantees that one account won’t be debited if the other is not credited as well.
  • Consistency refers to the database being in a legal state when the transaction begins and when it ends. This means that a transaction can’t break the rules, or integrity constraints, of the database. If an integrity constraint states that all accounts must have a positive balance, then any transaction violating this rule will be aborted.
  • Isolation refers to the ability of the application to make operations in a transaction appear isolated from all other operations. This means that no operation outside the transaction can ever see the data in an intermediate state; a bank manager can see the transferred funds on one account or the other, but never on both—even if she ran her query while the transfer was still being processed. More formally, isolation means the transaction history (or schedule) is serializable. For performance reasons, this ability is the most often relaxed constraint.
  • Durability refers to the guarantee that once the user has been notified of success, the transaction will persist, and not be undone. This means it will survive system failure, and that the database system has checked the integrity constraints and won’t need to abort the transaction. Typically, all transactions are written into a log that can be played back to recreate the system to its state right before the failure. A transaction can only be deemed committed after it is safely in the log.

Testing a new MySQL Transactional Storage Engine

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As part of my A call to arms! post about a month ago, I’ve had a number of unofficial comments of support. In addition, I’ve also been approached to assist in the completion of a MySQL Transactional support engine. More information on the PBXT engine will be forthcoming soon by it’s creator.

Anyway, I’ve taken on the responsiblity of assisting in testing this new storage engine. This will also give me the excuse of being able to pursue some other ideas about the performance of differing storage engines for differing tables in business circumstances, such as MyIsam verses InnoDB in a highly OLTP environment. Part of testing will be ensure ACID conformance in varying situations and multi-concurrency use. Of course the ability to also do performance and load testing would be a obvious extension.

Considering how I’m going to benchmark is an interesting approach. I of course want to use Java, my choice of language at present. This presents a problem, in another factor towards performance, however by using Java, I’m simulating a more real world environment of a programming overhead and JDBC Connector rather then just raw performance output.

Laying out a plan would include an ability to have an existing database structure and data, be able to bulk define SQL statements and transactions, and parameterise SQL during transactions. I would need to be able to verify the state of database from the transactions, and clearly identify any invalid data. I would also need the ability for handling threads, and of course adequate reporting of my results.

As of MySQL 5.1.4, there is a supported benchmarking tool called mysqlslap in MySQL. I’ve discounted using this because I figured at this early stage, the documentation and exposure of this is of course limiting, and I’m sure I’d still need to perform other development.

Along comes JMeter. Within Java development I use JUnit quite extensively. This is key in the test-driven agile methodology approach of Extreme Programming. In discussion with this problem with a collegue on a new project, I found that JMeter was used for extensive load testing for web applications, but also performed database testing, and provides the support to integrate JUnit tests.

So yesterday I had a quick look at JMeter. The capabilities for defining, reporting and threading are quite complete. It took litterally minutes to install, configure, run an initial test and view results all in a GUI interface. A little more work gave me scripting handling of my initial tests. I’ve posted my initial investigations of JMeter – Performance Testing Software and JMeter and Ant Integration earlier.

With this behind me, I’ve just got to define the approach for more complete transactional tests, explictly confirming the results (I’m hoping to achieve this in custom JUnit tests). If I can solve this, then I can spend the most of time in the defining of adequate tests. Let’s see what the next few days work provides.

Latest MySQL Versions under VMWare

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I made reference previously to Testing/Trialing new MySQL Releases using VMWare.

Well, I’ve just about completed my own Image for the lastest MySQL 5.0 (given I’m now running MySQL 5.1). I’m interested in sharing my experiences, and even providing some images for users if there is any demand out there.

What I’ve decided on is to use the VMWare supplied Browser Appliance which is Ubuntu 5.10. The great thing is the image autoboots into graphical mode, auto logins and loads a browser. My goal now is to get a suitable startup page describing the MySQL environment, links, manual etc.

The only requirements to run would be the Free VMware Player and a latest image.

I’m looking at providing a FTP and RSYNC download. Those savvy people will benefit a lot more from RSYNC when the image is upto 500MB.

I’m interested to know if anybody else would use this with the lastest 5.0, 5.1, 5.2 etc versions. Also, would it be of benefit to include other MySQL products such as Query Browser, Administrator, Workbench.

Check out the Innodb Site?

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Have a look at InnoDB. Well, ok your lazy, so here’s a screen print below.
Plastered thoughout the top section is the word MySQL. It’s in the core banner blurb, there’s a logo, and even links to the MySQL Documentation. And right in the middle of all this is “Innobase OY is an Oracle Company”, with the standard Oracle Logo.

So my question would be, is this a good thing or a bad thing from a MySQL advertising perspective?
Does it help or hinder MySQL?
Does it show Oracle as being in partnership with MySQL? Is this good for MySQL to increase it’s exposure into the Oracle world?
Does inclusion of InnoDB now within Oracle traffic and links improve exposure to MySQL within search engines?

Frankly, I’m a little surprised that Oracle Legal hasn’t got onto this, I’m sure somewhere there would be a decree, that no competitor logos should be shown with the official Oracle logo.

I’d suspect that the existing MySQL community know the deal re Oracle, so perhaps this will expose more Oracle specific people to MySQL!

Oracle Comments

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Some recent posts regarding Oracle (See Smart moves by MySQL AB and Larry Ellison still doesn’t understand open source) leads me to put in my 2 cents worth.

My background I’m sure like a lot of experienced MySQL people is in Oracle, and indeed in Ingres before that (starting in 1988). I have also worked for a number of years at Oracle Corporation. Ironically I started as their resident Ingres Specialist, in an international research project of DMS (Design & Migration Services) of re-engineering Ingres applications into an Oracle Designer Repository some 10 years ago in 1996. I of course moved into a number of other Oracle roles for clients following that. I still retain some contacts around the place.

It’s obvious Larry’s goal is to become more “Open Source”. This is of course a complex topic, and you can’t just say it like this. I’ll leave that for another day, but I’ve got some opinion on current trends.

It’s clear from recent purchases of JBoss, and SleepCat (Berkley DB) that Oracle has an intention of providing a suitable technology stack in a number of vertical marketspaces that Oracle presently cannot. For example, in the embedded space. Purchasing provides a much quicker solution, and also provides a different way to solve the problem instead of the legacy Oracle Product line. I haven’t seen any recent press, but I know that Xen was also in Oracle’s wallet space.

I would suspect that Oracle will move to providing a Stack solution (akin to SpikeSource for example) in a number of vertical spaces. These stacks will include non-traditional but now owner Oracle products, including Berkeley DB in lower end solutions. This along with the recent Oracle Express Edition (XE) free offering will enable Oracle to target market’s that were previously unavailable.

This is clearly not for a financial intention. There is no way to obtain a return on investment, however it’s all about upselling. By providing these offerings, Oracle now has a large marketplace to promote commercial product offerings.

Assuming, Oracle goes down this path, I’d assume they will also provide clear migration paths between stack offerings, as part of upselling. This will be more complex to achieve. I also suspect that Oracle will move towards a better Web 2.0 model, by providing products are no cost, but provide a service to support and maintain in these new marketspaces.

In closing, why did Oracle purchase InnoBase, the creators of the MySQL InnoDB Storage Engine? This question seems still unanswered. It doesn’t fit easily into the above ideas of differing technology stacks. Ultimately, money buys power, and I suspect it was just that, with no real future intentions or clear plan.

Update
Thanks for the comment about JBoss, yes, it’s not official, nor is Xen, but it took Oracle I think 15 months to get Peoplesoft.

I came across the Oracle Corporation Wikipedia entry in other work, the end of the history page reads a who’s who of acquisitions.

A call to arms!

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With Oracle Corporation purchasing InnoBase, the company providing the InnoDB Storage Engine, and now reliable rumors of the acquisition of SleepyCat, the BDB Storage Engine, both key transactional storage engines for MySQL are effectively owned by a competitor.

While the is a strange and probably unchartered territory for both organisations, I’m personally concerned. I use InnoDB extensively, however if there was a comparable alternative within MySQL I’d consider switching out of principle. Is Oracle purchasing these organisations a bad thing? We don’t know. That’s the problem. While MySQL will undoubtly continue to provide these storage engines as part of the MySQL Database I believe a call to arms is needed.

It’s true that Oracle helped more general adoption of Linux when it announced this as it’s primary platform some years back. I’m sure with a middleware suite such as JBoss this will benefit from Oracle’s exposure, but will it benefit in it’s development? Will funding for development skew the product torwards what Oracle wants, not the community? Even things such as BerkleyDB being embedded in Open Office, and Google wanting to spend into the refinement of Open Office for possible web services options just makes you wonder whats happening. I’m on holiday’s trying to relax, and not do any reading, developing or communicating, but the one thing that makes my mind turn is, why is Oracle doing this?

My concerns are: look what happened to the acquired big commercial competitors, the PeopleSoft, Siebel, JD Edwards. Now, it’s a little difficult with the Open Source software, but I’m no licence expert. While it will continue to be available in current licencing options, I’m sure there has to be some concerns. Even something trivial like, all MySQL downloads that include these engines must first be registered on the website, and all these statistics must go to Oracle. Can they do this? I have no idea, but what if they could.

I’m sure internally in MySQL AB there are plans afoot for alternative transactional storage engines. The pluggable nature of these within MySQL makes it easy to move in this direction. I think sometimes, some functionality is kept close to heart, and you only here about it when some actual work is released.

I’m interested to guage reaction to see if a public working group should be setup to specifically tackle the issue of an independent transactional storage engine. Are there others out there that feel the same way I do. Now let me be clear, I’m not anti Oracle, infact rather pro Oracle, but I’m very anti Microsoft. If it was Microsoft buying these companies how would people react?

In my opinion this should be a bold announcement from MySQL now. In stating the development and release of a new Transactional Storage Engine this year, and then not evening mentioning InnoDB and BDB, they are downplaying the Oracle buy in, and emphasising a true Open Source Company option. In no means say they are no longer supporting InnoDB and BDB, but if the media exposure from MySQL continues to mention them, then it’s going to bleed into some reference back to Oracle.

I can’t contribute to the actual development in C++, if it was Java that would be a different matter, but as I move more away from hardcore coding there are plenty of other areas in which I could contribute.

InnoDB, BDB. What is Big Red Doing!

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Last year saw a record number of acquisitions by Oracle Corporation. Of note was in October 2005 InnoBase (Read Press Release) which had a direct relationship with MySQL providing the InnoDB Storage Engine. It’s too early to tell what the impact to MySQL will be if any.

I’ve been in Singapore, and have not read any news in the past few days, but all information I’m receiving from those collegues in the know is that Sleepycat Software (the company behind Berkley DB, and the MySQL BDB Storage Engine) is now firmly in the sites of Oracle Acquisition. The rumors of JBoss is also definitely on the go. No official news from any Oracle Press Releases as yet.

So what is Oracle doing, and what impact will this have for MySQL? Both InnoDB and BDB are key transactional storage engines. Given that MySQL has the full capability for ease of plugin for new storage engines is this a prod to MySQL to consider another alternative?

If I wasn’t mistaken, it seems Larry Ellison is looking to be a big name in open source!