Pythian Group

Well the last busy day here in The Big Apple again a number of very good technical talks. It is not often that the developer of a key piece of a technology gives an intro talk so I grasped it when it came up. Robert Haas gave a very informative talk on the theory behind WAL (Write Ahead Logging) and how it is implemented on PostgreSQL as compared to other DBs. His talk never ventured into the neither world of techno-babel but gave just enough of the technical side to get the understanding out. In the second part of his talk Robert focused on a introduction of the ‘Buzz’ words of WAL that one might have to deal with. This was both very entertaining and armed one with a real understanding of WAL.

I next sat in on ‘Little Jim’ Mlodgenski’s ‘Scaling with GridSQL’ talk. Another great technical talk that did not get bogged down in little details. Jim illustrated how GridSQL leverages the Power of Nodes to create a scalable parallel query data ware-house by creating a controller that will split off most of a large query to the different nodes in a cluster take the results from these nodes and then applies the final touches. Jim clearly demonstrated that with simple aggregation queries one seen a linear gains in performance for each node added to the cluster. With more complex queries there was an exponential gain for the first few nodes but one sees a fall of after only 8. Jim was very open about the pitfalls of this form of scaling (eg backup can be problematic) but it a very good solution for quick scalable data-ware housing.

The final talk of the conference was Jake Luciani’s talk comparing Apache’s Casandra to PostgreSQL was a very good introduction to this rather novel No-SQL DB. Think of a ring of peer to peer hash tables that work together to scale, provide no single point of failure, automate replication and implement tunable consistency. Its basic concept is the opposite or the RDBMS ‘Store Many! Read Once’ which makes some sense when used in such situations as large blogs, photo libraries or even diverse catalogs. Jake also introduced us to something he called CQL a query language for thew No-SQL DB

The conference ended with one of the better open forums I have attended I am sure next year will be much better.

Hopefully I will be able to make it next year as well

Well day two here at PgEast has drawn to a close and it was another
very informative day.

Today I concentrated on the more common tasks of a Pg DBA so I attended three
talks (four if you count mine) that where rather heavy on the technical side of being a Pg DBA

Keven Kempter drew me back again with his excellent talk on Backup and recovery methods
this time giving some very good advice on how to use and abuse of pg_Dump_all and
PG_restore. He also touched on three different recipes PITR on ProstgreSQL and gave some handy
advice on when and why to use it.

I also caught another Mongo talk this time by Steve Francia it was on the application of Mongo
in a real world web retail store. He presented a very convincing argument for the NoSQL side of things in
the retail realm namely that RDBMS works great when you have but a few similar products
such as books, CDs and movies but what if you are a retailer who sells Jeans, Watches, Fresh fruit as well.

Mongo allows for a completely flexible schema and his fits the diverse retail model well.
Another good point he made is in the archiving pf transactions. Taking a product return
as an example one has to keep a recoded of all the details of the sale and you have to have some sort of mechanism to reconcile data points such as the price which might be stale they the time of the return. In
the Mongo world one just keeps the original sales record. A rather elegant solution.

I rounded out the day with two technical Pg talks the first by Magnus Hagander gave a very informative talk on the differing approaches to the ‘caching problem of web applications’ with PostgreSQL. By leveraging PostgreSQL notification system one can easily build a very robust and scalable cache with another open commercial product called Varnish.

I rounded out the day with an talk on Migrating from MySQL to PostgreQSL given by Paul Gross. This was an interesting case study of his experience where he was constrained by a 0 down time requirement. His solution was to use the ORM he was familiar with ‘ActiveRecord’ and use that to solve the many problems with data conversion he was encountering using just Ruby on its own. He used an iterative approach where he ran a script over and at each pass gathering up any changes in the originating MySQL into the PostgreSQL until they where exactly the same. This was successful with only a 30 second blackout time during the switchover to the new DB.

Well that is about it for day.

I guess I brought the snow with me to Ne York as I awoke to a nice 10cm dump. Anyway today would best be described as a day of ‘Disruptive Tech’

I first attended Kevin Kempters intro into PorstgreSQL High Availability. A very well balanced presentation that gave a very good overview of what is available out of the box for both Warm Standbys and Hot Standbys how they can be very easily implemented. He also gave a quick overview of other tools that can be used including Slony for detailed fail-overs and PgPool for load balancing and relication. Not very disruptive but it does show that Pg is on par with most of the heavy hitters such as MySQL and Oracle.

The keynote this year was by Ed Boyajian the CEO or EnerpriseDB and he gave an big picture of the DB in terms of market which is a whopping 26$ Billion a year in the US alone of which the the two five players have 90% of the market one having more than half.

He made the comparison between his time at Red Hat when there was a huge untapped market much the same situation exists today for PostgreSQL as it represents a ‘Disruptive player’ in the game is it is the last open source DB out there. In other words we can only grow in the future.

To continue on with my Disruptive theme I also attended B. W. McAdams and Justin Dearing’ s two talks on Mongo. Mongo is true disruptive technology as it is a NON-SQL Database. For an old timer relational chap I was a little skeptical. It is hard to thing of a DB without SQL, Schema, Joints or triggers but they made a good case for it. It is all a question of building the correct tool for the Job. Traditional relational DB where never intended to be used to create Blog web sites and as many of us have found out they might not be the ‘right’ tool. Mongo with its ‘Document’ orientation solves many of the ‘Blog’ problems very elegantly. Mongo is just not for Blogs both speakers gave a number of examples of its application for example in a quickie app that displays the nearest Subway station to you and one that acts as the cache for a large PostgreSQL DB

I also has to pleasure to hear a first time speaker Vanessa Hurst who presented on the topic of ORMs (Object Relational Mappers) and the problems they cause for DBs. It was good to hear some of these issues and she made the very good point that it is always a compromise between speed to market and long term goals. You might get an ORM db out in two months but in one year form now your DB may not work anymore because of single object files, lack of planning for scalability or just poor design that was forced upon the team from the ORM.

Well off to enjoy the ‘Le Comte Ory’ at the Met for me tonight

Cheers

Version of 1.28 of DBD::Oracle has been released. You can find it at CPAN DBD::Oracle.

DBD::Oracle is a Perl module that works with the DBI module to provide access to Oracle databases. It is maintained by me, John Scoles, under the auspices of Pythian as Open Source/Free Software.

This is a long overdue maintenance release that fixes a large number of bug and issues which are detailed below in the Changes.
Read the rest of this entry . . .

Here is the next latest and greatest DBD::Oracle for your programming pleasure.

You can find the Zip file here

DBD-Oracle-1.28_RC_2.tar

This time round we have cleaned a few compiler warnings and fixed up a few of the tests. Thanks to H. Merijn Brand and Charles Jardine for those.

Please enjoy.

John Scoles

Here is the latest and greatest DBD::Oracle for your programming pleasure.

You can find the Zip file here

DBD-Oracle-1.28-RC1.zip

This is a long overdue maintenance release that fixes a large number of bug and issues which are detailed below in the Changes.

Don’t worry there are some new goodies in this release namely I have added in 4 new
server side tracing/debugging attributes
Read the rest of this entry . . .

I just read on Metalink (1130327.1) that we Commodore 64 users who have to patch our 10.2.0.4. will get extened support untill April 30, 2011

8. Will I get more time to install 10.2.0.5 if it is released on my platform close to April 30, 2011?
Yes.  We will always support the previous patch set for at least 3 months, even if it is released after the one year to install the new patch set is up.  For example, patching for 10.2.0.4 generally expires on April 30, 2011.  If you are running 10.2.0.4 on the Commodore 64 platform and Oracle releases it after April 30, 2011, we will still patch 10.2.0.4 for you for 3 months following the 10.2.0.5 release on your platform.

Not sure about Amiga or Apple /// and Apple ][GS support but for the time being we have a question open on meta-link on it.

;)

Thanks to Chris Taylor for pointing this one out to us.

Sorry no funny nick name for version 1.27 but here is the scoop on it anyway

You can find the Zip file here

DBD-Oracle-1.27-RC1.zip

This version removes ‘PERL_POLLUTE’ and adds in PL_ so it will be fully compatible with Perl 5.13.

So in a nutshell 1.27 is a single issue maintenance release.

For those interested in the whole story you can have a look at this thread

Perl 5.13.3+ MAY BREAK COMPILED DRIVERS – Please test DBI 1.613_71

Any an all testing with differing Perls would be much appreciated

Cheers John Scoles

After enjoying the excellent hospitality of our host here in Pisa (6 courses) we were ready for our second day at YAPCEU 2010 here in sunny Pisa.

Larry’s new catch phrase “My Language is a four letter word” was the ‘Buzz word’ for today. We settled down to some very interesting talks, the highlight for me being Tim Bunce’s talk on using Devel::NYTProf to Optimize your code. Tim first gave us a quick and dirty overview of optimization which covered the basics of where to start and what to look for he followed up with real examples of Optimizer output and than wrapped up with a few before and after results on an optimization effort.

The rest of the day was dedicated in my opinion, to the future of DBs in with Nelson Ferraz giving an excellent presentation of his concepts for using Perl as to glue for a Data Warehouse application. Next on my agenda, Martin Berends reports on the present state of Perl 6 and interfaces database. There is progress here as we now have some access to the DBI for MySQL and some others. Also great news is the fact there is a good deal of development work going on.

Martin was quickly followed by Tim Bunce again who presented his proposal for the new Perl 6′s DBDI. Seems
we are going to use the JDBC specification with a little tweaking as our road map for the future. Tim also
showed of some Perl 6 black majik from Jonathan Worthington and he was able to how us DBI with DBD::Pg
running on Perl 6.

Allison Randal finished off today’s formal presentations with her “Migration Strategies” presentation. She
gave us some good insight into migration in that we, as developers, cannot force migration on the community. She also provided two examples of migrations: Apache, which took seven years but has almost full buy-in by users and Python, which was quick and dirty but has not received the same buy-in from the community.

Finally we all enjoyed the lightning talks as our wrap up. A number of neat quick ones such as ‘I speak Perl with a ‘c’ accent’, was a highlight for me.

Seems the videos and most of the slides (including my presentation on XS) may be online tomorrow. I will be sure to post them as soon as I see them.

Larry Wall gave another of his unique keynote addresses at the first day of YAPCEU 2010 here in sunny Pisa (yes the place with the tower)

This year was a little diversion from his usual pattern as Larry was assisted by his better half and his demon seed. Larry told us as a language designer his life is one of siting on the fence, not making up his mind until that one little voice in one ear (his better half) and that other little voice in the other ear (his demon seed) work it out somehow.

Larry also showed us some neat little one line Perl 6 tricks for playing perfect numbers. His demon seed seem very keen on ’6′ as it is the first perfect number.

Larry also talked about the latest high tech ‘buzz word’ that the three piece and office window crowd is bantering about these days: ‘Disruptive Technology’.

Something that may do some things bad but others very well.

Of course he pointed out that PERL was labeled the same way when it first appeared some years ago in the UNIX world. As it broke the cardinal rule in UNIX ‘Do one thing well’, Perl did most things sort of ‘OK’ and very sloppy to start, but got much better later. Sort of the idea that worse is better.

He left us pondering PERL 6 as we all know that it does ‘worse’ better and now that ‘worse’ is better it is the ‘worst’ as being better.