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RedGate SQL Server Concurrency: Locking, Blocking and Row Versioning - Book Review

Although this began as a usual book review, it quickly grew into an all-encompassing article as a result of the additional and extended commentary

While concurrency is always covered as part of a book on SQL Server, this title is totally dedicated to it. Exaggerated one might say; quite the opposite and with good reason I would say. It aims to raise awareness of this frequently underrated subject whose incomprehension can result in massive performance complications.

The problem lies in that no matter how well designed your application, database, or SQL queries are, all working harmonically in isolation, going multi-user without putting considerable effort into understanding concurrency (and how your specific DBMS goes about it), will sooner or later lead your edifice into collapsing, shaken by performance degradation, unacceptable waiting time or even corrupted data state.
So this is where this slim guide comes in, to properly educate anyone working with the RDBMS in k…

All about Perl 6 – interview of Jonathan Worthington (Part 3 of 3)

NV: The JVM has been primarily designed with statically typed languages in mind. The same goes for the CLR, and that is why the DLR (build on top of CLR) came into existence.  Have you at some point considered the DLR (maybe combined with Mono instead of the CLR) or JVM’s Dynalink, both of which admittedly have a good Meta Object protocol infrastructure, as a potential backend to Rakudo?

JW: One interesting thing to note about Perl 6 is that it’s  a gradually typed language, which means the considerations are a little different from if it was dynamically typed. In that sense, VMs which explicitly seek to do both static and dynamic typing well are especially interesting for Perl 6.
I can’t speak too well to the DLR, but I do know that Niecza, the Perl 6 on CLR implementation, went the way of not using it for a range of reasons. By contrast, the JVM’s invokedynamic instruction has been rather interesting from a Perl 6 implementation point of view.
Dynalink is certainly of …

All about Perl 6 – interview of Jonathan Worthington (Part 2 of 3)

NV: What does that say about the JVM’s project’s life expectancy? Will it run in parallel with MoarVM’s development? Does all this forecasts Parrot’s demise?

JW: The JVM is playing that difficult “second backend” role. Going from one target VM to two exposes all kinds of assumptions, such as places where things are not sufficiently well abstracted and so forth.  Such abstractions are not easy to design because you’re not only thinking about how to hide differences, but how to convey enough semantic information downwards in order to allow good code generation.

Having the second VM that  is already mature and well established is a huge help. OK, I did manage to segfault the JVM thanks to the odd invokedynamic bug I managed to hit upon. But by and large, if something is wrong, I can be pretty sure that the JVM itself will not be to blame. So, the JVM porting leads the way.

That naturally means we’ll get to a rather complete Rakudo on JVM some way ahead of getting there with …

Book review of 'Beginning Perl' by Ovid

Ovid takes an interesting approach. He attempts to fill the gap between learning a language and actually applying that knowledge for landing a job.

Most books on Perl teach the language itself, its constructs and how to use them, while the code examples and practical exercises re-enforce comprehension, but that can only take you so far.

They do not address the questions
'what do you do with that knowledge?', 
or 'which technical area should I focus on for landing a job?'

full review on i-programmer

All about Perl 6 – interview of Jonathan Worthington (Part 1 of 3)

The latest news is that Parrot Virtual Machine is no longer the only one enjoying Rakudo’s exclusivity.
Not long after Rakudo had been successfully ported to the JVM a new hosting candidate that aims to change the rules of the game, MoarVM, went public.
All that activity has raised a lot of questions regarding Parrot, Rakudo and the direction Perl 6 is heading for:
Is Parrot dead ? Why yet another VM and what’s up with the JVM?How does Perl 6 stack up against other modern languages like C# ?Is there any room in the programming world for it, after all? For getting the definitive answers to these intriguing questions, we’ve managed to get hold of Jonathan Worthington for an exclusive interview. Jonathan is the architectural mastermind and primary driving force behind not only Rakudo’s implementation, but also all the projects revolving around it, such as NQP, the port on the JVM, and now the brand new MoarVM.
As if simultaneously engaging in these cognitively demanding activit…