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Comments

sokhaty sokhaty
  • Expert to Expert: Inside LINQ-to-SharePoint

    Good discussion. Interesting perspective on how customer-extensible application meta-data affect all the layers above.

    And it's rather obvious that "like.. you know" Bart now works for Eric.

     

    Just out of curiosity, what is so special about SharePoint security that computation has to happen in the business layer as opposed to a stored procedure or even a correlated subquery in a SQL statement?

  • E2E2E: Meijer, Rys and Vick - Programming Data

    Oh, my. So many good discussion topics, so little time. I stopped counting after the first five. More E2E sessions would be nice.

    I'd like to hear more about developments in the area of type systems, relational (im)purity,  and programming languages to replace SQL.

    Cost based optimization and how things are evolving in that area would be interesting too.

     

    On a side topic, calling SQL relational is a blasphemy. It's as relational as a cow is a noble steed.

  • E2E: Erik Meijer and Patrick Dussud - Inside Garbage Collection

    On a loosely related subject, It would be interesting to know why SQL Server is still being shipped with two VMs - .NET one and a specialized one to run T-SQL code. Is .NET VM too generic (insufficently specialized) to provide good run-time for T-SQL?

    Is it the same or similar reason why guys from Jane Street Capital hint at .NET GC not being quite good enough to meet demands placed on run-time by a functional programming language (F#)?

     

    It looks logical to assume that any engineering solution (software or otherwise) has its range of applicability. Going below or above the applicable range requires some other engineering solutions. Is there any info out there on applicability limits of .NET GC and .NET VM for that matter (and how one would express those limits anyways - in terms of lattency or memory allocations per unit of measure, when being general purpose VM starts and ends?).

  • E2E: Erik Meijer and Dave Campbell: Data, Databases and the Cloud

    In a database of the future, I'd like to be able to declare my taxonomy, interval (including temporal) properties of objects and their attributes and functions to derive new truths about objects based on the truths obtained so far. Then I might want to specify how much of those computational graphs I want to store precomputed (which would allow me to have OLTP, data warehouses, cubes and whatever funky terms are currently used to descripbe various stages of truth discovery/derivation). Are there any developments in those directions?

    (I guess inclusion of MDM services into 2008 R2 may seem to hit that the answer is "soft of").

     

    To the subject of the code running closer to the data, this was obvious for quite a while now that shipping bits over network to have a copy in application memory and process it using (more often than not) less sophisticated algorithms than those already present at the point of storage doesn't make much sense. Database is a computational engine, so it should have a powerful language to create computational expressions. Unfortunately SQL in general is not quite that, and T-SQL in particular isn't either.

    Having F# inside database engine would be nice. Add "pure mode" for querying (which should be side effects free) and use imperative mode to produce side effects (data modifications).

     

  • The .NET4 Countdown Synchronization Primitive

    Yeah, that's a hack and is a bad one too. Why not to make "done adding" semantics explicit at least?

    Then instead of add one before, remove one after there will be explicit call to ce.NoMoreCounterIncrements()

    It doesn't guarantee that programmer won't forget to add it into the code, but that's one change to one code line as opposed to two (and it's a better "pattern" than the alternative).

     

    Plus, if this primitive constructor accepted nested lambdas, then AddCounter() and NoMoreCounterIncrements() could be hidden from the programmer all together. Just declare what you want to spawn and how many of those in a nested lambda and happily wait for completion.

  • E2E: Erik Meijer and Burton Smith - Concurrency, Parallelism and Programming

    On the subject of strict or linient evaluation.

    It seems that an adanced enough run-time can and should use both, based on the accumulated "knowledge" (stats) about workloads being executed.

     

    Expectation that something can be strictly evaluated in false in absolute sense, because each and every CPU instruction and/or memory read/write may fail because of faulty hardware. Yet, it can be statistically true. If hardware is somehow known to be 99.something% reliable, such assumption can be made safely (in statistical sense), otherwise nothing can be computed or done ever.

    (I believe that proponents of strict evaluation are stuck because they base their reasoning on incorrect assumptions without explicitly stating what those assumptions are, which is a known issue that plagued physics for centuries, and most likely still does)

     

    The same must apply to the algorithms as well. If algorithm is known to be predictable on a given workload (either statistically or by devine intervention of the mister human), it's OK to evaluate is strictly. If there is no prior knowledge, lazy evaluation is the way to go and please gather execution stats upon exit so it can be reused in the future evaluations/executions. And if it does not exit in the requested amount of time - abandon (preferrably kill first) the execution and and black list it (till the end of time or the next devine intervention).

     

    From 10000 feet it looks like a nice logical schema with a feed back loop, which is statistically a necessity for each and every successful eco system (observe the nature).

     

  • E2E: Erik Meijer and Burton Smith - Concurrency, Parallelism and Programming

    Right, and old ideas are just facades on even older ideas and so on recursively till the big bang Smiley

    In the end it will be about believes, whether one believe this or that language being "new" or not. Attempts to define "pure novelty" would end up nowhere.

  • The .NET4 Countdown Synchronization Primitive

    Ah, "Once zero it cannot be incremented" - that's what was missing. Then it's all cool and dandy Smiley

    I guess that the counter is NULL originally (if not set to any positive integer).

  • E2E: Erik Meijer and Burton Smith - Concurrency, Parallelism and Programming

    Actually, it's quite obvious. C#, Java, C++, C are sugar coated assembler. Reasoning about assembler, even sugar coated is a lost cause. Making those languages into something that can be reasoned about at compile and especially run-time would be practically impossible because of long hairy legacy that those languages carry around.

    In order to run a program on a parallel hardware, run-time would have to reason about side effects to come up with some strategy to partition computational graph into work loads that have minimal interactions between each other.

    If many core processors will have cores of different capabilities (which seems to be the case), run-time reasoning and JIT will be a necessity.

    It seems like none of the existing imperative languages would survive transition to parallel era. Of course run-times are still be written in something that is sugar coated assembly, yet for general-purpose programming completely new languages would be required.

    Declarative and richly typed presumably.

    Also to the point of run-time reasoning and code generation, to provide fault tolerance computational graph might need to be re-evaluated if a computation node returns exceptional value or goes into non-termination state. That in theory would allow automatic remediation for run-away queries in databases and handling of non-responding services in the cloud (as well as mutating hardware - failed or hot plugged general and special purpose CPUs, failed or hot plugged memory and so on).

    It probably will take another 10 to 20 years to get it right, but it looks like that's where things are going.

  • The .NET4 Countdown Synchronization Primitive

    It seems to me that in order to have a race condition ce.AddCount() should be inside lambda in the last code sample.

    As long as ce.AddCount() is inside foreach loop on the main thread there won't be any race conditions, so adding "one for the host" before and then taking it out after the loop is kind of pointless.

     

    Also, guys, _No Sound_ in SL3 on XP SP3 _again_.

     

    Cheers,

    Seva.