Search Results

Search found 12634 results on 506 pages for 'transactional memory'.

facebook twitter digg google delicious technorati stumbleupon myspace wordpress linkedin gmail igoogle windows live tumblr viadeo yahoo buzz yahoo mail yahoo bookmarks favorites email print

Page 315/506 | < Previous Page | 311 312 313 314 315 316 317 318 319 320 321 322  | Next Page >

  • In ruby on rails, is it possible to do a sum query with group by using the find_each batching?

    - by BarryOg
    I'm loading data from my database and I'm doing a sum calculation with a group by. ElectricityReading.sum(:electricity_value, :group => "electricity_timestamp", :having => ["electricity_timestamp = '2010-02-14 23:30:00'"]) My data sets are extremely large, 100k upwards so I was wondering if its possible to use the find_each to batch this to help with memory overhead. I can write the batching manually use limit and offset I guess but I'd like to avoid that if the code already exists.

    Read the article

  • Dynamic allocation in C

    - by Kerby82
    I'm writing a program and I have the following problem: char *tmp; sprintf (tmp,"%ld",(long)time_stamp_for_file_name); Could someone explain how much memory allocate for the string tmp. How many chars are a long variable? Thank you, I would appreciate also a link to an exahustive resource on this kind of information. Thank you

    Read the article

  • Java Multi threading - Avoid duplicate request processing

    - by seawaves
    I have following multi threaded environment scenario - Requests are coming to a method and I want to avoid the duplicate processing of concurrent requests coming. As multiple similar requests might be waiting for being processed in blocked state. I used hashtable to keep track of processed request, but it will create memory leaks, so how should keep track of processed request and avoid the same requests to be processed which may be in blocking state.

    Read the article

  • Concurrent processes do not utilize all available CPU

    - by metdos
    I run some processes on an EC2 cc2.8xlarge instance which has 32 virtual processors. For some type of processes, when I run 16 processes on parallel, all of them use 100% of CPU cycles. But for other type of processes, they are not using 100% CPU and they finish considerably slower than a single thread. There is no time spend on IO and all data is served from memory. Do you have any idea about the reason of this problem?

    Read the article

  • Efficiently generate numpy array from list comprehension output?

    - by shootingstars
    Is there a more efficient way than using numpy.asarray() to generate an array from output in the form of a list? This appears to be copying everything in memory, which doesn't seem like it would be that efficient with very large arrays. (Updated) Example: import numpy as np a1 = np.array([1,2,3,4,5,6,7,8,9,10]) # pretend this has thousands of elements a2 = np.array([3,7,8]) results = np.asarray([np.amax(np.where(a1 > element)) for element in a2])

    Read the article

  • Optimizing grep (or using AWK) in a shell script

    - by Ode
    Hi - In my shell script, I am trying to search using terms found in a $sourcefile against the same $targetfile over and over. My $sourcefile is formatted as such: pattern1 pattern2 etc... The inefficient loop I have to search with is: for line in $(< $sourcefile);do fgrep $line $targetfile | fgrep "RID" >> $outputfile done I understand it would be possible to improve this by either loading the whole $targetfile into memory, or perhaps by using AWK? Thanks

    Read the article

  • How do I check if a process is running from c++ code ?

    - by Maciek
    Hey all, I'm writing a C++ app that will communicate with another process via boost::interprocess, however I need to check if the other process is actually running first - as the other process is responsible for creating the inter-process shared memory. How do I check if the other process is running ? folks, I'm specifically required to check other processes

    Read the article

  • Is it worth setting pointers to NULL in a destructor?

    - by Rob
    Imagine I have a class that allocates memory (forget about smart pointers for now): class Foo { public: Foo() : bar(new Bar) { } ~Foo() { delete bar; } void doSomething() { bar->doSomething(); } private: Bar* bar; }; As well as deleting the objects in the destructor is it also worth setting them to NULL? I'm assuming that setting the pointer to NULL in the destructor of the example above is a waste of time.

    Read the article

  • Why thread specific data is required in pthread ?

    - by user504542
    Hi As i know, all the threads share memory location. For example a global variable changes in one thread will reflect in another thread. Since each thread has its own stack, the local variables that are created inside the thread is unique. In this case, why do we need to go for thread specific data mechanism?. Can't it be achieved by auto storage varibles inside the thread function ? Kindly clarify!!!. BR Rj

    Read the article

  • Indexing on only part of a field in MongoDB

    - by Rob Hoare
    Is there a way to create an index on only part of a field in MongoDB, for example on the first 10 characters? I couldn't find it documented (or asked about on here). The MySQL equivalent would be CREATE INDEX part_of_name ON customer (name(10));. Reason: I have a collection with a single field that varies in length from a few characters up to over 1000 characters, average 50 characters. As there are a hundred million or so documents it's going to be hard to fit the full index in memory (testing with 8% of the data the index is already 400MB, according to stats). Indexing just the first part of the field would reduce the index size by about 75%. In most cases the search term is quite short, it's not a full-text search. A work-around would be to add a second field of 10 (lowercased) characters for each item, index that, then add logic to filter the results if the search term is over ten characters (and that extra field is probably needed anyway for case-insensitive searches, unless anybody has a better way). Seems like an ugly way to do it though. [added later] I tried adding the second field, containing the first 12 characters from the main field, lowercased. It wasn't a big success. Previously, the average object size was 50 bytes, but I forgot that includes the _id and other overheads, so my main field length (there was only one) averaged nearer to 30 bytes than 50. Then, the second field index contains the _id and other overheads. Net result (for my 8% sample) is the index on the main field is 415MB and on the 12 byte field is 330MB - only a 20% saving in space, not worthwhile. I could duplicate the entire field (to work around the case insensitive search problem) but realistically it looks like I should reconsider whether MongoDB is the right tool for the job (or just buy more memory and use twice as much disk space). [added even later] This is a typical document, with the source field, and the short lowercased field: { "_id" : ObjectId("505d0e89f56588f20f000041"), "q" : "Continental Airlines", "f" : "continental " } Indexes: db.test.ensureIndex({q:1}); db.test.ensureIndex({f:1}); The 'f" index, working on a shorter field, is 80% of the size of the "q" index. I didn't mean to imply I included the _id in the index, just that it needs to use that somewhere to show where the index will point to, so it's an overhead that probably helps explain why a shorter key makes so little difference. Access to the index will be essentially random, no part of it is more likely to be accessed than any other. Total index size for the full file will likely be 5GB, so it's not extreme for that one index. Adding some other fields for other search cases, and their associated indexes, and copies of data for lower case, does start to add up, which I why I started looking into a more concise index.

    Read the article

  • why winform using external dll(VC) and ocx(VC) control can only import one?

    - by jack
    we have a .net framework application with a vc dll and a vc ocx, and now if we only import one dll ,it is ok, but when we import both, it will pop a messagebox saying: Debug Assertion Failed! and i studied the child module of our application that import the vc dll, i found after the framework import vc ocx and initialize , then the function LoadLibrary in our module importing the vc dll would return 0, that means memory limited or call improperly, i use getlasterror() the error code is 1114. so it is very frustrated ,hope someone can help me.

    Read the article

  • Playing multiple FLVs at the same time feasible?

    - by eb_Dev
    Hi, Is it feasible to play a number of FLV files at the same time on one SWF? Basically I have a brief to create a video banner with a number of FLVs of people playing at the same time but starting at different points in the videos. My concerns are with loading times, memory consumption and the starting of each FLV at a different point and looping it. The FLVs will be stored on a server and pseudo-streamed. Any tips would be greatly appreciated. Thanks, eb_dev

    Read the article

  • Facebook data collection ethical issues

    - by the_great_monkey
    If I have a Facebook app, and my users agree to allow my app to access their information, photos, friends, etc, is it ethical to grab their information when they log in, and then saving it in memory so that the next time he goes to my app, it can load faster? If so, what about when the user logged off? Is the right thing to do to is to delete all the cached information and photos that the user provided? Has Facebook got any way to detect that we're doing this (saving their information, etc)?

    Read the article

  • Why use one dimensional array instead of a two dimensional arrray?

    - by user3869145
    I was doing some work handling a lot of information and my partner told me that I was using too many matrices to manipulate the variables of the problem. The idea was to use one dimension arrays int a[] instead of the 2 dimensional arrays int b[][], to save memory and processing speed of the algorithm. How certain is that this change will accelerate the speed of execution or compilation of my code in c ++?

    Read the article

  • C# Dispose() -clarification

    - by nettguy
    When i call object.Dispose(); Will CLR immediately destroy the object from memory or mark the object for removal in it's next cycle?. We are calling GC.SuppressFinalize() immediately after Dispose(),Does it mean ,"Don't collect the object again for dispose,because it is already submitted to displose". Actually which generation is responsible for destruction ,i guess generation 2.

    Read the article

  • C/C++ variable length automatic array performance

    - by aaa
    hello. Is there significant cpu/memory overhead associated with using automatic arrays with g++/Intel on 64-bit x86 linux platform? int function(int N) { double array[N]; overhead compared to allocating array before hand (assuming function is called multiple times) overhead compared to using new overhead compared to using malloc range of N maybe from 1kb to 16kb roughly, stack overrun is not a problem Thank you

    Read the article

  • How to find where error is.

    - by gurugio
    How can I find where the error occurs? In C language, the return value means what error occurs, such as failure to open file or memory allocation. There is no information where the error occurs. For example, function 'foo' calls A,B,C,D. If foo returns an error value, it might be return value of A or B or C or D. I cannot find what function returns error. I have to run debugger or add some codes to find what function returns error.

    Read the article

  • What does it mean to flush a socket?

    - by User4748402
    I don't really know much about sockets except how to read and write to them as if they were files. I know a little about using socket selectors. I don't get why you have to flush a socket, what's actually happening there? The bits just hang out somewhere in memory until they get pushed off? I read some things online about sockets, but it's all very abstract and high level. What's actually happening here?

    Read the article

  • Performance analysis for java application

    - by user1827614
    I want to do a performance measurement of my application and would like to be able to configure the stats for specific module like (enable for specific module and disable for some) and I want to measure things like memory usage, threads, average band width etc.. Can any one suggest something please, I am new to this. I think Visual VM is good but it doesnot support configuring for different modules. Does Perf4j or Admin4j work here? any one has used these before?

    Read the article

facebook twitter digg google delicious technorati stumbleupon myspace wordpress linkedin gmail igoogle windows live tumblr viadeo yahoo buzz yahoo mail yahoo bookmarks favorites email print

< Previous Page | 311 312 313 314 315 316 317 318 319 320 321 322  | Next Page >