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  • Using variables inside macros in SQL

    - by Tim
    Hello I'm wanting to use variables inside my macro SQL on Teradata. I thought I could do something like the following: REPLACE MACRO DbName.MyMacro ( MacroNm VARCHAR(50) ) AS ( /* Variable to store last time the macro was run */ DECLARE V_LAST_RUN_DATE TIMESTAMP; /* Get last run date and store in V_LAST_RUN_DATE */ SELECT LastDate INTO V_LAST_RUN_DATE FROM DbName.RunLog WHERE MacroNm = :MacroNm; /* Update the last run date to now and save the old date in history */ EXECUTE MACRO DbName.RunLogUpdater( :MacroNm ,V_LAST_RUN_DATE ,CURRENT_TIMESTAMP ); ); However, that didn't work, so I thought of this instead: REPLACE MACRO DbName.MyMacro ( MacroNm VARCHAR(50) ) AS ( /* Variable to store last time the macro was run */ CREATE VOLATILE TABLE MacroVars AS ( SELECT LastDate AS V_LAST_RUN_DATE FROM DbName.RunLog WHERE MacroNm = :MacroNm; ) WITH DATA ON COMMIT PRESERVE ROWS; /* Update the last run date to now and save the old date in history */ EXECUTE MACRO DbName.RunLogUpdater( :MacroNm ,SELECT V_LAST_RUN_DATE FROM MacroVars ,CURRENT_TIMESTAMP ); ); I can do what I'm looking for with a Stored Procedure, however I want to avoid for performance. Do you have any ideas about this? Is there anything else I can try? Cheers Tim

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  • MYSQL fetch 10 posts, each w/ vote count, sorted by vote count, limited by where clause on posts

    - by nibblebot
    I want to fetch a set of Posts w/ vote count listed, sorted by vote count (e.g.) Post 1 - Post Body blah blah - Votes: 500 Post 2 - Post Body blah blah - Votes: 400 Post 3 - Post Body blah blah - Votes: 300 Post 4 - Post Body blah blah - Votes: 200 I have 2 tables: Posts - columns - id, body, is_hidden Votes - columns - id, post_id, vote_type_id Here is the query I've tried: SELECT p.*, v.yes_count FROM posts p LEFT JOIN (SELECT post_id, vote_type_id, COUNT(1) AS yes_count FROM votes WHERE (vote_type_id = 1) GROUP BY post_id ORDER BY yes_count DESC LIMIT 0, 10) v ON v.post_id = p.id WHERE (p.is_hidden = 0) ORDER BY yes_count DESC LIMIT 0, 10 Correctness: The above query almost works. The subselect is including votes for posts that have is_hidden = 1, so when I left join it to posts, if a hidden post is in the top 10 (ranked by votes), I can end up with records with NULL on the yes_count field. Performance: I have ~50k posts and ~500k votes. On my dev machine, the above query is running in .4sec. I'd like to stay at or below this execution time. Indexes: I have an index on the Votes table that covers the fields: vote_type_id and post_id EXPLAIN id select_type table type possible_keys key key_len ref rows Extra 1 PRIMARY p ALL NULL NULL NULL NULL 45985 Using where; Using temporary; Using filesort 1 PRIMARY <derived2> ALL NULL NULL NULL NULL 10 2 DERIVED votes ref VotingPost VotingPost 4 319881 Using where; Using index; Using temporary; Using filesort

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  • c# web extracting programming, which libraries, examples samples please

    - by user287745
    I have just started programming and have made a few small applications in C and C#. My understanding is that programming for web and thing related to web is nowadays a very easy task. Please note this is for personnel learning, not for rent a coder or any money making. An application which can run on any Windows platform even Windows 98. The application should start automatically at a scheduled time and do the following. Connect to a site which displays stock prices summary (high low current open). Capture the data (excluding the other things in the site.) And save it to disk (an SQL database) Please note:- Internet connection is assumed to be there always. Do not want to know how to make database schema or database. The stock exchange has no law prohibiting the use of the data provided on its site, but I do not want to mention the name in case I am wrong, but it's for personal private use only. The data of summary of pricing is arranged in a table such that when copied pasted to MS Excel it automatically forms a table. need steps guidance please, examples, lbraries

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  • Remove undesired indexed keywords from Sql Server FTS Index

    - by Scott
    Could anyone tell me if SQL Server 2008 has a way to prevent keywords from being indexed that aren't really relevant to the types of searches that will be performed? For example, we have the IFilters for PDF and Word hooked in and our documents are being indexed properly as far as I can tell. These documents, however, have lots of numeric values in them that people won't really be searching for or bring back meaningful results. These are still being indexed and creating lots of entries in the full text catalog. Basically we are trying to optimize our search engine in any way we can and assumed all these unnecessary entries couldn't be helping performance. I want my catalog to consist of alphabetic keywords only. The current iFilters work better than I would be able to write in the time I have but it just has more than I need. This is an example of some of the terms from sys.dm_fts_index_keywords_by_document that I want out: $1,000, $100, $250, 100, 101, 102, 103, 104, 105, 106, 107, 108, 109, 110, 111, 112, 113, 114, 129, 13.1, 14, 14.12, 145, 15, 16.2, 16.4, 18, 18.1, 18.2, 18.3, 18.4, 18.5 These are some examples from the same management view that I think are desirable for keeping and searching on: above, accordingly, accounts, add, addition, additional, additive Any help would be greatly appreciated!

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  • A map and set which uses contiguous memory and has a reserve function

    - by edA-qa mort-ora-y
    I use several maps and sets. The lack of contiguous memory, and high number of (de)allocations, is a performance bottleneck. I need a mainly STL-compatbile map and set class which can use a contiguous block of memory for internal objects (or multiple blocks). It also needs to have a reserve function so that I can preallocate for expected sizes. Before I write my own I'd like to check what is available first. Is there something in Boost which does this? Does somebody know of an available implementation elsewhere? Intrusive collection types are not usable here as the same objects need to exist in several collections. As far as I know STL memory pools are per-type, not per instance. These global pools are not efficient with respect to memory locality in mutli-cpu/core processing. Object pools don't work as the types will be shared between instance but their pool should not. In many cases a hash map may be an option in some cases.

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  • Best way to replace mass emails sent from Entourage with a proper mailing list solution?

    - by aaandre
    I am helping a Los Angeles choreographer to transition away from sending her announcements via Entourage. Here's the situation: She has multiple conact groups, and sends classes and performance announcements several times a month, to different groups. She manages the contact groups manually. The group size is between 1500 and 2500 people. Recently verizon blocked her outgoing port 25, presumably for spam activity. Again, her contacts are interested in the content. She is aware of mailchimp, constantcontact etc. but would like to be able to send the email via her email software and not have to create a newsletter for every single mailing. Also, she's very short on $$. So, what would be the best way to set up a system allowing her to send announcements from Entourage, with attached images, to her lists, without having Entourage send every single email? I am thinking of setting up a set of mailing lists, each corresponding to one of her groups. I have never set up a mailing list before and am wondering if it's possible to have a list accept emails from only one person (Admin) and distribute them to the group? Recipients should be able to unsubscribe easily, and by default reply to her but not the list. She should be the only one able to use the list for distribution, and should be able to send messages (with attachments) directly from her email client without modification. Is this possible? Where can I find step-by-step instructions? What are best practices to avoid her domain being blacklisted? What's the easiest way to convert her contact groups to mailing list subscribers? I am helping her for free, so the simpler the better :) Thank you! UPDATE: She has a standard linux hosting account allowing her to run php etc. And, ideally, the emails would come from her personally or at least from her domain name.

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  • 301 Redirecting URLs based on GET variables in .htaccess

    - by technicalbloke
    I have a few messy old URLs like... http://www.example.com/bunch.of/unneeded/crap?opendocument&part=1 http://www.example.com/bunch.of/unneeded/crap?opendocument&part=2 ...that I want to redirect to the newer, cleaner form... http://www.example.com/page.php/welcome http://www.example.com/page.php/prices I understand I can redirect one page to another with a simple redirect i.e. Redirect 301 /bunch.of/unneeded/crap http://www.example.com/page.php But the source page doesn't change, only it's GET vars. I can't figure out how to base the redirect on the value of these GET variables. Can anybody help pls!? I'm fairly handy with the old regexes so I can have a pop at using mod-rewrite if I have to but I'm not clear on the syntax for rewriting GET vars and I'd prefer to avoid the performance hit and use the cleaner Redirect directive. Is there a way? and if not can anyone clue me in as to the right mod-rewrite syntax pls? Cheers, Roger.

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  • How to combine twill and python into one code that could be run on "Google App Engine"?

    - by brilliant
    Hello everybody!!! I have installed twill on my computer (having previously installed Python 2.5) and have been using it recently. Python is installed on disk C on my computer: C:\Python25 And the twill folder (“twill-0.9”) is located here: E:\tmp\twill-0.9 Here is a code that I’ve been using in twill: go “some website’s sign-in page URL” formvalue 2 userid “my login” formvalue 2 pass “my password” submit go “URL of some other page from that website” save_html result.txt This code helps me to log in to one website, in which I have an account, record the HTML code of some other page of that website (that I can access only after logging in), and store it in a file named “result.txt” (of course, before using this code I firstly need to replace “my login” with my real login, “my password” with my real password, “some website’s sign-in page URL” and “URL of some other page from that website” with real URLs of that website, and number 2 with the number of the form on that website that is used as a sign-in form on that website’s log-in page) This code I store in “test.twill” file that is located in my “twill-0.9” folder: E:\tmp\twill-0.9\test.twill I run this file from my command prompt: python twill-sh test.twill Now, I also have installed “Google App Engine SDK” from “Google App Engine” and have also been using it for awhile. For example, I’ve been using this code: import hashlib m = hashlib.md5() m.update("Nobody inspects") m.update(" the spammish repetition ") print m.hexdigest() This code helps me transform the phrase “Nobody inspects the spammish repetition” into md5 digest. Now, how can I put these two pieces of code together into one python script that I could run on “Google App Engine”? Let’s say, I want my code to log in to a website from “Google App Engine”, go to another page on that website, record its HTML code (that’s what my twill code does) and than transform this HTML code into its md5 digest (that’s what my second code does). So, how can I combine those two codes into one python code? I guess, it should be done somehow by importing twill, but how can it be done? Can a python code - the one that is being run by “Google App Engine” - import twill from somewhere on the internet? Or, perhaps, twill is already installed on “Google App Engine”?

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  • How to react when asked a question you already know during an interview

    - by DevNull
    The short story:- If you are asked a tough algorithmic/puzzle question during an interview, whose solution is already known to you, do you:- Honestly tell the interviewer that you know this question already? -- this could result in bursting the interviewer's ego and him increasing the complexity level of the subsequent questions. Do an Oscar deserving performance and act as if you are thinking and trying hard and slowly getting to the solution? -- depending on your acting skills, could majorly impress the interviewer making the rest of the interview easier. Long story:- OK, this question comes as a result of what happened to me in a recent telephonic interview that I gave - the interview was supposed to be all algorithmic. The interviewer started with an algorithmic question which I had luckily already seen here on Stackoverflow. The best solution to that problem is not very intuitive and is more of a you-get-it-if-you-know-it kind. Now, just to not disappoint the interviewer too much, I took a few seconds as if I was pondering on the problem and then blurted out the answer which I knew too well having read and admired it on SO already. But I guess that gave it away to the interviewer that I already knew this question and since then, he started asking me for more efficient solutions and I kept coming up with approaches (even if not correct or more efficient, but I did touch a lot of different data structures and algos) and he kept asking for more efficient solutions and generally seemed put off by my initial salvo which was unexpected. What should I have done? Cheers!

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  • SQL 2008: Using separate tables for each datatype to return single row

    - by Thomas C
    Hi all I thought I'd be flexible this time around and let the users decide what contact information the wish to store in their database. In theory it would look as a single row containing, for instance; name, adress, zipcode, Category X, Listitems A. Example FieldType table defining the datatypes available to a user: FieldTypeID, FieldTypeName, TableName 1,"Integer","tblContactInt" 2,"String50","tblContactStr50" ... A user the define his fields in the FieldDefinition table: FieldDefinitionID, FieldTypeID, FieldDefinitionName 11,2,"Name" 12,2,"Adress" 13,1,"Age" Finally we store the actual contact data in separate tables depending on its datatype. Master table, only contains the ContactID tblContact: ContactID 21 22 tblContactStr50: ContactStr50ID,ContactID,FieldDefinitionID,ContactStr50Value 31,21,11,"Person A" 32,21,12,"Adress of person A" 33,22,11,"Person B" tblContactInt: ContactIntID,ContactID,FieldDefinitionID,ContactIntValue 41,22,13,27 Question: Is it possible to return the content of these tables in two rows like this: ContactID,Name,Adress,Age 21,"Person A","Adress of person A",NULL 22,"Person B",NULL,27 I have looked into using the COALESCE and Temp tables, wondering if this is at all possible. Even if it is: maybe I'm only adding complexity whilst sacrificing performance for benefit in datastorage and user definition option. What do you think? Best Regards /Thomas C

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  • is mysql index useful on column 'state' when only doing bit-operations on the column?

    - by Geert-Jan
    I have a lot of domain entities (stored in mysql) which undergo lots of different operations. Each operation is executed from a different program. I need to keep (flow)-state for these entities which I implemented in as a long field 'flowstate' used as a bitset. to query mysql for entities which have undergone a certain operation I do something like: select * from entities where state >> 7 & 1 = 1 Indicating bit 7 (cooresponding to operation 7) has run. (<-- simplified) Anyway, I really didn't pay attention to the performance implications of this setup in the beginning, and I think I'm in a bit of trouble since queries as the above run pretty slow. What I'd like to know: Does an mysql index on 'flowstate' help at all? After all it's not a single value Mysql can quickly find using a binary sort or whatever. If it doesn't, are there any other things I could do to speed things up? . Are there special 'mask-indices' for fields with use-cases as the above? TIA, Geert-jan

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  • C# Execute Method (with Parameters) with ThreadPool

    - by washtik
    We have the following piece of code (idea for this code was found on this website) which will spawn new threads for the method "Do_SomeWork()". This enables us to run the method multiple times asynchronously. The code is: var numThreads = 20; var toProcess = numThreads; var resetEvent = new ManualResetEvent(false); for (var i = 0; i < numThreads; i++) { new Thread(delegate() { Do_SomeWork(Parameter1, Parameter2, Parameter3); if (Interlocked.Decrement(ref toProcess) == 0) resetEvent.Set(); }).Start(); } resetEvent.WaitOne(); However we would like to make use of ThreadPool rather than create our own new threads which can be detrimental to performance. The question is how can we modify the above code to make use of ThreadPool keeping in mind that the method "Do_SomeWork" takes multiple parameters and also has a return type (i.e. method is not void). Also, this is C# 2.0.

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  • NSOperation and fwrite (Iphone)

    - by Sridhar
    Hi, I am having problem with this code.Basically I want to execute the fwrite from a timer function asyncronusly. Here is the code block in my Timer function. (This will call by the timer every 0.2 seconds. -(void)timerFunction { WriteFileOperation * operation = [WriteFileOperation writeFileWithBuffer:pFile buffer:readblePixels length:nBytes*15]; [_queue addOperation:operation]; // Here it is waiting to complete the fwrite } The WrtiteFilerOperation is an NSoperation class which it has to write the passing buffer to a file. I added this code in WriteFileOperation's "start" method. (void)start { if (![NSThread isMainThread]) { [self performSelectorOnMainThread:@selector(start) withObject:nil waitUntilDone:NO]; return; } [self willChangeValueForKey:@"isExecuting"]; _isExecuting = YES; [self didChangeValueForKey:@"isExecuting"]; NSLog(@"write bytes %d",fwrite(_buffer, 1, _nBytes, _file)); free(_buffer); [self finish]; } The problem here is , my timerFunction blocked by NSOperation until it writes the buffer into file.(I mean blocked till start method finishes its execution) and the performance seems same as directly placing the fwrite in timerFunction. I want to just return to timerFunction with out waiting from the start method execution to be completed. What I am doing wrong here ? Thanks In Advance Raghu

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  • Vim, LaTeX, and version controlI

    - by Bkkbrad
    I'm writing a LaTeX document in vim, and I have it hard wrapping at 80 characters to make reading easier. However, this causes problems with tracking changes with in version control. For example, inserting "Lorem ipsum" at the beginning of this text: 1 Dolor sit amet, consectetur adipiscing elit. Phasellus bibendum lobortis lectus 2 quis porta. Aenean vestibulum magna vel purus laoreet at molestie massa 3 suscipit. Vestibulum vestibulum, mauris nec convallis ultrices, tellus sapien 4 ullamcorper elit, dignissim consectetur justo tellus et nunc. results in: 1 Lorum ipsum dolor sit amet, consectetur adipiscing elit. Phasellus bibendum 2 lobortis lectus quis porta. Aenean vestibulum magna vel purus laoreet at 3 molestie massa suscipit. Vestibulum vestibulum, mauris nec convallis ultrices, 4 tellus sapien ullamcorper elit, dignissim consectetur justo tellus et nunc. When I review this change in git, it tells me that all the lines of the paragraph have changed because of the wrapping, even though only one semantic change has occurred. One way around this problem is to have every sentence on its own line. This looks the same in the rendered document, but the source now is harder to read, because each line has quite a different line length: 1 Lorum ipsum dolor sit amet, consectetur adipiscing elit. 2 Phasellus bibendum lobortis lectus quis porta. 3 Aenean vestibulum magna vel purus laoreet at molestie massa suscipit. 4 Vestibulum vestibulum, mauris nec convallis ultrices, tellus sapien ullamcorper elit, dignissim consectetur justo tellus et nunc. (If I soft wrap at 80, things still look bad, just in a different way.) Is it possible to have my text on disk with one newline per sentence, but display and edit it in vim as if the text of each paragraph was one long line, soft wrapped at 80 characters? I assume it requires some vim-foo rather than tweaking git or LaTeX.

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  • iPhone OS: Strategies for high density image work

    - by Jasconius
    I have a project that is coming around the bend this summer that is going to involve, potentially, an extremely high volume of image data for display. We are talking hundreds of 640x480-ish images in a given application session (scaled to a smaller resolution when displayed), and handfuls of very large (1280x1024 or higher) images at a time. I've already done some preliminary work and I've found that the typical 640x480ish image is just a shade under 1MB in memory when placed into a UIImageView and displayed... but the very large images can be a whopping 5+ MB's in some cases. This project is actually be targeted at the iPad, which, in my Instruments tests seems to cap out at about 80-100MB's of addressable physical memory. Details aside, I need to start thinking of how to move huge volumes of image data between virtual and physical memory while preserving the fluidity and responsiveness of the application, which will be high visibility. I'm probably on the higher ends of intermediate at Objective-C... so I am looking for some solid articles and advice on the following: 1) Responsible management of UIImage and UIImageView in the name of conserving physical RAM 2) Merits of using CGImage over UIImage, particularly for the huge images, and if there will be any performance gain 3) Anything dealing with memory paging particularly as it pertains to images I will epilogue by saying that the numbers I have above maybe off by about 10 or 15%. Images may or may not end up being bundled into the actual app itself as opposed to being loaded in from an external server.

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  • Caching page by parts; how to pass variables calculated in cached parts into never-cached parts?

    - by Kirzilla
    Hello, Let's imagine that I have a code like this... if (!$data = $cache->load("part1_cache_id")) { $item_id = $model->getItemId(); ob_start(); echo 'Here is the cached item id: '.$item_id; $data = ob_get_contents(); ob_end_clean(); $cache->save($data, "part1_cache_id"); } echo $data; echo never_cache_function($item_id); if (!$data_2 = $cache->load("part2_cache_id")) { ob_start(); echo 'Here is the another cached part of the page...'; $data_2 = ob_get_contents(); ob_end_clean(); $cache->save("part2_cache_id"); } echo $data_2; As far as you can see I need to pass $item_id variable into never_cache_function, but if fist part is cached (part1_cache_id) then I have no way to get $item_id value. I see the only solution - serialize all data from fist part (including $item_id value); then cache serialized string and unserialize it everytime when script is executed... Something like this... if (!$data = $cache->load("part1_cache_id")) { $item_id = $model->getItemId(); $data['item_id'] = $item_id; ob_start(); echo 'Here is the cached item id: '.$item_id; $data['html'] = ob_get_contents(); ob_end_clean(); $cache->save( serialize($data), "part1_cache_id" ); } $data = unserialize($data); echo $data['html'] echo never_cache_function($data['item_id']); Is there any other ways for doing such trick? I'm looking for the most high performance solution. Thank you UPDATED And another question is - how to implement such caching into controller without separating page into two templates? Is it possible? PS: Please, do not suggest Smarty, I'm really interested in implementing custom caching.

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  • Suitable ESXi Spec

    - by Canacourse
    Finally I have some money to buy a new server and replace the one I have been using for 10 years. Im thinking of running ESXi on the new server. And intend to use it as follows; One W2008 R2 Guest running Exchange, File store, SVN and an accounting application for day to day running of the company. Multiple Guest VMs W2K, XP, Vista & WIN7 that were setup for testing in-house & real customer images also for testing. Probably Two Server Guest Os's W2003 & W2008 running at the same time again for testing. One Guest VM for builds & Continuous integration. Possibly one Guest running W220R2 for a customer website (Portal) This server will have to last another 10 years so I want to get the spec right. Althought I am clear on the memory and disk requirments I am not so clear on the processor(s). Im thinking of 2 Quadcore processors but welcome advice on this. Proposed Spec 10GB Ram 2TB Sata Drives (Hardware Raid 1) 2 Processors (TBC) Normally 3 Server VM's will running concurrently and the other VMs will be started as required. Max expected VMs running about 7. Max users = 4. TIA..

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  • Query on object id in VQL

    - by Banang
    I'm currently working with the versant object database (using jvi), and have a case where I need to query the database based on an object id. What I'm trying to achieve is something along the lines of Employee employee = new Employee("Mr. Pickles"); session.commit(); FundVQLQuery q = new FundVQLQuery(session, "select * from Employee employee where employee = $1"); q.bind(employee); q.execute(); However, I'm finding out the hard way (I get an EVJ_NOT_A_VALID_KEY_TYPE error thrown at me) that this is infact not the way to do it. Anyone got any experience in working with VQL? Your help is much apreciated! A small clarification: The problem is I'm running some performance tests on the database using the pole position framework, and one of the tests in that framework requires me to fetch an object from the database using either an object reference or a low level object id. Thus, I'm not allowed to reference specific fields in the employee object, but must perform the query on the object in its entirety. So, it's not allowed for me to go "select * from Employee e where e.id = 4", I need it to use the entire object. Accepted answer: Since there is some sort of lunacy magic built into SO that prevents me to mark an accepted answer after a bounty has run out, readers should know that the answer posted by Chris Holmes solves this issue. Readers are encouraged to up-vote his post to further signalize the correctness of his answer to any future readers of this thread.

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  • How do I stop the m2eclipse plugin interfering with command line mvn builds?

    - by locka
    I use the m2eclipse plugin in Eclipse so that I can import a Maven project. The plugin reads the pom.xml and sorts out the dependencies in the projects in an Eclipse friendly way so I'm not looking at a sea of broken references and errors. I use Eclipse for code development however I usually build the projects from the command line, e.g. "mvn clean install". Unfortunately when I do this, m2eclipse detects disk activity and attempts to rebuild the workspace. This interferes with the command line build and sometimes results in a race condition. For example the command line might be in its clean phase but fails because it tries to delete a file or directory which is locked during the workspace rebuild. Aside from that workspace rebuilding is incredibly slow, and between failed builds and wasted CPU my build process is 2-3x longer than it should be. It isn't an option to not use Eclipse (e.g. to use Netbeans), or to disable m2eclipse. It is a useful plugin except for this behaviour. So my question is, how do I stop m2eclipse from rebuilding the workspace all the time? Can I invoke a manual refresh and otherwise disable this behaviour?

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  • Commit is VERY slow in my NHibernate / SQLite project

    - by Tom Bushell
    I've just started doing some real-world performance testing on my Fluent NHibernate / SQLite project, and am experiencing some serious delays when when I Commit to the database. By serious, I mean taking 20 - 30 seconds to Commit 30 K of data! This delay seems to get worse as the database grows. When the SQLite DB file is empty, commits happen almost instantly, but when it grows to 10 Meg, I see these huge delays. The database has 16 tables, averaging 10 columns each. One possible problem is that I'm storing a dozen or so IList members, but they are typically only 200 elements long. But this is a recent addition to Fluent NHibernate automapping, which stores each float in a single table row, so maybe that's a potential problem. Any suggestions on how to track this down? I suspect SQLite is the culprit, but maybe it's NHibernate? I don't have any experience with profilers, but am thinking of getting one. I'm aware of NHibernate Profiler - any recommendations for profilers that work well with SQLite? Here's the method that saves the data - it's just a SaveOrUpdate call and a Commit, if you ignore all the error handling and debug logging. public static void SaveMeasurement(object measurement) { Debug.WriteLine("\r\n---SaveMeasurement---"); // Get the application's database session var session = GetSession(); using (var transaction = session.BeginTransaction()) { try { session.SaveOrUpdate(measurement); } catch (Exception e) { throw new ApplicationException( "\r\n SaveMeasurement->SaveOrUpdate failed\r\n\r\n", e); } try { Debug.WriteLine("\r\n---Commit---"); transaction.Commit(); Debug.WriteLine("\r\n---Commit Complete---"); } catch (Exception e) { throw new ApplicationException( "\r\n SaveMeasurement->Commit failed\r\n\r\n", e); } } }

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  • How does PHP PDO work internally ?

    - by Rachel
    I want to use pdo in my application, but before that I want to understand how internally PDOStatement->fetch and PDOStatement->fetchAll. For my application, I want to do something like "SELECT * FROM myTable" and insert into csv file and it has around 90000 rows of data. My question is, if I use PDOStatement->fetch as I am using it here: // First, prepare the statement, using placeholders $query = "SELECT * FROM tableName"; $stmt = $this->connection->prepare($query); // Execute the statement $stmt->execute(); var_dump($stmt->fetch(PDO::FETCH_ASSOC)); while ($row = $stmt->fetch(PDO::FETCH_ASSOC)) { echo "Hi"; // Export every row to a file fputcsv($data, $row); } Will after every fetch from database, result for that fetch would be store in memory ? Meaning when I do second fetch, memory would have data of first fetch as well as data for second fetch. And so if I have 90000 rows of data and if am doing fetch every time than memory is being updated to take new fetch result without removing results from previous fetch and so for the last fetch memory would already have 89999 rows of data. Is this how PDOStatement::fetch works ? Performance wise how does this stack up against PDOStatement::fetchAll ?

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  • Why use bin2hex when inserting binary data from PHP into MySQL?

    - by Atli
    I heard a rumor that when inserting binary data (files and such) into MySQL, you should use the bin2hex() function and send it as a HEX-coded value, rather than just use mysql_real_escape_string on the binary string and use that. // That you should do $hex = bin2hex($raw_bin); $sql = "INSERT INTO `table`(`file`) VALUES (X'{$hex}')"; // Rather than $bin = mysql_real_escape_string($raw_bin); $sql = "INSERT INTO `table`(`file`) VALUES ('{$bin}')"; It is supposedly for performance reasons. Something to do with how MySQL handles large strings vs. how it handles HEX-coded values However, I am having a hard time confirming this. All my tests indicate the exact oposite; that the bin2hex method is ~85% slower and uses ~24% more memory. (I am testing this on PHP 5.3, MySQL 5.1, Win7 x64 - Using a farily simple insert loop.) For instance, this graph shows the private memory usage of the mysqld process while the test code was running: Does anybody have any explainations or reasources that would clarify this? Thanks.

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  • Question about creating device-compatible bitmaps in C#

    - by MusiGenesis
    I am storing bitmap-like data in a two-dimensional int array. To convert this array into a GDI-compatible bitmap (for use with BitBlt), I am using this function: public IntPtr GetGDIBitmap(int[,] data) { int w = data.GetLength(0); int h = data.GetLength(1); IntPtr ret = IntPtr.Zero; using (Bitmap bmp = new Bitmap(w, h)) { for (int x = 0; x < w; x++) { for (int y = 0; y < h; y++) { Color color = Color.FromArgb(data[x, y]); bmp.SetPixel(x, y, color); } } ret = bmp.GetHbitmap(); } return ret; } This works as expected, but the call to bmp.GetHbitmap() has to allocate memory for the returned bitmap. I'd like to modify this method in two (probably related) ways: I'd like to remove the intermediate Bitmap from the above code entirely, and go directly from my int[,] array to the device-compatible bitmap (i.e. the IntPtr). I presume this would involve calling CreateCompatibleBitmap, but I don't know how to go from that call to actually manipulating the pixel values. This should logically follow from the answer to the first, but I'd also like my method to re-use existing GDI bitmap handles (instead of creating a new bitmap each time). How can I do this? NOTE: I don't really use Bitmap.SetPixel(), as its performance could best be described as "glacial". The code is just for illustration.

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  • Custom UIView using CALayers disappears after 180º rotation or navigation controller pop

    - by Steve Madsen
    I have a created a custom UIView subclass that is exhibiting some strange behavior. It is a spinning wheel selector, and for performance reasons it is drawn entirely into two CALayer instances. The bottom layer is the wheel itself, which is rotated using setAffineTransform: according to touches. The top layer is eye candy. drawRect: is fairly simple. If the control hasn't been drawn yet (or it's been invalidated), it calls a method that creates the images and assigns them to the layer contents property. - (void) drawRect:(CGRect)rect { if (imageLayer == nil) { [self drawIntoImageLayer]; } [self updateWheelRotation]; } When the view controller using this view first appears, everything is fine. There are two instances where the view completely disappears, however: If the device is rotated a full 180°. After a view controller is popped off the navigation stack and the view becomes visible again. drawRect: is not called either time. Interestingly enough, it IS called after a 90° orientation change, and that causes the view to re-appear. How can I ensure that a custom view using CALayers is redrawn properly in these situations?

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  • Asp.Net tree view in SharePoint webpart- Input string error

    - by Faiz
    Hi All, I am facing a very strange issue. I have a SharePoint webpart that displays an asp.net tree view. It takes tree depth from a drop down. To improve performance of the tree view, i am setting the PopulateOnDemand property to true for the last level of the tree depth. For example, if i have a total of 10 levels in the data and the user selects tree depth as 3, then the third level data i set PopulateOnDemand to true. Now comes the strange part. When i click on the + image on the third level, and if there are children under that particular node then call back happens and node gets expanded. But if there no children for that particular node, then click + throws "Input string was not in the correct format" error. I have made sure that there is no server side error. Some things looks to be fishy when internet explorer is trying to bind construct the expanded node. Please let me know if any one faced similar issue or the resolution for the same? Thanks in advance

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