Search Results

Search found 13249 results on 530 pages for 'performance tuning'.

Page 471/530 | < Previous Page | 467 468 469 470 471 472 473 474 475 476 477 478  | Next Page >

• When is a good time to start thinking about scaling?

  - by Slokun

  I've been designing a site over the past couple days, and been doing some research into different aspects of scaling a site horizontally. If things go as planned, in a few months (years?) I know I'd need to worry about scaling the site up and out, since the resources it would end up consuming would be huge. So, this got me to thinking, when is the best time to start thinking about, and designing for, scalability? If you start too early on, you could easily over complicate your design, and make it impossible to actually build. You could also get too caught up in the details, the architecture, whatever, and wind up getting nothing done. Also, if you do get it working, but the site never takes off, you may have wasted a good chunk of extra effort. On the other hand, you could be saving yourself a ton of effort down the road. Designing it from the ground up to be big would make it much easier later on to let it grow big, with very little rewriting going on. I know for what I'm working on, I've decided to make at least a few choices now on the side of scaling, but I'm not going to do a complete change of thinking to get it to scale completely. Notably, I've redesigned my database from a conventional relational design to one similar to what was suggested on the Reddit site linked below, and I'm going to give memcache a try. So, the basic question, when is a good time to start thinking or worrying about scaling, and what are some good designs, tips, etc. for when doing so? A couple of things I've been reading, for those who are interested: http://www.codinghorror.com/blog/2009/06/scaling-up-vs-scaling-out-hidden-costs.html http://highscalability.com/blog/2010/5/17/7-lessons-learned-while-building-reddit-to-270-million-page.html http://developer.yahoo.com/performance/rules.html

  Read the article

• Are document-oriented databases any more suitable than relational ones for persisting objects?

  - by Owen Fraser-Green

  In terms of database usage, the last decade was the age of the ORM with hundreds competing to persist our object graphs in plain old-fashioned RMDBS. Now we seem to be witnessing the coming of age of document-oriented databases. These databases are highly optimized for schema-free documents but are also very attractive for their ability to scale out and query a cluster in parallel. Document-oriented databases also hold a couple of advantages over RDBMS's for persisting data models in object-oriented designs. As the tables are schema-free, one can store objects belonging to different classes in an inheritance hierarchy side-by-side. Also, as the domain model changes, so long as the code can cope with getting back objects from an old version of the domain classes, one can avoid having to migrate the whole database at every change. On the other hand, the performance benefits of document-oriented databases mainly appear to come about when storing deeper documents. In object-oriented terms, classes which are composed of other classes, for example, a blog post and its comments. In most of the examples of this I can come up with though, such as the blog one, the gain in read access would appear to be offset by the penalty in having to write the whole blog post "document" every time a new comment is added. It looks to me as though document-oriented databases can bring significant benefits to object-oriented systems if one takes extreme care to organize the objects in deep graphs optimized for the way the data will be read and written but this means knowing the use cases up front. In the real world, we often don't know until we actually have a live implementation we can profile. So is the case of relational vs. document-oriented databases one of swings and roundabouts? I'm interested in people's opinions and advice, in particular if anyone has built any significant applications on a document-oriented database.

  Read the article

• What is the base open source java package to filter/match URLs?

  - by Boaz

  Hi, I have an high performance application which deals with URLs. For every URL it needs to retrieve the appropriate settings from a predefined pool. Every settings object is associated with a URL pattern which indicates which URLs should use these settings. The matching rules are as follows: "google.com" match pattern should match all URLs pointing to the google domain (thus, maps.google.com and www.google.com/match are matched). "*.google.com" should match all URLs pointing to a subdomain of google.com (thus, maps.google.com matches, but google.com and www.google.com don't). "maps.google.com" should match all URLs pointing to this specific subdomain. Apart from the above rules, every match rule can contain a path, which means that the path part of the URL should start with the match rule path. So: "*.google.com/maps" matches "maps.google.com/maps" but not "maps.google.com/advanced". As you can see the rules above are overlapping. In the case two rules exist which match the same URL the most specific should apply. The list above is ranked from least specific to most specific. This seems to be such a standard problem that I was hoping to use a ready made library rather than program my self. Google reveals a couple of options but without a clear way to choose between them. What would you recommend as a good library for this task? Thanks, Boaz

  Read the article

• Is there a language with native pass-by-reference/pass-by-name semantics, which could be used in mod

  - by Bubba88

  Hi! This is a reopened question. I look for a language and supporting platform for it, where the language could have pass-by-reference or pass-by-name semantics by default. I know the history a little, that there were Algol, Fortran and there still is C++ which could make it possible; but, basically, what I look for is something more modern and where the mentioned value pass methodology is preferred and by default (implicitly assumed). I ask this question, because, to my mind, some of the advantages of pass-by-ref/name seem kind of obvious. For example when it is used in a standalone agent, where copyiong of values is not necessary (to some extent) and performance wouldn't be downgraded much in that case. So, I could employ it in e.g. rich client app or some game-style or standalone service-kind application. The main advantage to me is the clear separation between identity of a symbol, and its current value. I mean when there is no reduntant copying, you know that you're working with the exact symbol/path you have queried/received. And intristing boxing of values will not interfere with the actual logic of program. I know that there is C# ref keyword, but it's something not so intristic, though acceptable. Equally, I realize that pass-by-reference semantics could be simulated in virtually any language (Java as an instant example) and so on.. not sure about pass by name :) What would you recommend - create a something like DSL for such needs wherever it be appropriate; or use some languages that I already know? Maybe, there is something that I'm missing? Thank you!

  Read the article

• Floating Point Arithmetic - Modulo Operator on Double Type

  - by CrimsonX

  So I'm trying to figure out why the modulo operator is returning such a large unusual value. If I have the code: double result = 1.0d % 0.1d; it will give a result of 0.09999999999999995. I would expect a value of 0 Note this problem doesn't exist using the dividing operator - double result = 1.0d / 0.1d; will give a result of 10.0, meaning that the remainder should be 0. Let me be clear: I'm not surprised that an error exists, I'm surprised that the error is so darn large compared to the numbers at play. 0.0999 ~= 0.1 and 0.1 is on the same order of magnitude as 0.1d and only one order of magnitude away from 1.0d. Its not like you can compare it to a double.epsilon, or say "its equal if its < 0.00001 difference". I've read up on this topic on StackOverflow, in the following posts one two three, amongst others. Can anyone suggest explain why this error is so large? Any any suggestions to avoid running into the problems in the future (I know I could use decimal instead but I'm concerned about the performance of that).

  Read the article

• How to choose light version of database system

  - by adopilot

  I am starting one POS (Point of sale) project. Targeting system is going to be written in C# .NET 2 WinForms and as main database server We are going to use MS-SQL Server. As we have a lot of POS devices in chain for one store I will love to have backend local data base system on each POS device. Scenario are following: When main server goes down!! POS application should continue working "off-line" with local database, until connection to main server come up again. Now I am in dilemma which local database is going to be most adoptable for me. Here is some notes for helping me point me in right direction: To be Light "My POS devices art usually old and suffering with performances" To be Free "I have a lot of devices and I do not wont additional cost beside main SQL serer" One day Ill love to try all that port on Mono and Linux OS. Here is what I've researched so far: Simple XML "Light but I am afraid of performance, My main table of items is average of 10K records" SQL-Express "I am afraid that my POS devices is poor with hardware for SQLExpress, and also hard to install on each device and configure" Less known Advantage Database Server have free distribution of offline ADT system. DBF with extended Library,"Respect for good old DBFs but that era is behind Me with clipper and DBFs" MS Access Sqlite "Mostly like for now, but I am afraid how it is going to pair with MS SQL do they have same Data types". I know that in this SO is a lot of subjective data, but at least can someone recommended some others lite database system, or things that I shod most take attention before I choice database.

  Read the article

• Looking for combinations of server and embedded database engines

  - by codeelegance

  I'm redesigning an application that will be run as both a single user and multiuser application. It is a .NET 2.0 application. I'm looking for server and embedded databases that work well together. I want to deploy the embedded database in the single user setup and of course, the server in the multiuser setup. Past releases have been based on MSDE but in the past year we've been having a lot of install issues: new installs hanging and leaving the system in an unknown state, upgrades disconnecting the database, etc. I migrated the application to SQL Server 2005 and the install is more reliable (as long as a user doesn't try to install over a broken MSDE installation). Since next year's release will be a complete redesign I figured now's the best time to address the database issue as well. The database has been abstracted from the rest of the application so I just need to choose which database(s) to use and write an implementation for each one. So far I've considered: SQL Server/ SQL Server Compact Edition Firebird (same DB engine is available in two different server modes and an embedded dll) Each has its own merits but I'm also interested in any other suggestions. This is a fairly simple program and its data requirements are simple as well. I don't expect it to strain whatever database I eventually choose. So easy configuration and deployment hold more weight than performance.

  Read the article

• Guid Primary /Foreign Key dilemma SQL Server

  - by Xience

  Hi guys, I am faced with the dilemma of changing my primary keys from int identities to Guid. I'll put my problem straight up. It's a typical Retail management app, with POS and back office functionality. Has about 100 tables. The database synchronizes with other databases and receives/ sends new data. Most tables don't have frequent inserts, updates or select statements executing on them. However, some do have frequent inserts and selects on them, eg. products and orders tables. Some tables have upto 4 foreign keys in them. If i changed my primary keys from 'int' to 'Guid', would there be a performance issue when inserting or querying data from tables that have many foreign keys. I know people have said that indexes will be fragmented and 16 bytes is an issue. Space wouldn't be an issue in my case and apparently index fragmentation can also be taken care of using 'NEWSEQUENTIALID()' function. Can someone tell me, from there experience, if Guid will be problematic in tables with many foreign keys. I'll be much appreciative of your thoughts on it...

  Read the article

• Should we deploy a Webkit browser for our intranet applications?

  - by Jeff Meatball Yang

  At my place of employment, we are increasingly finding it difficult to develop for IE, which was historically the easiest browser to target, from an intranet-app point of view. It was already deployed. It already understood NTLM authentication, thus well integrated with our domain-level security. It had neat, albeit non-standard features such as XMLDOM and XmlHTTP. Now, we are increasingly irritated by issues presented by IE: There are several versions: IE 7, 8, and soon 9 beta, which all have slightly different issues related to performance, functionality (especially re:security and zones), and aesthetics. IE 7 and 8 are slower than Webkit-based browsers. Period. There are technology limitations such as missing canvas element, CSS bugs, etc. that make it hard to use 3rd party packages or even consistently write code across IE versions. Users are increasingly using Firefox or Chrome, even for intranet use. Does anyone have experience with making a transition? Any advice would be welcome.

  Read the article

• _dl_runtime_resolve -- When do the shared objects get loaded in to memory?

  - by windfinder

  We have a message processing system with high performance demands. Recently we have noticed that the first message takes many times longer then subsequent messages. A bunch of transformation and message augmentation happens as this goes through our system, much of it done by way of external lib. I just profiled this issue (using callgrind), comparing a "run" of just one message with a "run" of many messages (providing a baseline of comparison). The main difference I see is the function "do_lookup_x" taking up a huge amount of time. Looking at the various calls to this function, they all seem to be called by the common function: _dl_runtime_resolve. Not sure what this function does, but to me this looks like the first time the various shared libraries are being used, and are then being loaded in to memory by the ld. Is this a correct assumption? That the binary will not load the shared libraries in to memory until they are being prepped for use, therefore we will see a massive slowdown on the first message, but on none of the subsequent? How do we go about avoiding this? Note: We operate on the microsecond scale.

  Read the article

• What arguments to use to explain why a SQL DB is far better then a flat file

  - by jamone

  The higher ups in my company were told by good friends that flat files are the way to go, and we should switch from MS SQL server to them for everything we do. We have over 300 servers and hundreds of different databases. From just the few I'm involved with we have 10 billion records in quite a few of them with upwards of 100k new records a day and who knows how many updates... Me and a couple others need to come up with a response saying why we shouldn't do this. Most of our stuff is ASP.NET with some legacy ASP. We thought that making a simple console app that tests/times the same interactions between a flat file (stored on the network) and SQL over the network doing large inserts, searches, updates etc along with things like network disconnects randomly. This would show them how bad flat files can be espically when you are dealing with millions of records. What things should I use in my response? What should I do with my demo code to illustrate this? My sort list so far: Security Concurent access Performance with large ammounts of data Ammount of time to do such a massive rewrite/switch Lack of transactions PITA to map relational data to flat files I fear that this will be a great post on the Daily WTF someday if I can't stop it now.

  Read the article

• Trouble Running Leaks Instrument

  - by TheGeoff

  I'm having trouble running the Leaks Instrument since installing the 3.0 SDK. An NDA disclaimer here I don't think this is a 3.0 SDK issue, just a configuration problem. So I'm looking for advice on configuring the tools in question not the 3.0 SDK per se. Here’s the breakdown of the behavior I am seeing. My Application is compiled to OS version 2.2. I can run it out of XCode in debug mode on the Simulator and Device running 2.2, 2.2.1, 3.0. If I start it with Performance Tools - Leaks, I get an error message from the OS, “The application xxxx quit unexpectedly”, “Ignore, Report, Relaunch.” If I click “Ignore” one of two things will happen, either Leaks tells me it couldn’t attach, or Leaks stop responding to input and I have to Force Quit. Interesting thing is the Simulator starts in 3.0 OS. If I start Instruments Manually and attach to a running 2.2 Simulator it shows the same behavior. If I attach Leaks to an iPhone Device it works. It seems that once I launch Leaks my app won't run in the simulator until I do a new build. Any ideas for getting my Simulator/Leaks/Xcode synced back up? Thanks, Geoff

  Read the article

• django: control json serialization

  - by abolotnov

  Is there a way to control json serialization in django? Simple code below will return serialized object in json: co = Collection.objects.all() c = serializers.serialize('json',co) The json will look similar to this: [ { "pk": 1, "model": "picviewer.collection", "fields": { "urlName": "architecture", "name": "\u0413\u043e\u0440\u043e\u0434 \u0438 \u0430\u0440\u0445\u0438\u0442\u0435\u043a\u0442\u0443\u0440\u0430", "sortOrder": 0 } }, { "pk": 2, "model": "picviewer.collection", "fields": { "urlName": "nature", "name": "\u041f\u0440\u0438\u0440\u043e\u0434\u0430", "sortOrder": 1 } }, { "pk": 3, "model": "picviewer.collection", "fields": { "urlName": "objects", "name": "\u041e\u0431\u044a\u0435\u043a\u0442\u044b \u0438 \u043d\u0430\u0442\u044e\u0440\u043c\u043e\u0440\u0442", "sortOrder": 2 } } ] You can see it's serializing it in a way that you are able to re-create the whole model, shall you want to do this at some point - fair enough, but not very handy for simple JS ajax in my case: I want bring the traffic to minimum and make the whole thing little clearer. What I did is I created a view that passes the object to a .json template and the template will do something like this to generate "nicer" json output: [ {% if collections %} {% for c in collections %} {"id": {{c.id}},"sortOrder": {{c.sortOrder}},"name": "{{c.name}}","urlName": "{{c.urlName}}"}{% if not forloop.last %},{% endif %} {% endfor %} {% endif %} ] This does work and the output is much (?) nicer: [ { "id": 1, "sortOrder": 0, "name": "????? ? ???????????", "urlName": "architecture" }, { "id": 2, "sortOrder": 1, "name": "???????", "urlName": "nature" }, { "id": 3, "sortOrder": 2, "name": "??????? ? ?????????", "urlName": "objects" } ] However, I'm bothered by the fast that my solution uses templates (an extra step in processing and possible performance impact) and it will take manual work to maintain shall I update the model, for example. I'm thinking json generating should be part of the model (correct me if I'm wrong) and done with either native python-json and django implementation but can't figure how to make it strip the bits that I don't want. One more thing - even when I restrict it to a set of fields to serialize, it will keep the id always outside the element container and instead present it as "pk" outside of it.

  Read the article

• To implement a remote desktop sharing solution

  - by Cameigons

  Hi, I'm on planning/modeling phase to develop a remote desktop sharing solution, which must be web browser based. In other words: an user will be able to see and interact with someone's remote desktop using his web-browser. Everything the user who wants to share his desktop will need, besides his browser, is installing an add-in, which he's going to be prompted about when necessary. The add-in is required since (afaik) no browser technology allows desktop control from an app running within the browser alone. The add-in installation process must be as simple and transparent as possible to the user (similar to AdobeConnectNow, in case anyone's acquainted with it). The user can share his desktop with lots of people at the same time, but concede desktop control to only one of them at a time(makes no sense being otherwise). Project requirements: All technology employed must be open-source license compatible Both front ends are going to be in flash (browser) Must work on Linux, Windows XP(and later) and MacOSX. Must work at least with IE7(and later) and Firefox3.0(and later). At the very least, once the sharer's stream hits the server from where it'll be broadcast, hereon it must be broadcasted in flv (so I'm thinking whether to do the encoding at the client's machine (the one sharing the desktop) or send it in some other format to the server and encode it there). Performance and scalability are important: It must be able to handle hundreds of dozens of users(one desktop sharer, the rest viewers) We'll definitely be using red5. My doubts concern mostly implementing the desktop publisher side (add-in and streamer): 1) Are you aware of other projects that I could look into for ideas? (I'm aware of bigbluebutton.org and code.google.com/p/openmeetings) 2) Should I base myself on VNC ? 3) Bearing in mind the need to have it working cross-platform, what language should I go with? (My team is very used with java and I have some knowledge of C/C++, but anything goes really). 4) Any other advices are appreciated.

  Read the article

• Project management: Implementing custom errors in VS compilation process

  - by David Lively

  Like many architects, I've developed coding standards through years of experience to which I expect my developers to adhere. This is especially a problem with the crowd that believes that three or four years of experience makes you a senior-level developer.Approaching this as a training and code review issue has generated limited success. So, I was thinking that it would be great to be able to add custom compile-time errors to the build process to more strictly enforce this and other guidelines. For instance, we use stored procedures for ALL database access, which provides procedure-level security, db encapsulation (table structure is hidden from the app), and other benefits. (Note: I am not interested in starting a debate about this.) Some developers prefer inline SQL or parametrized queries, and that's fine - on their own time and own projects. I'd like a way to add a compilation check that finds, say, anything that looks like string sql = "insert into some_table (col1,col2) values (@col1, @col2);" and generates an error or, in certain circumstances, a warning, with a message like Inline SQL and parametrized queries are not permitted. Or, if they use the var keyword var x = new MyClass(); Variable definitions must be explicitly typed. Do Visual Studio and MSBuild provide a way to add this functionality? I'm thinking that I could use a regular expression to find unacceptable code and generate the correct error, but I'm not sure what, from a performance standpoint, is the best way to to integrate this into the build process. We could add a pre- or post-build step to run a custom EXE, but how can I return line- and file-specifc errors? Also, I'd like this to run after compilation of each file, rather than post-link. Is a regex the best way to perform this type of pattern matching, or should I go crazy and run the code through a C# parser, which would allow node-level validation via the parse tree? I'd appreciate suggestions and tales of prior experience.

  Read the article

• how to design a schema where the columns of a table are not fixed

  - by hIpPy

  I am trying to design a schema where the columns of a table are not fixed. Ex: I have an Employee table where the columns of the table are not fixed and vary (attributes of Employee are not fixed and vary). Nullable columns in the Employee table itself i.e. no normalization Instead of adding nullable columns, separate those columns out in their individual tables ex: if Address is a column to be added then create table Address[EmployeeId, AddressValue]. Create tables ExtensionColumnName [EmployeeId, ColumnName] and ExtensionColumnValue [EmployeeId, ColumnValue]. ExtensionColumnName would have ColumnName as "Address" and ExtensionColumnValue would have ColumnValue as address value. Employee table EmployeeId Name ExtensionColumnName table ColumnNameId EmployeeId ColumnName ExtensionColumnValue table EmployeeId ColumnNameId ColumnValue There is a drawback is the first two ways as the schema changes with every new attribute. Note that adding a new attribute is frequent. I am not sure if this is the good or bad design. If someone had a similar decision to make, please give an insight on things like foreign keys / data integrity, indexing, performance, reporting etc.

  Read the article

• What arguments to use to explain why SQL Server is far better then a flat file

  - by jamone

  The higher ups in my company were told by good friends that flat files are the way to go, and we should switch from SQL Server to them for everything we do. We have over 300 servers and hundreds of different databases. From just the few I'm involved with we have 10 billion records in quite a few of them with upwards of 100k new records a day and who knows how many updates... Me and a couple others need to come up with a response saying why we shouldn't do this. Most of our stuff is ASP.NET with some legacy ASP. We thought that making a simple console app that tests/times the same interactions between a flat file (stored on the network) and SQL over the network doing large inserts, searches, updates etc along with things like network disconnects randomly. This would show them how bad flat files can be especially when you are dealing with millions of records. What things should I use in my response? What should I do with my demo code to illustrate this? My sort list so far: Security Concurrent access Performance with large amounts of data Amount of time to do such a massive rewrite/switch Lack of transactions PITA to map relational data to flat files NTFS doesn't support tons of files in a directory well I fear that this will be a great post on the Daily WTF someday if I can't stop it now.

  Read the article

• Simply doing modelType.ToString() isn't sufficient, How can i use it via Activator.CreateInstance?

  - by programmerist

  public class MyController { public object CreateByEnum(DataModelType modeltype) { string enumText = modeltype.ToString(); // will return for example "Company" Type classType = Type.GetType(enumText); // the Type for Company class object t = Activator.CreateInstance(classType); // create an instance of Company class return t; } } public class CompanyView { public static List<Personel> GetPersonel() { MyController controller = new MyController(); _Company company = controller.CreateByEnum(DataModelType.Company) as _Company; return company.GetPersonel(); } } public enum DataModelType { xyz, klm, tucyz, Company } Yes, I agree Activator.CreateInstance() is very useful. Unfortunately, I need to pass in the correct type. That means building the correct string to pass to Type.GetType(). If I trace through the call to Controller.CreatebyEnum() in the code I posted above, simply doing modelType.ToString() isn't sufficient, even for the case of DataModelType.Company. My solution'll be maintenance bottleneck. What would be better is something that takes the results of modelType.ToString() and then recursively searches through all the types found in all the assemblies loaded in the current AppDomain. According to MSDN, Type.GetType() only searches the current calling assembly, and mscorlib.dll. How can i do that? . i need best performance?

  Read the article

• How to receive Email in JEE application

  - by Hank

  Obviously it's not so difficult to send out emails from a JEE application via JavaMail. What I am interested in is the best pattern to receive emails (notification bounces, mostly)? I am not interested in IMAP/POP3-based approaches (polling the inbox) - my application shall react to inbound emails. One approach I could think of would be Keep existing MTA (postfix on linux in my case) - ops team already knows how to configure / operate it For every mail that arrives, spawn a Java app that receives the data and sends it off via JMS. I could do this via an entry in /etc/aliases like myuser: "|/path/to/javahelper" with javahelper calling the Java app, passing STDIN along. MDB (part of JEE application) receives JMS message, parses it, detects bounce message and acts accordingly. Another approach could be Open a listening network socket on port 25 on the JEE application container. Associate a SessionBean with the socket. Bean is part of JEE application and can parse/detect bounces/handle the messages directly. Keep existing MTA as inbound relay, do all its security/spam filtering, but forward emails to myuser (that pass the filter) to the JEE application container, port 25. The first approach I have done before (albeit in a different language/setup). From a performance and (perceived) cleanliness point of view, I think the second approach is better, but it would require me to provide a proper SMTP transport implementation. Also, I don't know if it's at all possible to connect a network socket with a bean... What is your recommendation? Do you have details about the second approach?

  Read the article

• Best XML format for log events in terms of tool support for data mining and visualization?

  - by Thorbjørn Ravn Andersen

  We want to be able to create log files from our Java application which is suited for later processing by tools to help investigate bugs and gather performance statistics. Currently we use the traditional "log stuff which may or may not be flattened into text form and appended to a log file", but this works the best for small amounts of information read by a human. After careful consideration the best bet has been to store the log events as XML snippets in text files (which is then treated like any other log file), and then download them to the machine with the appropriate tool for post processing. I'd like to use as widely supported an XML format as possible, and right now I am in the "research-then-make-decision" phase. I'd appreciate any help both in terms of XML format and tools and I'd be happy to write glue code to get what I need. What I've found so far: log4j XML format: Supported by chainsaw and Vigilog. Lilith XML format: Supported by Lilith Uninvestigated tools: Microsoft Log Parser: Apparently supports XML. OS X log viewer: plus there is a lot of tools on http://www.loganalysis.org/sections/parsing/generic-log-parsers/ Any suggestions?

  Read the article

• What effects has working in rotating shifts on programming teams?

  - by eKek0

  I work in a bank, and the boss now want's that we, the programming team, work on rotating shifts. He wants that sometimes we work from 7am to 3pm, and sometimes on 11.30am to 7.30pm. He says that we will be more productive working this way, because he has worked with teams just like that and he just knows that. Nobody of the team wants this change, but we don't know how to effectively reject this new rule. I was trying to find some empirical (or almost) evidence about how rotating shifts affects performance of programming teams, and I couldn't. I had read something about rotating shifts, but not exactly about the effect of this on programming teams. Do you know any research about rotating shifts on programming teams? Did you have any experience with this kind of work? EDIT: Other teams of the company, like the database administrators team, the help desk team, the communication team or the network administrators team are already working in rotating shifts, and they don't like this but they do it anyway. I think the boss want that we work on rotating shifts too because of them, but since only we do programming I think the effects of rotating shifts could be, at least, different for us.

  Read the article

• Call method immediately after object construction in LINQ query

  - by Steffen

  I've got some objects which implement this interface: public interface IRow { void Fill(DataRow dr); } Usually when I select something out of db, I go: public IEnumerable<IRow> SelectSomeRows { DataTable table = GetTableFromDatabase(); foreach (DataRow dr in table.Rows) { IRow row = new MySQLRow(); // Disregard the MySQLRow type, it's not important row.Fill(dr); yield return row; } } Now with .Net 4, I'd like to use AsParallel, and thus LINQ. I've done some testing on it, and it speeds up things alot (IRow.Fill uses Reflection, so it's hard on the CPU) Anyway my problem is, how do I go about creating a LINQ query, which calls Fills as part of the query, so it's properly parallelized? For testing performance I created a constructor which took the DataRow as argument, however I'd really love to avoid this if somehow possible. With the constructor in place, it's obviously simple enough: public IEnumerable<IRow> SelectSomeRowsParallel { DataTable table = GetTableFromDatabase(); return from DataRow dr in table.Rows.AsParallel() select new MySQLRow(dr); } However like I said, I'd really love to be able to just stuff my Fill method into the LINQ query, and thus not need the constructor overload.

  Read the article

• SQL Server full text query across multiple tables - why so slow?

  - by Mikey Cee

  Hi. I'm trying to understand the performance of an SQL Server 2008 full-text query I am constructing. The following query, using a full-text index, returns the correct results immediately: SELECT O.ID, O.Name FROM dbo.EventOccurrence O WHERE FREETEXT(O.Name, 'query') ie, all EventOccurrences with the word 'query' in their name. And the following query, using a full-text index from a different table, also returns straight away: SELECT V.ID, V.Name FROM dbo.Venue V WHERE FREETEXT(V.Name, 'query') ie. all Venues with the word 'query' in their name. But if I try to join the tables and do both full-text queries at once, it 12 seconds to return: SELECT O.ID, O.Name FROM dbo.EventOccurrence O INNER JOIN dbo.Event E ON O.EventID = E.ID INNER JOIN dbo.Venue V ON E.VenueID = V.ID WHERE FREETEXT(E.Name, 'search') OR FREETEXT(V.Name, 'search') Here is the execution plan: http://uploadpad.com/files/query.PNG From my reading, I didn't think it was even possible to make a free text query across multiple tables in this way, so I'm not sure I am understanding this correctly. Note that if I remove the WHERE clause from this last query then it returns all results within a second, so it's definitely the full-text that is causing the issue here. Can someone explain (i) why this is so slow and (ii) if this is even supported / if I am even understanding this correctly. Thanks in advance for your help.

  Read the article

• Should java try blocks be scoped as tightly as possible?

  - by isme

  I've been told that there is some overhead in using the Java try-catch mechanism. So, while it is necessary to put methods that throw checked exception within a try block to handle the possible exception, it is good practice performance-wise to limit the size of the try block to contain only those operations that could throw exceptions. I'm not so sure that this is a sensible conclusion. Consider the two implementations below of a function that processes a specified text file. Even if it is true that the first one incurs some unnecessary overhead, I find it much easier to follow. It is less clear where exactly the exceptions come from just from looking at statements, but the comments clearly show which statements are responsible. The second one is much longer and complicated than the first. In particular, the nice line-reading idiom of the first has to be mangled to fit the readLine call into a try block. What is the best practice for handling exceptions in a funcion where multiple exceptions could be thrown in its definition? This one contains all the processing code within the try block: void processFile(File f) { try { // construction of FileReader can throw FileNotFoundException BufferedReader in = new BufferedReader(new FileReader(f)); // call of readLine can throw IOException String line; while ((line = in.readLine()) != null) { process(line); } } catch (FileNotFoundException ex) { handle(ex); } catch (IOException ex) { handle(ex); } } This one contains only the methods that throw exceptions within try blocks: void processFile(File f) { FileReader reader; try { reader = new FileReader(f); } catch (FileNotFoundException ex) { handle(ex); return; } BufferedReader in = new BufferedReader(reader); String line; while (true) { try { line = in.readLine(); } catch (IOException ex) { handle(ex); break; } if (line == null) { break; } process(line); } }

  Read the article

• How to make std::vector's operator[] compile doing bounds checking in DEBUG but not in RELEASE

  - by Edison Gustavo Muenz

  I'm using Visual Studio 2008. I'm aware that std::vector has bounds checking with the at() function and has undefined behaviour if you try to access something using the operator [] incorrectly (out of range). I'm curious if it's possible to compile my program with the bounds checking. This way the operator[] would use the at() function and throw a std::out_of_range whenever something is out of bounds. The release mode would be compiled without bounds checking for operator[], so the performance doesn't degrade. I came into thinking about this because I'm migrating an app that was written using Borland C++ to Visual Studio and in a small part of the code I have this (with i=0, j=1): v[i][j]; //v is a std::vector<std::vector<int> > The size of the vector 'v' is [0][1] (so element 0 of the vector has only one element). This is undefined behaviour, I know, but Borland is returning 0 here, VS is crashing. I like the crash better than returning 0, so if I can get more 'crashes' by the std::out_of_range exception being thrown, the migration would be completed faster (so it would expose more bugs that Borland was hiding).

  Read the article

< Previous Page | 467 468 469 470 471 472 473 474 475 476 477 478  | Next Page >