architecture

问题 Why do computer use Hex Number System at assembly language? Why don't they use any other number system like binary, octal, decimal? What thing forced computer designer to use hex system at assembly? Why it looked so beneficial to them? 回答1: Well it doesn't make a difference how you represent them but as we know that humans don't understand binary numbers, they are only to make the computer's life easier as it works on only two states true and false. So in order to make binary numbers

问题 I am in a situation where I have to perform a transaction master detail record ( Drop prev details, insert new details, Update Master status ) Master Business Object has 20 fields Details Business Object has 4 fields only Now I have to update only 1 field in master table and 4 fields in details table for insert. If I initialize a new master object, 19 fields are being wasted for a simple update. What do I do to efficiently handle this situation ? Can I make a new object and inherit only one

问题 I am in a situation where I have to perform a transaction master detail record ( Drop prev details, insert new details, Update Master status ) Master Business Object has 20 fields Details Business Object has 4 fields only Now I have to update only 1 field in master table and 4 fields in details table for insert. If I initialize a new master object, 19 fields are being wasted for a simple update. What do I do to efficiently handle this situation ? Can I make a new object and inherit only one

问题 I want to make my plugin subsystem using mef but i have few question because i am newbie in csharp and mef ( What i want to do: every plugin can create its own interface IPlugin1, IPlugin2 ... each of these interfaces must have specified functions Load, Unload using mef i want to enum all exports and call Load/Unload The questions: a. Is my solution good and if no how can i improve it (by using something else)? b. How to enum all exports using mef and call specified interface function? I

问题 hey guys android has some serious limitations with file system space on certain devices and my app starts giving me errors once my sqlite db file size grows beyond 5mb and i try to run the vaccum command i am thinking to separate my data across multiple sqlite files to break them into smaller db files so that i can simply delete the appropriate sqlite file when its data becomes obselete that way my main sqlite file never grows too big and i dont ever need to eat up space when doing vaccum

问题 We using Spring, Spring-Data and JPA in our project. For production servers, we would like to setup database cluster such that all read queries are directed to one server and all write queries are directed to another server. This obviously will require some changes in the way the DAOs are built. Does anyone know how to achieve this if one has, so far, been following cook-book style DAO creations using Spring-Data/JPA where a DAO implementation is responsible for both reads and writes? What

问题 I have a .NET application in which most of the UI is custom. On some of the pages, I am using ExtJS4 components, such as Grid, to display a table of Users for example. I also have another page where I display a user profile, and another page where I display an application form. There are many other pages that don't use ExtJS. I sparingly use ExtJS components and would like to have re-usable code for Stores and Models across all the pages where I use ExtJS. I am familiar with ExtJS MVC

问题 I am making a user interface which shows graphs and manipulates graphs. The class extends JFrame implements ActionListener. The ActionListener then calls different classes to manipulate graphs depending on the action. This worked while the class had few ActionListeners; however, now the class is becoming unmanageable. I know that in the interest of encapsulation, it would be best to have the ActionListener within the user interface class because it needs to access non-static components of the

问题 I'm working on an ASP.NET MVC project and I've come to the point where I want to start considering my caching strategy. I've tried to leave my framework as open as possible for the use in caching. From what I heard during Scott Hanselman's podcast StackOverflow.com uses page output caching and zips that content and puts it into RAM. This sounds like this would be great for user-wide cache but for something like personalized pages you would have to cache a version for each user and that could

问题 I get duplicate symbols error after I updated my Xcode . (find the code down) Does anybody get this too? And how could be solved? I tried to remove -ObjC linker flag from the "Other Linker Flags" section, check after imported .m instead of .h , switch the "No Common Blocks" compiler setting to NO, I went to Targets -> Build Phases -> Compile sources and no duplicates there, tried all with no results. Any other ideas? duplicate symbol _space in: /Users/a/Library/Developer/Xcode/DerivedData