Search Results

Search found 22277 results on 892 pages for 'multiple addresses'.

Page 568/892 | < Previous Page | 564 565 566 567 568 569 570 571 572 573 574 575  | Next Page >

• Tömörítés becslése - Compression Advisor

  - by lsarecz

  Az Oracle Database 11g verziójától már OLTP adatbázisok is hatékonyan tömöríthetok az Advanced Compression funkcióval. Nem csak a tárolandó adatok mennyisége csökken ezáltal felére, vagy akár negyedére, de az adatbázis teljesítménye is javulhat, amennyiben I/O korlátos a rendszer (és általában az). Hogy pontosan mekkora tömörítés várható az Advanced Compression bevezetésével, az kiválóan becsülheto a Compression Advisor eszközzel. Ez nem csak az OLTP tömörítés mértékét, de 11gR2 verziótól kezdve a HCC tömörítés arányát is becsülni tudja, amely Exadata Database Machine, Pillar Axiom illetve ZFS Storage alkalmazásával érheto el. A HCC tömörítés becsléséhez csak 11gR2 adatbázisra van szükség, nem kell hozzá a speciális célhardver (Exadata, Pillar, ZFS). A Compression Advisor valójában a DBMS_COMPRESSION package használatával érheto el. A package-hez tartozik 6 konstans, amellyel a kívánt tömörítési szintek választhatók ki: Constant Type Value Description COMP_NOCOMPRESS NUMBER 1 No compression COMP_FOR_OLTP NUMBER 2 OLTP compression COMP_FOR_QUERY_HIGH NUMBER 4 High compression level for query operations COMP_FOR_QUERY_LOW NUMBER 8 Low compression level for query operations COMP_FOR_ARCHIVE_HIGH NUMBER 16 High compression level for archive operations COMP_FOR_ARCHIVE_LOW NUMBER 32 Low compression level for archive operations A GET_COMPRESSION_RATIO tárolt eljárás elemzi a tömöríteni kívánt táblát. Mindig csak egy táblát, vagy opcionálisan annak egy partícióját tudja elemezni úgy, hogy a tábláról készít egy másolatot egy külön erre a célra kijelölt/létrehozott táblatérre. Amennyiben az elemzést egyszerre több tömörítési szintre futtatjuk, úgy a tábláról annyi másolatot készít. A jó közelítésu becslés (+-5%) feltétele, hogy táblánként/partíciónként minimum 1 millió sor legyen. 11gR1 esetében még a DBMS_COMP_ADVISOR csomag GET_RATIO eljárása volt használatos, de ez még nem támogatta a HCC becslést. Érdemes még megnézni és kipróbálni a Tyler Muth blogjában publikált formázó eszközt, amivel a compression advisor kimenete alakítható jól értelmezheto formátumúvá. Végül összegezném mit is tartalmaz az Advanced Compression opció, mivel gyakran nem világos a felhasználóknak miért kell fizetni: Data Guard Network Compression Data Pump Compression (COMPRESSION=METADATA_ONLY does not require the Advanced Compression option) Multiple RMAN Compression Levels (RMAN DEFAULT COMPRESS does not require the Advanced Compression option) OLTP Table Compression SecureFiles Compression and Deduplication Ez alapján RMAN esetében például a default compression (BZIP2) szint ingyen használható, viszont az új ZLIB Advanced Compression opciót igényel. A ZLIB hatékonyabban használja a CPU-t, azaz jóval gyorsabb, viszont kisebb tömörítési arány érheto el vele.

  Read the article

• New PeopleSoft Applications Search

  - by Matthew Haavisto

  As you may have seen from the PeopleTools 8.52 Release Value Proposition , PeopleTools intends to introduce a new search capability in release 8.52. We believe this feature will not only improve the ability of users to find content, but will fundamentally change the way people navigate around the PeopleSoft ecosystem. PeopleSoft applications will be delivering this new search in coming releases and feature packs. PeopleSoft Application Search is actually a framework—a group of features that provides an improved means of searching for a variety of content across PeopleSoft applications. From a user experience perspective, the new search offers a powerful, keyword-based search presented in a familiar, intuitive user experience. Rather than browsing through long menu hierarchies to find a page, data item, or transaction, users can use PeopleSoft Application Search to directly navigate to desired locations. We envision this to be similar to how people navigate across the internet. This capability may reduce or even eliminate the need to navigate PeopleSoft applications using the existing application menu system (though menus will still be available to people that prefer that method). The new search will be available at any point in an application and can be configured to span multiple PeopleSoft applications. It enables users to initiate transactions or navigate to key information without using the PeopleSoft application menus. In addition, filters and facets will enable people to narrow their search results sets, making it easier to identify and navigate to desired application content. Action menus are embedded directly in the search results, allowing users to navigate straight to specific related transactions – pre-populated with the selected search results data. PeopleSoft Applications Search framework uses Oracle’s Secure Enterprise Search as its search engine. Most Customers will benefit from the new search when it is delivered with applications. However, customers can start deploying it after a Tools-only upgrade. In this case, however, customers would have to create their own indices and implement security.

  Read the article

• Synergy to share mouse only (not keyboard)

  - by Stan

  Synergy is very handy for single mouse/keyboard set sharing between multiple PCs. But I have a laptop (WinXP SP3) and a desktop (OS X Snow Leopard), a mouse, a keyboard which plugs to desktop. I don't need to share keyboard since each has one. Is there any way to share mouse only? Since if keyboard sharing enable might cause inconvenience. Thanks. PS. Another quick question is how to stop synergy daemon on Mac OS? synergys --help doesn't give any information.

  Read the article

• embed file in Excel cell

  - by Crash893

  I'm working on a simple "DB" for some people at work and I don't want to do anything fancy. the fields should be something like name , number , notes , File:resume, notes (where file:notes is the acutall embedded resume. I cant see any obvious way to do this but i thought i would ask just the same. Is there a way to take a (pdf , doc , docx , txt) and throw it into a cell so a user can click on it and it will open the file in the approate program note: this db is going to be floating around between multiple sites so linking won't work.

  Read the article

• Dynamically changing DVT Graph at Runtime

  - by mona.rakibe(at)oracle.com

  I recently came across this requirement where the customer wanted to change the graph type at run-time based on some selection. After some internal discussions we realized this can be best achieved by using af:switcher to toggle between multiple graphs. In this blog I will be sharing the sample that I build to demonstrate this.[Note] : In the below sample, every-time user changes graph type there is a server trip, so please use this approach with performance implications in mind.This sample can be downloaded  from DynamicGraph.zipSet-up: Create a BAM data control using employees DO (sample)(Refer this entry)Steps:Create the View Create a new JSF page .From component palette drag and drop "Select One Radio" into this page Enter some Label and click "Finish"In Property Editor set the "AutoSubmit" property to trueNow drag and drop "Switcher" from components into this page.In the Structure pane select the af:switcher right click and surround with "PanelGroupLayout"In Property Editor set the "PartialTriggers"  property of PanelGroupLayout to the id of af:selectOneRadioAgain in the Structure pane select the af:switcher right click and select "Insert inside af:switcher->facet"Enter Facet name (ex: pie)Again in the Structure pane select the af:switcher right click and select "Insert inside af:switcher->facet" Enter  another Facet name (ex: bar)From "Data Controls" drag and drop "Employees->Query"  into the pie facet as "Graph->Pie" (Pie: Sales_Number and Slices: Salesperson)From "Data Controls" drag and drop "Employees->Query"  into the bar facet as "Graph->Bar" (Bars :Sales_Number and X-axis : Salesperson).Now wire the switcher to the af:selectOneRadio using their "facetName" and "value" property respectively.Now run the page, notice that graph renders as per the selection by user.

  Read the article

• No dual cpu support for VirtualBox with a CPU that doesn't support multicore?

  - by djangofan

  With VMWare it works fine and I can run multiple cores on a VMWare image. With Sun VirtualBox I can only run 1 cpu on a image. Its annoying. Why does Sun Virtualbox not work the same as VMWare in this respect?? My CPU is: XEON 3.00GHz Intel 90nm 2MBCache QUAD CPU x14 Socket 604 mPGA Family 15 Model 4(04) Stepping 3 Revision 05 MMX SSE3 XD SIV.exe tells me: No virtual machine extensions x86 with 64-bit support NO IA64 support MPS but with NO MCP 2 physical processors, 2 cores, 4 logical processors

  Read the article

• Open source alternative for Canonical Landscape? [on hold]

  - by netvope

  From Canonical: Landscape is an easy-to-use systems management and monitoring service that enables you to manage multiple Ubuntu machines as easily as one through a simple Web-based interface. However, Landscape is not free. The RedHat counterpart Satellite has a free version called Spacewalk, but it doesn't work on Ubuntu. (There is an attempt to port Spacewalk to Debian, but it doesn't look like it's stable yet.) Are there any open source alternative to Landscape? Better yet, are there any Spacewalk-like software that works for both RedHat-based and Debian-based systems?

  Read the article

• Should programmers itemize testing in testing? [on hold]

  - by Patton77

  I recently hired a programming team to do a port of my iPad app to the iPhone and Android platforms. Now, in a separate contract, I am asking them to implement a bunch of tips on how to play the app, similar like you would find in Candy Crush or Cut the Rope. They want to charge 12 hours @ $35/hr for the "Testing all of the Tips", telling me that normally it would take them more than 25 hours but that they will 'bear the difference'. I am not familiar with this level of itemization, but maybe it's a new practice? I am used to devs doing their own quality control, and then having a testing/acceptance period. They are using Cocos 2D-X, and they say that the tips going to multiple platforms makes all of the hours jack up. I feel like they might be overcharging, and it's difficult for me to know because it's kind of like with a mechanic. "It took us 5 hours to replace the radiator". How can you dispute that? It seems to me that most of you would charge for the work but NOT for hours that you are 'testing'. Am I missing something? Thanks for any help and advice you can give!

  Read the article

• How to make a system time-zone sensitive?

  - by Jerry Dodge

  I need to implement time zones in a very large and old Delphi system, where there's a central SQL Server database and possibly hundreds of client installations around the world in different time zones. The application already interacts with the database by only using the date/time of the database server. So, all the time stamps saved in both the database and on the client machines are the date/time of the database server when it happened, never the time of the client machine. So, when a client is about to display the date/time of something (such as a transaction) which is coming from this database, it needs to show the date/time converted to the local time zone. This is where I get lost. I would naturally assume there should be something in SQL to recognize the time zone and convert a DateTime field dynamically. I'm not sure if such a thing exists though. If so, that would be perfect, but if not, I need to figure out another way. This Delphi system (multiple projects) utilizes the SQL Server database using ADO components, VCL data-aware controls, and QuickReports (using data sources). So, there's many places where the data goes directly from the database query to rendering on the screen, without any code to actually put this data on the screen. In the end, I need to know when and how should I get the properly converted time? There must be a standard method for this, and I'm hoping SQL Server 2008 R2 has this covered...

  Read the article

• How do I serve only internal intranet requests for a site with Apache?

  - by purpletonic

  I have an externally facing web server on our domain that we use for testing multiple sites. I have a site on this server that I want only people from within our intranet to view. How do I prevent requests originating from outside the intranet from seeing this website? I tried the following in my apache config file, but I get a 403 error. <Directory /> Options FollowSymLinks Order Deny,Allow Allow from domain.com Allow from 10.0.0.0/10.255.255.255 Deny from All AllowOverride None </Directory> <Directory /var/www/sitename/public> Options Indexes FollowSymLinks MultiViews Order Deny,Allow Allow from domain.com Allow from 10.0.0.0/10.255.255.255 Deny from All AllowOverride None </Directory>

  Read the article

• Http 400 'Bad Request' and win32status 1450 when larger messages are sended to a WCF service

  - by Tim Mahy

  we sometimes receive Http 400 bad request resultcodes when posting a large file (10mb) to a WCF service hosted in IIS 6. We can reproduce this using SOAP UI and it seems that it is unpredictable when this happens. In our WCF log the call is not received, so we believe that the request does not reach the ASP.NET nor WCF runtime. This happens on multiple websites on the same machine each having their own application pool. All IIS settings are default, only in ASP.NET and WCF we allow bigger readerQuota's etc.... The win32status that is logged in the IIS log is 1450 which we think means "error no system resources". So now the question: a) how can we solve this b) (when a is not applicable :) ) which performance counters or logs are usefull to learn more about this problem? greetings, Tim

  Read the article

• Building Single Page Apps on the Microsoft Stack

  - by Stephen.Walther

  Thank you everyone who came to my talk last night on Building Single Page Apps on the Microsoft Stack. I’ve attached the slides and code samples below. Here’s a quick summary of the talk. I argued that Single Page Apps are better than traditional Server Side Apps because: Single Page Apps are Stateful – In a traditional server-side app, whenever you navigate to a new page, all of your previous state is lost. It is like rebooting your computer whenever you perform any action In a Single Page App, Your Presentation Layer is Not Miles Away – In a traditional server-side app, because everything happens on the server, your presentation layer is separated from the user by space and time. In a Single Page App, the presentation layer is in the browser and not the server (which is the right place for a presentation layer). A Single Page App Respects the Web – It is easier to take advantage of HTML5 and related standards when building a Single Page App. Next, I recommended using the following four technologies when building a web application: Knockout – This is how you create your presentation layer. ASP.NET Web API – This is how you expose JSON data from your web server and perform server-side validation. HTML5 – This is how you implement client-side validation. Sammy – This is how you implement client-side routing and create a Single Page App with multiple virtual pages. There are code samples in the download (look in the Samples folder) which demonstrate how all of these technologies work when building Single Page Apps. Powerpoint Sample Code

  Read the article

• Oracle and Microsoft Expand Choice and Flexibility in Deploying Oracle Software in the Cloud

  - by Gene Eun

  Oracle and Microsoft have entered into a new partnership that will help customers embrace cloud computing by providing greater choice and flexibility in how to deploy Oracle software.  Here are the key elements of the partnership: Effective today, our customers can run supported Oracle software on Windows Server Hyper-V and in Windows Azure Effective today, Oracle provides license mobility for customers who want to run Oracle software on Windows Azure Microsoft will add Infrastructure Services instances with popular configurations of Oracle software including Java, Oracle Database and Oracle WebLogic Server to the Windows Azure image gallery Microsoft will offer fully licensed and supported Java in Windows Azure Oracle will offer Oracle Linux, with a variety of Oracle software, as preconfigured instances on Windows Azure Oracle’s strategy and commitment is to support multiple platforms, and Microsoft Windows has long been an important supported platform.  Oracle is now extending that support to Windows Server Hyper-V and Window Azure by providing certification and support for Oracle applications, middleware, database, Java and Oracle Linux on Windows Server Hyper-V and Windows Azure. As of today, customers can deploy Oracle software on Microsoft private clouds and Windows Azure, as well as Oracle private and public clouds and other supported cloud environments. For information related to software licensing in Windows Azure, see Licensing Oracle Software in the Cloud Computing Environment. Also, Oracle Support policies as they apply to Oracle software running in Windows Azure or on Windows Server Hyper-V are covered in two My Oracle Support (MOS) notes which are shown below: MOS Note 1563794.1 Certified Software on Microsoft Windows Server 2012 Hyper-V - NEW MOS Note 417770.1 Oracle Linux Support Policies for Virtualization and Emulation - UPDATED

  Read the article

• Keyboard doesn't load in windows xp after Alureon infection

  - by alureonissue

  AVAST detected alureon in a number of system files including atapi.sys and kbdclass.sys iple I quarantined those files, and restarted my machine. After restarting, my keyboard and cdrom did not work (I assumed those drivers would be automatically replaced, but was apparently wrong.) I went into device manager, and checked for hardware changes, it fixed the cdrom (which works now) and looked as though it fixed the keyboard as well. It did not. After multiple reboots the keyboard is still not recognized. It works up until the XP login screen loads, after which it is completely unresponsive. Any advice would be appreciated. Thanks :)

  Read the article

• What's constitute an entry on the IPTables and how to find out which client it is originated from

  - by cbd

  I have a Billion BiPac 7700N Modem/Router/Access Point and I connect another router (TP-Link TL-WR1043ND) in wan-bypass mode to extend the wireless coverage. Lately, I noticed that the connection through TP-Link has been dropping out quite regularly. Having read some posts on the Internet, I checked system log on 7700N and found that there are many "nf_conntract: expectation table full" errors, which I suppose the iptables are full. My questions: What does constitute an entry on the iptable? Is it a client or a connection (which means one client can have multiple connections) How could I find out where are those connections originated from? Note: Many reported that the issue is usually related to having torrents running but I don't have any torrents running. Thank you.

  Read the article

• How compatible are VMWare and VirtualBox?

  - by MikeKusold

  At my workplace, everyone uses VMware Player (and some people have licenses for Workstation). We frequently share VMs to save time on development setup. However, I would really like to take advantage of the Snapshot feature in VirtualBox since I am unable to acquire a license for Workstation. I have read that VirtualBox has no issues reading VMWare VMs (including VMs with snapshots). However, I'm worried about how compatible things are the other way. In VirtualBox, I open up a VM created in VMware and create multiple snapshots. Can the resulting files be opened in VMware?

  Read the article

• Why does QuickTime lag in Firefox if I don't put my mouse over it?

  - by Jim McKeeth

  This has happened for me as long as I can remember. Since the first version of Firefox, on multiple computers and under different versions of Windows. QuickTime plays fine in IE and Chrome (even with Firefox in the background), but in Firefox if my mouse is not over the QuickTime window then it will start to studder, then lag and eventually just stop. To be honest, I do keep quite a few tabs open, but Firefox stays at 1% CPU (even when QuickTime runs) and I have a few gigs of free RAM. It is the same for any resolution of video or audio. If the mouse is just one pixel in the client area of the QuickTime then it usually plays fine. Other video formats typically play fine. Does anyone else notice this behavior? Ultimately I would like a fix besides keeping my mouse over the QuickTime window.

  Read the article

• Postgres error messages in Apache error log

  - by Warren Pena

  I'm running Apache 2.2, PHP 5.2, and Postgres 8.2 on Windows, and I'm seeing something funky in Apache's error.log file. Occasionally, I'll see the message "row number -1 is out of range 0..-1" pop up over and over. Unlike all the other lines in that log file, there's no timestamp or log level. Just that exact string. Googling around, it appears that message is, character for character, a common Postgres error message, but is not an Apache error. I've seen it happen multiple times, and on several different servers. I can't seem to reproduce it, though. I've tried throwing all sorts of error ridden database queries and result set inquiries at Postgres via PHP, and none of them seem to trigger that line being written to the log file. Is it possible for Postgres errors to be ending up in my Apache log file, and if so, how? What would trigger an error message like that? Thanks!

  Read the article

• SSMS Tools Pack 1.9.3 is out!

  - by Mladen Prajdic

  This release adds a great new feature and fixes a few bugs. The new feature called Window Content History saves the whole text in all all opened SQL windows every N minutes with the default being 30 minutes. This feature fixes the shortcoming of the Query Execution History which is saved only when the query is run. If you're working on a large script and never execute it, the existing Query Execution History wouldn't save it. By contrast the Window Content History saves everything in a .sql file so you can even open it in your SSMS. The Query Execution History and Window Content History files are correlated by the same directory and file name so when you search through the Query Execution History you get to see the whole saved Window Content History for that query. Because Window Content History saves data in simple searchable .sql files there isn't a special search editor built in. It is turned ON by default but despite the built in optimizations for space minimization, be careful to not let it fill your disk. You can see how it looks in the pictures in the feature list. The fixed bugs are: SSMS 2008 R2 slowness reported by few people. An object explorer context menu bug where it showed multiple SSMS Tools entries and showed wrong entries for a node. A datagrid bug in SQL snippets. Ability to read illegal XML characters from log files. Fixed the upper limit bug of a saved history text to 5 MB. A bug when searching through result sets prevents search. A bug with Text formatting erroring out for certain scripts. A bug with finding servers where it would return null even though servers existed. Run custom scripts objects had a bug where |SchemaName| didn't display the correct table schema for columns. This is fixed. Also |NodeName| and |ObjectName| values now show the same thing.   You can download the new version 1.9.3 here. Enjoy it!

  Read the article

• Ask the Readers: What Operating System Do You Use?

  - by Mysticgeek

  The three most popular choices out there when it comes to computer operating systems, is Windows, Mac OS X, and Linux. What we want to know is…which operating system do you use? Photo by ~Dudu,,]* Computer users today have more choices than ever when it comes to the operating system they use. In the Windows world, there are three versions out there in daily use. A lot of businesses and home users use XP, completely avoided Vista, and are starting to migrate to Windows 7. While a lot of home users received their new computer with Vista pre-installed and are still using it. Others were quick to jump to Windows 7, and some don’t want to leave the comforts of XP. Desktop Linux distro’s have been consistently growing in popularity as versions like Ubuntu become more user friendly. And let us not forget the loyal Apple users who would never give up OS X. You may have to use a certain OS at the workplace, but when you get home, your options are a lot more open. And now with the ease of virtualization, it’s easy to run multiple operating systems on one machine. Each OS offers different advantages that people pick based on their needs. Today we want to know, which operating system(s) do you use? Let us know in the comments and join the discussion! Similar Articles Productive Geek Tips Easily Set Default OS in a Windows 7 / Vista and XP Dual-boot SetupGet the Version of Solaris RunningDisable System Restore in Windows 7Disable ProFTP on CentOSShut Down or Reboot a Solaris System TouchFreeze Alternative in AutoHotkey The Icy Undertow Desktop Windows Home Server – Backup to LAN The Clear & Clean Desktop Use This Bookmarklet to Easily Get Albums Use AutoHotkey to Assign a Hotkey to a Specific Window Latest Software Reviews Tinyhacker Random Tips DVDFab 6 Revo Uninstaller Pro Registry Mechanic 9 for Windows PC Tools Internet Security Suite 2010 Out of band Security Update for Internet Explorer 7 Cool Looking Screensavers for Windows SyncToy syncs Files and Folders across Computers on a Network (or partitions on the same drive) If it were only this easy Classic Cinema Online offers 100’s of OnDemand Movies OutSync will Sync Photos of your Friends on Facebook and Outlook

  Read the article

• Relay thru external SMTP server on Exchange 2010

  - by MadBoy

  My client has dynamic IP on which he hosts Exchange 2010 with POP3 Connector running and gathering emails from his current hosting. Until he gets static IP he wants to send emails out. This will work most of the time but some servers won't accept such email sent by Exchange (from dynamic ip due to multiple reasons) so I would like to make a relay thru external SMTP server which hosts current mailboxes. Normally SMTP server could be set up to allow relay thru it but this would require static IP to be allowed on that server so it would know which IP is allowed to relay thru it. Or is there a way to setup relay in Exchange 2010 so it can use dynamic IP and kinda authenticates with user/password itself on the hosted server?

  Read the article

• bind9 dns proxy

  - by Zulakis

  We are offering multiple SSL-enabled services in our local network. To avoid certificate-warnings we bought certificates for server.ourdomain.tld and firewall.ourdomain.tld. We now created a zone in our local DNS-server in which we pointed the hosts to the corresponding private-ips. Now, each time another record for ourdomain.tld, like for example www.ourdomain.tld or alike are changed, we need to update it on both our public-dns-server AND the local dns-server. I would like our local bind-dns to serve all the information from our public-dns but serve different information for these 2 hosts. I know I could possibly have our private-ips in our public-dns but I don't want that for security reasons. The internet dns-server is being managed by a third party, while we have full control of the intranet one. Because of this I am looking for a solution which lets the intranet retrieve the records from the internet one.

  Read the article

• Re-streaming RTMP stream

  - by Yvan JANSSENS

  I have a set of local RTMP stream servers in my network, but I want them to be reachable outside. The bandwidth is too narrow to serve multiple clients on the streamservers of my network, so the idea is to pull the local RTMP streams on a computer serving as a gateway, which pushes them on his turn to a hosted streaming provider. It is not possible to let the sources of the stream push their stream directly to the server outside due to network policy restrictions. Scheme of what I'm trying to accomplish: Internal network | External network ------------ ------------ ----------------------- | internal | <---- | Gateway | ------> | streamserver outside| | streams | ------------ ----------------------- ------------ | ^ | | | ----------- | | clients | | ----------- My question now is: which application which can pull a live stream from an RTMP source (Flash Media Server) and push it to another one (Flash Media Server at hosting provider).

  Read the article

• IIS 7.x Application Pool Best Practices

  - by Eric

  We are about to deploy a bunch of sites to some new servers. I have the following questions about application pools: 1) It seems advisable to have an application pool per website. Are there any caveats to this approach? Can one application pool, for example, hog all the CPU, Memory, Etc...? 2) When should you allow multiple worker processes in an application pool. When should you not? 3) Can private memory limit be used to prevent one application pool from interfering with another? Will setting it too low cause valid requests to recycle the application pool without getting a valid response? 4) What is the difference between private and virtual memory limits? 5) Are there compelling reasons NOT to run one application pool per site? Thanks!

  Read the article

• Consistency of an object

  - by Stefano Borini

  I tend to keep my objects consistent during their lifetime. In some cases, setting up an object requires multiple calls to different routines. For example, a connection object may operate in this way: Connection c = new Connection(); c.setHost("http://whatever") c.setPort(8080) c.connect() please note this is just a stupid example to let you understand the point. In between calls to setHost and setPort the object is inconsistent, because the Port has not been specified yet, so this code would crash Connection c = new Connection(); c.setHost("http://whatever") c.connect() Meaning that it's a requisite for connect() to have previous calls to both setHost and setPort, otherwise it won't be able to operate as its state is inconsistent. You may fix the issue with a default value, but there may be cases where no sensible default may be devised. We assume in the later example that there's no default for the port, and therefore a call to c.connect() without first calling both setHost and setPort will be an inconsistent state of the object. This, to me, points at an incorrect interface design, but I may be wrong, so I want to hear your opinion. Do you organize your interface so that the object is always in a consistent (i.e. workable) state both before and after the call ? Edit: Please don't try to solve the problem I gave above. I know how to solve that. My question is much broader in sense. I am looking for a design principle, officially or informally stated, regarding consistency of object state between calls.

  Read the article

< Previous Page | 564 565 566 567 568 569 570 571 572 573 574 575  | Next Page >