Search Results

Search found 1097 results on 44 pages for 'don branson'.

Page 30/44 | < Previous Page | 26 27 28 29 30 31 32 33 34 35 36 37  | Next Page >

• How do I know if a boost thread is done ?

  - by jules

  I am using boost::thread to process messages in a queue. When a first message comes I start a message processing thread. When a second message comes I check if the message processing thread is done. if it is done I start a new one if it is not done I don nothing. How do I know if the thread is done ? I tried with joinable() but it is not working, as when the thread is done, it is still joinable. I also tried to interrupt the process at once, and add an interruption point at the end of my thread, but it did not work. Thanks

  Read the article

• Transitioning from C++ to C#

  - by Jim

  I am very experienced in C and C++ but am having problems finding current opportunities. I decided to switch to C# but noticed that while the syntax is very similar, the programming styles are very different (we don't have IEnumerable etc in C). So the problem I am having now is having 20 years of experience but is only a junior when it comes to interviewing for a C# job. Most of the problems are me not being able to answer questions like 1) How do you do XYZ in Sql Server? 2) What's the use of in Spring.NET In other words, the phone interviewers don;t care if you know DB programming or not - they want to know if you know SQL Server. I am frustrated because the guys who are doing the interviews seem to be so narrow sighted in knowing ONLY C#, .NET and SQL Server, that I don't know how to get past them.

  Read the article

• C# .NET 2.0 components

  - by Ervin

  How can I check what objects, tools, variables, anything... are used from .NET 2.0 in a C# application. How can I get a C# application run without .NET 2.0 ? UPDATE: sorry, I didn't clarify enought. Here's my situation: I have developed a pretty simple application in C#: embeded browser which displayes static webpages with an option of searching inside of these html pages. I'm using simple textbox, buttons components for this. The application will be distribuited for people wich have very old PCs, even with windows 95. I would like the app to be runable on it, or at least on win 98, without telling the people to install .NET 2.0, as the users don;t really have PC usage skills :) .

  Read the article

• Is it possible to use AutoMapper to map methods?

  - by Woj

  I have two classes: public class TestClass1 { public int TestInt { get; set; } public void TestMethod() { // Do something } } public class TestClass2 { public int TestInt { get; set; } public void TestMethod() { // Do something } } I want to create interface that I can use for both classes. The easiest solution is to implement the interface on TestClass1 and TestClass2 but I don;t have access to the implementation of these classes (external dll). I was wondering if I can create new interface and use AutoMapper to map TestClass1 and TestClass2 to ITestInterface: public interface ITestInterface { int TestInt { get; set; } void TestMethod(); }

  Read the article

• Functions without arguments, with unit as argument in scala

  - by scout

  def foo(x:Int, f:Unit=>Int) = println(f()) foo(2, {Unit => 3+4} //case1 def loop:Int = 7 foo(2, loop) //does not compile changing loop to //case 2 def loop():Int = 7 foo(2, loop) // does not compile changing loop to //case 3 def loop(x:Unit): Int = 7 //changing according to Don's Comments foo(2,loop) // compiles and works fine should'nt case 1 and case 2 also work? why are they not working? defining foo as def foo(x:Int, y:()=>Int) then case 2 works but not case 1. Arent they all supposed to work, defining the functions either way. //also i think ()=Int in foo is a bad style, y:=Int does not work, comments??

  Read the article

• Is it a good design to return value by parameter?

  - by aztack

  bool is_something_ok(int param,SomeStruct* p) { bool is_ok = false; // check if is_ok if(is_ok) // set p to some valid value else // set p to NULL return is_ok; } this function return true and set p to a valid value if "something is ok" otherwise return false and set p to NULL Is that a good or bad design? personally, i feel uncomfortable when i use it. If there is no document and comment, i really don know how to use it. BTW:Is there some authoritative book/article about API design?

  Read the article

• SQL Developer Database Diff – Compare Objects From Multiple Schemas

  - by thatjeffsmith

  Ever wonder why Database Diff isn’t called Schema Diff? One reason is because SQL Developer allows you select objects from more than one schema in the ‘Source’ connection for the compare. Simply use the ‘More’ dialog view and select as many tables from as many different schemas as you require Now, before you get around to testing this – as you should never believe what I say, trust but verify – two things you need to know: I’m using SQL Developer version 3.2 On the initial screen you need to use the ‘Maintain’ option Maintain tells SQL Developer to use the schema designation in the source connection to find the same corresponding object in the destination schema. Choose ‘maintain’ if you want to compare objects in the same schema in the destination but don’t have the user login for that schema. So after you’ve selected your databases, your diff preferences, and your objects – you’re ready to perform the compare and review your results. The DIFF Report Notice the highlighted text, SQL Developer is ‘maintaining’ the Schema context from the two databases. Short and sweet. That’s pretty much all there is to doing a compare with SQL Developer with multiple schemas involved. You may have noticed in some posts lately that my editor screenshots had a ‘green screen’ look and feel to them. What’s with the black background in your editors? In the SQL Developer preferences, you can set your editor color schemes. I started with the ‘Twilight’ scheme (team Jacob in case you’re wondering) and then customized it further by going with a default green font color. You could go pretty crazy in here, and I’m assuming 90% of you could care less and will just stick with the original. But for those of you who are particular about your IDE styling – go crazy! SQL Developer Editor Display Preferences

  Read the article

• Don’t miss rare Venus transit across Sun on June 5th. Once in a life time event.

  - by Gopinath

  Space lovers here is a rare event you don’t want to miss. On June 5th or 6th of 2012,depending on which part of the globe you live, the planet Venus will pass across Sun and it will not happen again until 2117. During the six hour long spectacular transit you can see the shadow of Venus cross Sun. The transit of Venus occurs in pairs eight years apart, with the previous one taking place in 2004. The next pair of transits occurs after 105.5 & 121.5 years later. The best place to watch the event would be a planetarium nearby with telescope facility. If not you watch it directly but must protect your eyes at all times with proper solar filters. Where can we see the transit? The transit of Venus is going to be clearly visible in Europe, Asia, United States and some part of Australia. Americans will be able to see transit in the evening of Tuesday, June 5, 2012. Eurasians and Africans can see the transit in the morning of June 6, 2012. At what time the event occurs? The principal events occurring during a transit are conveniently characterized by contacts, analogous to the contacts of an annular solar eclipse. The transit begins with contact I, the instant the planet’s disk is externally tangent to the Sun. Shortly after contact I, the planet can be seen as a small notch along the solar limb. The entire disk of the planet is first seen at contact II when the planet is internally tangent to the Sun. Over the course of several hours, the silhouetted planet slowly traverses the solar disk. At contact III, the planet reaches the opposite limb and once again is internally tangent to the Sun. Finally, the transit ends at contact IV when the planet’s limb is externally tangent to the Sun. Event Universal Time Contact I 22:09:38 Contact II 22:27:34 Greatest 01:29:36 Contact III 04:31:39 Contact IV 04:49:35   Transit of Venus animation Here is a nice video animation on the transit of Venus Map courtesy of Steven van Roode, source NASA

  Read the article

• MODx character encoding

  - by Piet

  Ahhh character encodings. Don’t you just love them? Having character issues in MODx? Then probably the MODx manager character encoding, the character encoding of the site itself, your database’s character encoding, or the encoding MODx/php uses to talk to MySQL isn’t correct. The Website Encoding Your MODx site’s character encoding can be configured in the manager under Tools/Configuration/Site/Character encoding. This is the encoding your website’s visitors will get. The Manager’s Encoding The manager’s encoding can be changed by setting $modx_manager_charset at manager/includes/lang/<language>.inc.php like this (for example): $modx_manager_charset = 'iso-8859-1'; To find out what language you’re using (and thus was file you need to change), check Tools/Configuration/Site/Language (1 line above the character encoding setting). This needs to be the same encoding as your site. You can’t have your manager in utf8 and your site in iso-8859-1. Your Database’s Encoding The charset MODx/php uses to talk to your database can be set by changing $database_connection_charset in manager/includes/config.inc.php. This needs to be the same as your database’s charset. Make sure you use the correct corresponding charset, for iso-8859-1 you need to use ‘latin1′. Utf8 is just utf8. Example: $database_connection_charset = 'latin1'; Now, if you check Reports/System info, the ‘Database Charset’ might say something else. This is because the mysql variable ‘character_set_database’ is displayed here, which contains the character set used by the default database and not the one for the current database/connection. However, if you’d change this to display ‘character_set_connection’, it could still say something else because the ’set character set’ statement used by MODx doesn’t change this value either. The ’set names’ statement does, but since it turns out my MODx install works now as expected I’ll just leave it at this before I get a headache. If I saved you a potential headache or you think I’m totally wrong or overlooked something, let me know in the comments. btw: I want to be able to use a real editor with MODx. Somehow.

  Read the article

• using ‘using’ and scope. Not try finally!

  - by Edward Boyle

  An object that implements IDisposable has, you guessed it, a Dispose() method. In the code you write you should both declare and instantiate any object that implements IDisposable with the using statement. The using statement allows you to set the scope of an object and when your code exits that scope, the object will be disposed of. Note that when an exception occurs, this will pull your code out of scope, so it still forces a Dispose() using (mObject o = new mObject()) { // do stuff } //<- out of Scope, object is disposed. // Note that you can also use multiple objects using // the using statement if of the same type: using (mObject o = new mObject(), o2 = new mObject(), o3 = new mObject()) { // do stuff } //<- out of Scope, objects are disposed. What about try{ }finally{}? It is not needed when you use the using statement. Additionally, using is preferred, Microsoft’s own documents put it this way: As a rule, when you use an IDisposable object, you should declare and instantiate it in a using statement. When I started out in .NET I had a very bad habit of not using the using statement. As a result I ran into what many developers do: #region BAD CODE - DO NOT DO try { mObject o = new mObject(); //do stuff } finally { o.Dispose(); // error - o is out of scope, no such object. } // and here is what I find on blogs all over the place as a solution // pox upon them for creating bad habits. mObject o = new mObject(); try { //do stuff } finally { o.Dispose(); } #endregion So when should I use the using statement? Very simple rule, if an object implements IDisposable, use it. This of course does not apply if the object is going to be used as a global object outside of a method. If that is the case, don’t forget to dispose of the object in code somewhere. It should be made clear that using the try{}finally{} code block is not going to break your code, nor cause memory leaks. It is perfectly acceptable coding practice, just not best coding practice in C#. This is how VB.NET developers must code, as there is no using equivalent for them to use.

  Read the article

• Oracle SQL Developer is for Oracle Database

  - by thatjeffsmith

  What is Oracle SQL Developer? Well, according to this document on OTN… What is SQL Developer? Date: May 2014 Oracle SQL Developer is the Oracle Database IDE. A free graphical user interface, Oracle SQL Developer allows database users and administrators to do their database tasks in fewer clicks and keystrokes. A productivity tool, SQL Developer’s main objective is to help the end user save time and maximize the return on investment in the Oracle Database technology stack. Ok, sounds pretty straightforward. Where does the confusion lie then? Some People Use SQL Developer to Connect to 3rd Party Databases SQL Developer allows you to register 3rd party database JDBC drivers. The 3rd party being a company OTHER than Oracle that makes a database product. You know who they are (SAP, MSFT, IBM, etc.) Registering 3rd party JDBC drivers in SQL Developer But maybe you don’t understand why we support these types of connections? It’s for one driving reason. To Help You Migrate to Oracle Database Yes, you get a worksheet and a tree to query and browse those systems. But, the real meat and bones there are around our migration projects and our translation scratch editor. At the end of the day, it’s there so you can move your data from say Sybase ASE to Oracle Database. On a side note, the migration technology was previously available in a separate application, the Migration Workbench. The technology and the awesome people behind it were folded into SQL Developer. So when asked what SQL Developer is, I say it’s the Database IDE and the official 3rd party database migration to Oracle platform. So anyways, when you ask for better support for another 3rd party provider, we deliver that support based on that business driver. If another 3rd party database jdbc driver is introduced, it’s because we have a lot of customers migrating from that platform. We’re not adding it to make it easier for you to work with SQL Server on your Mac. But, if you find that useful – that is cool. It’s just not why we’ve got the support for SQL Server connections in SQL Developer.

  Read the article

• Innovation, Adaptability and Agility Emerge As Common Themes at ACORD LOMA Insurance Forum

  - by [email protected]

  Helen Pitts, senior product marketing manager for Oracle Insurance is blogging from the show floor of the ACORD LOMA Insurance Forum this week. Sessions at the ACORD LOMA Insurance Forum this week highlighted the need for insurance companies to think creatively and be innovative with their technology in order to adapt to continuously shifting market dynamics and drive business efficiency and agility.  LOMA President & CEO Robert Kerzner kicked off the day on Tuesday, citing how the recent downtown and recovery has impacted the insurance industry and the ways that companies are doing business.  He encouraged carriers to look for new ways to deliver solutions and offer a better service experience for consumers.  ACORD President & CEO Gregory Maciag reinforced Kerzner's remarks, noting how the industry's approach to technology and development of industry standards has evolved over the association's 40-year history and cited how the continued rise of mobile computing will change the way many carriers are doing business today and in the future. Drawing from his own experiences, popular keynote speaker and Apple Co-Founder Steve Wozniak continued this theme, delving into ways that insurers can unite business with technology.  "iWoz" encouraged insurers to foster an entrepreneurial mindset in a corporate environment to create a culture of creativity and innovation.  He noted that true innovation in business comes from those who have a passion for what they do.  Innovation was also a common theme in several sessions throughout the day with topics ranging from modernization of core systems, automated underwriting, distribution management, CRM and customer communications management.  It was evident that insurers have begun to move past the "old school" processes and systems that constrain agility, implementing new process models and modern technology to become nimble and more adaptive to the market.   Oracle Insurance executives shared a few examples of how insurers are achieving innovation during our Platinum Sponsor session, "Adaptive System Transformation:  Making Agility More Than a Buzzword." Oracle Insurance Senior Vice President and General Manager Don Russo was joined by Chuck Johnston, vice president, global strategy and alliances, and Srini Venkatasantham, vice president of product strategy.  The three shared how Oracle's adaptive solutions for insurance, with a focus on how the key pillars of an adaptive systems - configurable applications, accessible information, extensible content and flexible process - have helped insurers respond rapidly, perform effectively and win more business. Insurers looking to innovate their business with adaptive insurance solutions including policy administration, business intelligence, enterprise document automation, rating and underwriting, claims, CRM and more stopped by the Oracle Insurance booth on the exhibit floor.  It was a premiere destination for many participating in the exhibit hall tours conducted throughout the day. Finally, red was definitely the color of the evening at the Oracle Insurance "Red Hot" customer celebration at the House of Blues. The event provided a great opportunity for our customers to come together and network with the Oracle Insurance team and their peers in the industry.  We look forward to visiting more with of our customers and making new connections today. Helen Pitts is senior product marketing manager for Oracle Insurance. 

  Read the article

• Check Your LIC Policy Status Through SMS

  - by Suganya

  Most of us in India hold at least one Life Insurance Policy today. While we all know everything gets computerized these days, LIC also supports payment via internet. You can view details about how payment is made through internet here. Few years back LIC started supporting SMS’es as well. Now you really don’t need to have internet rather check your LIC policy status while on road by sending just one SMS to 56677. Now that we know LIC answers to our SMS, lets see the format in which we have to send our SMS and their meaning. The format in which the SMS has to be sent is ASKLIC <Policy No> [PREMIUM/REVIVAL/BONUS/LOAN/NOM] Send any one of the following [PREMIUM/REVIVAL/BONUS/LOAN/NOM] to get the details. For instance, If you send ASKLIC <Policy No> Premium , it would return your Installment premium under policy ASKLIC <Policy No> Revival , it would check If policy is lapsed and return revival amount payable ASKLIC <Policy No> Bonus , it would check and return the amount of Bonus invested ASKLIC <Policy No> Loan , it would check and return the amount available as Loan ASKLIC <Policy No> NOM , it would check and return the details of Nomination Also, as everyone knows there are lots of pension schemes as well available in LIC and if one is interested in getting the pension details, then the format for sending the SMS is LICPension <Policy No> [STAT /ECDUE/ANNPD/PDTHRU/AMOUNT/CHQRET] For instance, If you send LICPension <Policy No> STAT gives you the IPP Policy status details LICPension <Policy No> ECDUE gives you the existence certificate due details LICPension <Policy No> ANNPD gives you the last annuity released date LICPension <Policy No> CHQ/ECS/NEFT (PDTHRU) gives the details about annuity payment through LICPension <Policy No> AMOUNT gives details about annuity amount LICPension <Policy No> CHQRET gives details about cheque return information Just with one SMS get all your policy details and make life easier. Each SMS that you send would be charged depending on your service provider. This article titled,Check Your LIC Policy Status Through SMS, was originally published at Tech Dreams. Grab our rss feed or fan us on Facebook to get updates from us.

  Read the article

• Grandparent – Parent – Child Reports in SQL Developer

  - by thatjeffsmith

  You’ll never see one of these family stickers on my car, but I promise not to judge…much. Parent – Child reports are pretty straightforward in Oracle SQL Developer. You have a ‘parent’ report, and then one or more ‘child’ reports which are based off of a value in a selected row or value from the parent. If you need a quick tutorial to get up to speed on the subject, go ahead and take 5 minutes Shortly before I left for vacation 2 weeks agao, I got an interesting question from one of my Twitter Followers: @thatjeffsmith any luck with the #Oracle awr reports in #SQLDeveloper?This is easy with multi generation parent>child Done in #dbvisualizer — Ronald Rood (@Ik_zelf) August 26, 2012 Now that I’m back from vacation, I can tell Ronald and everyone else that the answer is ‘Yes!’ And here’s how Time to Get Out Your XML Editor Don’t have one? That’s OK, SQL Developer can edit XML files. While the Reporting interface doesn’t surface the ability to create multi-generational reports, the underlying code definitely supports it. We just need to hack away at the XML that powers a report. For this example I’m going to start simple. A query that brings back DEPARTMENTs, then EMPLOYEES, then JOBs. We can build the first two parts of the report using the report editor. A Parent-Child report in Oracle SQL Developer (Departments – Employees) Save the Report to XML Once you’ve generated the XML file, open it with your favorite XML editor. For this example I’ll be using the build-it XML editor in SQL Developer. SQL Developer Reports in their raw XML glory! Right after the PDF element in the XML document, we can start a new ‘child’ report by inserting a DISPLAY element. I just copied and pasted the existing ‘display’ down so I wouldn’t have to worry about screwing anything up. Note I also needed to change the ‘master’ name so it wouldn’t confuse SQL Developer when I try to import/open a report that has the same name. Also I needed to update the binds tags to reflect the names from the child versus the original parent report. This is pretty easy to figure out on your own actually – I mean I’m no real developer and I got it pretty quick. <?xml version="1.0" encoding="UTF-8" ?> <displays> <display id="92857fce-0139-1000-8006-7f0000015340" type="" style="Table" enable="true"> <name><![CDATA[Grandparent]]></name> <description><![CDATA[]]></description> <tooltip><![CDATA[]]></tooltip> <drillclass><![CDATA[null]]></drillclass> <CustomValues> <TYPE>horizontal</TYPE> </CustomValues> <query> <sql><![CDATA[select * from hr.departments]]></sql> </query> <pdf version="VERSION_1_7" compression="CONTENT"> <docproperty title="" author="" subject="" keywords="" /> <cell toppadding="2" bottompadding="2" leftpadding="2" rightpadding="2" horizontalalign="LEFT" verticalalign="TOP" wrap="true" /> <column> <heading font="Courier" size="10" style="NORMAL" color="-16777216" rowshading="-1" labeling="FIRST_PAGE" /> <footing font="Courier" size="10" style="NORMAL" color="-16777216" rowshading="-1" labeling="NONE" /> <blob blob="NONE" zip="false" /> </column> <table font="Courier" size="10" style="NORMAL" color="-16777216" userowshading="false" oddrowshading="-1" evenrowshading="-1" showborders="true" spacingbefore="12" spacingafter="12" horizontalalign="LEFT" /> <header enable="false" generatedate="false"> <data> null </data> </header> <footer enable="false" generatedate="false"> <data value="null" /> </footer> <security enable="false" useopenpassword="false" openpassword="" encryption="EXCLUDE_METADATA"> <permission enable="false" permissionpassword="" allowcopying="true" allowprinting="true" allowupdating="false" allowaccessdevices="true" /> </security> <pagesetup papersize="LETTER" orientation="1" measurement="in" margintop="1.0" marginbottom="1.0" marginleft="1.0" marginright="1.0" /> </pdf> <display id="null" type="" style="Table" enable="true"> <name><![CDATA[Parent]]></name> <description><![CDATA[]]></description> <tooltip><![CDATA[]]></tooltip> <drillclass><![CDATA[null]]></drillclass> <CustomValues> <TYPE>horizontal</TYPE> </CustomValues> <query> <sql><![CDATA[select * from hr.employees where department_id = EPARTMENT_ID]]></sql> <binds> <bind id="DEPARTMENT_ID"> <prompt><![CDATA[DEPARTMENT_ID]]></prompt> <tooltip><![CDATA[DEPARTMENT_ID]]></tooltip> <value><![CDATA[NULL_VALUE]]></value> </bind> </binds> </query> <pdf version="VERSION_1_7" compression="CONTENT"> <docproperty title="" author="" subject="" keywords="" /> <cell toppadding="2" bottompadding="2" leftpadding="2" rightpadding="2" horizontalalign="LEFT" verticalalign="TOP" wrap="true" /> <column> <heading font="Courier" size="10" style="NORMAL" color="-16777216" rowshading="-1" labeling="FIRST_PAGE" /> <footing font="Courier" size="10" style="NORMAL" color="-16777216" rowshading="-1" labeling="NONE" /> <blob blob="NONE" zip="false" /> </column> <table font="Courier" size="10" style="NORMAL" color="-16777216" userowshading="false" oddrowshading="-1" evenrowshading="-1" showborders="true" spacingbefore="12" spacingafter="12" horizontalalign="LEFT" /> <header enable="false" generatedate="false"> <data> null </data> </header> <footer enable="false" generatedate="false"> <data value="null" /> </footer> <security enable="false" useopenpassword="false" openpassword="" encryption="EXCLUDE_METADATA"> <permission enable="false" permissionpassword="" allowcopying="true" allowprinting="true" allowupdating="false" allowaccessdevices="true" /> </security> <pagesetup papersize="LETTER" orientation="1" measurement="in" margintop="1.0" marginbottom="1.0" marginleft="1.0" marginright="1.0" /> </pdf> <display id="null" type="" style="Table" enable="true"> <name><![CDATA[Child]]></name> <description><![CDATA[]]></description> <tooltip><![CDATA[]]></tooltip> <drillclass><![CDATA[null]]></drillclass> <CustomValues> <TYPE>horizontal</TYPE> </CustomValues> <query> <sql><![CDATA[select * from hr.jobs where job_id = :JOB_ID]]></sql> <binds> <bind id="JOB_ID"> <prompt><![CDATA[JOB_ID]]></prompt> <tooltip><![CDATA[JOB_ID]]></tooltip> <value><![CDATA[NULL_VALUE]]></value> </bind> </binds> </query> <pdf version="VERSION_1_7" compression="CONTENT"> <docproperty title="" author="" subject="" keywords="" /> <cell toppadding="2" bottompadding="2" leftpadding="2" rightpadding="2" horizontalalign="LEFT" verticalalign="TOP" wrap="true" /> <column> <heading font="Courier" size="10" style="NORMAL" color="-16777216" rowshading="-1" labeling="FIRST_PAGE" /> <footing font="Courier" size="10" style="NORMAL" color="-16777216" rowshading="-1" labeling="NONE" /> <blob blob="NONE" zip="false" /> </column> <table font="Courier" size="10" style="NORMAL" color="-16777216" userowshading="false" oddrowshading="-1" evenrowshading="-1" showborders="true" spacingbefore="12" spacingafter="12" horizontalalign="LEFT" /> <header enable="false" generatedate="false"> <data> null </data> </header> <footer enable="false" generatedate="false"> <data value="null" /> </footer> <security enable="false" useopenpassword="false" openpassword="" encryption="EXCLUDE_METADATA"> <permission enable="false" permissionpassword="" allowcopying="true" allowprinting="true" allowupdating="false" allowaccessdevices="true" /> </security> <pagesetup papersize="LETTER" orientation="1" measurement="in" margintop="1.0" marginbottom="1.0" marginleft="1.0" marginright="1.0" /> </pdf> </display> </display> </display> </displays> Save the file and ‘Open Report…’ You’ll see your new report name in the tree. You just need to double-click it to open it. Here’s what it looks like running A 3 generation family Now Let’s Build an AWR Text Report Ronald wanted to have the ability to query AWR snapshots and generate the AWR reports. That requires a few inputs, including a START and STOP snapshot ID. That basically tells AWR what time period to use for generating the report. And here’s where it gets tricky. We’ll need to use aliases for the SNAP_ID column. Since we’re using the same column name from 2 different queries, we need to use different bind variables. Fortunately for us, SQL Developer’s clever enough to use the column alias as the BIND. Here’s what I mean: Grandparent Query SELECT snap_id start1, begin_interval_time, end_interval_time FROM dba_hist_snapshot ORDER BY 1 asc Parent Query SELECT snap_id stop1, begin_interval_time, end_interval_time, :START1 carry FROM dba_hist_snapshot WHERE snap_id > :START1 ORDER BY 1 asc And here’s where it gets even trickier – you can’t reference a bind from outside the parent query. My grandchild report can’t reference a value from the grandparent report. So I just carry the selected value down to the parent. In my parent query SELECT you see the ‘:START1′ at the end? That’s making that value available to me when I use it in my grandchild query. To complicate things a bit further, I can’t have a column name with a ‘:’ in it, or SQL Developer will get confused when I try to reference the value of the variable with the ‘:’ – and ‘::Name’ doesn’t work. But that’s OK, just alias it. Grandchild Query Select Output From Table(Dbms_Workload_Repository.Awr_Report_Text(1298953802, 1,:CARRY, :STOP1)); Ok, and the last trick – I hard-coded my report to use my database’s DB_ID and INST_ID into the AWR package call. Now a smart person could figure out a way to make that work on any database, but I got lazy and and ran out of time. But this should be far enough for you to take it from here. Here’s what my report looks like now: Caution: don’t run this if you haven’t licensed Enterprise Edition with Diagnostic Pack. The Raw XML for this AWR Report <?xml version="1.0" encoding="UTF-8" ?> <displays> <display id="927ba96c-0139-1000-8001-7f0000015340" type="" style="Table" enable="true"> <name><![CDATA[AWR Start Stop Report Final]]></name> <description><![CDATA[]]></description> <tooltip><![CDATA[]]></tooltip> <drillclass><![CDATA[null]]></drillclass> <CustomValues> <TYPE>horizontal</TYPE> </CustomValues> <query> <sql><![CDATA[SELECT snap_id start1, begin_interval_time, end_interval_time FROM dba_hist_snapshot ORDER BY 1 asc]]></sql> </query> <display id="null" type="" style="Table" enable="true"> <name><![CDATA[Stop SNAP_ID]]></name> <description><![CDATA[]]></description> <tooltip><![CDATA[]]></tooltip> <drillclass><![CDATA[null]]></drillclass> <CustomValues> <TYPE>horizontal</TYPE> </CustomValues> <query> <sql><![CDATA[SELECT snap_id stop1, begin_interval_time, end_interval_time, :START1 carry FROM dba_hist_snapshot WHERE snap_id > :START1 ORDER BY 1 asc]]></sql> </query> <display id="null" type="" style="Table" enable="true"> <name><![CDATA[AWR Report]]></name> <description><![CDATA[]]></description> <tooltip><![CDATA[]]></tooltip> <drillclass><![CDATA[null]]></drillclass> <CustomValues> <TYPE>horizontal</TYPE> </CustomValues> <query> <sql><![CDATA[Select Output From Table(Dbms_Workload_Repository.Awr_Report_Text(1298953802, 1,:CARRY, :STOP1 ))]]></sql> </query> </display> </display> </display> </displays> Should We Build Support for Multiple Levels of Reports into the User Interface? Let us know! A comment here or a suggestion on our SQL Developer Exchange might help your case!

  Read the article

• So it comes to PASS…

  - by Tony Davis

  How does your company gauge the benefit of attending a technical conference? What's the best change you made as a direct result of attendance? It's time again for the PASS Summit and I, like most people go with a set of general goals for enhancing technical knowledge; to learn more about PowerShell, to drill into SQL Server performance tuning techniques, and so on. Most will write up a brief report on the event for the rest of the team. Ideally, however, it will go a bit further than that; each conference should result in a specific improvement to one of your systems, or in the way you do your job. As co-editor of Simple-talk.com, and responsible for the majority of our SQL books, my “high level” goals don't vary much from conference to conference. I'm always on the lookout for good new authors. I target interesting new technologies and tools and try to learn more. I return with a list of actions, new articles to commission, and potential new authors. Three years ago, however, I started setting myself the goal of implementing “one new thing” after each conference. After one, I adopted Kanban for managing my workload, a technique that places strict limits on “work in progress” and makes the overall workload, and backlog, highly visible. After another I trialled a community book project. At PASS 2010, one of my general goals was to delve deeper into SQL Server transaction log mechanics, but on top of that, I set a specific goal of writing something useful on the topic. I started a Stairway series and, ultimately, it's turned into a book! If you're attending the PASS Summit this year, take some time to consider what specific improvement or change you'll implement as a result. Also, try to drop by the Red Gate booth (#101). During the Vendor event on Wednesday evening, Gail Shaw and I will be there to discuss, and hand out copies of the book. Cheers, Tony.  

  Read the article

• Oracle VM Deep Dives

  - by rickramsey

  "With IT staff now tasked to deliver on-demand services, datacenter virtualization requirements have gone beyond simple consolidation and cost reduction. Simply provisioning and delivering an operating environment falls short. IT organizations must rapidly deliver services, such as infrastructure-as-a-service (IaaS), platform-as-a-service (PaaS), and software-as-a-service (SaaS). Virtualization solutions need to be application-driven and enable:" "Easier deployment and management of business critical applications" "Rapid and automated provisioning of the entire application stack inside the virtual machine" "Integrated management of the complete stack including the VM and the applications running inside the VM." Application Driven Virtualization, an Oracle white paper That was published in August of 2011. The new release of Oracle VM Server delivers significant virtual networking performance improvements, among other things. If you're not sure how virtual networks work or how to use them, these two articles by Greg King and friends might help. Looking Under the Hood at Virtual Networking by Greg King Oracle VM Server for x86 lets you create logical networks out of physical Ethernet ports, bonded ports, VLAN segments, virtual MAC addresses (VNICs), and network channels. You can then assign channels (or "roles") to each logical network so that it handles the type of traffic you want it to. Greg King explains how you go about doing this, and how Oracle VM Server for x86 implements the network infrastructure you configured. He also describes how the VM interacts with paravirtualized guest operating systems, hardware virtualized operating systems, and VLANs. Finally, he provides an example that shows you how it all looks from the VM Manager view, the logical view, and the command line view of Oracle VM Server for x86. Fundamental Concepts of VLAN Networks by Greg King and Don Smerker Oracle VM Server for x86 supports a wide range of options in network design, varying in complexity from a single network to configurations that include network bonds, VLANS, bridges, and multiple networks connecting the Oracle VM servers and guests. You can create separate networks to isolate traffic, or you can configure a single network for multiple roles. Network design depends on many factors, including the number and type of network interfaces, reliability and performance goals, the number of Oracle VM servers and guests, and the anticipated workload. The Oracle VM Manager GUI presents four different ways to create an Oracle VM network: Bonds and ports VLANs Both bond/ports and VLANS A local network This article focuses the second option, designing a complex Oracle VM network infrastructure using only VLANs, and it steps through the concepts needed to create a robust network infrastructure for your Oracle VM servers and guests. More Resources Virtual Networking for Dummies Download Oracle VM Server for x86 Find technical resources for Oracle VM Server for x86 -Rick Follow me on: Blog | Facebook | Twitter | Personal Twitter | YouTube | The Great Peruvian Novel

  Read the article

• Regular Expressions Reference Tables Updated

  - by Jan Goyvaerts

  The regular expressions reference on the Regular-Expressions.info website was completely overhauled with the big update of that site last month. In the past, the reference section consisted of two parts. One part was a summary of the regex features commonly found in Perl-style regex flavors with short descriptions and examples. This part of the reference ignored differences between regex flavors and omitted most features that don’t have wide support. The other part was a regular expression flavor comparison that listed many more regex features along with YES/no indicators for many regex flavors, but without any explanations of the features. When reworking the site, I wanted to make the reference section more detailed, with descriptions and examples of all the syntax supported by the flavors discussed on the site. Doing that resulted in a reference that lists many features that are only supported by a few regex flavors. For such a reference to be usable, it needs to indicate which flavors support each feature. My original design for the new reference table used two rows for each feature. The first row had 4 columns with a label, syntax, description, and example, similar to the old reference tables. The second row had 20 columns indicating which versions of which flavors support these features. While the double-row design allowed all the information to fit within the table without requiring horizontal scrolling, it made it more difficult to quickly scan the tables for the feature you’re looking for. To make the new reference tables easier to read, they now have only a single row for each feature. The first 4 columns are the same as before. The remaining two columns show which versions of two regular expression flavors support the feature. You can use the drop-down lists above the table to choose the flavors the table should indicate. The site uses cookies to allow the flavor choices to persist while you navigate the reference. The result of this latest update is that the new regex tables are now just as easy to read as the ten-year-old tables on the old site were, while still covering all the features big and small of all the flavors discussed on the site.

  Read the article

• SQL Developer: Why Do You Require Semicolons When Executing SQL in the Worksheet?

  - by thatjeffsmith

  There are many database tools out there that support Oracle database. Oracle SQL Developer just happens to be the one that is produced and shipped by the same folks that bring you the database product. Several other 3rd party tools out there allow you to have a collection of SQL statements in their editor and execute them without requiring a statement delimiter (usually a semicolon.) Let’s look at a quick example: select * from scott.emp select * from hr.employees delete from HR_COPY.BEER where HR_COPY.BEER.STATE like '%West Virginia% In some tools, you can simply place your cursor on say the 2nd statement and ask to execute that statement. The tool assumes that the blank line between it and the next statement, a DELETE, serves as a statement delimiter. This is not bad in and of itself. However, it is very important to understand how your tools work. If you were to try the same trick by running the delete statement, it would empty my entire BEER table instead of just trimming out the breweries from my home state. SQL Developer only executes what you ask it to execute You can paste this same code into SQL Developer and run it without problems and without having to add semicolons to your statements. Highlight what you want executed, and hit Ctrl-Enter If you don’t highlight the text, here’s what you’ll see: See the statement at the cursor vs what SQL Developer actually executed? The parser looks for a query and keeps going until the statement is terminated with a semicolon – UNLESS it’s highlighted, then it assumes you only want to execute what is highlighted. In both cases you are being explicit with what is being sent to the database. Again, there’s not necessarily a ‘right’ or ‘wrong’ debate here. What you need to be aware of is the differences and to learn new workflows if you are moving from other database tools to Oracle SQL Developer. I say, when in doubt, back away from the tool, especially if you’re in production. Oh, and to answer the original question… Because we’re trying to emulate SQL*Plus behavior. You end statements in SQL*Plus with delimiters, and the default delimiter is a semicolon.

  Read the article

• SQL SERVER – A Puzzle – Fun with NULL – Fix Error 8117

  - by pinaldave

  During my 8 years of career, I have been involved in many interviews. Quite often, I act as the  interview. If I am the interviewer, I ask many questions – from easy questions to difficult ones. When I am the interviewee, I frequently get an opportunity to ask the interviewer some questions back. Regardless of the my capacity in attending the interview, I always make it a point to ask the interviewer at least one question. What is NULL? It’s always fun to ask this question during interviews, because in every interview, I get a different answer. NULL is often confused with false, absence of value or infinite value. Honestly, NULL is a very interesting subject as it bases its behavior in server settings. There are a few properties of NULL that are universal, but the knowledge about these properties is not known in a universal sense. Let us run this simple puzzle. Run the following T-SQL script: SELECT SUM(data) FROM (SELECT NULL AS data) t It will return the following error: Msg 8117, Level 16, State 1, Line 1 Operand data type NULL is invalid for sum operator. Now the error makes it very clear that NULL is invalid for sum Operator. Frequently enough, I have showed this simple query to many folks whom I came across. I asked them if they could modify the subquery and return the result as NULL. Here is what I expected: Even though this is a very simple looking query, so far I’ve got the correct answer from only 10% of the people to whom I have asked this question. It was common for me to receive this kind of answer – convert the NULL to some data type. However, doing so usually returns the value as 0 or the integer they passed. SELECT SUM(data) FROM (SELECT ISNULL(NULL,0) AS data) t I usually see many people modifying the outer query to get desired NULL result, but that is not allowed in this simple puzzle. This small puzzle made me wonder how many people have a clear understanding about NULL. Well, here is the answer to my simple puzzle. Just CAST NULL AS INT and it will return the final result as NULL: SELECT SUM(data) FROM (SELECT CAST(NULL AS INT) AS data) t Now that you know the answer, don’t you think it was very simple indeed? This blog post is especially dedicated to my friend Madhivanan who has written an excellent blog post about NULL. I am confident that after reading the blog post from Madhivanan, you will have no confusion regarding NULL in the future. Read: NULL, NULL, NULL and nothing but NULL. Reference: Pinal Dave (http://blog.sqlauthority.com) Filed under: PostADay, SQL, SQL Authority, SQL Puzzle, SQL Query, SQL Scripts, SQL Server, SQL Tips and Tricks, T SQL, Technology

  Read the article

• We’ve Got 10 Free Copies of Microsoft’s Networking Windows 7 eBook to Give Away. Get Yours!

  - by The Geek

  Last month, we reviewed our friend Ciprian’s new book by Microsoft Press, Network Your Computers & Devices: Step by Step—and we’ve twisted his arm until he decided to give away 10 free copies for our readers. First, the book: It’s a great book that covers networking between computers running Windows 7, XP, Vista, Linux, and even Mac OS X. Just as the title suggests, he’s got step-by-step tutorials that explain how to get your network up and running with a minimum of fuss. Want to see for yourself? You can grab a copy of the free sample chapter if you’d like, or you can look through the chapter outline: Chapter 1: Setting Up a Router and Devices Chapter 2: Setting User Accounts on All Computers Chapter 3: Setting Up Your Libraries on All Windows 7 Computers Chapter 4: Creating the Network Chapter 5: Customizing Network Sharing Settings in Windows 7 Chapter 6: Creating the Homegroup and Joining Windows 7 Computers Chapter 7: Sharing Libraries and Folders Chapter 8: Sharing and Working with Devices Chapter 9: Streaming Media Over the Network and the Internet Chapter 10: Sharing Between Windows XP, Windows Vista, and Windows 7 Computers Chapter 11: Sharing Between Mac OS X and Windows 7 Computers Chapter 12: Sharing Between Ubuntu Linux and Windows 7 Computers Chapter 13: Keeping the Network Secure Chapter 14: Setting Up Parental Controls Chapter 15: Troubleshooting Network and Internet Problems Whether you believe it’s the perfect book or not, we’re giving away one for free, so keep reading. Giveaway Details: Or What You Need to Do Since we’ve got an awful lot of subscribers, and we’ve only got 10 ebooks to give away, we need a few rules. So here’s how you can put your name into the hat for the giveaway: Method 1: Leave a comment on the giveaway post over on our Facebook Fan page. Obviously you’ll need to Like us before you can leave a comment. Method 2: If you don’t use Facebook, you can tweet this post using the Tweet button at the top of the article. Winners: We’ll randomly pick 10 winners from those who participate. Expiration: This giveaway expires in 3 days, give or take a day. We’ll announce the winners and contact them directly. So go forth, and get yourself a free ebook! Of course, if you want the print version, you can get that for a discount over on Amazon at the moment. Latest Features How-To Geek ETC Internet Explorer 9 RC Now Available: Here’s the Most Interesting New Stuff Here’s a Super Simple Trick to Defeating Fake Anti-Virus Malware How to Change the Default Application for Android Tasks Stop Believing TV’s Lies: The Real Truth About "Enhancing" Images The How-To Geek Valentine’s Day Gift Guide Inspire Geek Love with These Hilarious Geek Valentines MyPaint is an Open-Source Graphics App for Digital Painters Can the Birds and Pigs Really Be Friends in the End? [Angry Birds Video] Add the 2D Version of the New Unity Interface to Ubuntu 10.10 and 11.04 MightyMintyBoost Is a 3-in-1 Gadget Charger Watson Ties Against Human Jeopardy Opponents Peaceful Tropical Cavern Wallpaper

  Read the article

• Angry Bird Makers: Developers Love iOS Over Android To Make Money

  - by Gopinath

  These days web is buzzing with Apple iOS vs Google Android debates. Recently Fortune predicted that Android is going to explode in 2011 and it will surpass Apple’s iOS market share. Yes Android is set to spread its wings across all the devices – smartphones, TVs, set top boxes, in car entertainment devices, what not. Think of any device that requires operating system, Android can be used. On the other than iOS is only available on very selective Apple devices – iPods, iPhones and iPads. When it comes to the count of devices running on a specific OS, Android will be far ahead of iOS but when you consider a quality of devices and providing an eco system for business to make money iOS seems to be the winner. That is what experts and analysts are saysing. Here is an excerpt from Peter Vesterbacka, maker of the popular Angry Birds game, interview to Tech N Marketing site.  He says Apple will be the number one platform for a long time from a developer perspective, they have gotten so many things right. And they know what they are doing and they call the shots. Android is growing, but it’s also growing complexity at the same time. Device fragmentation not the issue, but rather the fragmentation of the ecosystem. So many different shops, so many different models. The carriers messing with the experience again. Open but not really open, a very Google centric ecosystem. And paid content just doesn’t work on Android. Peter says developer prefer iOS over Android as it’s not very easy to make money on Android market. That’s why they released a free version of Angry Birds game with ads support for Android devices. Free is the way to go with Android. Nobody has been successful selling content on Android. We will offer a way to remove the ads by paying for the app, but we don’t expect that to be a huge revenue stream. You can read full interview here. cc image credit: flickr/johanl This article titled,Angry Bird Makers: Developers Love iOS Over Android To Make Money, was originally published at Tech Dreams. Grab our rss feed or fan us on Facebook to get updates from us.

  Read the article

• links for 2011-03-15

  - by Bob Rhubart

  Dr. Frank Munz: Resize AWS EC2 Cloud Instances Dr Munz says: "You cannot dynamically resize a running cloud instance. E.g. there is no API call to ask for 2.2 GHz CPU speed instead of 1.8 GHz or to dynamically add another 3.5 GB of RAM." (tags: oracle cloud amazon ec2) Roddy Rodstein: Oracle VM Manager Architecture and Scalability Rodstein says: "Oracle VM Manager can be installed in an all-in-one configuration using the default Oracle 10g Express Database or in a more traditional two tier architecture with an OC4J web tier and a 10 or 11g database tier." (tags: oracle otn virtualization oraclevm) Mark Nelson: Getting started with Continuous Integration for SOA projects Nelson says: "I am exploring how to use Maven and Hudson to create a continuous integration capability for SOA and BPM projects. This will be the first post of several on this topic, and today we will look at setting up some simple continuous integration for a single SOA project." (tags: oracle maven hudson soa bpm) 5 New Java Champions (The Java Source) Tori Wieldt shares the big news. Congratulations to new Java Champs Jonas Bonér, James Strachan, Rickard Oberg, Régina ten Bruggencate, and Clara Ko. (tags: oracle java) Alert for Forms customers running Oracle Forms 10g (Grant Ronald's Blog) Ronald says: "While you might have been happily running your Forms 10g applications for about 5 years or so now, the end of premier support is creeping up and you need to start planning for a move to Oracle Forms 11g." (tags: oracle oracleforms) Brenda Michelson: Enterprise Architecture Rant #4,892 "I’m increasingly concerned about the macro-direction of our field, as we continue to suffer ivory tower enterprise architecture punditry, rigid frameworks and endless philosophical waxing." - Brenda Michelson (tags: entarch enterprisearchitecture ivorytower) Amitabh Apte: Enterprise Architecture - Different Perspectives "Business does not need Enterprise Architecture," says Apte, "it needs value and outcomes from the EA function." (tags: entarch enterprisearchitecture) First Ever MySQL on Windows Online Forum - March 16, 2011 (Oracle's MySQL Blog) Monica Kumar shares the details. (tags: oracle mysql mswindows) Jeff Davies: Running Multiple WebLogic and OSB Domains "There is a small 'gotcha' if you want to create multiple domains on a devevelopment machine," says Jeff Davies. But don't worry - there's a solution. (tags: oracle soa osb weblogic servicebus) The Arup Nanda Blog: Good Engineering "Engineering is not about being superficially creative," Nanda says, "it's about reliability and trustworthiness." (tags: oracle engineering software technology) Welcome to the SOA & E2.0 Partner Community Forum (SOA Partner Community Blog) (tags: ping.fm)

  Read the article

• When done is not done

  - by Tony Davis

  Most developers and DBAs will know what it’s like to be asked to do "a quick tidy up" on a project that, on closer inspection, turns out to be a barely working prototype: as the cynical programmer says, "when you’re told that a project is 90% done, prepare for the next 90%". It is easy to convince a layperson that an application is complete just by using test data, and sticking to the workflow that the development team has implemented and tested. The application is ‘done’ only in the sense that the anticipated paths through the software features, using known data, are fully supported. Reality often strikes only when testers reveal its strange and erratic behavior in response to behavior from the end user that strays from the "ideal". The problem is this: how do we measure progress, accurately and objectively? Development methods such as Scrum or Kanban, when implemented rigorously, can mitigate these problems for developers, to some extent. They force a team to progress one small, but complete feature at a time, to find out how long it really takes for this feature to be "done done"; in other words done to the point where its performance and scalability is understood, it is tested for all conceivable edge cases and doesn’t break…it is ready for prime time. At that point, the team has a much more realistic idea of how long it will take them to really complete all the remaining features, and so how far away the end is. However, it is when software crosses team boundaries that we feel the limitations of such techniques. No matter how well drilled the development team is, problems will still arise if they don’t deploy frequently to a production environment. If they work feverishly for months on end before finally tossing the finished piece of software over the fence for the DBA to deploy to the "real world" then once again will dawn the realization that "done done" is still out of reach, as the DBA uncovers poorly code transactions, un-scalable queries, inefficient caching, and so on. By deploying regularly, end users will also have a much earlier opportunity to tell you how far what you implemented strayed from what they wanted. If you have a tale to tell, anonymized of course, of a "quick polish" project that turned out to be anything but, and what the major problems were, please do share it. Cheers, Tony.

  Read the article

• Keyboard Shortcuts in Oracle SQL Developer

  - by thatjeffsmith

  The CTRL key, which stands for ConTRoL…aw, the good ole days What keyboard shortcuts should EVERY Oracle SQL Developer user know? How do you find new shortcuts to master, and how do you change them to match ones you’ve already learned in other tools? These are the driving questions for today’s post. While some of us may be keyboard ninjas, and others are more driven to use the mouse – everyone has probably picked up a few strategic keyboard shortcuts over the years. For example, I’ve personally JUST memorized the Cmd-Shift-4 ‘trick’ in Mac OS X. And of course we all know what F1 does, right? Right?!? Here are a few more keyboard shortcuts to commit to memory. My Favorite SQL Developer Shortcuts ctrl-enter : executes the current statement(s) F5 : executes the current code as a script (think SQL*Plus) ctrl-space : invokes code insight on demand Code Editor – Completion Insight – Enable Completion Auto-Popup (Keyword being Auto) ctrl-Up/Dn : replaces worksheet with previous/next SQL from SQL History ctrl-shift+Up/Dn : same as above but appends instead of replaces shift+F4 : opens a Describe window for current object at cursor ctrl+F7 : format SQL ctrl+/ : toggles line commenting ctrl+e : incremental search Configuring Keyboard Shortcuts in SQL Developer Tools Preferences Shortcut Keys Search by command name OR the keystroke itself Some tips… Sort by category Pay special attention to the ‘Code Editor’ and ‘Other’ categories Mind the conflicts when you change the defaults Be nice – share! You can save your new mappings with your co-workers using the Export and Import buttons Click on ‘More Actions’ to expose the Import and Export buttons When I get ‘bored’ or if I think I might be missing something, I peruse the Code Editor and Other categories, again! I’ve picked up quite a few cool editor tricks here. Then I blog about them, like they’re ‘magic.’ #EvilLaugh But the main tip is this – don’t let your previously memorized keyboard shortcuts SHORTCUT your usage of SQL Developer. If your fingers have already memorized some keystrokes, just re-program SQL Developer to match! What’s your favorite shortcut? I’ll use the most popular shortcut mentioned in the comments to round out my Top 10 list above!

  Read the article

• Can a Printer Print White?

  - by Jason Fitzpatrick

  The vast majority of the time we all print on white media: white paper, white cardstock, and other neutral white surfaces. But what about printing white? Can modern printers print white and if not, why not? Read on as we explore color theory, printer design choices, and why white is the foundation of the printing process. Today’s Question & Answer session comes to us courtesy of SuperUser—a subdivision of Stack Exchange, a community-driven grouping of Q&A web sites. Image by Coiote O.; available as wallpaper here. The Question SuperUser reader Curious_Kid is well, curious, about printers. He writes: I was reading about different color models, when this question hit my mind. Can the CMYK color model generate white color? Printers use CMYK color mode. What will happen if I try to print a white colored image (rabbit) on a black paper with my printer? Will I get any image on the paper? Does the CMYK color model have room for white? The Answer SuperUser contributor Darth Android offers some insight into the CMYK process: You will not get anything on the paper with a basic CMYK inkjet or laser printer. The CMYK color mixing is subtractive, meaning that it requires the base that is being colored to have all colors (i.e., White) So that it can create color variation through subtraction: White - Cyan - Yellow = Green White - Yellow - Magenta = Red White - Cyan - Magenta = Blue White is represented as 0 cyan, 0 yellow, 0 magenta, and 0 black – effectively, 0 ink for a printer that simply has those four cartridges. This works great when you have white media, as “printing no ink” simply leaves the white exposed, but as you can imagine, this doesn’t work for non-white media. If you don’t have a base color to subtract from (i.e., Black), then it doesn’t matter what you subtract from it, you still have the color Black. [But], as others are pointing out, there are special printers which can operate in the CMYW color space, or otherwise have a white ink or toner. These can be used to print light colors on top of dark or otherwise non-white media. You might also find my answer to a different question about color spaces helpful or informative. Given that the majority of printer media in the world is white and printing pure white on non-white colors is a specialty process, it’s no surprise that home and (most) commercial printers alike have no provision for it. Have something to add to the explanation? Sound off in the the comments. Want to read more answers from other tech-savvy Stack Exchange users? Check out the full discussion thread here.     

  Read the article

< Previous Page | 26 27 28 29 30 31 32 33 34 35 36 37  | Next Page >