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• What are the standard directory layouts for source code?

  - by splattered bits

  I'm in the process of proposing a new standard directory layout that will be used across all the projects in our organization. Projects can have compiled source code, setup scripts, build scripts, third-party libraries, database scripts, resources, web services, web sites, etc. This is partly inspired by discovering Maven's standard layout. Are there any other standard layouts that are generally accepted in the industry?

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• Unit-testing code that relies on untestable 3rd party code

  - by DudeOnRock

  Sometimes, especially when working with third party code, I write unit-test specific code in my production code. This happens when third party code uses singletons, relies on constants, accesses the file-system/a resource I don't want to access in a test situation, or overuses inheritance. The form my unit-test specific code takes is usually the following: if (accessing or importing a certain resource fails) I assume this is a test case and load a mock object Is this poor form, and if it is, what is normally done when writing tests for code that uses untestable third party code?

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• Should maven generate jaxb java code or just use java code from source control?

  - by Peter Turner

  We're trying to plan how to mash together a build server for our shiny new java backend. We use a lot of jaxb XSD code generation and I was getting into a heated argument with whoever cared that the build server should delete jaxb created structures that were checked in generate the code from XSD's use code generated from those XSD's Everyone else thought that it made more sense to just use the code they checked in (we check in the code generated from the XSD because Eclipse pretty much forces you to do this as far as I can tell). My only stale argument is in my reading of the Joel test is that making the build in one step means generating from the source code and the source code is not the java source, but the XSD's because if you're messing around with the generated code you're gonna get pinched eventually. So, given that we all agree (you may not agree) we should probably be checking in our generate java files, should we use them to generate our code or should we generate it using the XSD's?

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• Software for "High-level" source code (C++) Management

  - by Korchkidu

  after a lot of small-medium projects, I have a lot of libraries and test programs here and there. Also, I must admit that some of the "best practices" I learnt are not that "good" IMHO. In particular, documenting your code and making a "high-level" documentation is not useful in practice: High-level documentation are not maintain up to date = I prefer to read the source code directly; Browsing generated developer documentation is a pain (IMHO) = I prefer to read the source code directly. For that reason, I am looking for a tool who could help me organize all my source code directories in a more "readable manner". What I need is a tool which: Maintains an UML diagram from C++ source code. I don't need source code generation from UML; USE CASE: I am in this super-tool, I notice a design issue, I change the source code, when I get back, the UML diagram is updated; Maintains easily browsable call graphs; Lists references to methods, variables, etc. For example, when I want to see where/when a method is called; Helps writing pseudo-code from C++; Embeds a nice C++ source code browser; Is Open Source would be great; Works at least on Win7. The focus of this tool should be to browse source code to understand what's going on. For example, when you have a newcomer and you need him to go through source code. Do you know any great tool? Thanks in advance. PS: please do not answer doxygen (great tool however).

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• Design Code Outside of an IDE (C#)?

  - by ryanzec

  Does anyone design code outside of an IDE? I think that code design is great and all but the only place I find myself actually design code (besides in my head) is in the IDE itself. I generally think about it a little before hand but when I go to type it out, it is always in the IDE; no UML or anything like that. Now I think having UML of your code is really good because you are able to see a lot more of the code on one screen however the issue I have is that once I type it in UML, I then have to type the actual code and that is just a big duplicate for me. For those who work with C# and design code outside of Visual Studio (or at least outside Visual Studio's text editor), what tools do you use? Do those tools allow you to convert your design to actual skeleton code? It is also possible to convert code to the design (when you update the code and need an updated UML diagram or whatnot)?

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• how to set timer for calculate execution time

  - by ratty

  i like to set timer for calculating execution time in c# for particular process in my execution. how can i do this

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• Freelancing - Share the source code?

  - by Tec

  I have developed a couple of form based windows application in vb.net for a client and they all work well and he paid me through a freelance site. I have handed over the executable and the setup to the client and all was well. Now the client wants the source code for the application. Is there a general practice on sharing the source code with the client? Please note - the client never mentioned he needs the source code and he is now asking for it after a week after the app was completed and he made the payment. I don't mind sharing the source code, but I am not sure if I should. This probably means the client would not hire me again and the bigger question is the source code really his property? This question may have been asked a few times, but I cannot still draw a conclusion on what is right. update To answer some of the questions: The source code was not mentioned at all. There was no exclusive contract signed except for the usual agreement of the freelance site. I am not sure if software development comes under work for hire and is it valid for users outside of the US? The reason for not sharing the source code was this was a very small project and I got paid for a mere few hours. So if I have an option then definitely I would want to keep the source code to myself as that gives a possibility of the client coming back. The application works flawlessly and the code is solid. Also, the task that the client wanted to achieve was very challenging and I would not like other programmers (competitors) to know how I achieved it. So unless I get the confirmation that the source code is purely the property of the client, I would not be willing to share it.

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• Code Trivia #7

  - by João Angelo

  Lets go for another code trivia, it’s business as usual, you just need to find what’s wrong with the following code: static void Main(string[] args) { using (var file = new FileStream("test", FileMode.Create) { WriteTimeout = 1 }) { file.WriteByte(0); } } TIP: There’s something very wrong with this specific code and there’s also another subtle problem that arises due to how the code is structured.

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• Code review recommendations and Code Smells

  - by Michael Freidgeim

  Some time ago Twitter told that I am similar to Boris Lipschitz . Indeed he is also .Net programmer from Russia living in Australia. I‘ve read his list of Code Review points and found them quite comprehensive. A few points  were not clear for me, and it forced me for a further reading.In particular the statement “Exception should not be used to return a status or an error code.” wasn’t fully clear for me, because sometimes we store an exception as an object with all error details and I believe it’s a valid approach. However I agree that throwing exceptions should be avoided, if you expect to return error as a part of a normal flow. Related link: http://codeutopia.net/blog/2010/03/11/should-a-failed-function-return-a-value-or-throw-an-exception/ Another point slightly puzzled me“If Thread.Sleep() is used, can it be replaced with something else, ei Timer, AutoResetEvent, etc” . I believe, that there are very rare cases, when anyone using Thread.Sleep in any production code. Usually it is used in mocks and prototypes.I had to look further to clarify “Dependency injection is used instead of Service Location pattern”.Even most of articles has some preferences to Dependency injection, there are also advantages to use Service Location. E.g see http://geekswithblogs.net/KyleBurns/archive/2012/04/27/dependency-injection-vs.-service-locator.aspx. http://www.cookcomputing.com/blog/archives/000587.html  refers to Concluding Thoughts of Martin Fowler The choice between Service Locator and Dependency Injection is less important than the principle of separating service configuration from the use of services within an applicationThe post had a link to excellent article Code Smells of Jeff Atwood, but the statement, that “code should not pass a review if it violates any of the  code smells” sound too strict for my environment. In particular, I disagree with “Dead Code” recommendation “Ruthlessly delete code that isn't being used. That's why we have source control systems!”. If there is a chance that not used code will be required in a future, it is convenient to keep it as commented or #if/#endif blocks with appropriate explanation, why it could be required in the future. TFS is a good source control system, but context search in source code of current solution is much easier than finding something in the previous versions of the code.I also found a link to a good book “Clean Code.A.Handbook.of.Agile.Software”

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• Jquery validation does not stop execution of "code behind" code of asp.net button

  - by shahk26

  Hi, I have a asp.net button which has click event which basically adds data into datbase. I also have a radiobuttonlist(i.e Approve / Decline) and a textbox. If user selects decline, the textbox becomes visible. I want to run validation that when user clicks on submit button, if the decline is selected then the textbox can not blank. I have used jquery validation for that. when I click button, the message apppears next to textbox that the field is required but it does not stop the execution of code behind. i.e.It adds data into database. Here is my code. <script type="text/javascript" language="javascript"> $(function() { $('#declinediv').hide(); //////// var $radBtn = $("table.rblist input:radio"); $radBtn.click(function() { var $radChecked = $(':radio:checked'); var value = $radChecked.val(); if (value == 'Decline' || value == 'Approve') { if (value == 'Decline') $('#declinediv').show(); else $('#declinediv').hide(); } else { $('#declinediv').hide(); } }); ////////////////////////// $("#aspnetForm").validate({ rules: { <%=txtdeclinereason.UniqueID %>: { minlength: 2, required: true } }, messages: { <%=txtdeclinereason.UniqueID %>:{ required: "* Required Field *", minlength: "* Please enter atleast 2 characters *" } }, onsubmit: true }); ////////////////////////////////// $('#btnsubmit').click(function(evt){ var isValid = $("#aspnetForm").valid(); if (!isValid) { evt.preventDefault(); } }); }); function myredirect(v, m, f) { window.location.href = v; } </script> <table style="border: 1px black solid; text-align: center; vertical-align: middle" width="100%"> <tr> <td> <asp:RadioButtonList ID="rbtnlstapprover" runat="server" RepeatDirection="Horizontal" CssClass="rblist" DataTextField="username" DataValueField="emailaddress"> <asp:ListItem Text="Approve" Value="Approve" /> <asp:ListItem Text="Decline" Value="Decline" /> </asp:RadioButtonList> <asp:RequiredFieldValidator ID="RequiredFieldValidator1" runat="server" ControlToValidate="rbtnlstapprover" Text="*" ErrorMessage="Please select atleast one Approver" ValidationGroup="approvalgroup" Display="Dynamic" /> </td> </tr> <tr> <td> <div id="declinediv"> <asp:TextBox ID="txtdeclinereason" runat="server" TextMode="MultiLine" Columns="80" Rows="5" /> </div> </td> </tr> <tr> <td> <asp:Button ID="btnsubmit" runat="server" Text="Submit" CssClass="RegularButton" CausesValidation="true" ValidationGroup="approvalgroup" OnClick="btnsubmit_Click" /> </td> </tr> </table> How do I stop the execution of code behind? Thanks for your help.

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• What is New in ASP.NET 4.0 Code Access Security

  - by Xiaohong

  ASP.NET Code Access Security (CAS) is a feature that helps protect server applications on hosting multiple Web sites, ASP.NET lets you assign a configurable trust level that corresponds to a predefined set of permissions. ASP.NET has predefined ASP.NET Trust Levels and Policy Files that you can assign to applications, you also can assign custom trust level and policy files. Most web hosting companies run ASP.NET applications in Medium Trust to prevent that one website affect or harm another site etc. As .NET Framework's Code Access Security model has evolved, ASP.NET 4.0 Code Access Security also has introduced several changes and improvements. The main change in ASP.NET 4.0 CAS In ASP.NET v4.0 partial trust applications, application domain can have a default partial trust permission set as opposed to being full-trust, the permission set name is defined in the <trust /> new attribute permissionSetName that is used to initialize the application domain . By default, the PermissionSetName attribute value is "ASP.Net" which is the name of the permission set you can find in all predefined partial trust configuration files. <trust level="Something" permissionSetName="ASP.Net" /> This is ASP.NET 4.0 new CAS model. For compatibility ASP.NET 4.0 also support legacy CAS model where application domain still has full trust permission set. You can specify new legacyCasModel attribute on the <trust /> element to indicate whether the legacy CAS model is enabled. By default legacyCasModel is false which means that new 4.0 CAS model is the default. <trust level="Something" legacyCasModel="true|false" /> In .Net FX 4.0 Config directory, there are two set of predefined partial trust config files for each new CAS model and legacy CAS model, trust config files with name legacy.XYZ.config are for legacy CAS model: New CAS model: Legacy CAS model: web_hightrust.config legacy.web_hightrust.config web_mediumtrust.config legacy.web_mediumtrust.config web_lowtrust.config legacy.web_lowtrust.config web_minimaltrust.config legacy.web_minimaltrust.config   The figure below shows in ASP.NET 4.0 new CAS model what permission set to grant to code for partial trust application using predefined partial trust levels and policy files:    There also some benefits that comes with the new CAS model: You can lock down a machine by making all managed code no-execute by default (e.g. setting the MyComputer zone to have no managed execution code permissions), it should still be possible to configure ASP.NET web applications to run as either full-trust or partial trust. UNC share doesn’t require full trust with CASPOL at machine-level CAS policy. Side effect that comes with the new CAS model: processRequestInApplicationTrust attribute is deprecated  in new CAS model since application domain always has partial trust permission set in new CAS model.   In ASP.NET 4.0 legacy CAS model or ASP.NET 2.0 CAS model, even though you assign partial trust level to a application but the application domain still has full trust permission set. The figure below shows in ASP.NET 4.0 legacy CAS model (or ASP.NET 2.0 CAS model) what permission set to grant to code for partial trust application using predefined partial trust levels and policy files:     What $AppDirUrl$, $CodeGen$, $Gac$ represents: $AppDirUrl$ The application's virtual root directory. This allows permissions to be applied to code that is located in the application's bin directory. For example, if a virtual directory is mapped to C:\YourWebApp, then $AppDirUrl$ would equate to C:\YourWebApp. $CodeGen$ The directory that contains dynamically generated assemblies (for example, the result of .aspx page compiles). This can be configured on a per application basis and defaults to %windir%\Microsoft.NET\Framework\{version}\Temporary ASP.NET Files. $CodeGen$ allows permissions to be applied to dynamically generated assemblies. $Gac$ Any assembly that is installed in the computer's global assembly cache (GAC). This allows permissions to be granted to strong named assemblies loaded from the GAC by the Web application.   The new customization of CAS Policy in ASP.NET 4.0 new CAS model 1. Define which named permission set in partial trust configuration files By default the permission set that will be assigned at application domain initialization time is the named "ASP.Net" permission set found in all predefined partial trust configuration files. However ASP.NET 4.0 allows you set PermissionSetName attribute to define which named permission set in a partial trust configuration file should be the one used to initialize an application domain. Example: add "ASP.Net_2" named permission set in partial trust configuration file: <PermissionSet class="NamedPermissionSet" version="1" Name="ASP.Net_2"> <IPermission class="FileIOPermission" version="1" Read="$AppDir$" PathDiscovery="$AppDir$" /> <IPermission class="ReflectionPermission" version="1" Flags ="RestrictedMemberAccess" /> <IPermission class="SecurityPermission " version="1" Flags ="Execution, ControlThread, ControlPrincipal, RemotingConfiguration" /></PermissionSet> Then you can use "ASP.Net_2" named permission set for the application domain permission set: <trust level="Something" legacyCasModel="false" permissionSetName="ASP.Net_2" /> 2. Define a custom set of Full Trust Assemblies for an application By using the new fullTrustAssemblies element to configure a set of Full Trust Assemblies for an application, you can modify set of partial trust assemblies to full trust at the machine, site or application level. The configuration definition is shown below: <fullTrustAssemblies> <add assemblyName="MyAssembly" version="1.1.2.3" publicKey="hex_char_representation_of_key_blob" /></fullTrustAssemblies> 3. Define <CodeGroup /> policy in partial trust configuration files ASP.NET 4.0 new CAS model will retain the ability for developers to optionally define <CodeGroup />with membership conditions and assigned permission sets. The specific restriction in ASP.NET 4.0 new CAS model though will be that the results of evaluating custom policies can only result in one of two outcomes: either an assembly is granted full trust, or an assembly is granted the partial trust permission set currently associated with the running application domain. It will not be possible to use custom policies to create additional custom partial trust permission sets. When parsing the partial trust configuration file: Any assemblies that match to code groups associated with "PermissionSet='FullTrust'" will run at full trust. Any assemblies that match to code groups associated with "PermissionSet='Nothing'" will result in a PolicyError being thrown from the CLR. This is acceptable since it provides administrators with a way to do a blanket-deny of managed code followed by selectively defining policy in a <CodeGroup /> that re-adds assemblies that would be allowed to run. Any assemblies that match to code groups associated with other permissions sets will be interpreted to mean the assembly should run at the permission set of the appdomain. This means that even though syntactically a developer could define additional "flavors" of partial trust in an ASP.NET partial trust configuration file, those "flavors" will always be ignored. Example: defines full trust in <CodeGroup /> for my strong named assemblies in partial trust config files: <CodeGroup class="FirstMatchCodeGroup" version="1" PermissionSetName="Nothing"> <IMembershipCondition    class="AllMembershipCondition"    version="1" /> <CodeGroup    class="UnionCodeGroup"    version="1"    PermissionSetName="FullTrust"    Name="My_Strong_Name"    Description="This code group grants code signed full trust. "> <IMembershipCondition      class="StrongNameMembershipCondition" version="1"       PublicKeyBlob="hex_char_representation_of_key_blob" /> </CodeGroup> <CodeGroup   class="UnionCodeGroup" version="1" PermissionSetName="ASP.Net">   <IMembershipCondition class="UrlMembershipCondition" version="1" Url="$AppDirUrl$/*" /> </CodeGroup> <CodeGroup class="UnionCodeGroup" version="1" PermissionSetName="ASP.Net">   <IMembershipCondition class="UrlMembershipCondition" version="1" Url="$CodeGen$/*"   /> </CodeGroup></CodeGroup>   4. Customize CAS policy at runtime in ASP.NET 4.0 new CAS model ASP.NET 4.0 new CAS model allows to customize CAS policy at runtime by using custom HostSecurityPolicyResolver that overrides the ASP.NET code access security policy. Example: use custom host security policy resolver to resolve partial trust web application bin folder MyTrustedAssembly.dll to full trust at runtime: You can create a custom host security policy resolver and compile it to assembly MyCustomResolver.dll with strong name enabled and deploy in GAC: public class MyCustomResolver : HostSecurityPolicyResolver{ public override HostSecurityPolicyResults ResolvePolicy(Evidence evidence) { IEnumerator hostEvidence = evidence.GetHostEnumerator(); while (hostEvidence.MoveNext()) { object hostEvidenceObject = hostEvidence.Current; if (hostEvidenceObject is System.Security.Policy.Url) { string assemblyName = hostEvidenceObject.ToString(); if (assemblyName.Contains(“MyTrustedAssembly.dll”) return HostSecurityPolicyResult.FullTrust; } } //default fall-through return HostSecurityPolicyResult.DefaultPolicy; }} Because ASP.NET accesses the custom HostSecurityPolicyResolver during application domain initialization, and a custom policy resolver requires full trust, you also can add a custom policy resolver in <fullTrustAssemblies /> , or deploy in the GAC. You also need configure a custom HostSecurityPolicyResolver instance by adding the HostSecurityPolicyResolverType attribute in the <trust /> element: <trust level="Something" legacyCasModel="false" hostSecurityPolicyResolverType="MyCustomResolver, MyCustomResolver" permissionSetName="ASP.Net" />   Note: If an assembly policy define in <CodeGroup/> and also in hostSecurityPolicyResolverType, hostSecurityPolicyResolverType will win. If an assembly added in <fullTrustAssemblies/> then the assembly has full trust no matter what policy in <CodeGroup/> or in hostSecurityPolicyResolverType.   Other changes in ASP.NET 4.0 CAS Use the new transparency model introduced in .Net Framework 4.0 Change in dynamically compiled code generated assemblies by ASP.NET: In new CAS model they will be marked as security transparent level2 to use Framework 4.0 security transparent rule that means partial trust code is treated as completely Transparent and it is more strict enforcement. In legacy CAS model they will be marked as security transparent level1 to use Framework 2.0 security transparent rule for compatibility. Most of ASP.NET products runtime assemblies are also changed to be marked as security transparent level2 to switch to SecurityTransparent code by default unless SecurityCritical or SecuritySafeCritical attribute specified. You also can look at Security Changes in the .NET Framework 4 for more information about these security attributes. Support conditional APTCA If an assembly is marked with the Conditional APTCA attribute to allow partially trusted callers, and if you want to make the assembly both visible and accessible to partial-trust code in your web application, you must add a reference to the assembly in the partialTrustVisibleAssemblies section: <partialTrustVisibleAssemblies> <add assemblyName="MyAssembly" publicKey="hex_char_representation_of_key_blob" />/partialTrustVisibleAssemblies>   Most of ASP.NET products runtime assemblies are also changed to be marked as conditional APTCA to prevent use of ASP.NET APIs in partial trust environments such as Winforms or WPF UI controls hosted in Internet Explorer.   Differences between ASP.NET new CAS model and legacy CAS model: Here list some differences between ASP.NET new CAS model and legacy CAS model ASP.NET 4.0 legacy CAS model  : Asp.net partial trust appdomains have full trust permission Multiple different permission sets in a single appdomain are allowed in ASP.NET partial trust configuration files Code groups Machine CAS policy is honored processRequestInApplicationTrust attribute is still honored    New configuration setting for legacy model: <trust level="Something" legacyCASModel="true" ></trust><partialTrustVisibleAssemblies> <add assemblyName="MyAssembly" publicKey="hex_char_representation_of_key_blob" /></partialTrustVisibleAssemblies>   ASP.NET 4.0 new CAS model: ASP.NET will now run in homogeneous application domains. Only full trust or the app-domain's partial trust grant set, are allowable permission sets. It is no longer possible to define arbitrary permission sets that get assigned to different assemblies. If an application currently depends on fine-tuning the partial trust permission set using the ASP.NET partial trust configuration file, this will no longer be possible. processRequestInApplicationTrust attribute is deprecated Dynamically compiled assemblies output by ASP.NET build providers will be updated to explicitly mark assemblies as transparent. ASP.NET partial trust grant sets will be independent from any enterprise, machine, or user CAS policy levels. A simplified model for locking down web servers that only allows trusted managed web applications to run. Machine policy used to always grant full-trust to managed code (based on membership conditions) can instead be configured using the new ASP.NET 4.0 full-trust assembly configuration section. The full-trust assembly configuration section requires explicitly listing each assembly as opposed to using membership conditions. Alternatively, the membership condition(s) used in machine policy can instead be re-defined in a <CodeGroup /> within ASP.NET's partial trust configuration file to grant full-trust.   New configuration setting for new model: <trust level="Something" legacyCASModel="false" permissionSetName="ASP.Net" hostSecurityPolicyResolverType=".NET type string" ></trust><fullTrustAssemblies> <add assemblyName=”MyAssembly” version=”1.0.0.0” publicKey="hex_char_representation_of_key_blob" /></fullTrustAssemblies><partialTrustVisibleAssemblies> <add assemblyName="MyAssembly" publicKey="hex_char_representation_of_key_blob" /></partialTrustVisibleAssemblies>     Hope this post is helpful to better understand the ASP.Net 4.0 CAS. Xiaohong Tang ASP.NET QA Team

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• convincing C# compiler that execution will stop after a member returns

  - by Sarah Vessels

  I don't think this is currently possible or if it's even a good idea, but it's something I was thinking about just now. I use MSTest for unit testing my C# project. In one of my tests, I do the following: MyClass instance; try { instance = getValue(); } catch (MyException ex) { Assert.Fail("Caught MyException"); } instance.doStuff(); // Use of unassigned local variable 'instance' To make this code compile, I have to assign a value to instance either at its declaration or in the catch block. However, Assert.Fail will never, to the best of my knowledge, allow execution to proceed past it, hence instance will never be used without a value. Why is it then that I must assign a value to it? If I change the Assert.Fail to something like throw ex, the code compiles fine, I assume because it knows that exception will disallow execution to proceed to a point where instance would be used uninitialized. So is it a case of runtime versus compile-time knowledge about where execution will be allowed to proceed? Would it ever be reasonable for C# to have some way of saying that a member, in this case Assert.Fail, will never allow execution after it returns? Maybe that could be in the form of a method attribute. Would this be useful or an unnecessary complexity for the compiler?

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• Tips on a tool to measure code quality?

  - by Cristi Diaconescu

  I'm looking for a tool that can provide code quality metrics. For instance it could report very long functions (spaghetti code) very complex classes (which could contain do-it-all code) ... While we're on the (subjective:-) subject of code quality, what other code metrics would you suggest? I'm targetting C#/.NET code, but I'm sure this could extend to most programming languages.

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• Visual Studio 2013 Static Code Analysis in depth: What? When and How?

  - by Hosam Kamel

  In this post I'll illustrate in details the following points What is static code analysis? When to use? Supported platforms Supported Visual Studio versions How to use Run Code Analysis Manually Run Code Analysis Automatically Run Code Analysis while check-in source code to TFS version control (TFSVC) Run Code Analysis as part of Team Build Understand the Code Analysis results & learn how to fix them Create your custom rule set Q & A References What is static Rule analysis? Static Code Analysis feature of Visual Studio performs static code analysis on code to help developers identify potential design, globalization, interoperability, performance, security, and a lot of other categories of potential problems according to Microsoft's rules that mainly targets best practices in writing code, and there is a large set of those rules included with Visual Studio grouped into different categorized targeting specific coding issues like security, design, Interoperability, globalizations and others. Static here means analyzing the source code without executing it and this type of analysis can be performed through automated tools (like Visual Studio 2013 Code Analysis Tool) or manually through Code Review which already supported in Visual Studio 2012 and 2013 (check Using Code Review to Improve Quality video on Channel9) There is also Dynamic analysis which performed on executing programs using software testing techniques such as Code Coverage for example. When to use? Running Code analysis tool at regular intervals during your development process can enhance the quality of your software, examines your code for a set of common defects and violations is always a good programming practice. Adding that Code analysis can also find defects in your code that are difficult to discover through testing allowing you to achieve first level quality gate for you application during development phase before you release it to the testing team. Supported platforms .NET Framework, native (C and C++) Database applications. Support Visual Studio versions All version of Visual Studio starting Visual Studio 2013 (except Visual Studio Test Professional) check Feature comparisons Create and modify a custom rule set required Visual Studio Premium or Ultimate. How to use? Code Analysis can be run manually at any time from within the Visual Studio IDE, or even setup to automatically run as part of a Team Build or check-in policy for Team Foundation Server. Run Code Analysis Manually To run code analysis manually on a project, on the Analyze menu, click Run Code Analysis on your project or simply right click on the project name on the Solution Explorer choose Run Code Analysis from the context menu Run Code Analysis Automatically To run code analysis each time that you build a project, you select Enable Code Analysis on Build on the project's Property Page Run Code Analysis while check-in source code to TFS version control (TFSVC) Team Foundation Version Control (TFVC) provides a way for organizations to enforce practices that lead to better code and more efficient group development through Check-in policies which are rules that are set at the team project level and enforced on developer computers before code is allowed to be checked in. (This is available only if you're using Team Foundation Server) Require permissions on Team Foundation Server: you must have the Edit project-level information permission set to Allow typically your account must be part of Project Administrators, Project Collection Administrators, for more information about Team Foundation permissions check http://msdn.microsoft.com/en-us/library/ms252587(v=vs.120).aspx In Team Explorer, right-click the team project name, point to Team Project Settings, and then click Source Control. In the Source Control dialog box, select the Check-in Policy tab. Click Add to create a new check-in policy. Double-click the existing Code Analysis item in the Policy Type list to change the policy. Check or Uncheck the policy option based on the configurations you need to perform as illustrated below: Enforce check-in to only contain files that are part of current solution: code analysis can run only on files specified in solution and project configuration files. This policy guarantees that all code that is part of a solution is analyzed. Enforce C/C++ Code Analysis (/analyze): Requires that all C or C++ projects be built with the /analyze compiler option to run code analysis before they can be checked in. Enforce Code Analysis for Managed Code: Requires that all managed projects run code analysis and build before they can be checked in. Check Code analysis rule set reference on MSDN What is Rule Set? Rule Set is a group of code analysis rules like the example below where Microsoft.Design is the rule set name where "Do not declare static members on generic types" is the code analysis rule Once you configured the Analysis rule the policy will be enabled for all the team member in this project whenever a team member check-in any source code to the TFSVC the policy section will highlight the Code Analysis policy as below TFS is a very extensible platform so you can simply implement your own custom Code Analysis Check-in policy, check this link for more details http://msdn.microsoft.com/en-us/library/dd492668.aspx but you have to be aware also about compatibility between different TFS versions check http://msdn.microsoft.com/en-us/library/bb907157.aspx Run Code Analysis as part of Team Build With Team Foundation Build (TFBuild), you can create and manage build processes that automatically compile and test your applications, and perform other important functions. Code Analysis can be enabled in the Build Definition file by selecting the correct value for the build process parameter "Perform Code Analysis" Once configure, Kick-off your build definition to queue a new build, Code Analysis will run as part of build workflow and you will be able to see code analysis warning as part of build report Understand the Code Analysis results & learn how to fix them Now after you went through Code Analysis configurations and the different ways of running it, we will go through the Code Analysis result how to understand them and how to resolve them. Code Analysis window in Visual Studio will show all the analysis results based on the rule sets you configured in the project file properties, let's dig deep into what each result item contains: 1 Check ID The unique identifier for the rule. CheckId and Category are used for in-source suppression of a warning.       2 Title The title of warning message       3 Description A description of the problem or suggested fix 4 File Name File name and the line of code number which violate the code analysis rule set 5 Category The code analysis category for this error 6 Warning /Error Depend on how you configure it in the rule set the default is Warning level 7 Action Copy: copy the warning information to the clipboard Create Work Item: If you're connected to Team Foundation Server you can create a work item most probably you may create a Task or Bug and assign it for a developer to fix certain code analysis warning Suppress Message: There are times when you might decide not to fix a code analysis warning. You might decide that resolving the warning requires too much recoding in relation to the probability that the issue will arise in any real-world implementation of your code. Or you might believe that the analysis that is used in the warning is inappropriate for the particular context. You can suppress individual warnings so that they no longer appear in the Code Analysis window. Two options available: In Source inserts a SuppressMessage attribute in the source file above the method that generated the warning. This makes the suppression more discoverable. In Suppression File adds a SuppressMessage attribute to the GlobalSuppressions.cs file of the project. This can make the management of suppressions easier. Note that the SuppressMessage attribute added to GlobalSuppression.cs also targets the method that generated the warning. It does not suppress the warning globally.       Visual Studio makes it very easy to fix Code analysis warning, all you have to do is clicking on the Check Id hyperlink if you are not aware how to fix the warring and you'll be directed to MSDN online or local copy based on the configuration you did while installing Visual Studio and you will find all the information about the warring including how to fix it. Create a Custom Code Analysis Rule Set The Microsoft standard rule sets provide groups of rules that are organized by function and depth. For example, the Microsoft Basic Design Guidelines Rules and the Microsoft Extended Design Guidelines Rules contain rules that focus on usability and maintainability issues, with added emphasis on naming rules in the Extended rule set, you can create and modify a custom rule set to meet specific project needs associated with code analysis. To create a custom rule set, you open one or more standard rule sets in the rule set editor. Create and modify a custom rule set required Visual Studio Premium or Ultimate. You can check How to: Create a Custom Rule Set on MSDN for more details http://msdn.microsoft.com/en-us/library/dd264974.aspx Q & A Visual Studio static code analysis vs. FxCop vs. StyleCpp http://www.excella.com/blog/stylecop-vs-fxcop-difference-between-code-analysis-tools/ Code Analysis for SharePoint Apps and SPDisposeCheck? This post lists some of the rule set you can run specifically for SharePoint applications and how to integrate SPDisposeCheck as well. Code Analysis for SQL Server Database Projects? This post illustrate how to run static code analysis on T-SQL through SSDT ReSharper 8 vs. Visual Studio 2013? This document lists some of the features that are provided by ReSharper 8 but are missing or not as fully implemented in Visual Studio 2013. References A Few Billion Lines of Code Later: Using Static Analysis to Find Bugs in the Real World http://cacm.acm.org/magazines/2010/2/69354-a-few-billion-lines-of-code-later/fulltext What is New in Code Analysis for Visual Studio 2013 http://blogs.msdn.com/b/visualstudioalm/archive/2013/07/03/what-is-new-in-code-analysis-for-visual-studio-2013.aspx Analyze the code quality of Windows Store apps using Visual Studio static code analysis http://msdn.microsoft.com/en-us/library/windows/apps/hh441471.aspx [Hands-on-lab] Using Code Analysis with Visual Studio 2012 to Improve Code Quality http://download.microsoft.com/download/A/9/2/A9253B14-5F23-4BC8-9C7E-F5199DB5F831/Using%20Code%20Analysis%20with%20Visual%20Studio%202012%20to%20Improve%20Code%20Quality.docx Originally posted at "Hosam Kamel| Developer & Platform Evangelist" http://blogs.msdn.com/hkamel

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• Issuing Current Time Increments in StreamInsight (A Practical Example)

  The issuing of a Current Time Increment, Cti, in StreamInsight is very definitely one of the most important concepts to learn if you want your Streams to be responsive. A full discussion of how to issue Ctis is beyond the scope of this article but a very good explanation in addition to Books Online can be found in these three articles by a member of the StreamInsight team at Microsoft, Ciprian Gerea. Time in StreamInsight Series http://blogs.msdn.com/b/streaminsight/archive/2010/07/23/time-in-streaminsight-i.aspx http://blogs.msdn.com/b/streaminsight/archive/2010/07/30/time-in-streaminsight-ii.aspx http://blogs.msdn.com/b/streaminsight/archive/2010/08/03/time-in-streaminsight-iii.aspx A lot of the problems I see with unresponsive or stuck streams on the MSDN Forums are to do with how Ctis are enqueued or in a lot of cases not enqueued. If you enqueue events and never enqueue a Cti then StreamInsight will be perfectly happy. You, on the other hand, will never see data on the output as you have not told StreamInsight to flush the stream. This article deals with a specific implementation problem I had recently whilst working on a StreamInsight project. I look at some possible options and discuss why they would not work before showing the way I solved the problem. The stream of data I was dealing with on this project was very bursty that is to say when events were flowing they came through very quickly and in large numbers (1000 events/sec), but when the stream calmed down it could be a few seconds between each event. When enqueuing events into the StreamInsight engne it is best practice to do so with a StartTime that is given to you by the system producing the event . StreamInsight processes events and it doesn't matter whether those events are being pushed into the engine by a source system or the events are being read from something like a flat file in a directory somewhere. You can apply the same logic and temporal algebra to both situations. Reading from a file is an excellent example of where the time of the event on the source itself is very important. We could be reading that file a long time after it was written. Being able to read the StartTime from the events allows us to define windows that will hold the correct sets of events. I was able to do this with my stream but this is where my problems started. Below is a very simple script to create a SQL Server table and populate it with sample data that will show exactly the problem I had. CREATE TABLE [dbo].[t] ( [c1] [int] PRIMARY KEY, [c2] [datetime] NULL ) INSERT t VALUES (1,'20100810'),(2,'20100810'),(3,'20100810') Column c2 defines the StartTime of the event on the source and as you can see the values in all 3 rows of data is the same. If we read Ciprian’s articles we know that we can define how Ctis get injected into the stream in 3 different places The Stream Definition The Input Factory The Input Adapter I personally have always been a fan of enqueing Ctis through the factory. Below is code typical of what I would use to do this On the class itself I do some inheriting public class SimpleInputFactory : ITypedInputAdapterFactory<SimpleInputConfig>, ITypedDeclareAdvanceTimeProperties<SimpleInputConfig> And then I implement the following function public AdapterAdvanceTimeSettings DeclareAdvanceTimeProperties<TPayload>(SimpleInputConfig configInfo, EventShape eventShape) { return new AdapterAdvanceTimeSettings( new AdvanceTimeGenerationSettings(configInfo.CtiFrequency, TimeSpan.FromTicks(-1)), AdvanceTimePolicy.Adjust); } The configInfo .CtiFrequency property is a value I pass through to define after how many events I want a Cti to be injected and this in turn will flush through the stream of data. I usually pass a value of 1 for this setting. The second parameter determines the CTI timestamp in terms of a delay relative to the events. -1 ticks in the past results in 1 tick in the future, i.e., ahead of the event. The problem with this method though is that if consecutive events have the same StartTime then only one of those events will be enqueued. In this example I use the following to define how I assign the StartTime of my events currEvent.StartTime = (DateTimeOffset)dt.c2; If I go ahead and run my StreamInsight process with this configuration i can see on the output adapter that two events have been removed To see this in a little more depth I can use the StreamInsight Debugger and see what happens internally. What is happening here is that the first event arrives and a Cti is injected with a time of 1 tick after the StartTime of that event (Also the EndTime of the event). The second event arrives and it has a StartTime of before the Cti and even though we specified AdvanceTimePolicy.Adjust on the factory we know that a point event can never be adjusted like this and the event is dropped. The same happens for the third event as well (The second and third events get trumped by the Cti). For a more detailed discussion of why this happens look here http://www.sqlis.com/sqlis/post/AdvanceTimePolicy-and-Point-Event-Streams-In-StreamInsight.aspx We end up with a single event being pushed into the output adapter and our result now makes sense. The next way I tried to solve this problem by changing the value of the second parameter to TimeSpan.Zero Here is how my factory code now looks public AdapterAdvanceTimeSettings DeclareAdvanceTimeProperties<TPayload>(SimpleInputConfig configInfo, EventShape eventShape) { return new AdapterAdvanceTimeSettings( new AdvanceTimeGenerationSettings(configInfo.CtiFrequency, TimeSpan.Zero), AdvanceTimePolicy.Adjust); } What I am doing here is declaring a policy that says inject a Cti together with every event and stamp it with a StartTime that is equal to the start time of the event itself (TimeSpan.Zero). This method has plus points as well as a downside. The upside is that no events will be lost by having the same StartTime as previous events. The Downside is that because the Cti is declared with the StartTime of the event itself then it does not actually flush that particular event because in the StreamInsight algebra, a Cti commits only those events that occurred strictly before them. To flush the events we need a Cti to be enqueued with a greater StartTime than the events themselves. Here is what happened when I ran this configuration As you can see all we got through was the Cti and none of the events. The debugger output shows the stamps on the Cti and the events themselves. Because the Cti issued has the same timestamp (StartTime) as the events then none of the events get flushed. I was nearly there but not quite. Because my stream was bursty it was possible that the next event would not come along for a few seconds and this was far too long for an event to be enqueued and not be flushed to the output adapter. I needed another solution. Two possible solutions crossed my mind although only one of them made sense when I explored it some more. Where multiple events have the same StartTime I could add 1 tick to the first event, two to the second, three to third etc thereby giving them unique StartTime values. Add a timer to manually inject Ctis The problem with the first implementation is that I would be giving the events a new StartTime. This would cause me the following problems If I want to define windows over the stream then some events may not be captured in the right windows and therefore any calculations on those windows I did would be wrong What would happen if we had 10,000 events with the same StartTime? I would enqueue them with StartTime + n ticks. Along comes a genuine event with a StartTime of the very first event + 1 tick. It is now too far in the past as far as my stream is concerned and it would be dropped. Not what I would want to do at all. I decided then to look at the Timer based solution I created a timer on my input adapter that elapsed every 200ms. private Timer tmr; public SimpleInputAdapter(SimpleInputConfig configInfo) { ctx = new SimpleTimeExtractDataContext(configInfo.ConnectionString); this.configInfo = configInfo; tmr = new Timer(200); tmr.Elapsed += new ElapsedEventHandler(t_Elapsed); tmr.Enabled = true; } void t_Elapsed(object sender, ElapsedEventArgs e) { ts = DateTime.Now - dtCtiIssued; if (ts.TotalMilliseconds >= 200 && TimerIssuedCti == false) { EnqueueCtiEvent(System.DateTime.Now.AddTicks(-100)); TimerIssuedCti = true; } }   In the t_Elapsed event handler I find out the difference in time between now and when the last event was processed (dtCtiIssued). I then check to see if that is greater than or equal to 200ms and if the last issuing of a Cti was done by the timer or by a genuine event (TimerIssuedCti). If I didn’t do this check then I would enqueue a Cti every time the timer elapsed which is not something I wanted. If the difference between the two times is greater than or equal to 500ms and the last event enqueued was by a real event then I issue a Cti through the timer to flush the event Queue, otherwise I do nothing. When I enqueue the Ctis into my stream in my ProduceEvents method I also set the values of dtCtiIssued and TimerIssuedCti   currEvent = CreateInsertEvent(); currEvent.StartTime = (DateTimeOffset)dt.c2; TimerIssuedCti = false; dtCtiIssued = currEvent.StartTime; If I go ahead and run this configuration I see the following in my output. As we can see the first Cti gets enqueued as before but then another is enqueued by the timer and because this has a later timestamp it flushes the enqueued events through the engine. Conclusion Hopefully this has shown how the enqueuing of Ctis can have a dramatic effect on the responsiveness of your output in StreamInsight. Understanding the temporal nature of the product is for me one of the most important things you can learn. I have attached my solution for the demos. It is all in one project and testing each variation is a simple matter of commenting and un-commenting the parts in the code we have been dealing with here.

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• How can I promote clean coding at my workplace?

  - by Michael

  I work with a lot of legacy Java and RPG code on an internal company application. As you might expect, a lot of the code is written in many different styles, and often is difficult to read because of poorly named variables, inconsistent formatting, and contradictory comments (if they're there at all). Also, a good amount of code is not robust. Many times code is pushed to production quickly by the more experienced programmers, while code by newer programmers is held back by "code reviews" that IMO are unsatisfactory. (They usually take the form of, "It works, must be ok," than a serious critique of the code.) We have a fair number of production issues, which I feel could be lessened by giving more thought to the original design and testing. I have been working for this company for about 4 months, and have been complimented on my coding style a couple of times. My manager is also a fan of cleaner coding than is the norm. Is it my place to try to push for better style and better defensive coding, or should I simply code in the best way I can, and hope that my example will help others see how cleaner, more robust code (as well as aggressive refactoring) will result in less debugging and change time?

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• How should Code Review be Carried Out?

  - by Graviton

  My previous question has to do with how to advance code review among the developers. Here I am interested in how the code review session should be carried out, so that both the reviewer and reviewed are feeling comfortable about it. I have done some code review before, but the experience sucks big time. My previous manager would come to us-- on an ad hoc basis-- and tell us to explain our code to him. Since he wasn't very familiar with the code base, I spent a huge amount of times explaining just the most basic structure of my code to him. This took a long time and by the time we were done, we were both exhausted. Then he would raise issues with my code. Most issues he raised were cosmetic in nature ( e.g, don't use region for this code block, change the variable name from xxx to yyy even though the later makes even less sense, and so on). We did this a few rounds, and the review session didn't derive much benefits for us, and we stopped. What do you have to do, in order to make code review a natural, enjoyable, thought stimulating, bug-fixing and mutual-learning experience?

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• ?12c database ????Adaptive Execution Plans ????????

  - by Liu Maclean(???)

  12c R1 ????SQL??????- Adaptive Execution Plans ????????,???????optimizer ??????(runtime)???????????????, ????????????????????? SQL???????? ????????????, ?????????????????????????????????????????????????????????????adaptive plan ????????????????????????????????????,?????subplan???????????????????? ??????, ???????? ???????????????,?????????, ?????? ???????????????”???”????, ???????????????????buffer ???????  ????????????,?????,??????????????????? ???optimizer ?????????????????????????,?????????????????????????????????????????plan???? ??12C?????????????, ???????????????????,?????? ???????????? ????????????2???: Dynamic Plans????: ???????????????????????;??????,???optimizer??????????subplans??????????????, ???????????????????,?????????????? Reoptimization????: ?Dynamic Plans????,Reoptimization??????????????????????Reoptimization??,?????????????????????????,??reoptimization????? OPTIMIZER_ADAPTIVE_REPORTING_ONLY ???? report-only????????????????TRUE,?????????report-only????,???????????????,??????????????? Dynamic Plans ??????????????,????????????????????????, ?????????????,???????????,????????????????????????????????????????? ?????????????final plan??????????????default plan, ??final plan?default plan???????,????????????? subplan ???????????????,???????????????????????? ??????,???????statistics collector ?buffer???????????statistics collector?????????????????,???????????????????????????? ?????????????????????????????????????????,??????????,?????????????? ???????????,???????buffer???? ???????????????,?????????????????????????????,??????buffer,??????final plan? ????????,???????????????????????,????????????????? ?V$SQL??????IS_RESOLVED_DYNAMIC_PLAN??????????final plan???default plan? ??????dynamic plan ???????SQL PLAN directives?????? declare cursor PLAN_DIRECTIVE_IDS is select directive_id from DBA_SQL_PLAN_DIRECTIVES; begin for z in PLAN_DIRECTIVE_IDS loop DBMS_SPD.DROP_SQL_PLAN_DIRECTIVE(z.directive_id); end loop; end; / explain plan for select /*MALCEAN*/ product_name from oe.order_items o, oe.product_information p where o.unit_price=15 and quantity>1 and p.product_id=o.product_id; select * from table(dbms_xplan.display()); Plan hash value: 1255158658 www.askmaclean.com ------------------------------------------------------------------------------------------------------- | Id | Operation | Name | Rows | Bytes | Cost (%CPU)| Time | ------------------------------------------------------------------------------------------------------- | 0 | SELECT STATEMENT | | 4 | 128 | 7 (0)| 00:00:01 | | 1 | NESTED LOOPS | | | | | | | 2 | NESTED LOOPS | | 4 | 128 | 7 (0)| 00:00:01 | |* 3 | TABLE ACCESS FULL | ORDER_ITEMS | 4 | 48 | 3 (0)| 00:00:01 | |* 4 | INDEX UNIQUE SCAN | PRODUCT_INFORMATION_PK | 1 | | 0 (0)| 00:00:01 | | 5 | TABLE ACCESS BY INDEX ROWID| PRODUCT_INFORMATION | 1 | 20 | 1 (0)| 00:00:01 | ------------------------------------------------------------------------------------------------------- Predicate Information (identified by operation id): --------------------------------------------------- 3 - filter("O"."UNIT_PRICE"=15 AND "QUANTITY">1) 4 - access("P"."PRODUCT_ID"="O"."PRODUCT_ID") alter session set events '10053 trace name context forever,level 1'; OR alter session set events 'trace[SQL_Plan_Directive] disk highest'; select /*MALCEAN*/ product_name from oe.order_items o, oe.product_information p where o.unit_price=15 and quantity>1 and p.product_id=o.product_id; ---------------------------------------------------------------+-----------------------------------+ | Id | Operation | Name | Rows | Bytes | Cost | Time | ---------------------------------------------------------------+-----------------------------------+ | 0 | SELECT STATEMENT | | | | 7 | | | 1 | HASH JOIN | | 4 | 128 | 7 | 00:00:01 | | 2 | NESTED LOOPS | | | | | | | 3 | NESTED LOOPS | | 4 | 128 | 7 | 00:00:01 | | 4 | STATISTICS COLLECTOR | | | | | | | 5 | TABLE ACCESS FULL | ORDER_ITEMS | 4 | 48 | 3 | 00:00:01 | | 6 | INDEX UNIQUE SCAN | PRODUCT_INFORMATION_PK| 1 | | 0 | | | 7 | TABLE ACCESS BY INDEX ROWID | PRODUCT_INFORMATION | 1 | 20 | 1 | 00:00:01 | | 8 | TABLE ACCESS FULL | PRODUCT_INFORMATION | 1 | 20 | 1 | 00:00:01 | ---------------------------------------------------------------+-----------------------------------+ Predicate Information: ---------------------- 1 - access("P"."PRODUCT_ID"="O"."PRODUCT_ID") 5 - filter(("O"."UNIT_PRICE"=15 AND "QUANTITY">1)) 6 - access("P"."PRODUCT_ID"="O"."PRODUCT_ID") ===================================== SPD: BEGIN context at statement level ===================================== Stmt: ******* UNPARSED QUERY IS ******* SELECT /*+ OPT_ESTIMATE (@"SEL$1" JOIN ("P"@"SEL$1" "O"@"SEL$1") ROWS=13.000000 ) OPT_ESTIMATE (@"SEL$1" TABLE "O"@"SEL$1" ROWS=13.000000 ) */ "P"."PRODUCT_NAME" "PRODUCT_NAME" FROM "OE"."ORDER_ITEMS" "O","OE"."PRODUCT_INFORMATION" "P" WHERE "O"."UNIT_PRICE"=15 AND "O"."QUANTITY">1 AND "P"."PRODUCT_ID"="O"."PRODUCT_ID" Objects referenced in the statement PRODUCT_INFORMATION[P] 92194, type = 1 ORDER_ITEMS[O] 92197, type = 1 Objects in the hash table Hash table Object 92197, type = 1, ownerid = 6573730143572393221: No Dynamic Sampling Directives for the object Hash table Object 92194, type = 1, ownerid = 17822962561575639002: No Dynamic Sampling Directives for the object Return code in qosdInitDirCtx: ENBLD =================================== SPD: END context at statement level =================================== ======================================= SPD: BEGIN context at query block level ======================================= Query Block SEL$1 (#0) Return code in qosdSetupDirCtx4QB: NOCTX ===================================== SPD: END context at query block level ===================================== SPD: Return code in qosdDSDirSetup: NOCTX, estType = TABLE SPD: Generating finding id: type = 1, reason = 1, objcnt = 1, obItr = 0, objid = 92197, objtyp = 1, vecsize = 6, colvec = [4, 5, ], fid = 2896834833840853267 SPD: Inserted felem, fid=2896834833840853267, ftype = 1, freason = 1, dtype = 0, dstate = 0, dflag = 0, ver = YES, keep = YES SPD: qosdCreateFindingSingTab retCode = CREATED, fid = 2896834833840853267 SPD: qosdCreateDirCmp retCode = CREATED, fid = 2896834833840853267 SPD: Return code in qosdDSDirSetup: NOCTX, estType = TABLE SPD: Return code in qosdDSDirSetup: NOCTX, estType = INDEX_SCAN SPD: Return code in qosdDSDirSetup: NOCTX, estType = INDEX_FILTER SPD: Return code in qosdDSDirSetup: NOCTX, estType = INDEX_SCAN SPD: Return code in qosdDSDirSetup: NOCTX, estType = INDEX_FILTER SPD: Return code in qosdDSDirSetup: NOCTX, estType = JOIN SPD: Return code in qosdDSDirSetup: NOCTX, estType = INDEX_FILTER SPD: Return code in qosdDSDirSetup: NOCTX, estType = INDEX_SCAN SPD: Return code in qosdDSDirSetup: NOCTX, estType = INDEX_FILTER SPD: Return code in qosdDSDirSetup: NOCTX, estType = INDEX_SKIP_SCAN SPD: Return code in qosdDSDirSetup: NOCTX, estType = INDEX_FILTER SPD: Return code in qosdDSDirSetup: NOCTX, estType = JOIN SPD: Return code in qosdDSDirSetup: NOCTX, estType = INDEX_FILTER SPD: Return code in qosdDSDirSetup: NOCTX, estType = INDEX_SCAN SPD: Return code in qosdDSDirSetup: NOCTX, estType = INDEX_FILTER SPD: Return code in qosdDSDirSetup: NOCTX, estType = INDEX_SCAN SPD: Return code in qosdDSDirSetup: NOCTX, estType = INDEX_FILTER SPD: Return code in qosdDSDirSetup: NOCTX, estType = INDEX_SCAN SPD: Return code in qosdDSDirSetup: NOCTX, estType = INDEX_FILTER SPD: Return code in qosdDSDirSetup: NOCTX, estType = INDEX_SCAN SPD: Return code in qosdDSDirSetup: NOCTX, estType = INDEX_FILTER SPD: Return code in qosdDSDirSetup: NOCTX, estType = INDEX_SCAN SPD: Return code in qosdDSDirSetup: NOCTX, estType = INDEX_FILTER SPD: Return code in qosdDSDirSetup: NOCTX, estType = INDEX_SCAN SPD: Return code in qosdDSDirSetup: NOCTX, estType = INDEX_FILTER SPD: Return code in qosdDSDirSetup: NOCTX, estType = INDEX_SCAN SPD: Return code in qosdDSDirSetup: NOCTX, estType = INDEX_FILTER SPD: Return code in qosdDSDirSetup: NOCTX, estType = INDEX_SCAN SPD: Return code in qosdDSDirSetup: NOCTX, estType = INDEX_FILTER SPD: Return code in qosdDSDirSetup: NOCTX, estType = INDEX_SCAN SPD: Return code in qosdDSDirSetup: NOCTX, estType = INDEX_FILTER SPD: Return code in qosdDSDirSetup: NOCTX, estType = INDEX_SCAN SPD: Return code in qosdDSDirSetup: NOCTX, estType = INDEX_FILTER SPD: Return code in qosdDSDirSetup: NOCTX, estType = INDEX_SCAN SPD: Return code in qosdDSDirSetup: NOCTX, estType = INDEX_FILTER SPD: Return code in qosdDSDirSetup: NOCTX, estType = INDEX_SCAN SPD: Return code in qosdDSDirSetup: NOCTX, estType = INDEX_FILTER SPD: Return code in qosdDSDirSetup: NOCTX, estType = INDEX_SCAN SPD: Return code in qosdDSDirSetup: NOCTX, estType = INDEX_FILTER SPD: Return code in qosdDSDirSetup: NOCTX, estType = INDEX_SCAN SPD: Return code in qosdDSDirSetup: NOCTX, estType = INDEX_FILTER SPD: Generating finding id: type = 1, reason = 1, objcnt = 1, obItr = 0, objid = 92197, objtyp = 1, vecsize = 6, colvec = [4, 5, ], fid = 2896834833840853267 SPD: Modified felem, fid=2896834833840853267, ftype = 1, freason = 1, dtype = 0, dstate = 0, dflag = 0, ver = YES, keep = YES SPD: Generating finding id: type = 1, reason = 1, objcnt = 1, obItr = 0, objid = 92194, objtyp = 1, vecsize = 2, colvec = [1, ], fid = 5618517328604016300 SPD: Modified felem, fid=5618517328604016300, ftype = 1, freason = 1, dtype = 0, dstate = 0, dflag = 0, ver = NO, keep = NO SPD: Generating finding id: type = 1, reason = 1, objcnt = 1, obItr = 0, objid = 92194, objtyp = 1, vecsize = 2, colvec = [1, ], fid = 1142802697078608149 SPD: Modified felem, fid=1142802697078608149, ftype = 1, freason = 1, dtype = 0, dstate = 0, dflag = 0, ver = NO, keep = NO SPD: Generating finding id: type = 1, reason = 2, objcnt = 2, obItr = 0, objid = 92194, objtyp = 1, vecsize = 0, obItr = 1, objid = 92197, objtyp = 1, vecsize = 0, fid = 1437680122701058051 SPD: Modified felem, fid=1437680122701058051, ftype = 1, freason = 2, dtype = 0, dstate = 0, dflag = 0, ver = NO, keep = NO select * from table(dbms_xplan.display_cursor(format=>'report')) ; ????report????adaptive plan Adaptive plan: ------------- This cursor has an adaptive plan, but adaptive plans are enabled for reporting mode only.  The plan that would be executed if adaptive plans were enabled is displayed below. ------------------------------------------------------------------------------------------ | Id  | Operation          | Name                | Rows  | Bytes | Cost (%CPU)| Time     | ------------------------------------------------------------------------------------------ |   0 | SELECT STATEMENT   |                     |       |       |     7 (100)|          | |*  1 |  HASH JOIN         |                     |     4 |   128 |     7   (0)| 00:00:01 | |*  2 |   TABLE ACCESS FULL| ORDER_ITEMS         |     4 |    48 |     3   (0)| 00:00:01 | |   3 |   TABLE ACCESS FULL| PRODUCT_INFORMATION |     1 |    20 |     1   (0)| 00:00:01 | ------------------------------------------------------------------------------------------ SQL> select SQL_ID,IS_RESOLVED_DYNAMIC_PLAN,sql_text from v$SQL WHERE SQL_TEXT like '%MALCEAN%' and sql_text not like '%like%'; SQL_ID IS -------------------------- -- SQL_TEXT -------------------------------------------------------------------------------- 6ydj1bn1bng17 Y select /*MALCEAN*/ product_name from oe.order_items o, oe.product_information p where o.unit_price=15 and quantity>1 and p.product_id=o.product_id ???? explain plan for ????default plan, ??????optimizer???final plan,??V$SQL.IS_RESOLVED_DYNAMIC_PLAN???Y,????????????? DBA_SQL_PLAN_DIRECTIVES?????????????SQL PLAN DIRECTIVES, ???12c? ???MMON?????DML ???column usage??????????,????SMON??? MMON????SGA??PLAN DIRECTIVES??? ?????DBMS_SPD.flush_sql_plan_directive???? select directive_id,type,reason from DBA_SQL_PLAN_DIRECTIVES / DIRECTIVE_ID TYPE REASON ----------------------------------- -------------------------------- ----------------------------- 10321283028317893030 DYNAMIC_SAMPLING JOIN CARDINALITY MISESTIMATE 4757086536465754886 DYNAMIC_SAMPLING JOIN CARDINALITY MISESTIMATE 16085268038103121260 DYNAMIC_SAMPLING JOIN CARDINALITY MISESTIMATE SQL> set pages 9999 SQL> set lines 300 SQL> col state format a5 SQL> col subobject_name format a11 SQL> col col_name format a11 SQL> col object_name format a13 SQL> select d.directive_id, o.object_type, o.object_name, o.subobject_name col_name, d.type, d.state, d.reason 2 from dba_sql_plan_directives d, dba_sql_plan_dir_objects o 3 where d.DIRECTIVE_ID=o.DIRECTIVE_ID 4 and o.object_name in ('ORDER_ITEMS') 5 order by d.directive_id; DIRECTIVE_ID OBJECT_TYPE OBJECT_NAME COL_NAME TYPE STATE REASON ------------ ------------ ------------- ----------- -------------------------------- ----- ------------------------------------- --- 1.8156E+19 COLUMN ORDER_ITEMS UNIT_PRICE DYNAMIC_SAMPLING NEW SINGLE TABLE CARDINALITY MISESTIMATE 1.8156E+19 TABLE ORDER_ITEMS DYNAMIC_SAMPLING NEW SINGLE TABLE CARDINALITY MISESTIMATE 1.8156E+19 COLUMN ORDER_ITEMS QUANTITY DYNAMIC_SAMPLING NEW SINGLE TABLE CARDINALITY MISESTIMATE DBA_SQL_PLAN_DIRECTIVES????? _BASE_OPT_DIRECTIVE ? _BASE_OPT_FINDING SELECT d.dir_own#, d.dir_id, d.f_id, decode(type, 1, 'DYNAMIC_SAMPLING', 'UNKNOWN'), decode(state, 1, 'NEW', 2, 'MISSING_STATS', 3, 'HAS_STATS', 4, 'CANDIDATE', 5, 'PERMANENT', 6, 'DISABLED', 'UNKNOWN'), decode(bitand(flags, 1), 1, 'YES', 'NO'), cast(d.created as timestamp), cast(d.last_modified as timestamp), -- Please see QOSD_DAYS_TO_UPDATE and QOSD_PLUS_SECONDS for more details -- about 6.5 cast(d.last_used as timestamp) - NUMTODSINTERVAL(6.5, 'day') FROM sys.opt_directive$ d ??dbms_spd??? SQL PLAN DIRECTIVES, SQL PLAN DIRECTIVES???retention ???53?: Package: DBMS_SPD This package provides subprograms for managing Sql Plan Directives(SPD). SPD are objects generated automatically by Oracle server. For example, if server detects that the single table cardinality estimated by optimizer is off from the actual number of rows returned when accessing the table, it will automatically create a directive to do dynamic sampling for the table. When any Sql statement referencing the table is compiled, optimizer will perform dynamic sampling for the table to get more accurate estimate. Notes: DBMSL_SPD is a invoker-rights package. The invoker requires ADMINISTER SQL MANAGEMENT OBJECT privilege for executing most of the subprograms of this package. Also the subprograms commit the current transaction (if any), perform the operation and commit it again. DBA view dba_sql_plan_directives shows all the directives created in the system and the view dba_sql_plan_dir_objects displays the objects that are included in the directives. -- Default value for SPD_RETENTION_WEEKS SPD_RETENTION_WEEKS_DEFAULT CONSTANT varchar2(4) := '53'; | STATE : NEW : Newly created directive. | : MISSING_STATS : The directive objects do not | have relevant stats. | : HAS_STATS : The objects have stats. | : PERMANENT : A permanent directive. Server | evaluated effectiveness and these | directives are useful. | | AUTO_DROP : YES : Directive will be dropped | automatically if not | used for SPD_RETENTION_WEEKS. | This is the default behavior. | NO : Directive will not be dropped | automatically. Procedure: flush_sql_plan_directive This procedure allows manually flushing the Sql Plan directives that are automatically recorded in SGA memory while executing sql statements. The information recorded in SGA are periodically flushed by oracle background processes. This procedure just provides a way to flush the information manually. ????”_optimizer_dynamic_plans”(enable dynamic plans)????????,???TRUE??DYNAMIC PLAN? ???FALSE???????????? ????,Dynamic Plan????????????Nested Loop?Hash Join???case ,????????Nested loop???????????HASH JOIN,?HASH JOIN????????????????? ????????subplan?????,???? pass?? ?join method???,?????STATISTICS COLLECTOR???cardinality?,???????HASH JOIN?????Nested Loop,????????????subplan?????access path; ???????Sales??????????????????,????HASH JOIN,??SUBPLAN??customers?????????;?????Nested Loop,???????cust_id?????Range Scan+Access by Rowid? Cardinality feedback Cardinality feedback????????11.2????,????????re-optimization???;  ???????????,Cardinality feedback?????????????????????????? ???????????????????,?????????????????,??????????Cardinality feedback????????????? ????????????????????????? ??????????????Cardinality feedback ??: ????????,???????????,??????????,????????????????selectivity ??? ????????????: ??????,?????????????????????????????????,??????????????????? ????????????????????????????????????????,?????????????????????????? ?????????,???????????????,?????????? ??????????Cardinality ????,??????join Cardinality ????????? Cardinality feedback???????cursor?,?Cursor???aged out????? SELECT /*+ gather_plan_statistics */ product_name FROM order_items o, product_information p WHERE o.unit_price = 15 AND quantity > 1 AND p.product_id = o.product_id Plan hash value: 1553478007 ---------------------------------------------------------------------------------------------------------------------------------------- | Id | Operation | Name | Starts | E-Rows | A-Rows | A-Time | Buffers | Reads | OMem | 1Mem | Used-Mem | ---------------------------------------------------------------------------------------------------------------------------------------- | 0 | SELECT STATEMENT | | 1 | | 13 |00:00:00.01 | 24 | 20 | | | | |* 1 | HASH JOIN | | 1 | 4 | 13 |00:00:00.01 | 24 | 20 | 2061K| 2061K| 429K (0)| |* 2 | TABLE ACCESS FULL| ORDER_ITEMS | 1 | 4 | 13 |00:00:00.01 | 7 | 6 | | | | | 3 | TABLE ACCESS FULL| PRODUCT_INFORMATION | 1 | 1 | 288 |00:00:00.01 | 17 | 14 | | | | ---------------------------------------------------------------------------------------------------------------------------------------- SELECT /*+ gather_plan_statistics */ product_name FROM order_items o, product_information p WHERE o.unit_price = 15 AND quantity > 1 AND p.product_id = o.product_id Plan hash value: 1553478007 ------------------------------------------------------------------------------------------------------------------------------- | Id | Operation | Name | Starts | E-Rows | A-Rows | A-Time | Buffers | OMem | 1Mem | Used-Mem | ------------------------------------------------------------------------------------------------------------------------------- | 0 | SELECT STATEMENT | | 1 | | 13 |00:00:00.01 | 24 | | | | |* 1 | HASH JOIN | | 1 | 13 | 13 |00:00:00.01 | 24 | 2061K| 2061K| 413K (0)| |* 2 | TABLE ACCESS FULL| ORDER_ITEMS | 1 | 13 | 13 |00:00:00.01 | 7 | | | | | 3 | TABLE ACCESS FULL| PRODUCT_INFORMATION | 1 | 288 | 288 |00:00:00.01 | 17 | | | | ------------------------------------------------------------------------------------------------------------------------------- Note ----- - statistics feedback used for this statement SQL> select count(*) from v$SQL where SQL_ID='cz0hg2zkvd10y'; COUNT(*) ---------- 2 SQL>select sql_ID,USE_FEEDBACK_STATS FROM V$SQL_SHARED_CURSOR where USE_FEEDBACK_STATS ='Y'; SQL_ID U ------------- - cz0hg2zkvd10y Y ????????Cardinality feedback????,???????????????????????????,????????????order_items???????? ????2??????plan hash value??(??????????),?????2????child cursor??????gather_plan_statistics???actual : A-ROWS  estimate :E-ROWS????????? Automatic Re-optimization ???dynamic plan, Re-optimization???????????????  ?  ??????????????? ????????????????????????????????  ???????????,??????????????, ???????????????????? ???????????  Re-optimization??, ????????????????????? Re-optimization????dynamic plan??????????  dynamic plan????????????????????, ???????????????????? ????,??????????join order ??????????????,?????????????join order????? ??????,????????Re-optimization, ??Re-optimization ??????????????????? ?Oracle database 12c?,join statistics?????????????????????,??????????????????????Re-optimization???????????adaptive cursor sharing????? ????????????????,???????????? ????? ???????statistics collectors ????????????????????Re-optimization??????2?????????????,???????????????? ??????????????Re-optimization?????,?????????????????????? ???v$SQL??????IS_REOPTIMIZABLE?????????????????????Re-optimization,??????????Re-optimization???,?????Re-optimization ,???????reporting????? IS_REOPTIMIZABLE VARCHAR2(1) This columns shows whether the next execution matching this child cursor will trigger a reoptimization. The values are:   Y: If the next execution will trigger a reoptimization R: If the child cursor contains reoptimization information, but will not trigger reoptimization because the cursor was compiled in reporting mode N: If the child cursor has no reoptimization information ??1: select plan_table_output from table (dbms_xplan.display_cursor('gwf99gfnm0t7g',NULL,'ALLSTATS LAST')); SQL_ID  gwf99gfnm0t7g, child number 0 ------------------------------------- SELECT /*+ SFTEST gather_plan_statistics */ o.order_id, v.product_name FROM  orders o,   ( SELECT order_id, product_name FROM order_items o, product_information p     WHERE  p.product_id = o.product_id AND list_price < 50 AND min_price < 40  ) v WHERE o.order_id = v.order_id Plan hash value: 1906736282 ------------------------------------------------------------------------------------------------------------------------------------------- | Id  | Operation             | Name                | Starts | E-Rows | A-Rows |   A-Time   | Buffers | Reads  |  OMem |  1Mem | Used-Mem | ------------------------------------------------------------------------------------------------------------------------------------------- |   0 | SELECT STATEMENT      |                     |      1 |        |    269 |00:00:00.02 |    1336 |     18 |       |       |          | |   1 |  NESTED LOOPS         |                     |      1 |      1 |    269 |00:00:00.02 |    1336 |     18 |       |       |          | |   2 |   MERGE JOIN CARTESIAN|                     |      1 |      4 |   9135 |00:00:00.02 |      34 |     15 |       |       |          | |*  3 |    TABLE ACCESS FULL  | PRODUCT_INFORMATION |      1 |      1 |     87 |00:00:00.01 |      33 |     14 |       |       |          | |   4 |    BUFFER SORT        |                     |     87 |    105 |   9135 |00:00:00.01 |       1 |      1 |  4096 |  4096 | 4096  (0)| |   5 |     INDEX FULL SCAN   | ORDER_PK            |      1 |    105 |    105 |00:00:00.01 |       1 |      1 |       |       |          | |*  6 |   INDEX UNIQUE SCAN   | ORDER_ITEMS_UK      |   9135 |      1 |    269 |00:00:00.01 |    1302 |      3 |       |       |          | ------------------------------------------------------------------------------------------------------------------------------------------- Predicate Information (identified by operation id): ---------------------------------------------------    3 - filter(("MIN_PRICE"<40 AND "LIST_PRICE"<50))    6 - access("O"."ORDER_ID"="ORDER_ID" AND "P"."PRODUCT_ID"="O"."PRODUCT_ID") SQL_ID  gwf99gfnm0t7g, child number 1 ------------------------------------- SELECT /*+ SFTEST gather_plan_statistics */ o.order_id, v.product_name FROM  orders o,   ( SELECT order_id, product_name FROM order_items o, product_information p     WHERE  p.product_id = o.product_id AND list_price < 50 AND min_price < 40  ) v WHERE o.order_id = v.order_id Plan hash value: 35479787 -------------------------------------------------------------------------------------------------------------------------------------------- | Id  | Operation              | Name                | Starts | E-Rows | A-Rows |   A-Time   | Buffers | Reads  |  OMem |  1Mem | Used-Mem | -------------------------------------------------------------------------------------------------------------------------------------------- |   0 | SELECT STATEMENT       |                     |      1 |        |    269 |00:00:00.01 |      63 |      3 |       |       |          | |   1 |  NESTED LOOPS          |                     |      1 |    269 |    269 |00:00:00.01 |      63 |      3 |       |       |          | |*  2 |   HASH JOIN            |                     |      1 |    313 |    269 |00:00:00.01 |      42 |      3 |  1321K|  1321K| 1234K (0)| |*  3 |    TABLE ACCESS FULL   | PRODUCT_INFORMATION |      1 |     87 |     87 |00:00:00.01 |      16 |      0 |       |       |          | |   4 |    INDEX FAST FULL SCAN| ORDER_ITEMS_UK      |      1 |    665 |    665 |00:00:00.01 |      26 |      3 |       |       |          | |*  5 |   INDEX UNIQUE SCAN    | ORDER_PK            |    269 |      1 |    269 |00:00:00.01 |      21 |      0 |       |       |          | -------------------------------------------------------------------------------------------------------------------------------------------- Predicate Information (identified by operation id): ---------------------------------------------------    2 - access("P"."PRODUCT_ID"="O"."PRODUCT_ID")    3 - filter(("MIN_PRICE"<40 AND "LIST_PRICE"<50))    5 - access("O"."ORDER_ID"="ORDER_ID") Note -----    - statistics feedback used for this statement    SQL> select IS_REOPTIMIZABLE,child_number FROM V$SQL  A where A.SQL_ID='gwf99gfnm0t7g'; IS CHILD_NUMBER -- ------------ Y             0 N             1    1* select child_number,other_xml From v$SQL_PLAN  where SQL_ID='gwf99gfnm0t7g' and other_xml is not nul SQL> / CHILD_NUMBER OTHER_XML ------------ --------------------------------------------------------------------------------            1 <other_xml><info type="cardinality_feedback">yes</info><info type="db_version">1              2.1.0.1</info><info type="parse_schema"><![CDATA["OE"]]></info><info type="plan_              hash">35479787</info><info type="plan_hash_2">3382491761</info><outline_data><hi              nt><![CDATA[IGNORE_OPTIM_EMBEDDED_HINTS]]></hint><hint><![CDATA[OPTIMIZER_FEATUR              ES_ENABLE('12.1.0.1')]]></hint><hint><![CDATA[DB_VERSION('12.1.0.1')]]></hint><h              int><![CDATA[ALL_ROWS]]></hint><hint><![CDATA[OUTLINE_LEAF(@"SEL$F5BB74E1")]]></              hint><hint><![CDATA[MERGE(@"SEL$2")]]></hint><hint><![CDATA[OUTLINE(@"SEL$1")]]>              </hint><hint><![CDATA[OUTLINE(@"SEL$2")]]></hint><hint><![CDATA[FULL(@"SEL$F5BB7              4E1" "P"@"SEL$2")]]></hint><hint><![CDATA[INDEX_FFS(@"SEL$F5BB74E1" "O"@"SEL$2"              ("ORDER_ITEMS"."ORDER_ID" "ORDER_ITEMS"."PRODUCT_ID"))]]></hint><hint><![CDATA[I              NDEX(@"SEL$F5BB74E1" "O"@"SEL$1" ("ORDERS"."ORDER_ID"))]]></hint><hint><![CDATA[              LEADING(@"SEL$F5BB74E1" "P"@"SEL$2" "O"@"SEL$2" "O"@"SEL$1")]]></hint><hint><![C              DATA[USE_HASH(@"SEL$F5BB74E1" "O"@"SEL$2")]]></hint><hint><![CDATA[USE_NL(@"SEL$              F5BB74E1" "O"@"SEL$1")]]></hint></outline_data></other_xml>            0 <other_xml><info type="db_version">12.1.0.1</info><info type="parse_schema"><![C              DATA["OE"]]></info><info type="plan_hash">1906736282</info><info type="plan_hash              _2">2579473118</info><outline_data><hint><![CDATA[IGNORE_OPTIM_EMBEDDED_HINTS]]>              </hint><hint><![CDATA[OPTIMIZER_FEATURES_ENABLE('12.1.0.1')]]></hint><hint><![CD              ATA[DB_VERSION('12.1.0.1')]]></hint><hint><![CDATA[ALL_ROWS]]></hint><hint><![CD              ATA[OUTLINE_LEAF(@"SEL$F5BB74E1")]]></hint><hint><![CDATA[MERGE(@"SEL$2")]]></hi              nt><hint><![CDATA[OUTLINE(@"SEL$1")]]></hint><hint><![CDATA[OUTLINE(@"SEL$2")]]>              </hint><hint><![CDATA[FULL(@"SEL$F5BB74E1" "P"@"SEL$2")]]></hint><hint><![CDATA[              INDEX(@"SEL$F5BB74E1" "O"@"SEL$1" ("ORDERS"."ORDER_ID"))]]></hint><hint><![CDATA              [INDEX(@"SEL$F5BB74E1" "O"@"SEL$2" ("ORDER_ITEMS"."ORDER_ID" "ORDER_ITEMS"."PROD              UCT_ID"))]]></hint><hint><![CDATA[LEADING(@"SEL$F5BB74E1" "P"@"SEL$2" "O"@"SEL$1              " "O"@"SEL$2")]]></hint><hint><![CDATA[USE_MERGE_CARTESIAN(@"SEL$F5BB74E1" "O"@"              SEL$1")]]></hint><hint><![CDATA[USE_NL(@"SEL$F5BB74E1" "O"@"SEL$2")]]></hint></o              utline_data></other_xml> ??2: SELECT /*+gather_plan_statistics*/ * FROM customers WHERE cust_state_province='CA' AND country_id='US'; SELECT * FROM TABLE(DBMS_XPLAN.DISPLAY_CURSOR(FORMAT=>'ALLSTATS LAST')); PLAN_TABLE_OUTPUT ------------------------------------- SQL_ID b74nw722wjvy3, child number 0 ------------------------------------- select /*+gather_plan_statistics*/ * from customers where CUST_STATE_PROVINCE='CA' and country_id='US' Plan hash value: 1683234692 -------------------------------------------------------------------------------------------------- | Id | Operation | Name | Starts | E-Rows | A-Rows | A-Time | Buffers | Reads | -------------------------------------------------------------------------------------------------- | 0 | SELECT STATEMENT | | 1 | | 29 |00:00:00.01 | 17 | 14 | |* 1 | TABLE ACCESS FULL| CUSTOMERS | 1 | 8 | 29 |00:00:00.01 | 17 | 14 | -------------------------------------------------------------------------------------------------- Predicate Information (identified by operation id): --------------------------------------------------- 1 - filter(("CUST_STATE_PROVINCE"='CA' AND "COUNTRY_ID"='US')) SELECT SQL_ID, CHILD_NUMBER, SQL_TEXT, IS_REOPTIMIZABLE FROM V$SQL WHERE SQL_TEXT LIKE 'SELECT /*+gather_plan_statistics*/%'; SQL_ID CHILD_NUMBER SQL_TEXT I ------------- ------------ ----------- - b74nw722wjvy3 0 select /*+g Y ather_plan_ statistics* / * from cu stomers whe re CUST_STA TE_PROVINCE ='CA' and c ountry_id=' US' EXEC DBMS_SPD.FLUSH_SQL_PLAN_DIRECTIVE; SELECT TO_CHAR(d.DIRECTIVE_ID) dir_id, o.OWNER, o.OBJECT_NAME, o.SUBOBJECT_NAME col_name, o.OBJECT_TYPE, d.TYPE, d.STATE, d.REASON FROM DBA_SQL_PLAN_DIRECTIVES d, DBA_SQL_PLAN_DIR_OBJECTS o WHERE d.DIRECTIVE_ID=o.DIRECTIVE_ID AND o.OWNER IN ('SH') ORDER BY 1,2,3,4,5; DIR_ID OWNER OBJECT_NAME COL_NAME OBJECT TYPE STATE REASON ----------------------- ----- ------------- ----------- ------ ---------------- ----- ------------------------ 1484026771529551585 SH CUSTOMERS COUNTRY_ID COLUMN DYNAMIC_SAMPLING NEW SINGLE TABLE CARDINALITY MISESTIMATE 1484026771529551585 SH CUSTOMERS CUST_STATE_ COLUMN DYNAMIC_SAMPLING NEW SINGLE TABLE CARDINALITY PROVINCE MISESTIMATE 1484026771529551585 SH CUSTOMERS TABLE DYNAMIC_SAMPLING NEW SINGLE TABLE CARDINALITY MISESTIMATE SELECT /*+gather_plan_statistics*/ * FROM customers WHERE cust_state_province='CA' AND country_id='US'; ELECT * FROM TABLE(DBMS_XPLAN.DISPLAY_CURSOR(FORMAT=>'ALLSTATS LAST')); PLAN_TABLE_OUTPUT ------------------------------------- SQL_ID b74nw722wjvy3, child number 1 ------------------------------------- select /*+gather_plan_statistics*/ * from customers where CUST_STATE_PROVINCE='CA' and country_id='US' Plan hash value: 1683234692 ----------------------------------------------------------------------------------------- | Id | Operation | Name | Starts | E-Rows | A-Rows | A-Time | Buffers | ----------------------------------------------------------------------------------------- | 0 | SELECT STATEMENT | | 1 | | 29 |00:00:00.01 | 17 | |* 1 | TABLE ACCESS FULL| CUSTOMERS | 1 | 29 | 29 |00:00:00.01 | 17 | ----------------------------------------------------------------------------------------- Predicate Information (identified by operation id): --------------------------------------------------- 1 - filter(("CUST_STATE_PROVINCE"='CA' AND "COUNTRY_ID"='US')) Note ----- - cardinality feedback used for this statement SELECT SQL_ID, CHILD_NUMBER, SQL_TEXT, IS_REOPTIMIZABLE FROM V$SQL WHERE SQL_TEXT LIKE 'SELECT /*+gather_plan_statistics*/%'; SQL_ID CHILD_NUMBER SQL_TEXT I ------------- ------------ ----------- - b74nw722wjvy3 0 select /*+g Y ather_plan_ statistics* / * from cu stomers whe re CUST_STA TE_PROVINCE ='CA' and c ountry_id=' US' b74nw722wjvy3 1 select /*+g N ather_plan_ statistics* / * from cu stomers whe re CUST_STA TE_PROVINCE ='CA' and c ountry_id=' US' SELECT /*+gather_plan_statistics*/ CUST_EMAIL FROM CUSTOMERS WHERE CUST_STATE_PROVINCE='MA' AND COUNTRY_ID='US'; SELECT * FROM TABLE(DBMS_XPLAN.DISPLAY_CURSOR(FORMAT=>'ALLSTATS LAST')); PLAN_TABLE_OUTPUT ------------------------------------- SQL_ID 3tk6hj3nkcs2u, child number 0 ------------------------------------- Select /*+gather_plan_statistics*/ cust_email From customers Where cust_state_province='MA' And country_id='US' Plan hash value: 1683234692 ------------------------------------------------------------------------------- |Id | Operation | Name | Starts|E-Rows|A-Rows| A-Time |Buffers| ------------------------------------------------------------------------------- | 0 | SELECT STATEMENT | | 1 | | 2 |00:00:00.01| 16 | |*1 | TABLE ACCESS FULL| CUSTOMERS | 1 | 2| 2 |00:00:00.01| 16 | ----------------------------------------------------------------------------- Predicate Information (identified by operation id): --------------------------------------------------- 1 - filter(("CUST_STATE_PROVINCE"='MA' AND "COUNTRY_ID"='US')) Note ----- - dynamic sampling used for this statement (level=2) - 1 Sql Plan Directive used for this statement EXEC DBMS_SPD.FLUSH_SQL_PLAN_DIRECTIVE; SELECT TO_CHAR(d.DIRECTIVE_ID) dir_id, o.OWNER, o.OBJECT_NAME, o.SUBOBJECT_NAME col_name, o.OBJECT_TYPE, d.TYPE, d.STATE, d.REASON FROM DBA_SQL_PLAN_DIRECTIVES d, DBA_SQL_PLAN_DIR_OBJECTS o WHERE d.DIRECTIVE_ID=o.DIRECTIVE_ID AND o.OWNER IN ('SH') ORDER BY 1,2,3,4,5; DIR_ID OW OBJECT_NA COL_NAME OBJECT TYPE STATE REASON ------------------- -- --------- ---------- ------- --------------- ------------- ------------------------ 1484026771529551585 SH CUSTOMERS COUNTRY_ID COLUMN DYNAMIC_SAMPLING MISSING_STATS SINGLE TABLE CARDINALITY MISESTIMATE 1484026771529551585 SH CUSTOMERS CUST_STATE_ COLUMN DYNAMIC_SAMPLING MISSING_STATS SINGLE TABLE CARDINALITY PROVINCE MISESTIMATE 1484026771529551585 SH CUSTOMERS TABLE DYNAMIC_SAMPLING MISSING_STATS SINGLE TABLE CARDINALITY MISESTIMATE

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• Advancing Code Review and Unit Testing Practice

  - by Graviton

  As a team lead managing a group of developers with no experience ( and see no need) in code review and unit testing, how can you advance code review and unit testing practice? How are you going to create a way so that code review and unit testing to naturally fit into the developer's flow? One of the resistance of these two areas is that "we are always tight on dateline, so no time for code review and unit testing". Another resistance for code review is that we currently don't know how to do it. Should we review the code upon every check-in, or review the code at a specified date?

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• Mouse Clicks, Reactive Extensions and StreamInsight Mashup

  I had an hour spare this afternoon so I wanted to have another play with Reactive Extensions in .Net and StreamInsight.  I also didn’t want to simply use a console window as a way of gathering events so I decided to use a windows form instead. The task I set myself was this. Whenever I click on my form I want to subscribe to the event and output its location to the console window and also the timestamp of the event.  In addition to this I want to know for every mouse click I do, how many mouse clicks have happened in the last 5 seconds. The second point here is really interesting.  I have often found this when working with people on problems.  It is how you ask the question that determines how you tackle the problem.  I will show 2 ways of possibly answering the second question depending on how the question was interpreted. As a side effect of this example I will show how time in StreamInsight can stand still.  This is an important concept and we can see it in the output later. Now to the code.  I will break it all down in this blogpost but you can download the solution and see it all together. I created a Console application and then instantiate a windows form.   frm = new Form(); Thread g = new Thread(CallUI); g.SetApartmentState(ApartmentState.STA); g.Start();   Call UI looks like this   static void CallUI() { System.Windows.Forms.Application.Run(frm); frm.Activate(); frm.BringToFront(); }   Now what we need to do is create an observable from the MouseClick event on the form.  For this we use the Reactive Extensions.   var lblevt = Observable.FromEvent<MouseEventArgs>(frm, "MouseClick").Timestamp();   As mentioned earlier I have two objectives in this example and to solve the first I am going to again use the Reactive extensions.  Let’s subscribe to the MouseClick event and output the location and timestamp to the console. lblevt.Subscribe(evt => { Console.WriteLine("Clicked: {0}, {1} ", evt.Value.EventArgs.Location,evt.Timestamp); }); That should take care of obective #1 but what about the second objective.  For that we need some temporal windowing and this means StreamInsight.  First we need to turn our Observable collection of MouseClick events into a PointStream Server s = Server.Create("Default"); Microsoft.ComplexEventProcessing.Application a = s.CreateApplication("MouseClicks"); var input = lblevt.ToPointStream( a, evt => PointEvent.CreateInsert( evt.Timestamp, new { loc = evt.Value.EventArgs.Location.ToString(), ts = evt.Timestamp.ToLocalTime().ToString() }), AdvanceTimeSettings.IncreasingStartTime);   Now that we have created out PointStream we need to do something with it and this is where we get to our second objective.  It is pretty clear that we want some kind of windowing but what? Here is one way of doing it.  It might not be what you wanted but again it is how the second objective is interpreted   var q = from i in input.TumblingWindow(TimeSpan.FromSeconds(5), HoppingWindowOutputPolicy.ClipToWindowEnd) select new { CountOfClicks = i.Count() };   The above code creates tumbling windows of 5 seconds and counts the number of events in the windows.  If there are no events in the window then no result is output.  Likewise until an event (MouseClick) is issued then we do not see anything in the output (that is not strictly true because it is the CTI strapped to our MouseClick events that flush the events through the StreamInsight engine not the events themselves).  This approach is centred around the windows and not the events.  Until the windows complete and a CTI is issued then no events are pushed through. An alternate way of answering our second question is below   var q = from i in input.AlterEventDuration(evt => TimeSpan.FromSeconds(5)).SnapshotWindow(SnapshotWindowOutputPolicy.Clip) select new { CountOfClicks = i.Count() };   In this code we extend the duration of each MouseClick to five seconds.  We then create  Snapshot Windows over those events.  Snapshot windows are discussed in detail here.  With this solution we are centred around the events.  It is the events that are driving the output.  Let’s have a look at the output from this solution as it may be a little confusing. First though let me show how we get the output from StreamInsight into the Console window. foreach (var x in q.ToPointEnumerable().Where(e => e.EventKind != EventKind.Cti)) { Console.WriteLine(x.Payload.CountOfClicks); }   Ok so now to the output.   The table at the top shows the output from our routine and the table at the bottom helps to explain the output.  One of the things that will help as well is, you will note that for our PointStream we set the issuing of CTIs to be IncreasingStartTime.  What this means is that the CTI is placed right at the start of the event so will not flush the event with which it was issued but will flush those prior to it.  In the bottom table the Blue fill is where we issued a click.  Yellow fill is the duration and boundaries of our events.  The numbers at the bottom indicate the count of events   Clicked 22:40:16                                 Clicked 23:40:18                                 1                                   Clicked 23:40:20                                 2                                   Clicked 23:40:22                                 3                                   2                                   Clicked 23:40:24                                 3                                   2                                   Clicked 23:40:32                                 3                                   2                                   1                                                                                                         secs 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32                                                                                                                                                                                                                         counts   1   2 3 2 3 2 3   2   1           What we can see here in the output is that the counts include all the end edges that have occurred between the mouse clicks.  If we look specifically at the mouse click at 22:40:32. then we see that 3 events are returned to us. These include the following End Edge count at 22:40:25 End Edge count at 22:40:27 End Edge count at 22:40:29 Another thing we notice is that until we actually issue a CTI at 22:40:32 then those last 3 snapshot window counts will never be reported. Hopefully this has helped to explain  a few concepts around StreamInsight and the IObservable() pattern.   You can download this solution from here and play.  You will need the Reactive Framework from here and StreamInsight 1.1

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• PLINQ delayed execution

  - by tbischel

  I'm trying to understand how parallelism might work using PLINQ, given delayed execution. Here is a simple example. string[] words = { "believe", "receipt", "relief", "field" }; bool result = words.AsParallel().Any(w => w.Contains("ei")); With LINQ, I would expect the execution to reach the "receipt" value and return true, without executing the query for rest of the values. If we do this in parallel, the evaluation of "relief" may have began before the result of "receipt" has returned. But once the query knows that "receipt" will cause a true result, will the other threads yield immediately? In my case, this is important because the "any" test may be very expensive, and I would want to free up the processors for execution of other tasks.

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• Limit a program's execution time in C (Monte Carlo technique)

  - by rrs90

  I am working on a project which has no determined algorithm to solve using C language. I am Using Monte Carlo technique for solving that problem. And the number of random guesses I want to limit to the execution time specified by the user. This means I want to make full use of the execution time limit defined by the user (as a command line argument) to make as many random iterations as possible. Can I check the execution time elapsed so far for a loop condition. Eg: for(trials=0;execution_time P.S. I am using code blocks 10.05 for coding and GNU compiler.

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• Different execution plan for similar queries

  - by Graham Clements

  I am running two very similar update queries but for a reason unknown to me they are using completely different execution plans. Normally this wouldn't be a problem but they are both updating exactly the same amount of rows but one is using an execution plan that is far inferior to the other, 4 secs vs 2 mins, when scaled up this is causing me a massive problem. The only difference between the two queries is one is using the column CLI and the other DLI. These columns are exactly the same datatype, and are both indexed exactly the same, but for the DLI query execution plan, the index is not used. Any help as to why this is happening is much appreciated. -- Query 1 UPDATE a SET DestKey = ( SELECT TOP 1 b.PrefixKey FROM refPrefixDetail AS b WHERE a.DLI LIKE b.Prefix + '%' ORDER BY len(b.Prefix) DESC ) FROM CallData AS a -- Query 2 UPDATE a SET DestKey = ( SELECT TOP 1 b.PrefixKey FROM refPrefixDetail b WHERE a.CLI LIKE b.Prefix + '%' ORDER BY len(b.Prefix) DESC ) FROM CallData AS a

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• Remote execution in a domain environment

  - by T. Crancker

  I have a windows domain environment and it contains only Server 2008 Os's. I'm trying to execute a script or a program from 1 server on multiple servers, but I can't configure or install any applications. I was trying to user powershell v2.0 (invoke-command) but its not configured and I cant configure it. I'm looking for an alternative maybe WMI. Psexec and rcmd are not installed on any servers. Any advise could help a lot.

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• SQL SERVER – Discard Results After Query Execution – SSMS

  - by pinaldave

  The first thing I do any day is to turn on the computer. Today I woke up and as soon as I turned on the computer I saw a chat message from a friend. He was a bit confused and wanted me to help him. Just as usual I am keeping the relevant conversation in focus and documenting our conversation as chat. Let us call him Ajit. Ajit: Pinal, every time I run a query there is no result displayed in the SSMS but when I run the query in my application it works and returns an appropriate result. Pinal:  Have you tried with different parameters? Ajit: Same thing. However, it works from another computer when I connect to the same server with the same query parameters? Pinal: What? That is new and I believe it is something to do with SSMS and not with the server. Send me screenshot please. Ajit: I believe so, let me send you a screenshot, Pinal: (looking at the screenshot) Oh man, there is no result-tab at all. Ajit: That is what the problem is. It does not have the tab which displays the result. This works just fine from another computer. Pinal: Have you referred Nakul’s blog post – SSMS – Query result options – Discard result after query executes, that talks about setting which can discard the query results after execution. (After a while) Ajit: I think it seems like on the computer where I am running the query my SSMS seems to have the option enabled related to discarding results. I fixed it by following Nakul’s blog post. Pinal: Great! Quite often I get the question what is the importance of the feature. Let us first see how to turn on or turn off this feature in SQL Server Management Studio 2012. In SSMS 2012 go to Tools >> Options >> Query Results > SQL Server >> Results to Grid >> Discard Results After Query Execution. When enabled this option will discard results after the execution. The advantage of disabling the option is that it will improve the performance by using less memory. However the real question is why would someone enable or disable the option. What are the cases when someone wants to run the query but do not care about the result? Matter of the fact, it does not make sense at all to run query and not care about the result. The matter of the fact, I can see quite a few reasons for using this option. I often enable this option when I am doing performance tuning exercise. During performance tuning exercise when I am working with execution plans and do not need results to verify every time or when I am tuning Indexes and its effect on execution plan I do not need the results. In this kind of situations I do keep this option on and discard the results. It always helps me big time as in most of the performance tuning exercise I am dealing with huge amount of the data and dealing with this data can be expensive. Nakul’s has done the experiment here already but I am going to repeat the same again using AdventureWorks Database. Run following T-SQL Script with and without enabling the option to discard the results. USE AdventureWorks2012 GO SELECT * FROM Sales.SalesOrderDetail GO 10 After enabling Discard Results After Query Execution After disabling Discard Results After Query Execution Well, this is indeed a good option when someone is debugging the execution plan or does not want the result to be displayed. Please note that this option does not reduce IO or CPU usage for SQL Server. It just discards the results after execution and a good help for debugging on the development server. Reference: Pinal Dave (http://blog.sqlauthority.com) Filed under: PostADay, SQL, SQL Authority, SQL Query, SQL Server, SQL Server Management Studio, SQL Tips and Tricks, T SQL, Technology

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