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• How to delete rows based on comparison from Data Flow Task in an SSIS?

  - by vikasde

  I have a DataFlow task with two OLE DB Source objects. This is the SQL I want to achieve using SSIS: Insert into server2.db.dbo.[table2] (...) Select col1, col2, col3 ... from Server1.db.dbo.[table1] where [table1.col1] not in (Select col5 from server2.db.dbo.[table2] Where ...) I am pretty new to SSIS and not sure how to achieve this. I thought I could do this using the Data Flow task and populating the first source with the data from server1.db.dbo.table1 and the second source with server2.db.dbo.[table2] and then do the conditional check before inserting it into server2.db.dbo.[table2]. I am not sure how to do the conditional check though. Any help is appreciated.

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• How can I change the flow through this PAM (programmable authentication module) file?

  - by Jamie

  I'd like the PAM module to skip the pam_mount.so line when a unix login succeeds. I've tried various things including: auth [success=2 default=ignore] pam_unix.so nullok_secure auth [success=2 default=ignore] pam_winbind.so krb5_auth krb5_ccache_type=FILE cached_login try_first_pass auth requisite pam_deny.so auth requisite pam_permit.so auth required pam_permit.so auth optional pam_mount.so But can't get it to work. Conversely, when a session shuts down, how can I modify the following os that an unmount command (via pam_mount.so) is avoided during a unix login? session [default=1] pam_permit.so session requisite pam_deny.so session required pam_permit.so session required pam_unix.so session optional pam_winbind.so session optional pam_mount.so

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• How Do I Implement parameterMaps for ADF Regions and Dynamic Regions?

  - by david.giammona

  parameterMap objects defined by managed beans can help reduce the number of child <parameter> elements listed under an ADF region or dynamic region page definition task flow binding. But more importantly, the parameterMap approach also allows greater flexibility in determining what input parameters are passed to an ADF region or dynamic region. This can be especially helpful when using dynamic regions where each task flow utilized can provide an entirely different set of input parameters. The parameterMap is specified within an ADF region or dynamic region page definition task flow binding as shown below: <taskFlow id="checkoutflow1" taskFlowId="/WEB-INF/checkout-flow.xml#checkout-flow" activation="deferred" xmlns="http://xmlns.oracle.com/adf/controller/binding" parametersMap="#{pageFlowScope.userInfoBean.parameterMap}"/> The parameter map object must implement the java.util.Map interface. The keys it specifies match the names of input parameters defined by the task flows utilized within the task flow binding. An example parameterMap object class is shown below: import java.util.HashMap; import java.util.Map; public class UserInfoBean { private Map<String, Object> parameterMap = new HashMap<String, Object>(); public Map getParameterMap() { parameterMap.put("isLoggedIn", getSecurity().isAuthenticated()); parameterMap.put("principalName", getSecurity().getPrincipalName()); return parameterMap; }

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• How do I get SSIS Data Flow to put '0.00' in a flat file?

  - by theog

  I have an SSIS package with a Data Flow that takes an ADO.NET data source (just a small table), executes a select * query, and outputs the query results to a flat file (I've also tried just pulling the whole table and not using a SQL select). The problem is that the data source pulls a column that is a Money datatype, and if the value is not zero, it comes into the text flat file just fine (like '123.45'), but when the value is zero, it shows up in the destination flat file as '.00'. I need to know how to get the leading zero back into the flat file. I've tried various datatypes for the output (in the Flat File Connection Manager), including currency and string, but this seems to have no effect. I've tried a case statement in my select, like this: CASE WHEN columnValue = 0 THEN '0.00' ELSE columnValue END (still results in '.00') I've tried variations on that like this: CASE WHEN columnValue = 0 THEN convert(decimal(12,2), '0.00') ELSE convert(decimal(12,2), columnValue) END (Still results in '.00') and: CASE WHEN columnValue = 0 THEN convert(money, '0.00') ELSE convert(money, columnValue) END (results in '.0000000000000000000') This silly little issue is killin' me. Can anybody tell me how to get a zero Money datatype database value into a flat file as '0.00'?

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• Incorrect logic flow? function that gets coordinates for a sudoku game

  - by igor

  This function of mine keeps on failing an autograder, I am trying to figure out if there is a problem with its logic flow? Any thoughts? Basically, if the row is wrong, "invalid row" should be printed, and clearInput(); called, and return false. When y is wrong, "invalid column" printed, and clearInput(); called and return false. When both are wrong, only "invalid row" is to be printed (and still clearInput and return false. Obviously when row and y are correct, print no error and return true. My function gets through most of the test cases, but fails towards the end, I'm a little lost as to why. bool getCoords(int & x, int & y) { char row; bool noError=true; cin>>row>>y; row=toupper(row); if(row>='A' && row<='I' && isalpha(row) && y>=1 && y<=9) { x=row-'A'; y=y-1; return true; } else if(!(row>='A' && row<='I')) { cout<<"Invalid row"<<endl; noError=false; clearInput(); return false; } else { if(noError) { cout<<"Invalid column"<<endl; } clearInput(); return false; } }

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• I have created a PHP script and I am lacking to extract the primary key, I have given flow below, pl

  - by Parth

  I am using MySQL DB, working for Joomla, My requirement is tracking the activity like insert/update/delete on any table and store it in another audit table using triggers, i.e. I am doing Auditing. DB's table structure: Few tables dont have any PK nor auto increment key Flow of my script is : I fetch out all table from DB. I check whether the table have any trigger or not. If yes then it moves to check nfor next table and so on. If it does'nt find any trigger then it creates the triggers for the table, such that, -it first checks if the table has any primary key or not(for inserting in Tracking audit table for every change made) if it has the primary key then it uses it further in creation of trigger. if it doesnt find any PK then it proceeds further in creating the trigger without inserting any id in audit table Now here, My problem is I need the PK every time so that I can record the id of any particular table in which the insert/update/delete is performed, so that further i can use this audit track table to replicate in production DB.. Now as I haave mentioned earlier that I am not available with PK/auto-incremented in some table, then what should I do get the particular id in which change is done? please guide me...GEEKS!!!

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• How to control the "flow" of an ASP.NET MVC (3.0) web app that relies on Facebook membership, with Facebook C# SDK?

  - by Chad

  I want to totally remove the standard ASP.NET membership system and use Facebook only for my web app's membership. Note, this is not a Facebook canvas app question. Typically, in an ASP.NET app you have some key properties & methods to control the "flow" of an app. Notably: Request.IsAuthenticated, [Authorize] (in MVC apps), Membership.GetUser() and Roles.IsUserInRole(), among others. It looks like [FacebookAuthorize] is equivalent to [Authorize]. Also, there's some standard work I do across all controllers in my site. So I built a BaseController that overrides OnActionExecuting(FilterContext). Typically, I populate ViewData with the user's profile within this action. Would performance suffer if I made a call to fbApp.Get("me") in this action? I use the Facebook Javascript SDK to do registration, which is nice and easy. But that's all client-side, and I'm having a hard time wrapping my mind around when to use client-side facebook calls versus server-side. There will be a point when I need to grab the user's facebook uid and store it in a "profile" table along with a few other bits of data. That would probably be best handled on the return url from the registration plugin... correct? On a side note, what data is returned from fbApp.Get("me")?

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• Securing an ADF Application using OES11g: Part 2

  - by user12587121

  To validate the integration with OES we need a sample ADF Application that is rich enough to allow us to test securing the various ADF elements.  To achieve this we can add some items including bounded task flows to the application developed in this tutorial. A sample JDeveloper 11.1.1.6 project is available here. It depends on the Fusion Order Demo (FOD) database schema which is easily created using the FOD build scripts.In the deployment we have chosen to enable only ADF Authentication as we will delegate Authorization, mostly, to OES.The welcome page of the application with all the links exposed looks as follows: The Welcome, Browse Products, Browse Stock and System Administration links go to pages while the Supplier Registration and Update Stock are bounded task flows.  The Login link goes to a basic login page and once logged in a link is presented that goes to a logout page.  Only the Browse Products and Browse Stock pages are really connected to the database--the other pages and task flows do not really perform any operations on the database. Required Security Policies We make use of a set of test users and roles as decscribed on the welcome page of the application.  In order to exercise the different authorization possibilities we would like to enforce the following sample policies: Anonymous users can see the Login, Welcome and Supplier Registration links. They can also see the Welcome page, the Login page and follow the Supplier Registration task flow.  They can see the icon adjacent to the Login link indicating whether they have logged in or not. Authenticated users can see the Browse Product page. Only staff granted the right can see the Browse Product page cost price value returned from the database and then only if the value is below a configurable limit. Suppliers and staff can see the Browse Stock links and pages.  Customers cannot. Suppliers can see the Update Stock link but only those with the update permission are allowed to follow the task flow that it launches.  We could hide the link but leave it exposed here so we can easily demonstrate the method call activity protecting the task flow. Only staff granted the right can see the System Administration link and the System Administration page it accesses. Implementing the required policies In order to secure the application we will make use of the following techniques: EL Expressions and Java backing beans: JSF has the notion of EL expressions to reference data from backing Java classes.  We use these to control the presentation of links on the navigation page which respect the security contraints.  So a user will not see links that he is not allowed to click on into. These Java backing beans can call on to OES for an authorization decision.  Important Note: naturally we would configure the WLS domain where our ADF application is running as an OES WLS SM, which would allow us to efficiently query OES over the PEP API.  However versioning conflicts between OES 11.1.1.5 and ADF 11.1.1.6 mean that this is not possible.  Nevertheless, we can make use of the OES RESTful gateway technique from this posting in order to call into OES. You can easily create and manage backing beans in Jdeveloper as follows: Custom ADF Phase Listener: ADF extends the JSF page lifecycle flow and allows one to hook into the flow to intercept page rendering.  We use this to put a check prior to rendering any protected pages, again calling on to OES via the backing bean.  Phase listeners are configured in the adf-settings.xml file.  See the MyPageListener.java class in the project.  Here, for example,  is the code we use in the listener to check for allowed access to the sysadmin page, navigating back to the welcome page if authorization is not granted:                         if (page != null && (page.equals("/system.jspx") || page.equals("/system"))){                             System.out.println("MyPageListener: Checking Authorization for /system");                             if (getValue("#{oesBackingBean.UIAccessSysAdmin}").toString().equals("false") ){                                   System.out.println("MyPageListener: Forcing navigation away from system" +                                       "to welcome");                                 NavigationHandler nh = fc.getApplication().getNavigationHandler();                                   nh.handleNavigation(fc, null, "welcome");                               } else {                                 System.out.println("MyPageListener: access allowed");                              }                         } Method call activity: our app makes use of bounded task flows to implement the sequence of pages that update the stock or allow suppliers to self register.  ADF takes care of ensuring that a bounded task flow can be entered by only one page.  So a way to protect all those pages is to make a call to OES in the first activity and then either exit the task flow or continue depending on the authorization decision.  The method call returns a String which contains the name of the transition to effect. This is where we configure the method call activity in JDeveloper: We implement each of the policies using the above techniques as follows: Policies 1 and 2: as these policies concern the coarse grained notions of controlling access to anonymous and authenticated users we can make use of the container’s security constraints which can be defined in the web.xml file.  The allPages constraint is added automatically when we configure Authentication for the ADF application.  We have added the “anonymousss” constraint to allow access to the the required pages, task flows and icons: <security-constraint>    <web-resource-collection>      <web-resource-name>anonymousss</web-resource-name>      <url-pattern>/faces/welcome</url-pattern>      <url-pattern>/afr/*</url-pattern>      <url-pattern>/adf/*</url-pattern>      <url-pattern>/key.png</url-pattern>      <url-pattern>/faces/supplier-reg-btf/*</url-pattern>      <url-pattern>/faces/supplier_register_complete</url-pattern>    </web-resource-collection>  </security-constraint> Policy 3: we can place an EL expression on the element representing the cost price on the products.jspx page: #{oesBackingBean.dataAccessCostPrice}. This EL Expression references a method in a Java backing bean that will call on to OES for an authorization decision.  In OES we model the authorization requirement by requiring the view permission on the resource /MyADFApp/data/costprice and granting it only to the staff application role.  We recover any obligations to determine the limit.  Policy 4: is implemented by putting an EL expression on the Browse Stock link #{oesBackingBean.UIAccessBrowseStock} which checks for the view permission on the /MyADFApp/ui/stock resource. The stock.jspx page is protected by checking for the same permission in a custom phase listener—if the required permission is not satisfied then we force navigation back to the welcome page. Policy 5: the Update Stock link is protected with the same EL expression as the Browse Link: #{oesBackingBean.UIAccessBrowseStock}.  However the Update Stock link launches a bounded task flow and to protect it the first activity in the flow is a method call activity which will execute an EL expression #{oesBackingBean.isUIAccessSupplierUpdateTransition}  to check for the update permission on the /MyADFApp/ui/stock resource and either transition to the next step in the flow or terminate the flow with an authorization error. Policy 6: the System Administration link is protected with an EL Expression #{oesBackingBean.UIAccessSysAdmin} that checks for view access on the /MyADF/ui/sysadmin resource.  The system page is protected in the same way at the stock page—the custom phase listener checks for the same permission that protects the link and if not satisfied we navigate back to the welcome page. Testing the Application To test the application: deploy the OES11g Admin to a WLS domain deploy the OES gateway in a another domain configured to be a WLS SM. You must ensure that the jps-config.xml file therein is configured to allow access to the identity store, otherwise the gateway will not b eable to resolve the principals for the requested users.  To do this ensure that the following elements appear in the jps-config.xml file: <serviceProvider type="IDENTITY_STORE" name="idstore.ldap.provider" class="oracle.security.jps.internal.idstore.ldap.LdapIdentityStoreProvider">             <description>LDAP-based IdentityStore Provider</description>  </serviceProvider> <serviceInstance name="idstore.ldap" provider="idstore.ldap.provider">             <property name="idstore.config.provider" value="oracle.security.jps.wls.internal.idstore.WlsLdapIdStoreConfigProvider"/>             <property name="CONNECTION_POOL_CLASS" value="oracle.security.idm.providers.stdldap.JNDIPool"/></serviceInstance> <serviceInstanceRef ref="idstore.ldap"/> download the sample application and change the URL to the gateway in the MyADFApp OESBackingBean code to point to the OES Gateway and deploy the application to an 11.1.1.6 WLS domain that has been extended with the ADF JRF files. You will need to configure the FOD database connection to point your database which contains the FOD schema. populate the OES Admin and OES Gateway WLS LDAP stores with the sample set of users and groups.  If  you have configured the WLS domains to point to the same LDAP then it would only have to be done once.  To help with this there is a directory called ldap_scripts in the sample project with ldif files for the test users and groups. start the OES Admin console and configure the required OES authorization policies for the MyADFApp application and push them to the WLS SM containing the OES Gateway. Login to the MyADFApp as each of the users described on the login page to test that the security policy is correct. You will see informative logging from the OES Gateway and the ADF application to their respective WLS consoles. Congratulations, you may now login to the OES Admin console and change policies that will control the behaviour of your ADF application--change the limit value in the obligation for the cost price for example, or define Role Mapping policies to determine staff access to the system administration page based on user profile attributes. ADF Development Notes Some notes on ADF development which are probably typical gotchas: May need this on WLS startup in order to allow us to overwrite credentials for the database, the signal here is that there is an error trying to access the data base: -Djps.app.credential.overwrite.allowed=true Best to call Bounded Task flows via a CommandLink (as opposed to a go link) as you cannot seem to start them again from a go link, even having completed the task flow correctly with a return activity. Once a bounded task flow (BTF) is initated it must complete correctly  via a return activity—attempting to click on any other link whilst in the context of a  BTF has no effect.  See here for example: When using the ADF Authentication only security approach it seems to be awkward to allow anonymous access to the welcome and registration pages.  We can achieve anonymous access using the web.xml security constraint shown above (where no auth-constraint is specified) however it is not clear what needs to be listed in there….for example the /afr/* and /adf/* are in there by trial and error as sometimes the welcome page will not render if we omit those items.  I was not able to use the default allPages constraint with for example the anonymous-role or the everyone WLS group in order to be able to allow anonymous access to pages. The ADF security best practice advises placing all pages under the public_html/WEB-INF folder as then ADF will not allow any direct access to the .jspx pages but will only allow acces via a link of the form /faces/welcome rather than /faces/welcome.jspx.  This seems like a very good practice to follow as having multiple entry points to data is a source of confusion in a web application (particulary from a security point of view). In Authentication+Authorization mode only pages with a Page definition file are protected.  In order to add an emty one right click on the page and choose Go to Page Definition.  This will create an empty page definition and now the page will require explicit permission to be seen. It is advisable to give a unique context root via the weblogic.xml for the application, as otherwise the application will clash with any other application with the same context root and it will not deploy

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• Does correcting a value in an validation method mark the object as dirty?

  - by dontWatchMyProfile

  From the docs: If you change the input value in a validate:error: method, you must ensure that you only change the value if it is invalid or uncoerced. The reason is that, since the object and context are now dirtied, Core Data may validate that key again later. If you keep performing a coercion in a validation method, this can therefore produce an infinite loop. So when I modify a value in a validation method, the context gets dirtied? And the next time I save, the validation happens again - and when I change the value even if the validation is OK, then the context is again dirtied, and revalidated again - and I change the value, and Core Data validates, again, because the context is dirtied. And so on...for ever... is that right? Or did they try to say something different?

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• More than one unique key for HashMap problem (Java)

  - by Alex Cheng

  This question is a continuation of this thread: In short: To solve my problem, I want to use Map<Set<String>, String>. However, after I sort my data entries in Excel, remove the unnecessary parameters, and the following came out: flow content ==> content content flow content ==> content depth distance flow content ==> content depth within flow content ==> content depth within distance flow content ==> content within flow content ==> content within distance I have more than one unique key for the hashmap if that is the case. How do I go around this... anyone have any idea? I was thinking of maybe Map<Set <String>, List <String>> so that I can do something like: Set <flow content>, List <'content content','content depth distance','content depth within ', ..., 'content within distance'> But because I am parsing the entries line by line I can't figure out the way how to store values of the same repeated keys (flow content) into the same list and add it to the map. Anyone have a rough logic on how can this be done in Java? Thanks in advance.

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• Is it safe to set MySQL isolation to "Read Uncommitted" (dirty reads) for typical Web usage? Even with replication?

  - by Continuation

  I'm working on a website with typical CRUD web usage pattern: similar to blogs or forums where users create/update contents and other users read the content. Seems like it's OK to set the database's isolation level to "Read Uncommitted" (dirty reads) in this case. My understanding of the general drawback of "Read Uncommitted" is that a reader may read uncommitted data that will later be rollbacked. In a CRUD blog/forum usage pattern, will there ever be any rollback? And even if there is, is there any major problem with reading uncommitted data? Right now I'm not using any replication, but in the future if I want to use replication (row-based, not statement-based) will a "Read Uncommitted" isolation level prevent me from doing so? What do you think? Has anyone tried using "Read Uncommitted" on their RDBMS?

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• ???Past Image(pi)

  - by todd.bao(at)oracle.com

  Past Image???RAC??????????,????????????????????????????????,Past Image??????????,?????????????????,?????????????????,??????????????(pi)?????????????????Past Image,????????????:HR.EMPLOYEES??100????101?????5????88???????????????,???????????# ??1: ?????????SYS@RAC1//scripts> select inst_id,status from gv$bh where file#=5 and block#=88;no rows selected# ??1???(???Steve King, ????24000????)SYS@RAC1//scripts> update hr.employees set salary=1 where employee_id=100;1 row updated.# ??2: ????1??xcur????????????,?????????SYS@RAC1//scripts> select inst_id,dirty,status from gv$bh where file#=5 and  block#=88;   INST_ID + D + STATUS---------- + - + -------         1 + Y + xcur1 row selected.# ??2???SYS@RAC2//scripts> update hr.employees set salary=2 where employee_id=101;1 row updated.# ??3: ????2?,?????1??pi??Past Image,???????????????????????SYS@RAC1//scripts> select inst_id,dirty,status from gv$bh where file#=5 and  block#=88;   INST_ID + D + STATUS---------- + - + -------         1 + Y + pi         2 + Y + xcur2 rows selected.# ??1???SYS@RAC1//scripts> update hr.employees set salary=3 where employee_id=100;1 row updated.# ??4: ????1?,?????2???1???????2???????1???????SYS@RAC1//scripts> select inst_id,dirty,status from gv$bh where file#=5 and  block#=88;   INST_ID + D + STATUS---------- + - + -------         1 + Y + pi         1 + Y + xcur         2 + Y + pi3 rows selected.# ??2????SYS@RAC2//scripts> update hr.employees set salary=4 where employee_id=101;1 row updated.# ??5: ????2?,??????????????,DBWR??,??????,??(pi)?????????????(cr)??????????????????????????SYS@RAC1//scripts> select inst_id,dirty,status from gv$bh where file#=5 and  block#=88;   INST_ID + D + STATUS---------- + - + -------         1 + N + cr         1 + N + cr         2 + Y + xcur3 rows selected.# ?????1???SYS@RAC1//scripts> update hr.employees set salary=5 where employee_id=100;1 row updated.# ??6: ????1?,?????2????????????????,?????????SYS@RAC1//scripts> select inst_id,dirty,status from gv$bh where file#=5 and  block#=88;   INST_ID + D + STATUS---------- + - + -------         1 + Y + xcur         1 + N + cr         1 + N + cr         2 + Y + pi4 rows selected.# ??2???SYS@RAC2//scripts> update hr.employees set salary=6 where employee_id=101;1 row updated.# ??7: ????2?,?????1?2????1???????2?????????????4,????????????????SYS@RAC1//scripts> select inst_id,dirty,status from gv$bh where file#=5 and  block#=88;   INST_ID + D + STATUS---------- + - + -------         1 + Y + pi         2 + Y + pi         2 + Y + xcur3 rows selected.# ??1???SYS@RAC1//scripts> update hr.employees set salary=7 where employee_id=100;1 row updated.# ??8: ????1?,?????2?1????2???????1????????????2????????????????????????????????????(????????)????SYS@RAC1//scripts> select inst_id,dirty,status from gv$bh where file#=5 and  block#=88;   INST_ID + D + STATUS---------- + - + -------         1 + Y + pi         1 + Y + xcur         2 + Y + pi         2 + N + cr4 rows selected.??????????, ?xcur??????????:??????xcur????pi?????pi?(?????)???cr?,???cr?????,pi????????????????????????????:?????????????A?B?A:SYS@RAC1//scripts> run  1  begin  2  for i in 1..100000 loop  3  update hr.employees set salary=i where employee_id=100;  4  end loop;  5* end;B:SYS@RAC2//scripts> run  1  begin  2  for i in 1..100000 loop  3  update hr.employees set salary=i where employee_id=101;  4  end loop;  5* end;?????????,???5???88?????buffer cache???????:SYS@RAC2//scripts> select count(*) from gv$bh where file#=5 and block#=88;  COUNT(*)----------       4121 row selected.??409?????????(cur):SYS@RAC2//scripts> select count(*) from gv$bh where file#=5 and block#=88 where status='cr';  COUNT(*)----------       4091 row selected.1????????(xcur):SYS@RAC2//scripts> select count(*) from gv$bh where file#=5 and block#=88 where status='xcur';  COUNT(*)----------           11 row selected.??...2??????--????(pi)??????????SYS@RAC1//scripts> select inst_id,dirty,status from gv$bh where file#=5 and block#=88 and status='pi';   INST_ID + D + STATUS---------- + - + -------         1 + Y + pi         2 + Y + pi2 rows selected.????,???RAC??????????????(cr)?,????????????????????????xcur?pi??cr??????pi?????? ?????????,???????????pi???cr?,?????????cr???,???xcur???????,pi??????xcur?,[email protected]

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• performance issue in a select query from a single table

  - by daedlus

  Hi , I have a table as below dbo.UserLogs ------------------------------------- Id | UserId |Date | Name| P1 | Dirty ------------------------------------- There can be several records per userId[even in millions] I have clustered index on Date column and query this table very frequently in time ranges. The column 'Dirty' is non-nullable and can take either 0 or 1 only so I have no indexes on 'Dirty' I have several millions of records in this table and in one particular case in my application i need to query this table to get all UserId that have at least one record that is marked dirty. I tried this query - select distinct(UserId) from UserLogs where Dirty=1 I have 10 million records in total and this takes like 10min to run and i want this to run much faster than this. [i am able to query this table on date column in less than a minute.] Any comments/suggestion are welcome. my env 64bit,sybase15.0.3,Linux

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• Coherence Data Guarantees for Data Reads - Basic Terminology

  - by jpurdy

  When integrating Coherence into applications, each application has its own set of requirements with respect to data integrity guarantees. Developers often describe these requirements using expressions like "avoiding dirty reads" or "making sure that updates are transactional", but we often find that even in a small group of people, there may be a wide range of opinions as to what these terms mean. This may simply be due to a lack of familiarity, but given that Coherence sits at an intersection of several (mostly) unrelated fields, it may be a matter of conflicting vocabularies (e.g. "consistency" is similar but different in transaction processing versus multi-threaded programming). Since almost all data read consistency issues are related to the concept of concurrency, it is helpful to start with a definition of that, or rather what it means for two operations to be concurrent. Rather than implying that they occur "at the same time", concurrency is a slightly weaker statement -- it simply means that it can't be proven that one event precedes (or follows) the other. As an example, in a Coherence application, if two client members mutate two different cache entries sitting on two different cache servers at roughly the same time, it is likely that one update will precede the other by a significant amount of time (say 0.1ms). However, since there is no guarantee that all four members have their clocks perfectly synchronized, and there is no way to precisely measure the time it takes to send a given message between any two members (that have differing clocks), we consider these to be concurrent operations since we can not (easily) prove otherwise. So this leads to a question that we hear quite frequently: "Are the contents of the near cache always synchronized with the underlying distributed cache?". It's easy to see that if an update on a cache server results in a message being sent to each near cache, and then that near cache being updated that there is a window where the contents are different. However, this is irrelevant, since even if the application reads directly from the distributed cache, another thread update the cache before the read is returned to the application. Even if no other member modifies a cache entry prior to the local near cache entry being updated (and subsequently read), the purpose of reading a cache entry is to do something with the result, usually either displaying for consumption by a human, or by updating the entry based on the current state of the entry. In the former case, it's clear that if the data is updated faster than a human can perceive, then there is no problem (and in many cases this can be relaxed even further). For the latter case, the application must assume that the value might potentially be updated before it has a chance to update it. This almost aways the case with read-only caches, and the solution is the traditional optimistic transaction pattern, which requires the application to explicitly state what assumptions it made about the old value of the cache entry. If the application doesn't want to bother stating those assumptions, it is free to lock the cache entry prior to reading it, ensuring that no other threads will mutate the entry, a pessimistic approach. The optimistic approach relies on what is sometimes called a "fuzzy read". In other words, the application assumes that the read should be correct, but it also acknowledges that it might not be. (I use the qualifier "sometimes" because in some writings, "fuzzy read" indicates the situation where the application actually sees an original value and then later sees an updated value within the same transaction -- however, both definitions are roughly equivalent from an application design perspective). If the read is not correct it is called a "stale read". Going back to the definition of concurrency, it may seem difficult to precisely define a stale read, but the practical way of detecting a stale read is that is will cause the encompassing transaction to roll back if it tries to update that value. The pessimistic approach relies on a "coherent read", a guarantee that the value returned is not only the same as the primary copy of that value, but also that it will remain that way. In most cases this can be used interchangeably with "repeatable read" (though that term has additional implications when used in the context of a database system). In none of cases above is it possible for the application to perform a "dirty read". A dirty read occurs when the application reads a piece of data that was never committed. In practice the only way this can occur is with multi-phase updates such as transactions, where a value may be temporarily update but then withdrawn when a transaction is rolled back. If another thread sees that value prior to the rollback, it is a dirty read. If an application uses optimistic transactions, dirty reads will merely result in a lack of forward progress (this is actually one of the main risks of dirty reads -- they can be chained and potentially cause cascading rollbacks). The concepts of dirty reads, fuzzy reads, stale reads and coherent reads are able to describe the vast majority of requirements that we see in the field. However, the important thing is to define the terms used to define requirements. A quick web search for each of the terms in this article will show multiple meanings, so I've selected what are generally the most common variations, but it never hurts to state each definition explicitly if they are critical to the success of a project (many applications have sufficiently loose requirements that precise terminology can be avoided).

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• AngularJs not working with dynamic html

  - by user2541753

  In my cshtml file I have a form named 'ApplyMedicalMain' and I want to show a dynamically loaded division when the form is dirty but its not happening even though the form is dirty ... Below is my code that i got in Firefox Inspect Element: <form class="form_section ng-dirty ng-valid ng-valid-required" name="ApplyMedicalMain" method="post" action="/MVC/Quote/ApplyMedical"> <div id="Step1_PartialView" class="QuoteStep1"> <script type="text/javascript" src="/Scripts/Renderings/Presales/ApplyMedical.js"> <div name="Conditions" id="conditions_or_symptoms" ng-hide="ApplyMedicalMain.$dirty"> <div class="generic_error_message select"> <div class="error_icn_message"></div> </div> As you can see above, I have mentioned ng-hide for the division name='conditions' but it is not getting hidden even though the form has class 'ng-dirty'.And please note that the the division 'conditions' is loaded dynamically from other partial view. can someone help me ?

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• Windows Workflow and sql script in declarative config like InRule

  - by Satish

  We have been using InRule for our Rule needs we have found that it does not scale well and so are investigating the Windows Work Flow. Within InRule we could configure pretty much have any task for example our sql scripts and stored procedures where all part of a separate rule config file, I am wondering if there is a similar functionality within windows work flow where I could just call a declarative task and pass it a bunch of parameters – This task should contain the sql script I would be executing , we should be able to change the script at runtime without recompilation to the WF code. Is this possible in Windows Work flow – How can I accomplish this within work flow. Additionally for sql execution within Work Flow, how does it get the connection string. Should it be passed from the calling program – is passing it as input parameter from the Calling app via the Dictionary object the best way or can the work flow code have visibility to my calling program app.config and get the connection string ?

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• Android: How to get a custom view to redraw partially?

  - by Peterdk

  I have a custom view that fills my entire screen. (A piano keyboard) When a user touches the key, it would cause a invalidate() to be called and the whole keyboard gets redrawn to show the new state with a touched key. Currently the view is very simple, but I plan to add a bit more nice graphics. Since the whole keyboard is dynamically rendered this would make redrawing the entire keyboard more expensive. So I thought, let's look into partial redrawing. Now I call invalidate(Rect dirty) with the correct dirty region. I set my onDraw(Canvas canvas) method to only draw the keys in the dirty region if I do indeed want a partial redraw. This results in those keys being drawn, but the rest of the keyboard is totally black/not drawn at all. Am I wrong in expecting that calling invalidate(Rect dirty) would "cache" the current canvas, and only "allows" drawing in the dirty region? Is there any way I can achieve what I want? (A way to "cache" the canvas and only redraw the dirty area?"

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• how can I handle user defined exceptions and after handling them resume the flow of program. here is

  - by fari

  /** * An exception thrown when an illegal side pit was * specified (i.e. not in the range 1-6) for a move */ public class IllegalSidePitNumException extends RuntimeException { /** * Exception constructor. * @param sidePitNum the illegal side pit that was selected. */ public IllegalSidePitNumException(int sidePitNum) { super("No such side pit number: "+sidePitNum); } } how do i use this ina program and then resume for there. I do not want the program to end but want to handle the exception and continue.

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• What is stopping data flow with .NET 3.5 asynchronous System.Net.Sockets.Socket?

  - by TonyG

  I have a .NET 3.5 client/server socket interface using the asynchronous methods. The client connects to the server and the connection should remain open until the app terminates. The protocol consists of the following pattern: send stx receive ack send data1 receive ack send data2 (repeat 5-6 while more data) receive ack send etx So a single transaction with two datablocks as above would consist of 4 sends from the client. After sending etx the client simply waits for more data to send out, then begins the next transmission with stx. I do not want to break the connection between individual exchanges or after each stx/data/etx payload. Right now, after connection, the client can send the first stx, and get a single ack, but I can't put more data onto the wire after that. Neither side disconnects, the socket is still intact. The client code is seriously abbreviated as follows - I'm following the pattern commonly available in online code samples. private void SendReceive(string data) { // ... SocketAsyncEventArgs completeArgs; completeArgs.Completed += new EventHandler<SocketAsyncEventArgs>(OnSend); clientSocket.SendAsync(completeArgs); // two AutoResetEvents, one for send, one for receive if ( !AutoResetEvent.WaitAll(autoSendReceiveEvents , -1) ) Log("failed"); else Log("success"); // ... } private void OnSend( object sender , SocketAsyncEventArgs e ) { // ... Socket s = e.UserToken as Socket; byte[] receiveBuffer = new byte[ 4096 ]; e.SetBuffer(receiveBuffer , 0 , receiveBuffer.Length); e.Completed += new EventHandler<SocketAsyncEventArgs>(OnReceive); s.ReceiveAsync(e); // ... } private void OnReceive( object sender , SocketAsyncEventArgs e ) {} // ... if ( e.BytesTransferred > 0 ) { Int32 bytesTransferred = e.BytesTransferred; String received = Encoding.ASCII.GetString(e.Buffer , e.Offset , bytesTransferred); dataReceived += received; } autoSendReceiveEvents[ SendOperation ].Set(); // could be moved elsewhere autoSendReceiveEvents[ ReceiveOperation ].Set(); // releases mutexes } The code on the server is very similar except that it receives first and then sends a response - the server is not doing anything (that I can tell) to modify the connection after it sends a response. The problem is that the second time I hit SendReceive in the client, the connection is already in a weird state. Do I need to do something in the client to preserve the SocketAsyncEventArgs, and re-use the same object for the lifetime of the socket/connection? I'm not sure which eventargs object should hang around during the life of the connection or a given exchange. Do I need to do something, or Not do something in the server to ensure it continues to Receive data? The server setup and response processing looks like this: void Start() { // ... listenSocket.Bind(...); listenSocket.Listen(0); StartAccept(null); // note accept as soon as we start. OK? mutex.WaitOne(); } void StartAccept(SocketAsyncEventArgs acceptEventArg) { if ( acceptEventArg == null ) { acceptEventArg = new SocketAsyncEventArgs(); acceptEventArg.Completed += new EventHandler<SocketAsyncEventArgs>(OnAcceptCompleted); } Boolean willRaiseEvent = this.listenSocket.AcceptAsync(acceptEventArg); if ( !willRaiseEvent ) ProcessAccept(acceptEventArg); // ... } private void OnAcceptCompleted( object sender , SocketAsyncEventArgs e ) { ProcessAccept(e); } private void ProcessAccept( SocketAsyncEventArgs e ) { // ... SocketAsyncEventArgs readEventArgs = new SocketAsyncEventArgs(); readEventArgs.SetBuffer(dataBuffer , 0 , Int16.MaxValue); readEventArgs.Completed += new EventHandler<SocketAsyncEventArgs>(OnIOCompleted); readEventArgs.UserToken = e.AcceptSocket; dataReceived = ""; // note server is degraded for single client/thread use // As soon as the client is connected, post a receive to the connection. Boolean willRaiseEvent = e.AcceptSocket.ReceiveAsync(readEventArgs); if ( !willRaiseEvent ) this.ProcessReceive(readEventArgs); // Accept the next connection request. this.StartAccept(e); } private void OnIOCompleted( object sender , SocketAsyncEventArgs e ) { // switch ( e.LastOperation ) case SocketAsyncOperation.Receive: ProcessReceive(e); // similar to client code // operate on dataReceived here case SocketAsyncOperation.Send: ProcessSend(e); // similar to client code } // execute this when a data has been processed into a response (ack, etc) private SendResponseToClient(string response) { // create buffer with response // currentEventArgs has class scope and is re-used currentEventArgs.SetBuffer(sendBuffer , 0 , sendBuffer.Length); Boolean willRaiseEvent = currentClient.SendAsync(currentEventArgs); if ( !willRaiseEvent ) ProcessSend(currentEventArgs); } A .NET trace shows the following when sending ABC\r\n: Socket#7588182::SendAsync() Socket#7588182::SendAsync(True#1) Data from Socket#7588182::FinishOperation(SendAsync) 00000000 : 41 42 43 0D 0A Socket#7588182::ReceiveAsync() Exiting Socket#7588182::ReceiveAsync() - True#1 And it stops there. It looks just like the first send from the client but the server shows no activity. I think that could be info overload for now but I'll be happy to provide more details as required. Thanks!

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• Do you know of a free .Net component for visual flow model graph design and editing?

  - by Ivan

  An app (C#4, WinForms, Entity Framework, SQL Server 2008) of mine maintains a graph of interconnected objects, each having some simple member fields and a set of many directed (in and out) one-to-one links to other objects. I'd like to offer a user an ability to view and edit this graph visually some way, creating and removing connections, modifying objects attributes values and introducing/dropping objects. I suppose there has to be a framework (at list a primitive kind of) for this as visual model design tools are pretty common to meet. Do you know one?

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• how i set real password / lofin in stack over flow instad the openid?

  - by user268302

  i can't find this option any ware in the site . i like to set password / login and not the the open id login i have now

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• how to represent static variable declaration in a flow chart documentation?

  - by volting

  Im in the process of documenting some firmware but I'm unsure what the standard is (if there is one)for representing static variable declaration in flowcharts Regards, V

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• How to call/execute another ASP.net page from the parent ASP.Net page without disrupting the flow of

  - by NJTechGuy

  When a button/link is clicked, I want this URL to be called followed by the execution of the following statements. The ASP.Net page is in C# btw. Function A statement A call abc.apsx statement B abc.aspx is a silent page, doesn't display anything on the page but creates an output.txt file. So when abc.aspx is called, output.txt file is created and Statement B is executed seamlessly. Hope I made sense. I have no .Net programming knowledge. Please help me. Thank you..

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• How to find whole graph coverage path in dynamic state-flow diagram?

  - by joseph

  Hello, As I've been researching algorithms for path finding in graph, I found interesting problem. Definition of situation: 1)State diagram can have p states, and s Boolean Fields, and z Int Fields 2)Every state can have q ingoing and r outgoing transitions, and h Int fields (h belongs to z - see above) 3)Every transition can have only 1 event, and only 1 action 4)every action can change n Boolean Fields, and x Int Fields 5)every event can have one trigger from combination of any count of Boolean Fields in diagram 6)Transition can be in OPEN/CLOSED form. If the transition is open/closed depends on trigger2 compounded from 0..c Boolean fields. 7) I KNOW algorithm for finding shortest paths from state A to state B. 8) I KNOW algorithm for finding path that covers all states and transitions of whole state diagram, if all transitions are OPEN. Now, what is the goal: I need to find shortest path that covers all states and transitions in dynamically changing state diagram described above. When an action changes some int field, the algorithm should go through all states that have changed int field. The algorithm should also be able to open and close transition (by going through transitions that open and close another transitions by action) in the way that the founded path will be shortest and covers all transitions and states. Any idea how to solve it? I will be really pleased for ANY idea. Thanks for answers.

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• How to make BoxLayout vertical but children flow top-aligned?

  - by user291701

  I'm trying to get get a vertical, top-aligned layout to work. This is what I have: JPanel pane = new JPanel(); pane.setLayout(new BoxLayout(pane, BoxLayout.Y_AXIS)); MyImagePanel panelImage = new MyImagePanel(); panelImage.setSize(400, 400); pane.add(new JComboBox()); pane.add(panelImage); pane.add(new JButton("1")); pane.add(new JButton("2")); pane.add(new JButton("3")); JFrame frame = new JFrame("Title"); frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE); frame.setSize(800, 600); frame.add(pane); frame.pack(); frame.setVisible(true); All the controls appear, but it looks like padding is being applied at run time between their tops and bottoms so they're somewhat vertically centered. This is what I'm going for: ----------------------------------------------------- | ComboBox | | ------------ | | | | | Image | | | | | ------------ | | Button 1 | Any additional space fills the right | ------------ | | Button 2 | | ------------ | | Button 3 | | ------------ | | | | Any additional space fills the bottom | | | ----------------------------------------------------- How do I get BoxLayout to do that? Thanks ------------------------- Update ------------------------- Was able to use this: Box vertical = Box.createVerticalBox(); frame.add(vertical, BorderLayout.NORTH); vertical.add(new JComboBox()); vertical.add(new JButton("1")); ... to get what I wanted.

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