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  • onUpdate in MySQL means?

    - by ajsie
    i know that if you create a foreign key on a field (parent_id) in a child table that refer to a parent table's primary key (id), then if this parent table is deleted the child class will be deleted as well if you set onDelete to cascade when creating the foreign key in the child class. but what happens if i set it to onUpdate = cascade?

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  • Does grails support logging from the src/java classes?

    - by rainyday
    I have a grails app (v 1.1.2) the logging is working fine from the groovy classes, but I can't get it to work from within a java source... I have a class in package com.mforms.devices., it imports apache log4j, defines the logger as follows private final org.apache.log4j.Logger loggy = Logger.getLogger(this.getClass()); then refer to it later by doing loggy.error("...") my Config.groovy has the following log4j = { error 'com.mforms' root { error 'stdout', 'file' additivity = true } } What am I doing wrong?!?!

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  • How to insert item which type is QString to a ComboBox in Qt?

    - by Hanny
    I have an item which type is QString: for example: QString name="Name" the question is: How can I put this name variable into a combobox? I've read the Qt 4.6.2 docs but still cant figure out how to do that. Please dont refer me back to that Qt 4.6.2 docs again.. Please help me ASAP!! this is really urgent! thank you very much!! :)

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  • iPhone dev: Get keys (public / private)

    - by Jonny
    I'm using another computer than normal to do iPhone dev. Now I'm trying to get my apps onto my iPhone, but fail with the certificates, keys and stuff. Refer to this thread: http://stackoverflow.com/questions/613719/iphone-provisioning-problem-public-private-key Actually I'm able to download my cert no problem from Apple's site, but how would I get at the keys needed? (private, public), I see no way of getting them...

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  • valid attributes sequence of input type tag

    - by I Like PHP
    hello, I know it's very basic question and hope not so important, but i want to know the answer, please don't suggest only refer links. we all daily face <input> type tag and their attributes(type, class, id, value, name, size, maxlength, tabindex etc..), i just want to know that is there any sequence list of attributes in tag or we can use any sequence? is there any sequence then what it is?

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  • MySQL grouping by a previously declared alias, what do I wrap it in? ' OR `

    - by cgmojoco
    I have an SQL query that has an alias in the SELECT statement SELECT CONCAT(YEAR(r.Date),_utf8'-',_utf8'Q',QUARTER(r.Date)) AS 'QuarterYear' Later, I want to refer to this in my group by statement. I'm a little confused...should I wrap this with backticks, single quote or just leave it unwrapped int he group by GROUP BY `QuarterYear ` or should I do this?: GROUP BY 'QuarterYear' or just this?: GROUP BY QuarterYear

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  • C# equivalent of typeof for fields

    - by rwallace
    With reflection, you can look up a class from a string at run time, but you can also say typeof(Foo) and get compile time type checking, auto completion etc. If what you want is a field not a class, you can look it up from a string at runtime, but if you want compile time type checking etc., is there anyway to say something like fieldof(Foo.Bar)? I know the name of both the class and the field in advance, and I want to be able to refer to the field at compile time rather than with a run-time string lookup.

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  • How to make a remove frame script in JavaScript?

    - by Daniel
    I am making websites I refer to from my site load up in a frame (similar to google images). But I also want to give users the ability to break out of that frame. Like with google image's "Remove Frame" link at the bottom right corner of their frame. How can I do this possiblyusing Javascript?

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  • best way to implement a deck for a card game in python

    - by matt1024
    What is the best way to store the cards and suits in python so that I can hold a reference to these values in another variable? For example, if I have a list called hand (cards in players hand), how could I hold values that could refer to the names of suits and values of specific cards, and how would these names and values of suits and cards be stored?

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  • Is there a shorthand term for O(n log n)?

    - by jemfinch
    We usually have a single-word shorthand for most complexities we encounter in algorithmic analysis: O(1) == "constant" O(log n) == "logarithmic" O(n) == "linear" O(n^2) == "quadratic" O(n^3) == "cubic" O(2^n) == "exponential" We encounter algorithms with O(n log n) complexity with some regularity (think of all the algorithms dominated by sort complexity) but as far as I know, there's no single word we can use in English to refer to that complexity. Is this a gap in my knowledge, or a real gap in our English discourse on computational complexity?

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  • Live Wallpaper Engine Abstraction

    - by user1459142
    I am trying to obtain an instance of my live wallpaper engine in another class, here is my code... In the other class: WallpaperEngine wpe = (WallpaperEngine) LiveWallpaperService.onCreateEngine(); In LiveWallpaperService: @Override public Engine onCreateEngine() { // TODO Auto-generated method stub return new WallpaperEngine(); } But when I refer to an object in my engine (i.e, "wpe.variable"), I get a NullPointerException and the wallpaper force closes.

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  • Couldn't drop privileges: User is missing UID (see mail_uid setting)

    - by drecute
    I'm hoping I can use some help. I'm configuring dovecot_ldap, but I can't seem to be able to get dovecot to authenticate the ldap user. Below is my config and log info: hosts = 192.168.128.45:3268 dn = cn=Administrator,cn=Users,dc=company,dc=example,dc=com dnpass = "passwd" auth_bind = yes ldap_version = 3 base = dc=company, dc=example, dc=com user_attrs = sAMAccountName=home=/var/vmail/example.com/%$,uid=1001,gid=1001 user_filter = (&(sAMAccountName=%Ln)) pass_filter = (&(ObjectClass=person)(sAMAccountName=%u)) dovecot.conf # 2.0.19: /etc/dovecot/dovecot.conf # OS: Linux 3.2.0-33-generic x86_64 Ubuntu 12.04 LTS auth_mechanisms = plain login auth_realms = example.com auth_verbose = yes disable_plaintext_auth = no mail_access_groups = mail mail_location = mbox:~/mail:INBOX=/var/mail/%u mail_privileged_group = mail passdb { driver = pam } passdb { driver = passwd } passdb { args = /etc/dovecot/dovecot-ldap.conf.ext driver = ldap } passdb { args = scheme=CRYPT username_format=%u /etc/dovecot/users driver = passwd-file } protocols = " imap pop3" service auth { unix_listener /var/spool/postfix/private/auth { group = postfix mode = 0660 user = postfix } } service imap-login { inet_listener imap { port = 143 } inet_listener imaps { port = 993 ssl = yes } } ssl_cert = </etc/ssl/certs/dovecot.pem ssl_key = </etc/ssl/private/dovecot.pem userdb { driver = passwd } userdb { args = /etc/dovecot/dovecot-ldap.conf.ext driver = ldap } userdb { args = username_format=%u /etc/dovecot/users driver = passwd-file } protocol imap { imap_client_workarounds = tb-extra-mailbox-sep imap_logout_format = bytes=%i/%o mail_plugins = } mail.log Nov 29 10:51:44 mail dovecot: auth-worker: pam(charyorde,10.10.1.28): pam_authenticate() failed: Authentication failure (password mismatch?) Nov 29 10:51:44 mail dovecot: auth-worker: passwd(charyorde,10.10.1.28): unknown user Nov 29 10:51:44 mail dovecot: auth: passwd(charyorde,10.10.1.28): unknown user Nov 29 10:51:44 mail dovecot: imap-login: Login: user=<charyorde>, method=PLAIN, rip=10.10.1.28, lip=10.10.1.30, mpid=1892, TLS Nov 29 10:51:44 mail dovecot: imap(charyorde): Error: user charyorde: Couldn't drop privileges: User is missing UID (see mail_uid setting) Nov 29 10:51:44 mail dovecot: imap(charyorde): Error: Internal error occurred. Refer to server log for more information. Nov 29 10:51:46 mail dovecot: auth-worker: pam(charyorde,10.10.1.28): pam_authenticate() failed: Authentication failure (password mismatch?) Nov 29 10:51:46 mail dovecot: auth-worker: passwd(charyorde,10.10.1.28): unknown user Nov 29 10:51:46 mail dovecot: auth: passwd(charyorde,10.10.1.28): unknown user Nov 29 10:51:46 mail dovecot: imap-login: Login: user=<charyorde>, method=PLAIN, rip=10.10.1.28, lip=10.10.1.30, mpid=1894, TLS Nov 29 10:51:46 mail dovecot: imap(charyorde): Error: user charyorde: Couldn't drop privileges: User is missing UID (see mail_uid setting) Nov 29 10:51:46 mail dovecot: imap(charyorde): Error: Internal error occurred. Refer to server log for more information. Nov 29 10:51:48 mail dovecot: auth-worker: pam([email protected],10.10.1.28): pam_authenticate() failed: Authentication failure (password mismatch?) Nov 29 10:51:48 mail dovecot: auth-worker: passwd([email protected],10.10.1.28): unknown user Nov 29 10:51:48 mail dovecot: auth: ldap([email protected],10.10.1.28): unknown user Nov 29 10:51:48 mail dovecot: auth: passwd-file([email protected],10.10.1.28): unknown user Nov 29 10:51:54 mail postfix/smtpd[1880]: idle timeout -- exiting Nov 29 10:51:54 mail postfix/smtpd[1879]: idle timeout -- exiting Nov 29 10:51:54 mail postfix/smtpd[1886]: proxymap stream disconnect Nov 29 10:51:54 mail postfix/smtpd[1887]: proxymap stream disconnect Nov 29 10:51:54 mail postfix/smtpd[1886]: auto_clnt_close: disconnect private/tlsmgr stream Nov 29 10:51:54 mail postfix/smtpd[1887]: auto_clnt_close: disconnect private/tlsmgr stream Nov 29 10:51:54 mail postfix/smtpd[1887]: idle timeout -- exiting Nov 29 10:51:54 mail postfix/smtpd[1886]: idle timeout -- exiting Nov 29 10:51:56 mail dovecot: auth-worker: pam([email protected],10.10.1.28): pam_authenticate() failed: Authentication failure (password mismatch?) Nov 29 10:51:56 mail dovecot: auth-worker: passwd([email protected],10.10.1.28): unknown user Nov 29 10:51:56 mail dovecot: auth: ldap([email protected],10.10.1.28): unknown user Nov 29 10:51:56 mail dovecot: auth: passwd-file([email protected],10.10.1.28): unknown user Nov 29 10:52:04 mail dovecot: auth-worker: pam([email protected],10.10.1.28): pam_authenticate() failed: Authentication failure (password mismatch?) Nov 29 10:52:04 mail dovecot: auth-worker: passwd([email protected],10.10.1.28): unknown user Nov 29 10:52:04 mail dovecot: auth: ldap([email protected],10.10.1.28): unknown user Nov 29 10:52:04 mail dovecot: auth: passwd-file([email protected],10.10.1.28): unknown user Nov 29 10:52:06 mail dovecot: imap-login: Disconnected (auth failed, 3 attempts): user=<[email protected]>, method=PLAIN, rip=10.10.1.28, lip=10.10.1.30, TLS Thank you for looking into this.

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  • Heaps of Trouble?

    - by Paul White NZ
    If you’re not already a regular reader of Brad Schulz’s blog, you’re missing out on some great material.  In his latest entry, he is tasked with optimizing a query run against tables that have no indexes at all.  The problem is, predictably, that performance is not very good.  The catch is that we are not allowed to create any indexes (or even new statistics) as part of our optimization efforts. In this post, I’m going to look at the problem from a slightly different angle, and present an alternative solution to the one Brad found.  Inevitably, there’s going to be some overlap between our entries, and while you don’t necessarily need to read Brad’s post before this one, I do strongly recommend that you read it at some stage; he covers some important points that I won’t cover again here. The Example We’ll use data from the AdventureWorks database, copied to temporary unindexed tables.  A script to create these structures is shown below: CREATE TABLE #Custs ( CustomerID INTEGER NOT NULL, TerritoryID INTEGER NULL, CustomerType NCHAR(1) COLLATE SQL_Latin1_General_CP1_CI_AI NOT NULL, ); GO CREATE TABLE #Prods ( ProductMainID INTEGER NOT NULL, ProductSubID INTEGER NOT NULL, ProductSubSubID INTEGER NOT NULL, Name NVARCHAR(50) COLLATE SQL_Latin1_General_CP1_CI_AI NOT NULL, ); GO CREATE TABLE #OrdHeader ( SalesOrderID INTEGER NOT NULL, OrderDate DATETIME NOT NULL, SalesOrderNumber NVARCHAR(25) COLLATE SQL_Latin1_General_CP1_CI_AI NOT NULL, CustomerID INTEGER NOT NULL, ); GO CREATE TABLE #OrdDetail ( SalesOrderID INTEGER NOT NULL, OrderQty SMALLINT NOT NULL, LineTotal NUMERIC(38,6) NOT NULL, ProductMainID INTEGER NOT NULL, ProductSubID INTEGER NOT NULL, ProductSubSubID INTEGER NOT NULL, ); GO INSERT #Custs ( CustomerID, TerritoryID, CustomerType ) SELECT C.CustomerID, C.TerritoryID, C.CustomerType FROM AdventureWorks.Sales.Customer C WITH (TABLOCK); GO INSERT #Prods ( ProductMainID, ProductSubID, ProductSubSubID, Name ) SELECT P.ProductID, P.ProductID, P.ProductID, P.Name FROM AdventureWorks.Production.Product P WITH (TABLOCK); GO INSERT #OrdHeader ( SalesOrderID, OrderDate, SalesOrderNumber, CustomerID ) SELECT H.SalesOrderID, H.OrderDate, H.SalesOrderNumber, H.CustomerID FROM AdventureWorks.Sales.SalesOrderHeader H WITH (TABLOCK); GO INSERT #OrdDetail ( SalesOrderID, OrderQty, LineTotal, ProductMainID, ProductSubID, ProductSubSubID ) SELECT D.SalesOrderID, D.OrderQty, D.LineTotal, D.ProductID, D.ProductID, D.ProductID FROM AdventureWorks.Sales.SalesOrderDetail D WITH (TABLOCK); The query itself is a simple join of the four tables: SELECT P.ProductMainID AS PID, P.Name, D.OrderQty, H.SalesOrderNumber, H.OrderDate, C.TerritoryID FROM #Prods P JOIN #OrdDetail D ON P.ProductMainID = D.ProductMainID AND P.ProductSubID = D.ProductSubID AND P.ProductSubSubID = D.ProductSubSubID JOIN #OrdHeader H ON D.SalesOrderID = H.SalesOrderID JOIN #Custs C ON H.CustomerID = C.CustomerID ORDER BY P.ProductMainID ASC OPTION (RECOMPILE, MAXDOP 1); Remember that these tables have no indexes at all, and only the single-column sampled statistics SQL Server automatically creates (assuming default settings).  The estimated query plan produced for the test query looks like this (click to enlarge): The Problem The problem here is one of cardinality estimation – the number of rows SQL Server expects to find at each step of the plan.  The lack of indexes and useful statistical information means that SQL Server does not have the information it needs to make a good estimate.  Every join in the plan shown above estimates that it will produce just a single row as output.  Brad covers the factors that lead to the low estimates in his post. In reality, the join between the #Prods and #OrdDetail tables will produce 121,317 rows.  It should not surprise you that this has rather dire consequences for the remainder of the query plan.  In particular, it makes a nonsense of the optimizer’s decision to use Nested Loops to join to the two remaining tables.  Instead of scanning the #OrdHeader and #Custs tables once (as it expected), it has to perform 121,317 full scans of each.  The query takes somewhere in the region of twenty minutes to run to completion on my development machine. A Solution At this point, you may be thinking the same thing I was: if we really are stuck with no indexes, the best we can do is to use hash joins everywhere. We can force the exclusive use of hash joins in several ways, the two most common being join and query hints.  A join hint means writing the query using the INNER HASH JOIN syntax; using a query hint involves adding OPTION (HASH JOIN) at the bottom of the query.  The difference is that using join hints also forces the order of the join, whereas the query hint gives the optimizer freedom to reorder the joins at its discretion. Adding the OPTION (HASH JOIN) hint results in this estimated plan: That produces the correct output in around seven seconds, which is quite an improvement!  As a purely practical matter, and given the rigid rules of the environment we find ourselves in, we might leave things there.  (We can improve the hashing solution a bit – I’ll come back to that later on). Faster Nested Loops It might surprise you to hear that we can beat the performance of the hash join solution shown above using nested loops joins exclusively, and without breaking the rules we have been set. The key to this part is to realize that a condition like (A = B) can be expressed as (A <= B) AND (A >= B).  Armed with this tremendous new insight, we can rewrite the join predicates like so: SELECT P.ProductMainID AS PID, P.Name, D.OrderQty, H.SalesOrderNumber, H.OrderDate, C.TerritoryID FROM #OrdDetail D JOIN #OrdHeader H ON D.SalesOrderID >= H.SalesOrderID AND D.SalesOrderID <= H.SalesOrderID JOIN #Custs C ON H.CustomerID >= C.CustomerID AND H.CustomerID <= C.CustomerID JOIN #Prods P ON P.ProductMainID >= D.ProductMainID AND P.ProductMainID <= D.ProductMainID AND P.ProductSubID = D.ProductSubID AND P.ProductSubSubID = D.ProductSubSubID ORDER BY D.ProductMainID OPTION (RECOMPILE, LOOP JOIN, MAXDOP 1, FORCE ORDER); I’ve also added LOOP JOIN and FORCE ORDER query hints to ensure that only nested loops joins are used, and that the tables are joined in the order they appear.  The new estimated execution plan is: This new query runs in under 2 seconds. Why Is It Faster? The main reason for the improvement is the appearance of the eager Index Spools, which are also known as index-on-the-fly spools.  If you read my Inside The Optimiser series you might be interested to know that the rule responsible is called JoinToIndexOnTheFly. An eager index spool consumes all rows from the table it sits above, and builds a index suitable for the join to seek on.  Taking the index spool above the #Custs table as an example, it reads all the CustomerID and TerritoryID values with a single scan of the table, and builds an index keyed on CustomerID.  The term ‘eager’ means that the spool consumes all of its input rows when it starts up.  The index is built in a work table in tempdb, has no associated statistics, and only exists until the query finishes executing. The result is that each unindexed table is only scanned once, and just for the columns necessary to build the temporary index.  From that point on, every execution of the inner side of the join is answered by a seek on the temporary index – not the base table. A second optimization is that the sort on ProductMainID (required by the ORDER BY clause) is performed early, on just the rows coming from the #OrdDetail table.  The optimizer has a good estimate for the number of rows it needs to sort at that stage – it is just the cardinality of the table itself.  The accuracy of the estimate there is important because it helps determine the memory grant given to the sort operation.  Nested loops join preserves the order of rows on its outer input, so sorting early is safe.  (Hash joins do not preserve order in this way, of course). The extra lazy spool on the #Prods branch is a further optimization that avoids executing the seek on the temporary index if the value being joined (the ‘outer reference’) hasn’t changed from the last row received on the outer input.  It takes advantage of the fact that rows are still sorted on ProductMainID, so if duplicates exist, they will arrive at the join operator one after the other. The optimizer is quite conservative about introducing index spools into a plan, because creating and dropping a temporary index is a relatively expensive operation.  It’s presence in a plan is often an indication that a useful index is missing. I want to stress that I rewrote the query in this way primarily as an educational exercise – I can’t imagine having to do something so horrible to a production system. Improving the Hash Join I promised I would return to the solution that uses hash joins.  You might be puzzled that SQL Server can create three new indexes (and perform all those nested loops iterations) faster than it can perform three hash joins.  The answer, again, is down to the poor information available to the optimizer.  Let’s look at the hash join plan again: Two of the hash joins have single-row estimates on their build inputs.  SQL Server fixes the amount of memory available for the hash table based on this cardinality estimate, so at run time the hash join very quickly runs out of memory. This results in the join spilling hash buckets to disk, and any rows from the probe input that hash to the spilled buckets also get written to disk.  The join process then continues, and may again run out of memory.  This is a recursive process, which may eventually result in SQL Server resorting to a bailout join algorithm, which is guaranteed to complete eventually, but may be very slow.  The data sizes in the example tables are not large enough to force a hash bailout, but it does result in multiple levels of hash recursion.  You can see this for yourself by tracing the Hash Warning event using the Profiler tool. The final sort in the plan also suffers from a similar problem: it receives very little memory and has to perform multiple sort passes, saving intermediate runs to disk (the Sort Warnings Profiler event can be used to confirm this).  Notice also that because hash joins don’t preserve sort order, the sort cannot be pushed down the plan toward the #OrdDetail table, as in the nested loops plan. Ok, so now we understand the problems, what can we do to fix it?  We can address the hash spilling by forcing a different order for the joins: SELECT P.ProductMainID AS PID, P.Name, D.OrderQty, H.SalesOrderNumber, H.OrderDate, C.TerritoryID FROM #Prods P JOIN #Custs C JOIN #OrdHeader H ON H.CustomerID = C.CustomerID JOIN #OrdDetail D ON D.SalesOrderID = H.SalesOrderID ON P.ProductMainID = D.ProductMainID AND P.ProductSubID = D.ProductSubID AND P.ProductSubSubID = D.ProductSubSubID ORDER BY D.ProductMainID OPTION (MAXDOP 1, HASH JOIN, FORCE ORDER); With this plan, each of the inputs to the hash joins has a good estimate, and no hash recursion occurs.  The final sort still suffers from the one-row estimate problem, and we get a single-pass sort warning as it writes rows to disk.  Even so, the query runs to completion in three or four seconds.  That’s around half the time of the previous hashing solution, but still not as fast as the nested loops trickery. Final Thoughts SQL Server’s optimizer makes cost-based decisions, so it is vital to provide it with accurate information.  We can’t really blame the performance problems highlighted here on anything other than the decision to use completely unindexed tables, and not to allow the creation of additional statistics. I should probably stress that the nested loops solution shown above is not one I would normally contemplate in the real world.  It’s there primarily for its educational and entertainment value.  I might perhaps use it to demonstrate to the sceptical that SQL Server itself is crying out for an index. Be sure to read Brad’s original post for more details.  My grateful thanks to him for granting permission to reuse some of his material. Paul White Email: [email protected] Twitter: @PaulWhiteNZ

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  • Simple way of converting server side objects into client side using JSON serialization for asp.net websites

    - by anil.kasalanati
     Introduction:- With the growth of Web2.0 and the need for faster user experience the spotlight has shifted onto javascript based applications built using REST pattern or asp.net AJAX Pagerequest manager. And when we are working with javascript wouldn’t it be much better if we could create objects in an OOAD way and easily push it to the client side.  Following are the reasons why you would push the server side objects onto client side -          Easy availability of the complex object. -          Use C# compiler and rick intellisense to create and maintain the objects but use them in the javascript. You could run code analysis etc. -          Reduce the number of calls we make to the server side by loading data on the pageload.   I would like to explain about the 3rd point because that proved to be highly beneficial to me when I was fixing the performance issues of a major website. There could be a scenario where in you be making multiple AJAX based webrequestmanager calls in order to get the same response in a single page. This happens in the case of widget based framework when all the widgets are independent but they need some common information available in the framework to load the data. So instead of making n multiple calls we could load the data needed during pageload. The above picture shows the scenario where in all the widgets need the common information and then call GetData webservice on the server side. Ofcourse the result can be cached on the client side but a better solution would be to avoid the call completely.  In order to do that we need to JSONSerialize the content and send it in the DOM.                                                                                                                                                                                                                                                                                                                                                                                            Example:- I have developed a simple application to demonstrate the idea and I would explaining that in detail here. The class called SimpleClass would be sent as serialized JSON to the client side .   And this inherits from the base class which has the implementation for the GetJSONString method. You can create a single base class and all the object which need to be pushed to the client side can inherit from that class. The important thing to note is that the class should be annotated with DataContract attribute and the methods should have the Data Member attribute. This is needed by the .Net DataContractSerializer and this follows the opt-in mode so if you want to send an attribute to the client side then you need to annotate the DataMember attribute. So if I didn’t want to send the Result I would simple remove the DataMember attribute. This is default WCF/.Net 3.5 stuff but it provides the flexibility of have a fullfledged object on the server side but sending a smaller object to the client side. Sometimes you may hide some values due to security constraints. And thing you will notice is that I have marked the class as Serializable so that it can be stored in the Session and used in webfarm deployment scenarios. Following is the implementation of the base class –  This implements the default DataContractJsonSerializer and for more information or customization refer to following blogs – http://softcero.blogspot.com/2010/03/optimizing-net-json-serializing-and-ii.html http://weblogs.asp.net/gunnarpeipman/archive/2010/12/28/asp-net-serializing-and-deserializing-json-objects.aspx The next part is pretty simple, I just need to inject this object into the aspx page.   And in the aspx markup I have the following line – <script type="text/javascript"> var data =(<%=SimpleClassJSON  %>);   alert(data.ResultText); </script>   This will output the content as JSON into the variable data and this can be any element in the DOM. And you can verify the element by checking data in the Firebug console.    Design Consideration – If you have a lot of javascripts then you need to think about using Script # and you can write javascript in C#. Refer to Nikhil’s blog – http://projects.nikhilk.net/ScriptSharp Ensure that you are taking security into consideration while exposing server side objects on to client side. I have seen application exposing passwords, secret key so it is not a good practice.   The application can be tested using the following url – http://techconsulting.vpscustomer.com/Samples/JsonTest.aspx The source code is available at http://techconsulting.vpscustomer.com/Source/HistoryTest.zip

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  • How to archive data from a table to a local or remote database in SQL 2005 and SQL 2008

    - by simonsabin
    Often you have the need to archive data from a table. This leads to a number of challenges 1. How can you do it without impacting users 2. How can I make it transactionally consistent, i.e. the data I put in the archive is the data I remove from the main table 3. How can I get it to perform well Points 1 is very much tied to point 3. If it doesn't perform well then the delete of data is going to cause lots of locks and thus potentially blocking. For points 1 and 3 refer to my previous posts DELETE-TOP-x-rows-avoiding-a-table-scan and UPDATE-and-DELETE-TOP-and-ORDER-BY---Part2. In essence you need to be removing small chunks of data from your table and you want to do that avoiding a table scan. So that deals with the delete approach but archiving is about inserting that data somewhere else. Well in SQL 2008 they introduced a new feature INSERT over DML (Data Manipulation Language, i.e. SQL statements that change data), or composable DML. The ability to nest DML statements within themselves, so you can past the results of an insert to an update to a merge. I've mentioned this before here SQL-Server-2008---MERGE-and-optimistic-concurrency. This feature is currently limited to being able to consume the results of a DML statement in an INSERT statement. There are many restrictions which you can find here http://msdn.microsoft.com/en-us/library/ms177564.aspx look for the section "Inserting Data Returned From an OUTPUT Clause Into a Table" Even with the restrictions what we can do is consume the OUTPUT from a DELETE and INSERT the results into a table in another database. Note that in BOL it refers to not being able to use a remote table, remote means a table on another SQL instance. To show this working use this SQL to setup two databases foo and fooArchive create database foo go --create the source table fred in database foo select * into foo..fred from sys.objects go create database fooArchive go if object_id('fredarchive',DB_ID('fooArchive')) is null begin     select getdate() ArchiveDate,* into fooArchive..FredArchive from sys.objects where 1=2       end go And then we can use this simple statement to archive the data insert into fooArchive..FredArchive select getdate(),d.* from (delete top (1)         from foo..Fred         output deleted.*) d         go In this statement the delete can be any delete statement you wish so if you are deleting by ids or a range of values then you can do that. Refer to the DELETE-TOP-x-rows-avoiding-a-table-scan post to ensure that your delete is going to perform. The last thing you want to do is to perform 100 deletes each with 5000 records for each of those deletes to do a table scan. For a solution that works for SQL2005 or if you want to archive to a different server then you can use linked servers or SSIS. This example shows how to do it with linked servers. [ONARC-LAP03] is the source server. begin transaction insert into fooArchive..FredArchive select getdate(),d.* from openquery ([ONARC-LAP03],'delete top (1)                     from foo..Fred                     output deleted.*') d commit transaction and to prove the transactions work try, you should get the same number of records before and after. select (select count(1) from foo..Fred) fred        ,(select COUNT(1) from fooArchive..FredArchive ) fredarchive   begin transaction insert into fooArchive..FredArchive select getdate(),d.* from openquery ([ONARC-LAP03],'delete top (1)                     from foo..Fred                     output deleted.*') d rollback transaction   select (select count(1) from foo..Fred) fred        ,(select COUNT(1) from fooArchive..FredArchive ) fredarchive The transactions are very important with this solution. Look what happens when you don't have transactions and an error occurs   select (select count(1) from foo..Fred) fred        ,(select COUNT(1) from fooArchive..FredArchive ) fredarchive   insert into fooArchive..FredArchive select getdate(),d.* from openquery ([ONARC-LAP03],'delete top (1)                     from foo..Fred                     output deleted.*                     raiserror (''Oh doo doo'',15,15)') d                     select (select count(1) from foo..Fred) fred        ,(select COUNT(1) from fooArchive..FredArchive ) fredarchive Before running this think what the result would be. I got it wrong. What seems to happen is that the remote query is executed as a transaction, the error causes that to rollback. However the results have already been sent to the client and so get inserted into the

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  • C#/.NET Little Wonders: Tuples and Tuple Factory Methods

    - by James Michael Hare
    Once again, in this series of posts I look at the parts of the .NET Framework that may seem trivial, but can really help improve your code by making it easier to write and maintain.  This week, we look at the System.Tuple class and the handy factory methods for creating a Tuple by inferring the types. What is a Tuple? The System.Tuple is a class that tends to inspire a reaction in one of two ways: love or hate.  Simply put, a Tuple is a data structure that holds a specific number of items of a specific type in a specific order.  That is, a Tuple<int, string, int> is a tuple that contains exactly three items: an int, followed by a string, followed by an int.  The sequence is important not only to distinguish between two members of the tuple with the same type, but also for comparisons between tuples.  Some people tend to love tuples because they give you a quick way to combine multiple values into one result.  This can be handy for returning more than one value from a method (without using out or ref parameters), or for creating a compound key to a Dictionary, or any other purpose you can think of.  They can be especially handy when passing a series of items into a call that only takes one object parameter, such as passing an argument to a thread's startup routine.  In these cases, you do not need to define a class, simply create a tuple containing the types you wish to return, and you are ready to go? On the other hand, there are some people who see tuples as a crutch in object-oriented design.  They may view the tuple as a very watered down class with very little inherent semantic meaning.  As an example, what if you saw this in a piece of code: 1: var x = new Tuple<int, int>(2, 5); What are the contents of this tuple?  If the tuple isn't named appropriately, and if the contents of each member are not self evident from the type this can be a confusing question.  The people who tend to be against tuples would rather you explicitly code a class to contain the values, such as: 1: public sealed class RetrySettings 2: { 3: public int TimeoutSeconds { get; set; } 4: public int MaxRetries { get; set; } 5: } Here, the meaning of each int in the class is much more clear, but it's a bit more work to create the class and can clutter a solution with extra classes. So, what's the correct way to go?  That's a tough call.  You will have people who will argue quite well for one or the other.  For me, I consider the Tuple to be a tool to make it easy to collect values together easily.  There are times when I just need to combine items for a key or a result, in which case the tuple is short lived and so the meaning isn't easily lost and I feel this is a good compromise.  If the scope of the collection of items, though, is more application-wide I tend to favor creating a full class. Finally, it should be noted that tuples are immutable.  That means they are assigned a value at construction, and that value cannot be changed.  Now, of course if the tuple contains an item of a reference type, this means that the reference is immutable and not the item referred to. Tuples from 1 to N Tuples come in all sizes, you can have as few as one element in your tuple, or as many as you like.  However, since C# generics can't have an infinite generic type parameter list, any items after 7 have to be collapsed into another tuple, as we'll show shortly. So when you declare your tuple from sizes 1 (a 1-tuple or singleton) to 7 (a 7-tuple or septuple), simply include the appropriate number of type arguments: 1: // a singleton tuple of integer 2: Tuple<int> x; 3:  4: // or more 5: Tuple<int, double> y; 6:  7: // up to seven 8: Tuple<int, double, char, double, int, string, uint> z; Anything eight and above, and we have to nest tuples inside of tuples.  The last element of the 8-tuple is the generic type parameter Rest, this is special in that the Tuple checks to make sure at runtime that the type is a Tuple.  This means that a simple 8-tuple must nest a singleton tuple (one of the good uses for a singleton tuple, by the way) for the Rest property. 1: // an 8-tuple 2: Tuple<int, int, int, int, int, double, char, Tuple<string>> t8; 3:  4: // an 9-tuple 5: Tuple<int, int, int, int, double, int, char, Tuple<string, DateTime>> t9; 6:  7: // a 16-tuple 8: Tuple<int, int, int, int, int, int, int, Tuple<int, int, int, int, int, int, int, Tuple<int,int>>> t14; Notice that on the 14-tuple we had to have a nested tuple in the nested tuple.  Since the tuple can only support up to seven items, and then a rest element, that means that if the nested tuple needs more than seven items you must nest in it as well.  Constructing tuples Constructing tuples is just as straightforward as declaring them.  That said, you have two distinct ways to do it.  The first is to construct the tuple explicitly yourself: 1: var t3 = new Tuple<int, string, double>(1, "Hello", 3.1415927); This creates a triple that has an int, string, and double and assigns the values 1, "Hello", and 3.1415927 respectively.  Make sure the order of the arguments supplied matches the order of the types!  Also notice that we can't half-assign a tuple or create a default tuple.  Tuples are immutable (you can't change the values once constructed), so thus you must provide all values at construction time. Another way to easily create tuples is to do it implicitly using the System.Tuple static class's Create() factory methods.  These methods (much like C++'s std::make_pair method) will infer the types from the method call so you don't have to type them in.  This can dramatically reduce the amount of typing required especially for complex tuples! 1: // this 4-tuple is typed Tuple<int, double, string, char> 2: var t4 = Tuple.Create(42, 3.1415927, "Love", 'X'); Notice how much easier it is to use the factory methods and infer the types?  This can cut down on typing quite a bit when constructing tuples.  The Create() factory method can construct from a 1-tuple (singleton) to an 8-tuple (octuple), which of course will be a octuple where the last item is a singleton as we described before in nested tuples. Accessing tuple members Accessing a tuple's members is simplicity itself… mostly.  The properties for accessing up to the first seven items are Item1, Item2, …, Item7.  If you have an octuple or beyond, the final property is Rest which will give you the nested tuple which you can then access in a similar matter.  Once again, keep in mind that these are read-only properties and cannot be changed. 1: // for septuples and below, use the Item properties 2: var t1 = Tuple.Create(42, 3.14); 3:  4: Console.WriteLine("First item is {0} and second is {1}", 5: t1.Item1, t1.Item2); 6:  7: // for octuples and above, use Rest to retrieve nested tuple 8: var t9 = new Tuple<int, int, int, int, int, int, int, 9: Tuple<int, int>>(1,2,3,4,5,6,7,Tuple.Create(8,9)); 10:  11: Console.WriteLine("The 8th item is {0}", t9.Rest.Item1); Tuples are IStructuralComparable and IStructuralEquatable Most of you know about IComparable and IEquatable, what you may not know is that there are two sister interfaces to these that were added in .NET 4.0 to help support tuples.  These IStructuralComparable and IStructuralEquatable make it easy to compare two tuples for equality and ordering.  This is invaluable for sorting, and makes it easy to use tuples as a compound-key to a dictionary (one of my favorite uses)! Why is this so important?  Remember when we said that some folks think tuples are too generic and you should define a custom class?  This is all well and good, but if you want to design a custom class that can automatically order itself based on its members and build a hash code for itself based on its members, it is no longer a trivial task!  Thankfully the tuple does this all for you through the explicit implementations of these interfaces. For equality, two tuples are equal if all elements are equal between the two tuples, that is if t1.Item1 == t2.Item1 and t1.Item2 == t2.Item2, and so on.  For ordering, it's a little more complex in that it compares the two tuples one at a time starting at Item1, and sees which one has a smaller Item1.  If one has a smaller Item1, it is the smaller tuple.  However if both Item1 are the same, it compares Item2 and so on. For example: 1: var t1 = Tuple.Create(1, 3.14, "Hi"); 2: var t2 = Tuple.Create(1, 3.14, "Hi"); 3: var t3 = Tuple.Create(2, 2.72, "Bye"); 4:  5: // true, t1 == t2 because all items are == 6: Console.WriteLine("t1 == t2 : " + t1.Equals(t2)); 7:  8: // false, t1 != t2 because at least one item different 9: Console.WriteLine("t2 == t2 : " + t2.Equals(t3)); The actual implementation of IComparable, IEquatable, IStructuralComparable, and IStructuralEquatable is explicit, so if you want to invoke the methods defined there you'll have to manually cast to the appropriate interface: 1: // true because t1.Item1 < t3.Item1, if had been same would check Item2 and so on 2: Console.WriteLine("t1 < t3 : " + (((IComparable)t1).CompareTo(t3) < 0)); So, as I mentioned, the fact that tuples are automatically equatable and comparable (provided the types you use define equality and comparability as needed) means that we can use tuples for compound keys in hashing and ordering containers like Dictionary and SortedList: 1: var tupleDict = new Dictionary<Tuple<int, double, string>, string>(); 2:  3: tupleDict.Add(t1, "First tuple"); 4: tupleDict.Add(t2, "Second tuple"); 5: tupleDict.Add(t3, "Third tuple"); Because IEquatable defines GetHashCode(), and Tuple's IStructuralEquatable implementation creates this hash code by combining the hash codes of the members, this makes using the tuple as a complex key quite easy!  For example, let's say you are creating account charts for a financial application, and you want to cache those charts in a Dictionary based on the account number and the number of days of chart data (for example, a 1 day chart, 1 week chart, etc): 1: // the account number (string) and number of days (int) are key to get cached chart 2: var chartCache = new Dictionary<Tuple<string, int>, IChart>(); Summary The System.Tuple, like any tool, is best used where it will achieve a greater benefit.  I wouldn't advise overusing them, on objects with a large scope or it can become difficult to maintain.  However, when used properly in a well defined scope they can make your code cleaner and easier to maintain by removing the need for extraneous POCOs and custom property hashing and ordering. They are especially useful in defining compound keys to IDictionary implementations and for returning multiple values from methods, or passing multiple values to a single object parameter. Tweet Technorati Tags: C#,.NET,Tuple,Little Wonders

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  • Anatomy of a .NET Assembly - PE Headers

    - by Simon Cooper
    Today, I'll be starting a look at what exactly is inside a .NET assembly - how the metadata and IL is stored, how Windows knows how to load it, and what all those bytes are actually doing. First of all, we need to understand the PE file format. PE files .NET assemblies are built on top of the PE (Portable Executable) file format that is used for all Windows executables and dlls, which itself is built on top of the MSDOS executable file format. The reason for this is that when .NET 1 was released, it wasn't a built-in part of the operating system like it is nowadays. Prior to Windows XP, .NET executables had to load like any other executable, had to execute native code to start the CLR to read & execute the rest of the file. However, starting with Windows XP, the operating system loader knows natively how to deal with .NET assemblies, rendering most of this legacy code & structure unnecessary. It still is part of the spec, and so is part of every .NET assembly. The result of this is that there are a lot of structure values in the assembly that simply aren't meaningful in a .NET assembly, as they refer to features that aren't needed. These are either set to zero or to certain pre-defined values, specified in the CLR spec. There are also several fields that specify the size of other datastructures in the file, which I will generally be glossing over in this initial post. Structure of a PE file Most of a PE file is split up into separate sections; each section stores different types of data. For instance, the .text section stores all the executable code; .rsrc stores unmanaged resources, .debug contains debugging information, and so on. Each section has a section header associated with it; this specifies whether the section is executable, read-only or read/write, whether it can be cached... When an exe or dll is loaded, each section can be mapped into a different location in memory as the OS loader sees fit. In order to reliably address a particular location within a file, most file offsets are specified using a Relative Virtual Address (RVA). This specifies the offset from the start of each section, rather than the offset within the executable file on disk, so the various sections can be moved around in memory without breaking anything. The mapping from RVA to file offset is done using the section headers, which specify the range of RVAs which are valid within that section. For example, if the .rsrc section header specifies that the base RVA is 0x4000, and the section starts at file offset 0xa00, then an RVA of 0x401d (offset 0x1d within the .rsrc section) corresponds to a file offset of 0xa1d. Because each section has its own base RVA, each valid RVA has a one-to-one mapping with a particular file offset. PE headers As I said above, most of the header information isn't relevant to .NET assemblies. To help show what's going on, I've created a diagram identifying all the various parts of the first 512 bytes of a .NET executable assembly. I've highlighted the relevant bytes that I will refer to in this post: Bear in mind that all numbers are stored in the assembly in little-endian format; the hex number 0x0123 will appear as 23 01 in the diagram. The first 64 bytes of every file is the DOS header. This starts with the magic number 'MZ' (0x4D, 0x5A in hex), identifying this file as an executable file of some sort (an .exe or .dll). Most of the rest of this header is zeroed out. The important part of this header is at offset 0x3C - this contains the file offset of the PE signature (0x80). Between the DOS header & PE signature is the DOS stub - this is a stub program that simply prints out 'This program cannot be run in DOS mode.\r\n' to the console. I will be having a closer look at this stub later on. The PE signature starts at offset 0x80, with the magic number 'PE\0\0' (0x50, 0x45, 0x00, 0x00), identifying this file as a PE executable, followed by the PE file header (also known as the COFF header). The relevant field in this header is in the last two bytes, and it specifies whether the file is an executable or a dll; bit 0x2000 is set for a dll. Next up is the PE standard fields, which start with a magic number of 0x010b for x86 and AnyCPU assemblies, and 0x20b for x64 assemblies. Most of the rest of the fields are to do with the CLR loader stub, which I will be covering in a later post. After the PE standard fields comes the NT-specific fields; again, most of these are not relevant for .NET assemblies. The one that is is the highlighted Subsystem field, and specifies if this is a GUI or console app - 0x20 for a GUI app, 0x30 for a console app. Data directories & section headers After the PE and COFF headers come the data directories; each directory specifies the RVA (first 4 bytes) and size (next 4 bytes) of various important parts of the executable. The only relevant ones are the 2nd (Import table), 13th (Import Address table), and 15th (CLI header). The Import and Import Address table are only used by the startup stub, so we will look at those later on. The 15th points to the CLI header, where the CLR-specific metadata begins. After the data directories comes the section headers; one for each section in the file. Each header starts with the section's ASCII name, null-padded to 8 bytes. Again, most of each header is irrelevant, but I've highlighted the base RVA and file offset in each header. In the diagram, you can see the following sections: .text: base RVA 0x2000, file offset 0x200 .rsrc: base RVA 0x4000, file offset 0xa00 .reloc: base RVA 0x6000, file offset 0x1000 The .text section contains all the CLR metadata and code, and so is by far the largest in .NET assemblies. The .rsrc section contains the data you see in the Details page in the right-click file properties page, but is otherwise unused. The .reloc section contains address relocations, which we will look at when we study the CLR startup stub. What about the CLR? As you can see, most of the first 512 bytes of an assembly are largely irrelevant to the CLR, and only a few bytes specify needed things like the bitness (AnyCPU/x86 or x64), whether this is an exe or dll, and the type of app this is. There are some bytes that I haven't covered that affect the layout of the file (eg. the file alignment, which determines where in a file each section can start). These values are pretty much constant in most .NET assemblies, and don't affect the CLR data directly. Conclusion To summarize, the important data in the first 512 bytes of a file is: DOS header. This contains a pointer to the PE signature. DOS stub, which we'll be looking at in a later post. PE signature PE file header (aka COFF header). This specifies whether the file is an exe or a dll. PE standard fields. This specifies whether the file is AnyCPU/32bit or 64bit. PE NT-specific fields. This specifies what type of app this is, if it is an app. Data directories. The 15th entry (at offset 0x168) contains the RVA and size of the CLI header inside the .text section. Section headers. These are used to map between RVA and file offset. The important one is .text, which is where all the CLR data is stored. In my next post, we'll start looking at the metadata used by the CLR directly, which is all inside the .text section.

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  • New ways for backup, recovery and restore of Essbase Block Storage databases – part 2 by Bernhard Kinkel

    - by Alexandra Georgescu
    After discussing in the first part of this article new options in Essbase for the general backup and restore, this second part will deal with the also rather new feature of Transaction Logging and Replay, which was released in version 11.1, enhancing existing restore options. Tip: Transaction logging and replay cannot be used for aggregate storage databases. Please refer to the Oracle Hyperion Enterprise Performance Management System Backup and Recovery Guide (rel. 11.1.2.1). Even if backups are done on a regular, frequent base, subsequent data entries, loads or calculations would not be reflected in a restored database. Activating Transaction Logging could fill that gap and provides you with an option to capture these post-backup transactions for later replay. The following table shows, which are the transactions that could be logged when Transaction Logging is enabled: In order to activate its usage, corresponding statements could be added to the Essbase.cfg file, using the TRANSACTIONLOGLOCATION command. The complete syntax reads: TRANSACTIONLOGLOCATION [ appname [ dbname]] LOGLOCATION NATIVE ?ENABLE | DISABLE Where appname and dbname are optional parameters giving you the chance in combination with the ENABLE or DISABLE command to set Transaction Logging for certain applications or databases or to exclude them from being logged. If only an appname is specified, the setting applies to all databases in that particular application. If appname and dbname are not defined, all applications and databases would be covered. LOGLOCATION specifies the directory to which the log is written, e.g. D:\temp\trlogs. This directory must already exist or needs to be created before using it for log information being written to it. NATIVE is a reserved keyword that shouldn’t be changed. The following example shows how to first enable logging on a more general level for all databases in the application Sample, followed by a disabling statement on a more granular level for only the Basic database in application Sample, hence excluding it from being logged. TRANSACTIONLOGLOCATION Sample Hyperion/trlog/Sample NATIVE ENABLE TRANSACTIONLOGLOCATION Sample Basic Hyperion/trlog/Sample NATIVE DISABLE Tip: After applying changes to the configuration file you must restart the Essbase server in order to initialize the settings. A maybe required replay of logged transactions after restoring a database can be done only by administrators. The following options are available: In Administration Services selecting Replay Transactions on the right-click menu on the database: Here you can select to replay transactions logged after the last replay request was originally executed or after the time of the last restored backup (whichever occurred later) or transactions logged after a specified time. Or you can replay transactions selectively based on a range of sequence IDs, which can be accessed using Display Transactions on the right-click menu on the database: These sequence ID s (0, 1, 2 … 7 in the screenshot below) are assigned to each logged transaction, indicating the order in which the transaction was performed. This helps to ensure the integrity of the restored data after a replay, as the replay of transactions is enforced in the same order in which they were originally performed. So for example a calculation originally run after a data load cannot be replayed before having replayed the data load first. After a transaction is replayed, you can replay only transactions with a greater sequence ID. For example, replaying the transaction with sequence ID of 4 includes all preceding transactions, while afterwards you can only replay transactions with a sequence ID of 5 or greater. Tip: After restoring a database from a backup you should always completely replay all logged transactions, which were executed after the backup, before executing new transactions. But not only the transaction information itself needs to be logged and stored in a specified directory as described above. During transaction logging, Essbase also creates archive copies of data load and rules files in the following default directory: ARBORPATH/app/appname/dbname/Replay These files are then used during the replay of a logged transaction. By default Essbase archives only data load and rules files for client data loads, but in order to specify the type of data to archive when logging transactions you can use the command TRANSACTIONLOGDATALOADARCHIVE as an additional entry in the Essbase.cfg file. The syntax for the statement is: TRANSACTIONLOGDATALOADARCHIVE [appname [dbname]] [OPTION] While to the [appname [dbname]] argument the same applies like before for TRANSACTIONLOGLOCATION, the valid values for the OPTION argument are the following: Make the respective setting for which files copies should be logged, considering from which location transactions are usually taking place. Selecting the NONE option prevents Essbase from saving the respective files and the data load cannot be replayed. In this case you must first manually load the data before you can replay the transactions. Tip: If you use server or SQL data and the data and rules files are not archived in the Replay directory (for example, you did not use the SERVER or SERVER_CLIENT option), Essbase replays the data that is actually in the data source at the moment of the replay, which may or may not be the data that was originally loaded. You can find more detailed information in the following documents: Oracle Hyperion Enterprise Performance Management System Backup and Recovery Guide (rel. 11.1.2.1) Oracle Essbase Online Documentation (rel. 11.1.2.1)) Enterprise Performance Management System Documentation (including previous releases) Or on the Oracle Technology Network. If you are also interested in other new features and smart enhancements in Essbase or Hyperion Planning stay tuned for coming articles or check our training courses and web presentations. You can find general information about offerings for the Essbase and Planning curriculum or other Oracle-Hyperion products here; (please make sure to select your country/region at the top of this page) or in the OU Learning paths section, where Planning, Essbase and other Hyperion products can be found under the Fusion Middleware heading (again, please select the right country/region). Or drop me a note directly: [email protected]. About the Author: Bernhard Kinkel started working for Hyperion Solutions as a Presales Consultant and Consultant in 1998 and moved to Hyperion Education Services in 1999. He joined Oracle University in 2007 where he is a Principal Education Consultant. Based on these many years of working with Hyperion products he has detailed product knowledge across several versions. He delivers both classroom and live virtual courses. His areas of expertise are Oracle/Hyperion Essbase, Oracle Hyperion Planning and Hyperion Web Analysis. Disclaimer: All methods and features mentioned in this article must be considered and tested carefully related to your environment, processes and requirements. As guidance please always refer to the available software documentation. This article does not recommend or advise any explicit action or change, hence the author cannot be held responsible for any consequences due to the use or implementation of these features.

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  • Improving Manageability of Virtual Environments

    - by Jeff Victor
    Boot Environments for Solaris 10 Branded Zones Until recently, Solaris 10 Branded Zones on Solaris 11 suffered one notable regression: Live Upgrade did not work. The individual packaging and patching tools work correctly, but the ability to upgrade Solaris while the production workload continued running did not exist. A recent Solaris 11 SRU (Solaris 11.1 SRU 6.4) restored most of that functionality, although with a slightly different concept, different commands, and without all of the feature details. This new method gives you the ability to create and manage multiple boot environments (BEs) for a Solaris 10 Branded Zone, and modify the active or any inactive BE, and to do so while the production workload continues to run. Background In case you are new to Solaris: Solaris includes a set of features that enables you to create a bootable Solaris image, called a Boot Environment (BE). This newly created image can be modified while the original BE is still running your workload(s). There are many benefits, including improved uptime and the ability to reboot into (or downgrade to) an older BE if a newer one has a problem. In Solaris 10 this set of features was named Live Upgrade. Solaris 11 applies the same basic concepts to the new packaging system (IPS) but there isn't a specific name for the feature set. The features are simply part of IPS. Solaris 11 Boot Environments are not discussed in this blog entry. Although a Solaris 10 system can have multiple BEs, until recently a Solaris 10 Branded Zone (BZ) in a Solaris 11 system did not have this ability. This limitation was addressed recently, and that enhancement is the subject of this blog entry. This new implementation uses two concepts. The first is the use of a ZFS clone for each BE. This makes it very easy to create a BE, or many BEs. This is a distinct advantage over the Live Upgrade feature set in Solaris 10, which had a practical limitation of two BEs on a system, when using UFS. The second new concept is a very simple mechanism to indicate the BE that should be booted: a ZFS property. The new ZFS property is named com.oracle.zones.solaris10:activebe (isn't that creative? ). It's important to note that the property is inherited from the original BE's file system to any BEs you create. In other words, all BEs in one zone have the same value for that property. When the (Solaris 11) global zone boots the Solaris 10 BZ, it boots the BE that has the name that is stored in the activebe property. Here is a quick summary of the actions you can use to manage these BEs: To create a BE: Create a ZFS clone of the zone's root dataset To activate a BE: Set the ZFS property of the root dataset to indicate the BE To add a package or patch to an inactive BE: Mount the inactive BE Add packages or patches to it Unmount the inactive BE To list the available BEs: Use the "zfs list" command. To destroy a BE: Use the "zfs destroy" command. Preparation Before you can use the new features, you will need a Solaris 10 BZ on a Solaris 11 system. You can use these three steps - on a real Solaris 11.1 server or in a VirtualBox guest running Solaris 11.1 - to create a Solaris 10 BZ. The Solaris 11.1 environment must be at SRU 6.4 or newer. Create a flash archive on the Solaris 10 system s10# flarcreate -n s10-system /net/zones/archives/s10-system.flar Configure the Solaris 10 BZ on the Solaris 11 system s11# zonecfg -z s10z Use 'create' to begin configuring a new zone. zonecfg:s10z create -t SYSsolaris10 zonecfg:s10z set zonepath=/zones/s10z zonecfg:s10z exit s11# zoneadm list -cv ID NAME STATUS PATH BRAND IP 0 global running / solaris shared - s10z configured /zones/s10z solaris10 excl Install the zone from the flash archive s11# zoneadm -z s10z install -a /net/zones/archives/s10-system.flar -p You can find more information about the migration of Solaris 10 environments to Solaris 10 Branded Zones in the documentation. The rest of this blog entry demonstrates the commands you can use to accomplish the aforementioned actions related to BEs. New features in action Note that the demonstration of the commands occurs in the Solaris 10 BZ, as indicated by the shell prompt "s10z# ". Many of these commands can be performed in the global zone instead, if you prefer. If you perform them in the global zone, you must change the ZFS file system names. Create The only complicated action is the creation of a BE. In the Solaris 10 BZ, create a new "boot environment" - a ZFS clone. You can assign any name to the final portion of the clone's name, as long as it meets the requirements for a ZFS file system name. s10z# zfs snapshot rpool/ROOT/zbe-0@snap s10z# zfs clone -o mountpoint=/ -o canmount=noauto rpool/ROOT/zbe-0@snap rpool/ROOT/newBE cannot mount 'rpool/ROOT/newBE' on '/': directory is not empty filesystem successfully created, but not mounted You can safely ignore that message: we already know that / is not empty! We have merely told ZFS that the default mountpoint for the clone is the root directory. List the available BEs and active BE Because each BE is represented by a clone of the rpool/ROOT dataset, listing the BEs is as simple as listing the clones. s10z# zfs list -r rpool/ROOT NAME USED AVAIL REFER MOUNTPOINT rpool/ROOT 3.55G 42.9G 31K legacy rpool/ROOT/zbe-0 1K 42.9G 3.55G / rpool/ROOT/newBE 3.55G 42.9G 3.55G / The output shows that two BEs exist. Their names are "zbe-0" and "newBE". You can tell Solaris that one particular BE should be used when the zone next boots by using a ZFS property. Its name is com.oracle.zones.solaris10:activebe. The value of that property is the name of the clone that contains the BE that should be booted. s10z# zfs get com.oracle.zones.solaris10:activebe rpool/ROOT NAME PROPERTY VALUE SOURCE rpool/ROOT com.oracle.zones.solaris10:activebe zbe-0 local Change the active BE When you want to change the BE that will be booted next time, you can just change the activebe property on the rpool/ROOT dataset. s10z# zfs get com.oracle.zones.solaris10:activebe rpool/ROOT NAME PROPERTY VALUE SOURCE rpool/ROOT com.oracle.zones.solaris10:activebe zbe-0 local s10z# zfs set com.oracle.zones.solaris10:activebe=newBE rpool/ROOT s10z# zfs get com.oracle.zones.solaris10:activebe rpool/ROOT NAME PROPERTY VALUE SOURCE rpool/ROOT com.oracle.zones.solaris10:activebe newBE local s10z# shutdown -y -g0 -i6 After the zone has rebooted: s10z# zfs get com.oracle.zones.solaris10:activebe rpool/ROOT rpool/ROOT com.oracle.zones.solaris10:activebe newBE local s10z# zfs mount rpool/ROOT/newBE / rpool/export /export rpool/export/home /export/home rpool /rpool Mount the original BE to see that it's still there. s10z# zfs mount -o mountpoint=/mnt rpool/ROOT/zbe-0 s10z# ls /mnt Desktop export platform Documents export.backup.20130607T214951Z proc S10Flar home rpool TT_DB kernel sbin bin lib system boot lost+found tmp cdrom mnt usr dev net var etc opt Patch an inactive BE At this point, you can modify the original BE. If you would prefer to modify the new BE, you can restore the original value to the activebe property and reboot, and then mount the new BE to /mnt (or another empty directory) and modify it. Let's mount the original BE so we can modify it. (The first command is only needed if you haven't already mounted that BE.) s10z# zfs mount -o mountpoint=/mnt rpool/ROOT/zbe-0 s10z# patchadd -R /mnt -M /var/sadm/spool 104945-02 Note that the typical usage will be: Create a BE Mount the new (inactive) BE Use the package and patch tools to update the new BE Unmount the new BE Reboot Delete an inactive BE ZFS clones are children of their parent file systems. In order to destroy the parent, you must first "promote" the child. This reverses the parent-child relationship. (For more information on this, see the documentation.) The original rpool/ROOT file system is the parent of the clones that you create as BEs. In order to destroy an earlier BE that is that parent of other BEs, you must first promote one of the child BEs to be the ZFS parent. Only then can you destroy the original BE. Fortunately, this is easier to do than to explain: s10z# zfs promote rpool/ROOT/newBE s10z# zfs destroy rpool/ROOT/zbe-0 s10z# zfs list -r rpool/ROOT NAME USED AVAIL REFER MOUNTPOINT rpool/ROOT 3.56G 269G 31K legacy rpool/ROOT/newBE 3.56G 269G 3.55G / Documentation This feature is so new, it is not yet described in the Solaris 11 documentation. However, MOS note 1558773.1 offers some details. Conclusion With this new feature, you can add and patch packages to boot environments of a Solaris 10 Branded Zone. This ability improves the manageability of these zones, and makes their use more practical. It also means that you can use the existing P2V tools with earlier Solaris 10 updates, and modify the environments after they become Solaris 10 Branded Zones.

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