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  • Linq to Entities Joins

    - by Bob Avallone
    I have a question about joins when using Linq to Entities. According to the documentation the use on the join without a qualifier performs like a left outer join. However when I execute the code below, I get a count returned of zero. But if I comment out the three join lines I get a count of 1. That would indicate that the join are acting as inner join. I have two questions. One which is right inner or outer as the default? Second how do I do the other one i.e. inner or outer? The key words on inner and outer do not work. var nprs = (from n in db.FMCSA_NPR join u in db.FMCSA_USER on n.CREATED_BY equals u.ID join t in db.LKUP_NPR_TYPE on n.NPR_TYPE_ID equals t.ID join s in db.LKUP_AUDIT_STATUS on n.NPR_STATUS_ID equals s.ID where n.ROLE_ID == pRoleId && n.OWNER_ID == pOwnerId && n.NPR_STATUS_ID == pNPRStatusId && n.ACTIVE == pActive select n).ToList(); if (nprs.Count() == 0) return null;

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  • In Python, how to make sure database connection will always close before leaving a code block?

    - by Cawas
    I want to prevent database connection being open as much as possible, because this code will run on an intensive used server and people here already told me database connections should always be closed as soon as possible. def do_something_that_needs_database (): dbConnection = MySQLdb.connect(host=args['database_host'], user=args['database_user'], passwd=args['database_pass'], db=args['database_tabl'], cursorclass=MySQLdb.cursors.DictCursor) dbCursor = dbConnection.cursor() dbCursor.execute('SELECT COUNT(*) total FROM table') row = dbCursor.fetchone() if row['total'] == 0: print 'error: table have no records' dbCursor.execute('UPDATE table SET field="%s"', whatever_value) return None print 'table is ok' dbCursor.execute('UPDATE table SET field="%s"', another_value) # a lot more of workflow done here dbConnection.close() # even more stuff would come below I believe that leaves a database connection open when there is no row on the table, tho I'm still really not sure how it works. Anyway, maybe that is bad design in the sense that I could open and close a DB connection after each small block of execute. And sure, I could just add a close right before the return in that case... But how could I always properly close the DB without having to worry if I have that return, or a raise, or continue, or whatever in the middle? I'm thinking in something like a code block, similar to using try, like in the following suggestion, which obviously doesn't work: def do_something_that_needs_database (): dbConnection = MySQLdb.connect(host=args['database_host'], user=args['database_user'], passwd=args['database_pass'], db=args['database_tabl'], cursorclass=MySQLdb.cursors.DictCursor) try: dbCursor = dbConnection.cursor() dbCursor.execute('SELECT COUNT(*) total FROM table') row = dbCursor.fetchone() if row['total'] == 0: print 'error: table have no records' dbCursor.execute('UPDATE table SET field="%s"', whatever_value) return None print 'table is ok' dbCursor.execute('UPDATE table SET field="%s"', another_value) # again, that same lot of line codes done here except ExitingCodeBlock: closeDb(dbConnection) # still, that "even more stuff" from before would come below I don't think there is anything similar to ExitingCodeBlock for an exception, tho I know there is the try else, but I hope Python already have a similar feature... Or maybe someone can suggest me a paradigm move and tell me this is awful and highly advise me to never do that. Maybe this is just something to not worry about and let MySQLdb handle it, or is it?

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  • C# Linq to SQL connection string (newbie)

    - by Chris'o
    i am a new linq to sql learner and this is my very first attempt to create a data viewer program. The idea is simple, i'd like to create a software that is able to view content of a table in a database. That's it. I got an early problem here already and i have seen many tutes and articles online but I still cant fix the bug. Here is my code: static void Main(string[] args) { string cs = "Data Source=localhost;Initial Catalog=somedb;Integrated Security=SSPI;"; var db = new DataClasses1DataContext(cs); db.Connection.Open(); foreach (var b in db.Mapping.GetTables()) Console.WriteLine(b.TableName); Console.ReadKey(true); } When I tried to check db.connection.equals(null); it returns false, so i thought i have connected successfully to the database since there is no error at all. But the code above doesn't print anything out to the screen. I kind of lost and don't know what's going on here. Does anyone know what is going wrong here?

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  • uploading database file in assets not returning a record

    - by Alexander
    I have a problem with a database file not being read I have added the database file in assets called mydb but when i run my code it says its not being located. It is calling this toast Toast.makeText(this, "No contact found", Toast.LENGTH_LONG).show(); This is being called because no records are being returned. This is an example form Android Application Development book. public class DatabaseActivity extends Activity { /** Called when the activity is first created. */ TextView quest, response1, response2; @Override public void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.main); TextView quest = (TextView) findViewById(R.id.quest); try { String destPath = "/data/data/" + getPackageName() + "/databases/MyDB"; File f = new File(destPath); if (!f.exists()) { CopyDB( getBaseContext().getAssets().open("mydb"), new FileOutputStream(destPath)); } } catch (FileNotFoundException e) { e.printStackTrace(); } catch (IOException e) { e.printStackTrace(); } DBAdapter db = new DBAdapter(this); //---get a contact--- db.open(); Cursor c = db.getContact(2); if (c.moveToFirst()) DisplayContact(c); else Toast.makeText(this, "No contact found", Toast.LENGTH_LONG).show(); db.close(); } public void CopyDB(InputStream inputStream, OutputStream outputStream) throws IOException { //---copy 1K bytes at a time--- byte[] buffer = new byte[1024]; int length; while ((length = inputStream.read(buffer)) > 0) { outputStream.write(buffer, 0, length); } inputStream.close(); outputStream.close(); } public void DisplayContact(Cursor c) { quest.setText(String.valueOf(c.getString(1))); //quest.setText(String.valueOf("this is a text string")); } }

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  • Paging using Linq-To-Sql based on two parameters in asp.net mvc...

    - by Pandiya Chendur
    As two parameters i say currentPage and pagesize .....I thus far used sql server stored procedures and implemented paging like this, GO ALTER PROCEDURE [dbo].[GetMaterialsInView] -- Add the parameters for the stored procedure here @CurrentPage INT, @PageSize INT AS BEGIN -- SET NOCOUNT ON added to prevent extra result sets from -- interfering with SELECT statements. SET NOCOUNT ON; SELECT *,ROW_NUMBER() OVER (ORDER BY Id) AS Row FROM ( SELECT *,ROW_NUMBER() OVER (ORDER BY Id) AS Row FROM InTimePagingView ) AS InTimePages WHERE Row >= (@CurrentPage - 1) * @PageSize + 1 AND Row <= @CurrentPage*@PageSize SELECT COUNT(*) as TotalCount FROM InTimePagingView SELECT CEILING(COUNT(*) / CAST(@PageSize AS FLOAT)) NumberOfPages FROM InTimePagingView END Now i am using Linq-to-sql and i use this, public IQueryable<MaterialsObj> FindAllMaterials() { var materials = from m in db.Materials join Mt in db.MeasurementTypes on m.MeasurementTypeId equals Mt.Id where m.Is_Deleted == 0 select new MaterialsObj() { Id = Convert.ToInt64(m.Mat_id), Mat_Name = m.Mat_Name, Mes_Name = Mt.Name, }; return materials; } Now i want to return the records,TotalCount where i use Total count to generate pagenumbers..... Is this possible... Any suggestion... EDIT: Just found this... NorthWindDataContext db = new NorthWindDataContext(); var query = from c in db.Customers select c.CompanyName; //Assuming Page Number = 2, Page Size = 10 int iPageNum = 2; int iPageSize = 10; var PagedData = query.Skip((iPageNum - 1) * iPageSize).Take(iPageSize); ObjectDumper.Write(PagedData);

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  • LINQ to SQL - database relationships won't update after submit

    - by Quantic Programming
    I have a Database with the tables Users and Uploads. The important columns are: Users -> UserID Uploads -> UploadID, UserID The primary key in the relationship is Users -> UserID and the foreign key is Uploads -> UserID. In LINQ to SQL, I do the following operations: Retrieve files var upload = new Upload(); upload.UserID = user.UserID; upload.UploadID = XXX; db.Uploads.InsertOnSubmit(upload) db.SubmitChanges(); If I do that and rerun the application (and the db object is re-built, of course) - if do something like this: foreach(var upload in user.Uploads) I get all the uploads with that user's ID. (like added in the previous example) The problem is, that my application, after adding an upload an submitting changes, doesn't update the user.Uploads collection. i.e - I don't get the newly added uploads. The user object is stored in the Session object. At first, I though that the LINQ to SQL Framework doesn't update the reference of the object, therefore I should simply "reset" the user object from a new SQL request. I mean this: Session["user"] = db.Users.Where(u => u.UserID == user.UserID).SingleOrDefault(); (Where user is the previous user) But it didn't help. Please note: After rerunning the application, user.Uploads does have the new upload! Did anyone experience this type of problem, or is it normal behavior? I am a newbie to this framework. I would gladly take any advice. Thank you!

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  • How do I do a table join on two fields in my second table?

    - by Cannonade
    I have two tables: Messages - Amongst other things, has a to_id and a from_id field. People - Has a corresponding person_id I am trying to figure out how to do the following in a single linq query: Give me all messages that have been sent to and from person x (idself). I had a couple of cracks at this. Not quite right MsgPeople = (from p in db.people join m in db.messages on p.person_id equals m.from_id where (m.from_id == idself || m.to_id == idself) orderby p.name descending select p).Distinct(); This almost works, except I think it misses one case: "people who have never received a message, just sent one to me" How this works in my head So what I really need is something like: join m in db.messages on (p.people_id equals m.from_id or p.people_id equals m.to_id) Gets me a subset of the people I am after It seems you can't do that. I have tried a few other options, like doing two joins: MsgPeople = (from p in db.people join m in AllMessages on p.person_id equals m.from_id join m2 in AllMessages on p.person_id equals m2.to_id where (m2.from_id == idself || m.to_id == idself) orderby p.name descending select p).Distinct(); but this gives me a subset of the results I need, I guess something to do with the order the joins are resolved. My understanding of LINQ (and perhaps even database theory) is embarrassingly superficial and I look forward to having some light shed on my problem.

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  • WCF operationcontract with List type unavailable in (Silverlight) client

    - by Dave
    This is the first time I have tried returning a List of data to a Silverlight client, so I'm having trouble getting the client to recognize this operationcontract. All others are fine. I have a method on the server called ReadOwFileData that needs to return a List. ReadOwFileDataCompletedEventArgs shows up in the Object Browser in the client, but not ReadOwFileDataAsync. What I want is similar to the tutorial here. The Dictionary collection type on the client is set to System.Collections.Generic.List. I tried deleting and recreating the service reference. Web.Config on the server is using basicHttpBinding. Here is the operationcontract on the server: [OperationContract] public List<OwFileData> ReadOwFileData(string OrderID) { DataClasses1DataContext db = new DataClasses1DataContext(); var dFileData = (from p in db.OwFileDatas where p.OrderID == OrderID select p).ToList(); List<OwFileData> x = new List<OwFileData>(dFileData); return x; } Incidently, this works fine: [OperationContract] public Customer GetShippingAndContactInfo(string login, string ordernum) { DataClasses1DataContext db = new DataClasses1DataContext(); Customer dInfo = (from p in db.Customers where p.Login == login select p).Single(); return dInfo; } I would like to read this data in the client and place it into an object I created called ObservableCollection. But that obviously can't happen until the client can see the method on the server. I do not know if this is an acceptable start, but this is what is on the client so far. The ReadOwFileDataAsync object is null: void populatefilesReceivedDataSource(string OrderID) { ArtUpload.ServiceReference1.UploadServiceClient client = new ArtUpload.ServiceReference1.UploadServiceClient(); var myList = client.ReadOwFileDataAsync(OrderID); // can I just itterate thru the list instead of 'binding' }

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  • Project Naming Convention Feedback Please

    - by Sam Striano
    I am creating a ASP.NET MVC 3 application using Entity Framework 4. I am using the Repository/Service Pattern and was looking for feedback. I currently have the following: MVC Application (GTG.dll) GTG GTG.Controllers GTG.ViewModels Business POCO's (GTG.Business.dll) This contains all business objects (Customer, Order, Invoice, etc...) EF Model/Repositories (GTG.Data.dll) GTG.Business (GTG.Context.tt) I used the Entity POCO Generator Templates. GTG.Data.Repositories Service Layer (GTG.Data.Services.dll) GTG.Data.Services - Contains all of the service objects, one per aggregate root. The following is a little sample code: Controller Namespace Controllers Public Class HomeController Inherits System.Web.Mvc.Controller Function Index() As ActionResult Return View(New Models.HomeViewModel) End Function End Class End Namespace Model Namespace Models Public Class HomeViewModel Private _Service As CustomerService Public Property Customers As List(Of Customer) Public Sub New() _Service = New CustomerService _Customers = _Service.GetCustomersByBusinessName("Striano") End Sub End Class End Namespace Service Public Class CustomerService Private _Repository As ICustomerRepository Public Sub New() _Repository = New CustomerRepository End Sub Function GetCustomerByID(ByVal ID As Integer) As Customer Return _Repository.GetByID(ID) End Function Function GetCustomersByBusinessName(ByVal Name As String) As List(Of Customer) Return _Repository.Query(Function(x) x.CompanyName.StartsWith(Name)).ToList End Function End Class Repository Namespace Data.Repositories Public Class CustomerRepository Implements ICustomerRepository Public Sub Add(ByVal Entity As Business.Customer) Implements IRepository(Of Business.Customer).Add End Sub Public Sub Delete(ByVal Entity As Business.Customer) Implements IRepository(Of Business.Customer).Delete End Sub Public Function GetByID(ByVal ID As Integer) As Business.Customer Implements IRepository(Of Business.Customer).GetByID Using db As New GTGContainer Return db.Customers.FirstOrDefault(Function(x) x.ID = ID) End Using End Function Public Function Query(ByVal Predicate As System.Linq.Expressions.Expression(Of System.Func(Of Business.Customer, Boolean))) As System.Linq.IQueryable(Of Business.Customer) Implements IRepository(Of Business.Customer).Query Using db As New GTGContainer Return db.Customers.Where(Predicate) End Using End Function Public Sub Save(ByVal Entity As Business.Customer) Implements IRepository(Of Business.Customer).Save End Sub End Class End Namespace

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  • how to print data in a table from mysql

    - by robertdd
    hello, i want to extract the last eight entries from my database and print them into a 2 columns table!like this: |1|2| |3|4| |5|6| |7|8| is that possible? this is my code: $db = new Database(DB_SERVER, DB_USER, DB_PASS, DB_DATABASE); $db->connect(); $sql = "SELECT ID, movieno FROM movies ORDER BY ID DESC LIMIT 8 "; $rows = $db->query($sql); print '<table width="307" border="0" cellspacing="5" cellpadding="4">'; while ($record = $db->fetch_array($rows)) { $vidaidi = $record['movieno']; print <<<END <tr> <td> <a href="http://www.youtube.com/watch?v=$vidaidi" target="_blank"> <img src="http://img.youtube.com/vi/$vidaidi/1.jpg" width="123" height="80"></a> </td> </tr> END; } print '</table>';

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  • Weird Rails database errors

    - by Jason Swett
    I've had some trouble getting my Rails app to connect to PostgreSQL so I decided to just say screw it and use SQLite for now. (I'm using the tutorial here: http://guides.rubyonrails.org/getting_started.html) I started a BRAND NEW, fresh Rails app from this tutorial. When I visit my app in the browser after deleting public/index.html, I get this the first time: Please install the pg adapter: `gem install activerecord-pg-adapter` (no such file to load -- active_record/connection_adapters/pg_adapter) That's odd to me because I'm not mentioning PostgreSQL anywhere. Here's my databases.yml: # SQLite version 3.x # gem install sqlite3-ruby (not necessary on OS X Leopard) development: adapter: sqlite3 database: db/development.sqlite3 pool: 5 timeout: 5000 # Warning: The database defined as "test" will be erased and # re-generated from your development database when you run "rake". # Do not set this db to the same as development or production. test: adapter: sqlite3 database: db/test.sqlite3 pool: 5 timeout: 5000 production: adapter: sqlite3 database: db/production.sqlite3 pool: 5 timeout: 5000 To make things more confusing, I only get that "pg adapter" error on the first load. For every subsequent page request, I get this error: ActiveRecord::ConnectionNotEstablished So even though I removed all mention of PostgreSQL, I'm still getting errors. What could be going on?

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  • Null reference but it's not?

    - by Clint Davis
    This is related to my previous question but it is a different problem. I have two classes: Server and Database. Public Class Server Private _name As String Public Property Name() As String Get Return _name End Get Set(ByVal value As String) _name = value End Set End Property Private _databases As List(Of Database) Public Property Databases() As List(Of Database) Get Return _databases End Get Set(ByVal value As List(Of Database)) _databases = value End Set End Property Public Sub LoadTables() Dim db As New Database(Me) db.Name = "test" Databases.Add(db) End Sub End Class Public Class Database Private _server As Server Private _name As String Public Property Name() As String Get Return _name End Get Set(ByVal value As String) _name = value End Set End Property Public Property Server() As Server Get Return _server End Get Set(ByVal value As Server) _server = value End Set End Property Public Sub New(ByVal ser As Server) Server = ser End Sub End Class Fairly simple. I use like this: Dim s As New Server s.Name = "Test" s.LoadTables() The problem is in the LoadTables in the Server class. When it hits Databases.Add(db) it gives me a NullReference error (Object reference not set). I don't understand how it is getting that, all the objects are set. Any ideas? Thanks.

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  • Facebook / Offline Permission - Trying to perform an action on a set of offline users.

    - by blueigloo
    Hi there, We're building an app which in part of its functionality tries to capture the number of likes associated to a particular video owned by a user. Users of the app are asked for extended off-line access and we capture the key for each user: The format is like this: 2.hg2QQuYeftuHx1R84J1oGg__.XXXX.1272394800-nnnnnn Each user has their offline / infinite key stored in a table in a DB. The object_id which we're interested in is also stored in the DB. At a later stage (offline) we try to run a batch job which reads the number of likes for each user's video. (See attached code) For some reason however, after the first iteration of the loop - which yields the likes correctly, we get a failure with the oh so familiar message: "Session key is invalid or no longer valid" Any insight would be most appreciated. Thanks, B List<DVideo> videoList = db.SelectVideos(); foreach (DVideo video in videoList) { long userId = 0; ConnectSession fbSession = new ConnectSession(APPLICATION_KEY, SECRET_KEY); //session key is attached to the video object for now. fbSession.SessionKey = video.UserSessionKey; fbSession.SessionExpires = false; string fbuid =video.FBUID; long.TryParse(fbuid, out userId); if (userId > 0) { fbSession.UserId = userId; fbSession.Login(); Api fbApi = new Facebook.Rest.Api(fbSession); string xmlQueryResult = fbApi.Fql.Query("SELECT user_id FROM like WHERE object_id = " + video.FBVID); XmlDocument xmlDoc = new XmlDocument(); xmlDoc.Load(new StringReader(xmlQueryResult)); int likesCount = xmlDoc.GetElementsByTagName("user_id").Count; //Write entry in VideoWallLikes if (likesCount > 0) { db.CountWallLikes(video.ID, likesCount); } fbSession.Logout(); } fbSession = null; }

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  • PHP - Calling function inside another class -> function

    - by Kolind
    I'm trying to do this: class database { function editProvider($post) { $sql = "UPDATE tbl SET "; foreach($post as $key => $val): if($key != "providerId") { $val = formValidate($val); $sqlE[] = "`$key`='$val'"; } endforeach; $sqlE = implode(",", $sqlE); $where = ' WHERE `id` = \''.$post['id'].'\''; $sql = $sql . $sqlE . $where; $query = mysql_query($sql); if($query){ return true; } } // }//end class And then use this function * INSIDE of another class *: function formValidate($string){ $string = trim($string); $string = mysql_real_escape_string($string); return $string; } // .. on $val. Why doesn't this work? if I write in a field of the form, it's not escaping anything at all. How can that be? * UPDATE * handler.php: if(isset($_GET['do'])){ if($_GET['do'] == "addLogin") { $addLogin = $db->addLogin($_POST); } if($_GET['do'] == "addProvider") { $addProvider = $db->addProvider($_POST); } if($_GET['do'] == "editProfile") { $editProfile = $db->editProfile($_POST); } if($_GET['do'] == "editProvider") { $editProvider = $db->editProvider($_POST); } } //end if isset get do ** The editProvider function works fine except for this :-) **

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  • Pickled my dictionary from ZODB but i got a less in size one?

    - by Someone Someoneelse
    I use ZODB and i want to copy my 'database_1.fs' file to another 'database_2.fs', so I opened the root dictionary of that 'database_1.fs' and I (pickle.dump) it in a text file. Then I (pickle.load) it in a dictionary-variable, in the end I update the root dictionary of the other 'database_2.fs' with the dictionary-variable. It works, but I wonder why the size of the 'database_1.fs' not equal to the size of the other 'database_2.fs'. They are still copies of each other. def openstorage(store): #opens the database data={} data['file']=filestorage data['db']=DB(data['file']) data['conn']=data['db'].open() data['root']=data['conn'].root() return data def getroot(dicty): return dicty['root'] def closestorage(dicty): #close the database after Saving transaction.commit() dicty['file'].close() dicty['db'].close() dicty['conn'].close() transaction.get().abort() then that's what i do:- import pickle loc1='G:\\database_1.fs' op1=openstorage(loc1) root1=getroot(op1) loc2='G:database_2.fs' op2=openstorage(loc2) root2=getroot(op2) >>> len(root1) 215 >>> len(root2) 0 pickle.dump( root1, open( "save.txt", "wb" )) item=pickle.load( open( "save.txt", "rb" ) ) #now item is a dictionary root2.update(item) closestorage(op1) closestorage(op2) #after I open both of the databases #I get the same keys in both databases #But `database_2.fs` is smaller that `database_2.fs` in size I mean. >>> len(root2)==len(root1)==215 #they have the same keys True Note: (1) there are persistent dictionaries and lists in the original database_1.fs (2) both of them have the same length and the same indexes.

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  • Create ImageButton programatically depending on local database records

    - by user2507920
    As i described in title, i have a local db in sqlite. I want to create ImageButton parametrically. How many times is local database loop executing? Please see code below : RelativeLayout outerRelativeLayout = (RelativeLayout)findViewById(R.id.relativeLayout2_making_dynamically); db.open(); Cursor c = db.getAllLocal_Job_Data(); if(c!=null){ if(c.moveToFirst()){ do { RelativeLayout innerRelativeLayout = new RelativeLayout(CalendarActivity.this); innerRelativeLayout.setGravity(Gravity.CENTER); ImageButton imgBtn = new ImageButton(CalendarActivity.this); imgBtn.setBackgroundResource(R.drawable.color_001); RelativeLayout.LayoutParams imageViewParams = new RelativeLayout.LayoutParams(ViewGroup.LayoutParams.WRAP_CONTENT, ViewGroup.LayoutParams.WRAP_CONTENT); imgBtn.setLayoutParams(imageViewParams); // Adding the textView to the inner RelativeLayout as a child innerRelativeLayout.addView(imgBtn, new RelativeLayout.LayoutParams( ViewGroup.LayoutParams.WRAP_CONTENT, ViewGroup.LayoutParams.WRAP_CONTENT)); outerRelativeLayout.addView(innerRelativeLayout, new RelativeLayout.LayoutParams(ViewGroup.LayoutParams.WRAP_CONTENT, ViewGroup.LayoutParams.WRAP_CONTENT)); } while (c.moveToNext()); } } db.close(); But when i run the project, i can see only one button created there. I think there are many buttons but here image button is creating on last created image button. I think i should use android:layout_toRightOf with previous created button but i cant find how to place it here. I have tried some ideas but it did not change any thing. So please anybody has any idea to solve my problem then please share it with me.

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  • How to initialize list with parent child relation

    - by user2917702
    Let's say I have the following classes. public class Parent { public string name; IList<Children> children; } public class Child { public string parentName; public int age; } As it is understandable, each parent can have multiple children, and we can have multiple parents. What is the best way to initialize these classes? Is it better to get all of the parents, and all of the children from database then use LINQ? IList<Parent> parents = GetParents()//assume this gets parents from db IList<Child> children = GetChildren() //assume this gets children from db foreach(Parent parent in parents) { parent.children = children.Where(x=>x.parentName==parent.name).ToList(); } or get all of the parents and iterate through each parent to query database by parentName to get children information? Due to requirement that I have, I cannot use datatable or dataset; I can only use datareader. IList<Parent> parents = GetParents()//assume this gets parents from db foreach(Parent parent in parents) { parent.children = GetChildrenByParentName();//assume this gets parents from db by parentName } Thank you

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  • How to get a specific attribute from an object list?

    - by anarhikos
    I've an array keeping a list of Group objects. I want to set this list to the DropDownChoice component. However I want to show the end user only the name attribute of Group objects, and then get the selected values' id attribute to add database. What to do? private List<Group> groupTypes; DatabaseApp db = new DatabaseApp(); groupTypes = db.getGroups(); groupDropDownChoice = new DropDownChoice("type", groupTypes); ... ... addUserForm.add(new Button("submit"){ @Override public void onSubmit(){ Group group = (Group) groupDropDownChoice.getModelObject(); ... ... db.addUser(group.getId(), den, name, login, email, password1); DatabaseApp.java public List<Group> getGroups() throws SQLException{ List<Group> groups = new ArrayList<Group>(); try { String query = "SELECT * FROM [GROUP]"; Statement statement = db.createStatement(); ResultSet result = statement.executeQuery(query); while(result.next()){ int id = result.getInt("ID"); String name = result.getString("NAME"); groups.add(new Group(id, name)); } result.close(); } catch (SQLException ex) { throw new SQLException(ex.getMessage()); } return groups; }

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  • codeigniter and JSON

    - by ole
    Hello all i having a problem that it only get 1 value in my database and its my title and i want to show content and username from the same table to. here is my JSON kode <script type="text/javascript"> $.getJSON( 'ajax/forumThreads', function(data) { alert(data[0].overskrift); alert(data[0].indhold); } ); </script> my controller <?php class ajax extends Controller { function forumThreads() { $this->load->model('ajax_model'); $data['forum_list'] = $this->ajax_model->forumList(); if ($data['forum_list'] !== false) { echo json_encode($data['forum_list']); } } } my model fle <?php class ajax_model extends Model { function forumList() { $this->db->select('overskrift', 'indhold', 'brugernavn', 'dato'); $this->db->order_by('id', 'desc'); $this->db->limit(5); $forum_list = $this->db->get('forum_traad'); if($forum_list->num_rows() > 0) { return $forum_list->result_array(); } else { return false; } } }

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  • PHP function to handle most database queries has a problem with results. I am getting the right numb

    - by asdasds
    Here is my little function. It does not handle the results correctly. I do get all the rows that I want, but all the rows of the $results array contain the exact same values. So i make 2 arrays, a temporary array to hold the values after each fetch, and another array to hold all the temporary arrays. First i take the temp array and map its keys to the column names. Then i give it to bind_result, and call fetch() and use it like I would any other result value. Could this be because I re-use the $results array? numresults is the number of values you are taking from each row. if 0, you are not getting any results back. function db_query($db, $query, $params = NULL, $numresults = 0) { if($stmt = $db -> prepare($query)) { if($params != NULL) { call_user_func_array(array($stmt, 'bind_param'), $params); } if(!$stmt -> execute()) { //echo 'exec error:',$db->error; return false; } if($numresults > 0) { $results = array(); $tmpresult = array(); $meta = $stmt->result_metadata(); while ($columnName = $meta->fetch_field()) $tmpresult[] = &$results[$columnName->name]; call_user_func_array(array($stmt, 'bind_result'), $tmpresult); $meta->close(); $results = array(); while($stmt -> fetch()) $results[] = $tmpresult; } $stmt -> close(); } else { //echo 'prepare error: ',$db->error; return false; } if($numresults == 0) return true; return $results; }

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  • Is it best to make fewer calls to the database and output the results in an array?

    - by Jonathan
    I'm trying to create a more succinct way to make hundreds of db calls. Instead of writing the whole query out every time I wanted to output a single field, I tried to port the code into a class that did all the query work. This is the class I have so far: class Listing { /* Connect to the database */ private $mysql; function __construct() { $this->mysql = new mysqli(DB_LOC, DB_USER, DB_PASS, DB) or die('Could not connect'); } function getListingInfo($l_id = "", $category = "", $subcategory = "", $username = "", $status = "active") { $condition = "`status` = '$status'"; if (!empty($l_id)) $condition .= "AND `L_ID` = '$l_id'"; if (!empty($category)) $condition .= "AND `category` = '$category'"; if (!empty($subcategory)) $condition .= "AND `subcategory` = '$subcategory'"; if (!empty($username)) $condition .= "AND `username` = '$username'"; $result = $this->mysql->query("SELECT * FROM listing WHERE $condition") or die('Error fetching values'); $info = $result->fetch_object() or die('Could not create object'); return $info; } } This makes it easy to access any info I want from a single row. $listing = new Listing; echo $listing->getListingInfo('','Books')->title; This outputs the title of the first listing in the category "Books". But if I want to output the price of that listing, I have to make another call to getListingInfo(). This makes another query on the db and again returns only the first row. This is much more succinct than writing the entire query each time, but I feel like I may be calling the db too often. Is there a better way to output the data from my class and still be succinct in accessing it (maybe outputting all the rows to an array and returning the array)? If yes, How?

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  • find the difference between two very large list

    - by user157195
    I have two large list(could be a hundred million items), the source of each list can be either from a database table or a flat file. both lists are of comparable sizes, both unsorted. I need to find the difference between them. so I have 3 scenarios: 1. List1 is a database table(assume each row simply have one item(key) that is a string), List2 is a large file. 2. Both lists are from 2 db tables. 3. both lists are from two files. in case 2, I plan to use: select a.item from MyTable a where a.item not in (select b.item form MyTable b) this clearly is inefficient, is there a better way? Another approach is: I plan to sort each list, and then walk down both of them to find the diff. If the list is from a file, I have to read it into a db table first, then use db sorting to output the list. Is the run time complexity still O(nlogn) in db sorting? either approach is a pain and seems would be very slow when the list involved has hundreds of millions of items. any suggestions?

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  • Java EE 6 and NoSQL/MongoDB on GlassFish using JPA and EclipseLink 2.4 (TOTD #175)

    - by arungupta
    TOTD #166 explained how to use MongoDB in your Java EE 6 applications. The code in that tip used the APIs exposed by the MongoDB Java driver and so requires you to learn a new API. However if you are building Java EE 6 applications then you are already familiar with Java Persistence API (JPA). Eclipse Link 2.4, scheduled to release as part of Eclipse Juno, provides support for NoSQL databases by mapping a JPA entity to a document. Their wiki provides complete explanation of how the mapping is done. This Tip Of The Day (TOTD) will show how you can leverage that support in your Java EE 6 applications deployed on GlassFish 3.1.2. Before we dig into the code, here are the key concepts ... A POJO is mapped to a NoSQL data source using @NoSQL or <no-sql> element in "persistence.xml". A subset of JPQL and Criteria query are supported, based upon the underlying data store Connection properties are defined in "persistence.xml" Now, lets lets take a look at the code ... Download the latest EclipseLink 2.4 Nightly Bundle. There is a Installer, Source, and Bundle - make sure to download the Bundle link (20120410) and unzip. Download GlassFish 3.1.2 zip and unzip. Install the Eclipse Link 2.4 JARs in GlassFish Remove the following JARs from "glassfish/modules": org.eclipse.persistence.antlr.jar org.eclipse.persistence.asm.jar org.eclipse.persistence.core.jar org.eclipse.persistence.jpa.jar org.eclipse.persistence.jpa.modelgen.jar org.eclipse.persistence.moxy.jar org.eclipse.persistence.oracle.jar Add the following JARs from Eclipse Link 2.4 nightly build to "glassfish/modules": org.eclipse.persistence.antlr_3.2.0.v201107111232.jar org.eclipse.persistence.asm_3.3.1.v201107111215.jar org.eclipse.persistence.core.jpql_2.4.0.v20120407-r11132.jar org.eclipse.persistence.core_2.4.0.v20120407-r11132.jar org.eclipse.persistence.jpa.jpql_2.0.0.v20120407-r11132.jar org.eclipse.persistence.jpa.modelgen_2.4.0.v20120407-r11132.jar org.eclipse.persistence.jpa_2.4.0.v20120407-r11132.jar org.eclipse.persistence.moxy_2.4.0.v20120407-r11132.jar org.eclipse.persistence.nosql_2.4.0.v20120407-r11132.jar org.eclipse.persistence.oracle_2.4.0.v20120407-r11132.jar Start MongoDB Download latest MongoDB from here (2.0.4 as of this writing). Create the default data directory for MongoDB as: sudo mkdir -p /data/db/sudo chown `id -u` /data/db Refer to Quickstart for more details. Start MongoDB as: arungup-mac:mongodb-osx-x86_64-2.0.4 <arungup> ->./bin/mongod./bin/mongod --help for help and startup optionsMon Apr  9 12:56:02 [initandlisten] MongoDB starting : pid=3124 port=27017 dbpath=/data/db/ 64-bit host=arungup-mac.localMon Apr  9 12:56:02 [initandlisten] db version v2.0.4, pdfile version 4.5Mon Apr  9 12:56:02 [initandlisten] git version: 329f3c47fe8136c03392c8f0e548506cb21f8ebfMon Apr  9 12:56:02 [initandlisten] build info: Darwin erh2.10gen.cc 9.8.0 Darwin Kernel Version 9.8.0: Wed Jul 15 16:55:01 PDT 2009; root:xnu-1228.15.4~1/RELEASE_I386 i386 BOOST_LIB_VERSION=1_40Mon Apr  9 12:56:02 [initandlisten] options: {}Mon Apr  9 12:56:02 [initandlisten] journal dir=/data/db/journalMon Apr  9 12:56:02 [initandlisten] recover : no journal files present, no recovery neededMon Apr  9 12:56:02 [websvr] admin web console waiting for connections on port 28017Mon Apr  9 12:56:02 [initandlisten] waiting for connections on port 27017 Check out the JPA/NoSQL sample from SVN repository. The complete source code built in this TOTD can be downloaded here. Create Java EE 6 web app Create a Java EE 6 Maven web app as: mvn archetype:generate -DarchetypeGroupId=org.codehaus.mojo.archetypes -DarchetypeArtifactId=webapp-javaee6 -DgroupId=model -DartifactId=javaee-nosql -DarchetypeVersion=1.5 -DinteractiveMode=false Copy the model files from the checked out workspace to the generated project as: cd javaee-nosqlcp -r ~/code/workspaces/org.eclipse.persistence.example.jpa.nosql.mongo/src/model src/main/java Copy "persistence.xml" mkdir src/main/resources cp -r ~/code/workspaces/org.eclipse.persistence.example.jpa.nosql.mongo/src/META-INF ./src/main/resources Add the following dependencies: <dependency> <groupId>org.eclipse.persistence</groupId> <artifactId>org.eclipse.persistence.jpa</artifactId> <version>2.4.0-SNAPSHOT</version> <scope>provided</scope></dependency><dependency> <groupId>org.eclipse.persistence</groupId> <artifactId>org.eclipse.persistence.nosql</artifactId> <version>2.4.0-SNAPSHOT</version></dependency><dependency> <groupId>org.mongodb</groupId> <artifactId>mongo-java-driver</artifactId> <version>2.7.3</version></dependency> The first one is for the EclipseLink latest APIs, the second one is for EclipseLink/NoSQL support, and the last one is the MongoDB Java driver. And the following repository: <repositories> <repository> <id>EclipseLink Repo</id> <url>http://www.eclipse.org/downloads/download.php?r=1&amp;nf=1&amp;file=/rt/eclipselink/maven.repo</url> <snapshots> <enabled>true</enabled> </snapshots> </repository>  </repositories> Copy the "Test.java" to the generated project: mkdir src/main/java/examplecp -r ~/code/workspaces/org.eclipse.persistence.example.jpa.nosql.mongo/src/example/Test.java ./src/main/java/example/ This file contains the source code to CRUD the JPA entity to MongoDB. This sample is explained in detail on EclipseLink wiki. Create a new Servlet in "example" directory as: package example;import java.io.IOException;import java.io.PrintWriter;import javax.servlet.ServletException;import javax.servlet.annotation.WebServlet;import javax.servlet.http.HttpServlet;import javax.servlet.http.HttpServletRequest;import javax.servlet.http.HttpServletResponse;/** * @author Arun Gupta */@WebServlet(name = "TestServlet", urlPatterns = {"/TestServlet"})public class TestServlet extends HttpServlet { protected void processRequest(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { response.setContentType("text/html;charset=UTF-8"); PrintWriter out = response.getWriter(); try { out.println("<html>"); out.println("<head>"); out.println("<title>Servlet TestServlet</title>"); out.println("</head>"); out.println("<body>"); out.println("<h1>Servlet TestServlet at " + request.getContextPath() + "</h1>"); try { Test.main(null); } catch (Exception ex) { ex.printStackTrace(); } out.println("</body>"); out.println("</html>"); } finally { out.close(); } } @Override protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { processRequest(request, response); } @Override protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { processRequest(request, response); }} Build the project and deploy it as: mvn clean packageglassfish3/bin/asadmin deploy --force=true target/javaee-nosql-1.0-SNAPSHOT.war Accessing http://localhost:8080/javaee-nosql/TestServlet shows the following messages in the server.log: connecting(EISLogin( platform=> MongoPlatform user name=> "" MongoConnectionSpec())) . . .Connected: User: Database: 2.7  Version: 2.7 . . .Executing MappedInteraction() spec => null properties => {mongo.collection=CUSTOMER, mongo.operation=INSERT} input => [DatabaseRecord( CUSTOMER._id => 4F848E2BDA0670307E2A8FA4 CUSTOMER.NAME => AMCE)]. . .Data access result: [{TOTALCOST=757.0, ORDERLINES=[{DESCRIPTION=table, LINENUMBER=1, COST=300.0}, {DESCRIPTION=balls, LINENUMBER=2, COST=5.0}, {DESCRIPTION=rackets, LINENUMBER=3, COST=15.0}, {DESCRIPTION=net, LINENUMBER=4, COST=2.0}, {DESCRIPTION=shipping, LINENUMBER=5, COST=80.0}, {DESCRIPTION=handling, LINENUMBER=6, COST=55.0},{DESCRIPTION=tax, LINENUMBER=7, COST=300.0}], SHIPPINGADDRESS=[{POSTALCODE=L5J1H7, PROVINCE=ON, COUNTRY=Canada, CITY=Ottawa,STREET=17 Jane St.}], VERSION=2, _id=4F848E2BDA0670307E2A8FA8,DESCRIPTION=Pingpong table, CUSTOMER__id=4F848E2BDA0670307E2A8FA7, BILLINGADDRESS=[{POSTALCODE=L5J1H8, PROVINCE=ON, COUNTRY=Canada, CITY=Ottawa, STREET=7 Bank St.}]}] You'll not see any output in the browser, just the output in the console. But the code can be easily modified to do so. Once again, the complete Maven project can be downloaded here. Do you want to try accessing relational and non-relational (aka NoSQL) databases in the same PU ?

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  • Improved Performance on PeopleSoft Combined Benchmark using SPARC T4-4

    - by Brian
    Oracle's SPARC T4-4 server running Oracle's PeopleSoft HCM 9.1 combined online and batch benchmark achieved a world record 18,000 concurrent users experiencing subsecond response time while executing a PeopleSoft Payroll batch job of 500,000 employees in 32.4 minutes. This result was obtained with a SPARC T4-4 server running Oracle Database 11g Release 2, a SPARC T4-4 server running PeopleSoft HCM 9.1 application server and a SPARC T4-2 server running Oracle WebLogic Server in the web tier. The SPARC T4-4 server running the application tier used Oracle Solaris Zones which provide a flexible, scalable and manageable virtualization environment. The average CPU utilization on the SPARC T4-2 server in the web tier was 17%, on the SPARC T4-4 server in the application tier it was 59%, and on the SPARC T4-4 server in the database tier was 47% (online and batch) leaving significant headroom for additional processing across the three tiers. The SPARC T4-4 server used for the database tier hosted Oracle Database 11g Release 2 using Oracle Automatic Storage Management (ASM) for database files management with I/O performance equivalent to raw devices. Performance Landscape Results are presented for the PeopleSoft HRMS Self-Service and Payroll combined benchmark. The new result with 128 streams shows significant improvement in the payroll batch processing time with little impact on the self-service component response time. PeopleSoft HRMS Self-Service and Payroll Benchmark Systems Users Ave Response Search (sec) Ave Response Save (sec) Batch Time (min) Streams SPARC T4-2 (web) SPARC T4-4 (app) SPARC T4-4 (db) 18,000 0.988 0.539 32.4 128 SPARC T4-2 (web) SPARC T4-4 (app) SPARC T4-4 (db) 18,000 0.944 0.503 43.3 64 The following results are for the PeopleSoft HRMS Self-Service benchmark that was previous run. The results are not directly comparable with the combined results because they do not include the payroll component. PeopleSoft HRMS Self-Service 9.1 Benchmark Systems Users Ave Response Search (sec) Ave Response Save (sec) Batch Time (min) Streams SPARC T4-2 (web) SPARC T4-4 (app) 2x SPARC T4-2 (db) 18,000 1.048 0.742 N/A N/A The following results are for the PeopleSoft Payroll benchmark that was previous run. The results are not directly comparable with the combined results because they do not include the self-service component. PeopleSoft Payroll (N.A.) 9.1 - 500K Employees (7 Million SQL PayCalc, Unicode) Systems Users Ave Response Search (sec) Ave Response Save (sec) Batch Time (min) Streams SPARC T4-4 (db) N/A N/A N/A 30.84 96 Configuration Summary Application Configuration: 1 x SPARC T4-4 server with 4 x SPARC T4 processors, 3.0 GHz 512 GB memory Oracle Solaris 11 11/11 PeopleTools 8.52 PeopleSoft HCM 9.1 Oracle Tuxedo, Version 10.3.0.0, 64-bit, Patch Level 031 Java Platform, Standard Edition Development Kit 6 Update 32 Database Configuration: 1 x SPARC T4-4 server with 4 x SPARC T4 processors, 3.0 GHz 256 GB memory Oracle Solaris 11 11/11 Oracle Database 11g Release 2 PeopleTools 8.52 Oracle Tuxedo, Version 10.3.0.0, 64-bit, Patch Level 031 Micro Focus Server Express (COBOL v 5.1.00) Web Tier Configuration: 1 x SPARC T4-2 server with 2 x SPARC T4 processors, 2.85 GHz 256 GB memory Oracle Solaris 11 11/11 PeopleTools 8.52 Oracle WebLogic Server 10.3.4 Java Platform, Standard Edition Development Kit 6 Update 32 Storage Configuration: 1 x Sun Server X2-4 as a COMSTAR head for data 4 x Intel Xeon X7550, 2.0 GHz 128 GB memory 1 x Sun Storage F5100 Flash Array (80 flash modules) 1 x Sun Storage F5100 Flash Array (40 flash modules) 1 x Sun Fire X4275 as a COMSTAR head for redo logs 12 x 2 TB SAS disks with Niwot Raid controller Benchmark Description This benchmark combines PeopleSoft HCM 9.1 HR Self Service online and PeopleSoft Payroll batch workloads to run on a unified database deployed on Oracle Database 11g Release 2. The PeopleSoft HRSS benchmark kit is a Oracle standard benchmark kit run by all platform vendors to measure the performance. It's an OLTP benchmark where DB SQLs are moderately complex. The results are certified by Oracle and a white paper is published. PeopleSoft HR SS defines a business transaction as a series of HTML pages that guide a user through a particular scenario. Users are defined as corporate Employees, Managers and HR administrators. The benchmark consist of 14 scenarios which emulate users performing typical HCM transactions such as viewing paycheck, promoting and hiring employees, updating employee profile and other typical HCM application transactions. All these transactions are well-defined in the PeopleSoft HR Self-Service 9.1 benchmark kit. This benchmark metric is the weighted average response search/save time for all the transactions. The PeopleSoft 9.1 Payroll (North America) benchmark demonstrates system performance for a range of processing volumes in a specific configuration. This workload represents large batch runs typical of a ERP environment during a mass update. The benchmark measures five application business process run times for a database representing large organization. They are Paysheet Creation, Payroll Calculation, Payroll Confirmation, Print Advice forms, and Create Direct Deposit File. The benchmark metric is the cumulative elapsed time taken to complete the Paysheet Creation, Payroll Calculation and Payroll Confirmation business application processes. The benchmark metrics are taken for each respective benchmark while running simultaneously on the same database back-end. Specifically, the payroll batch processes are started when the online workload reaches steady state (the maximum number of online users) and overlap with online transactions for the duration of the steady state. Key Points and Best Practices Two PeopleSoft Domain sets with 200 application servers each on a SPARC T4-4 server were hosted in 2 separate Oracle Solaris Zones to demonstrate consolidation of multiple application servers, ease of administration and performance tuning. Each Oracle Solaris Zone was bound to a separate processor set, each containing 15 cores (total 120 threads). The default set (1 core from first and third processor socket, total 16 threads) was used for network and disk interrupt handling. This was done to improve performance by reducing memory access latency by using the physical memory closest to the processors and offload I/O interrupt handling to default set threads, freeing up cpu resources for Application Servers threads and balancing application workload across 240 threads. A total of 128 PeopleSoft streams server processes where used on the database node to complete payroll batch job of 500,000 employees in 32.4 minutes. See Also Oracle PeopleSoft Benchmark White Papers oracle.com SPARC T4-2 Server oracle.com OTN SPARC T4-4 Server oracle.com OTN PeopleSoft Enterprise Human Capital Managementoracle.com OTN PeopleSoft Enterprise Human Capital Management (Payroll) oracle.com OTN Oracle Solaris oracle.com OTN Oracle Database 11g Release 2 oracle.com OTN Disclosure Statement Copyright 2012, Oracle and/or its affiliates. All rights reserved. Oracle and Java are registered trademarks of Oracle and/or its affiliates. Other names may be trademarks of their respective owners. Results as of 8 November 2012.

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  • The SPARC SuperCluster

    - by Karoly Vegh
    Oracle has been providing a lead in the Engineered Systems business for quite a while now, in accordance with the motto "Hardware and Software Engineered to Work Together." Indeed it is hard to find a better definition of these systems.  Allow me to summarize the idea. It is:  Build a compute platform optimized to run your technologies Develop application aware, intelligently caching storage components Take an impressively fast network technology interconnecting it with the compute nodes Tune the application to scale with the nodes to yet unseen performance Reduce the amount of data moving via compression Provide this all in a pre-integrated single product with a single-pane management interface All these ideas have been around in IT for quite some time now. The real Oracle advantage is adding the last one to put these all together. Oracle has built quite a portfolio of Engineered Systems, to run its technologies - and run those like they never ran before. In this post I'll focus on one of them that serves as a consolidation demigod, a multi-purpose engineered system.  As you probably have guessed, I am talking about the SPARC SuperCluster. It has many great features inherited from its predecessors, and it adds several new ones. Allow me to pick out and elaborate about some of the most interesting ones from a technological point of view.  I. It is the SPARC SuperCluster T4-4. That is, as compute nodes, it includes SPARC T4-4 servers that we learned to appreciate and respect for their features: The SPARC T4 CPUs: Each CPU has 8 cores, each core runs 8 threads. The SPARC T4-4 servers have 4 sockets. That is, a single compute node can in parallel, simultaneously  execute 256 threads. Now, a full-rack SPARC SuperCluster has 4 of these servers on board. Remember the keyword demigod.  While retaining the forerunner SPARC T3's exceptional throughput, the SPARC T4 CPUs raise the bar with single performance too - a humble 5x better one than their ancestors.  actually, the SPARC T4 CPU cores run in both single-threaded and multi-threaded mode, and switch between these two on-the-fly, fulfilling not only single-threaded OR multi-threaded applications' needs, but even mixed requirements (like in database workloads!). Data security, anyone? Every SPARC T4 CPU core has a built-in encryption engine, that is, encryption algorithms cast into silicon.  A PCI controller right on the chip for customers who need I/O performance.  Built-in, no-cost Virtualization:  Oracle VM for SPARC (the former LDoms or Logical Domains) is not a server-emulation virtualization technology but rather a serverpartitioning one, the hypervisor runs in the server firmware, and all the VMs' HW resources (I/O, CPU, memory) are accessed natively, without performance overhead.  This enables customers to run a number of Solaris 10 and Solaris 11 VMs separated, independent of each other within a physical server II. For Database performance, it includes Exadata Storage Cells - one of the main reasons why the Exadata Database Machine performs at diabolic speed. What makes them important? They provide DB backend storage for your Oracle Databases to run on the SPARC SuperCluster, that is what they are built and tuned for DB performance.  These storage cells are SQL-aware.  That is, if a SPARC T4 database compute node executes a query, it doesn't simply request tons of raw datablocks from the storage, filters the received data, and throws away most of it where the statement doesn't apply, but provides the SQL query to the storage node too. The storage cell software speaks SQL, that is, it is able to prefilter and through that transfer only the relevant data. With this, the traffic between database nodes and storage cells is reduced immensely. Less I/O is a good thing - as they say, all the CPUs of the world do one thing just as fast as any other - and that is waiting for I/O.  They don't only pre-filter, but also provide data preprocessing features - e.g. if a DB-node requests an aggregate of data, they can calculate it, and handover only the results, not the whole set. Again, less data to transfer.  They support the magical HCC, (Hybrid Columnar Compression). That is, data can be stored in a precompressed form on the storage. Less data to transfer.  Of course one can't simply rely on disks for performance, there is Flash Storage included there for caching.  III. The low latency, high-speed backbone network: InfiniBand, that interconnects all the members with: Real High Speed: 40 Gbit/s. Full Duplex, of course. Oh, and a really low latency.  RDMA. Remote Direct Memory Access. This technology allows the DB nodes to do exactly that. Remotely, directly placing SQL commands into the Memory of the storage cells. Dodging all the network-stack bottlenecks, avoiding overhead, placing requests directly into the process queue.  You can also run IP over InfiniBand if you please - that's the way the compute nodes can communicate with each other.  IV. Including a general-purpose storage too: the ZFSSA, which is a unified storage, providing NAS and SAN access too, with the following features:  NFS over RDMA over InfiniBand. Nothing is faster network-filesystem-wise.  All the ZFS features onboard, hybrid storage pools, compression, deduplication, snapshot, replication, NFS and CIFS shares Storageheads in a HA-Cluster configuration providing availability of the data  DTrace Live Analytics in a web-based Administration UI Being a general purpose application data storage for your non-database applications running on the SPARC SuperCluster over whichever protocol they prefer, easily replicating, snapshotting, cloning data for them.  There's a lot of great technology included in Oracle's SPARC SuperCluster, we have talked its interior through. As for external scalability: you can start with a half- of full- rack SPARC SuperCluster, and scale out to several racks - that is, stacking not separate full-rack SPARC SuperClusters, but extending always one large instance of the size of several full-racks. Yes, over InfiniBand network. Add racks as you grow.  What technologies shall run on it? SPARC SuperCluster is a general purpose scaleout consolidation/cloud environment. You can run Oracle Databases with RAC scaling, or Oracle Weblogic (end enjoy the SPARC T4's advantages to run Java). Remember, Oracle technologies have been integrated with the Oracle Engineered Systems - this is the Oracle on Oracle advantage. But you can run other software environments such as SAP if you please too. Run any application that runs on Oracle Solaris 10 or Solaris 11. Separate them in Virtual Machines, or even Oracle Solaris Zones, monitor and manage those from a central UI. Here the key takeaways once again: The SPARC SuperCluster: Is a pre-integrated Engineered System Contains SPARC T4-4 servers with built-in virtualization, cryptography, dynamic threading Contains the Exadata storage cells that intelligently offload the burden of the DB-nodes  Contains a highly available ZFS Storage Appliance, that provides SAN/NAS storage in a unified way Combines all these elements over a high-speed, low-latency backbone network implemented with InfiniBand Can grow from a single half-rack to several full-rack size Supports the consolidation of hundreds of applications To summarize: All these technologies are great by themselves, but the real value is like in every other Oracle Engineered System: Integration. All these technologies are tuned to perform together. Together they are way more than the sum of all - and a careful and actually very time consuming integration process is necessary to orchestrate all these for performance. The SPARC SuperCluster's goal is to enable infrastructure operations and offer a pre-integrated solution that can be architected and delivered in hours instead of months of evaluations and tests. The tedious and most importantly time and resource consuming part of the work - testing and evaluating - has been done.  Now go, provide services.   -- charlie  

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