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  • Moving a lotus database causes incoming mail failure

    - by Logman
    Hey all, I moved a couple lotus note databases to another hd (ran out of space) by using a directory link/pointer on the domino server. USed a text file with the .DIR ext with the desired new path etc... well that works fine. I open up a lotus notes client, use the id and then OPEN the database. The directory link works fine, the new location of the db is opened with no problems. We found out that we couldnt FORWARD any mail: We did the following to make it work: Goto menu FILE|MOBILE|EDIT CURRENT LOCATION Goto tab MAIL and enter the correct path for "Mail File:" example: it should read "mail\morespace\flabor" and not "mail\flabor" "morespace" = directory link/pointer we can forward and reply to emails fine after that fix. The problem is that the user has no incoming email. Domino is still trying to send the incoming mail of that user to its old db location "mail\flabor" instead of "mail\morespace\flabor". Delivery error saying user does not exist. Is this a cache problem? We have reset the server ("Q" at the prompt), though we have not completely shut it down though. Thanks Frank

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  • How to create a mysql database that can contain any character, also different languages

    - by Jakke
    I'm trying to create a database that has to contain articles in different languages. I'm using Mariadb as my server and I know bits of SQL. My knowledge doesn't really cover details like the differences between engines like MyISAM, InnoDB etc or character sets like utf8/16/32, latin 5/7/etc. I do know that the character set has importance, I guess what I'm looking for is an all-encompassing character set and an engine that best deals with this type of content. Also, is there an advantage in storing articles in multiple data rows (equivalent of different pages) to make things a little faster, or would you store a whole article in a single data row. Or does that depend on the size of the articles? Sorry for my noobish question, I know the information is all out on the internet but it would take me quite a long time to research and get a grip on everything. Would be cool if someone with experience could give me a little head start and point me in the right direction. This is for a intranet site, consider the content to be somewhat like a blog (and no, I don't want wordpress or something similar at this point). Not sure if it matters, but I tend to create and manipulate my tables with phpmyadmin, I use apache as web server and it all runs on Linux.

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  • Issues with "There is already an object named 'xxx' in the database'

    - by Hoser
    I'm fairly new to SQL so this may be an easy mistake, but I haven't been able to find a solid solution anywhere else. Problem is whenever I try to use my temp table, it tells me it cannot be used because there is already an object with that name. I frequently try switching up the names, and sometimes it'll let me work with the table for a little while, but it never lasts for long. Am I dropping the table incorrectly? Also, I've had people suggest to just use a permanent table, but this database does not allow me to do that. create table #RandomTableName(NameOfObject varchar(50), NameOfCounter varchar(50), SampledValue decimal) select vPerformanceRule.ObjectName, vPerformanceRule.CounterName, Perf.vPerfRaw.SampleValue into #RandomTableName from vPerformanceRule, vPerformanceRuleInstance, Perf.vPerfRaw where (ObjectName like 'Processor' AND CounterName like '% Processor Time') OR(ObjectName like 'System' AND CounterName like 'Processor Queue Length') OR(ObjectName like 'Memory' AND CounterName like 'Pages/Sec') OR(ObjectName like 'Physical Disk' AND CounterName like 'Avg. Disk Queue Length') OR(ObjectName like 'Physical Disk' AND CounterName like 'Avg. Disk sec/Read') OR(ObjectName like 'Physical Disk' and CounterName like '% Disk Time') OR(ObjectName like 'Logical Disk' and CounterName like '% Free Space' AND SampleValue > 70 AND SampleValue < 100) order by ObjectName, SampleValue drop table #RandomTableName

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  • How can i clear a SQLite database each time i start my app

    - by AndroidUser99
    Hi, i want that each time i start my app my SQLite database get's cleaned for this, i need to make a method on my class MyDBAdapter.java code examples are welcome, i have no idea how to do it this is the dbadapter/helper i'm using: public class MyDbAdapter { private static final String TAG = "NotesDbAdapter"; private DatabaseHelper mDbHelper; private SQLiteDatabase mDb; private static final String DATABASE_NAME = "gpslocdb"; private static final String PERMISSION_TABLE_CREATE = "CREATE TABLE permission ( fk_email1 varchar, fk_email2 varchar, validated tinyint, hour1 time default '08:00:00', hour2 time default '20:00:00', date1 date, date2 date, weekend tinyint default '0', fk_type varchar, PRIMARY KEY (fk_email1,fk_email2))"; private static final String USER_TABLE_CREATE = "CREATE TABLE user ( email varchar, password varchar, fullName varchar, mobilePhone varchar, mobileOperatingSystem varchar, PRIMARY KEY (email))"; private static final int DATABASE_VERSION = 2; private final Context mCtx; private static class DatabaseHelper extends SQLiteOpenHelper { DatabaseHelper(Context context) { super(context, DATABASE_NAME, null, DATABASE_VERSION); } @Override public void onCreate(SQLiteDatabase db) { db.execSQL(PERMISSION_TABLE_CREATE); db.execSQL(USER_TABLE_CREATE); } @Override public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) { db.execSQL("DROP TABLE IF EXISTS user"); db.execSQL("DROP TABLE IF EXISTS permission"); onCreate(db); } } /** * Constructor - takes the context to allow the database to be * opened/created * * @param ctx the Context within which to work */ public MyDbAdapter(Context ctx) { this.mCtx = ctx; } /** * Open the database. If it cannot be opened, try to create a new * instance of the database. If it cannot be created, throw an exception to * signal the failure * * @return this (self reference, allowing this to be chained in an * initialization call) * @throws SQLException if the database could be neither opened or created */ public MyDbAdapter open() throws SQLException { mDbHelper = new DatabaseHelper(mCtx); mDb = mDbHelper.getWritableDatabase(); return this; } public void close() { mDbHelper.close(); } public long createUser(String email, String password, String fullName, String mobilePhone, String mobileOperatingSystem) { ContentValues initialValues = new ContentValues(); initialValues.put("email",email); initialValues.put("password",password); initialValues.put("fullName",fullName); initialValues.put("mobilePhone",mobilePhone); initialValues.put("mobileOperatingSystem",mobileOperatingSystem); return mDb.insert("user", null, initialValues); } public Cursor fetchAllUsers() { return mDb.query("user", new String[] {"email", "password", "fullName", "mobilePhone", "mobileOperatingSystem"}, null, null, null, null, null); } public Cursor fetchUser(String email) throws SQLException { Cursor mCursor = mDb.query(true, "user", new String[] {"email", "password", "fullName", "mobilePhone", "mobileOperatingSystem"} , "email" + "=" + email, null, null, null, null, null); if (mCursor != null) { mCursor.moveToFirst(); } return mCursor; } public List<Friend> retrieveAllUsers() { List <Friend> friends=new ArrayList<Friend>(); Cursor result=fetchAllUsers(); if( result.moveToFirst() ){ do{ //note.getString(note.getColumnIndexOrThrow(NotesDbAdapter.KEY_TITLE))); friends.add(new Friend(result.getString(result.getColumnIndexOrThrow("email")), "","","","")); }while( result.moveToNext() ); } return friends; } }

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  • Doesn't get the output in Java Database Connectivity

    - by Dooree
    I'm working on Java Database Connectivity through Eclipse IDE. I built a database through Ubuntu Terminal, and I need to connect and work with it. However, when I tried to run the following code, I don't get any error, but the following output is showed, anybody knows why I don't get the output from the code ? //STEP 1. Import required packages import java.sql.*; public class FirstExample { // JDBC driver name and database URL static final String JDBC_DRIVER = "com.mysql.jdbc.Driver"; static final String DB_URL = "jdbc:mysql://localhost/EMP"; // Database credentials static final String USER = "username"; static final String PASS = "password"; public static void main(String[] args) { Connection conn = null; Statement stmt = null; try{ //STEP 2: Register JDBC driver Class.forName("com.mysql.jdbc.Driver"); //STEP 3: Open a connection System.out.println("Connecting to database..."); conn = DriverManager.getConnection(DB_URL,USER,PASS); //STEP 4: Execute a query System.out.println("Creating statement..."); stmt = conn.createStatement(); String sql; sql = "SELECT id, first, last, age FROM Employees"; ResultSet rs = stmt.executeQuery(sql); //STEP 5: Extract data from result set while(rs.next()){ //Retrieve by column name int id = rs.getInt("id"); int age = rs.getInt("age"); String first = rs.getString("first"); String last = rs.getString("last"); //Display values System.out.print("ID: " + id); System.out.print(", Age: " + age); System.out.print(", First: " + first); System.out.println(", Last: " + last); } //STEP 6: Clean-up environment rs.close(); stmt.close(); conn.close(); }catch(SQLException se){ //Handle errors for JDBC se.printStackTrace(); }catch(Exception e){ //Handle errors for Class.forName e.printStackTrace(); }finally{ //finally block used to close resources try{ if(stmt!=null) stmt.close(); }catch(SQLException se2){ }// nothing we can do try{ if(conn!=null) conn.close(); }catch(SQLException se){ se.printStackTrace(); }//end finally try }//end try System.out.println("Goodbye!"); }//end main }//end FirstExample <ConnectionProperties> <PropertyCategory name="Connection/Authentication"> <Property name="user" required="No" default="" sortOrder="-2147483647" since="all"> The user to connect as </Property> <Property name="password" required="No" default="" sortOrder="-2147483646" since="all"> The password to use when connecting </Property> <Property name="socketFactory" required="No" default="com.mysql.jdbc.StandardSocketFactory" sortOrder="4" since="3.0.3"> The name of the class that the driver should use for creating socket connections to the server. This class must implement the interface 'com.mysql.jdbc.SocketFactory' and have public no-args constructor. </Property> <Property name="connectTimeout" required="No" default="0" sortOrder="9" since="3.0.1"> Timeout for socket connect (in milliseconds), with 0 being no timeout. Only works on JDK-1.4 or newer. Defaults to '0'. </Property> ...

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  • Persisting objects to a database using a loop

    - by ChaoticLoki
    I have a form that returns multiple values and each value I would like to store in a database, I created a test form for this purpose <form method="post" action="{{ path('submit_exercise', {'page': 1}) }}"> <input type="hidden" name="answers[]" value="Answer 1" "/> <input type="hidden" name="answers[]" value="Answer 2" "/> <input type="hidden" name="answers[]" value="Answer 3" "/> <input type="hidden" name="answers[]" value="Answer 4" "/> <input type="hidden" name="answers[]" value="Answer 5" "/> <input type="hidden" name="answers[]" value="Answer 6" "/> <input type="hidden" name="answers[]" value="Answer 7" "/> <input type="submit" name="submit" /> </form> </body> </html> My submit answers Action is currently written like so. public function submitAnswersAction($page) { //get submitted data $data = $this->get('request')->request->all(); $answers = $data['answers']; //get student ID $user = $this->get('security.context')->getToken()->getUser(); $studentID = $user->getId(); //Get Current time $currentTime = new \DateTime(date("Y-m-d H:m:s")); //var_dump($answers); //var_dump($studentID); //var_dump($currentTime); for($index = 0; $index < count($answers); $index++) { /*echo "Question ". ($index + 1) ."<br />"; echo "Student ID: ". $studentID."<br />"; echo "Page Number: $page <br />"; echo "Answer: $answers[$index]"."<br />"; echo "<br />";*/ $studentAnswer = new StudentAnswer(); $studentAnswer->setStudentID($studentID); $studentAnswer->setPageID($page); $studentAnswer->setQuestionID($index+1); $studentAnswer->setAnswer($answers[$index]); $studentAnswer->setDateCreated($currentTime); $studentAnswer->setReadStatus(0); $database = $this->getDoctrine()->getManager(); $database->persist($studentAnswer); $database->flush(); } return new Response('Answers saved for Student: '.$user->getFullName().' for page: '.$page); When I do a var_dump everything seems to be associated correctly, meaning that the answers array is populated with the right data and so is every other variable, my problem is actually persisting it to the database. when run it returns with this error which seems to me like it doesn't know what variables to put into the row. An exception occurred while executing 'INSERT INTO Student_Answer (student_id, page_id, question_id, answer, read, date_created) VALUES (?, ?, ?, ?, ?, ?)' with params {"1":2,"2":"1","3":1,"4":"Answer 1","5":0,"6":"2012-12-11 12:12:20"}: Any help would be greatly appreciated as this is a personal project to help me try and understand web development a bit more.

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  • TOTD #166: Using NoSQL database in your Java EE 6 Applications on GlassFish - MongoDB for now!

    - by arungupta
    The Java EE 6 platform includes Java Persistence API to work with RDBMS. The JPA specification defines a comprehensive API that includes, but not restricted to, how a database table can be mapped to a POJO and vice versa, provides mechanisms how a PersistenceContext can be injected in a @Stateless bean and then be used for performing different operations on the database table and write typesafe queries. There are several well known advantages of RDBMS but the NoSQL movement has gained traction over past couple of years. The NoSQL databases are not intended to be a replacement for the mainstream RDBMS. As Philosophy of NoSQL explains, NoSQL database was designed for casual use where all the features typically provided by an RDBMS are not required. The name "NoSQL" is more of a category of databases that is more known for what it is not rather than what it is. The basic principles of NoSQL database are: No need to have a pre-defined schema and that makes them a schema-less database. Addition of new properties to existing objects is easy and does not require ALTER TABLE. The unstructured data gives flexibility to change the format of data any time without downtime or reduced service levels. Also there are no joins happening on the server because there is no structure and thus no relation between them. Scalability and performance is more important than the entire set of functionality typically provided by an RDBMS. This set of databases provide eventual consistency and/or transactions restricted to single items but more focus on CRUD. Not be restricted to SQL to access the information stored in the backing database. Designed to scale-out (horizontal) instead of scale-up (vertical). This is important knowing that databases, and everything else as well, is moving into the cloud. RBDMS can scale-out using sharding but requires complex management and not for the faint of heart. Unlike RBDMS which require a separate caching tier, most of the NoSQL databases comes with integrated caching. Designed for less management and simpler data models lead to lower administration as well. There are primarily three types of NoSQL databases: Key-Value stores (e.g. Cassandra and Riak) Document databases (MongoDB or CouchDB) Graph databases (Neo4J) You may think NoSQL is panacea but as I mentioned above they are not meant to replace the mainstream databases and here is why: RDBMS have been around for many years, very stable, and functionally rich. This is something CIOs and CTOs can bet their money on without much worry. There is a reason 98% of Fortune 100 companies run Oracle :-) NoSQL is cutting edge, brings excitement to developers, but enterprises are cautious about them. Commercial databases like Oracle are well supported by the backing enterprises in terms of providing support resources on a global scale. There is a full ecosystem built around these commercial databases providing training, performance tuning, architecture guidance, and everything else. NoSQL is fairly new and typically backed by a single company not able to meet the scale of these big enterprises. NoSQL databases are good for CRUDing operations but business intelligence is extremely important for enterprises to stay competitive. RDBMS provide extensive tooling to generate this data but that was not the original intention of NoSQL databases and is lacking in that area. Generating any meaningful information other than CRUDing require extensive programming. Not suited for complex transactions such as banking systems or other highly transactional applications requiring 2-phase commit. SQL cannot be used with NoSQL databases and writing simple queries can be involving. Enough talking, lets take a look at some code. This blog has published multiple blogs on how to access a RDBMS using JPA in a Java EE 6 application. This Tip Of The Day (TOTD) will show you can use MongoDB (a document-oriented database) with a typical 3-tier Java EE 6 application. Lets get started! The complete source code of this project can be downloaded here. Download MongoDB for your platform from here (1.8.2 as of this writing) and start the server as: arun@ArunUbuntu:~/tools/mongodb-linux-x86_64-1.8.2/bin$./mongod./mongod --help for help and startup optionsSun Jun 26 20:41:11 [initandlisten] MongoDB starting : pid=11210port=27017 dbpath=/data/db/ 64-bit Sun Jun 26 20:41:11 [initandlisten] db version v1.8.2, pdfile version4.5Sun Jun 26 20:41:11 [initandlisten] git version:433bbaa14aaba6860da15bd4de8edf600f56501bSun Jun 26 20:41:11 [initandlisten] build sys info: Linuxbs-linux64.10gen.cc 2.6.21.7-2.ec2.v1.2.fc8xen #1 SMP Fri Nov 2017:48:28 EST 2009 x86_64 BOOST_LIB_VERSION=1_41Sun Jun 26 20:41:11 [initandlisten] waiting for connections on port 27017Sun Jun 26 20:41:11 [websvr] web admin interface listening on port 28017 The default directory for the database is /data/db and needs to be created as: sudo mkdir -p /data/db/sudo chown `id -u` /data/db You can specify a different directory using "--dbpath" option. Refer to Quickstart for your specific platform. Using NetBeans, create a Java EE 6 project and make sure to enable CDI and add JavaServer Faces framework. Download MongoDB Java Driver (2.6.3 of this writing) and add it to the project library by selecting "Properties", "LIbraries", "Add Library...", creating a new library by specifying the location of the JAR file, and adding the library to the created project. Edit the generated "index.xhtml" such that it looks like: <h1>Add a new movie</h1><h:form> Name: <h:inputText value="#{movie.name}" size="20"/><br/> Year: <h:inputText value="#{movie.year}" size="6"/><br/> Language: <h:inputText value="#{movie.language}" size="20"/><br/> <h:commandButton actionListener="#{movieSessionBean.createMovie}" action="show" title="Add" value="submit"/></h:form> This page has a simple HTML form with three text boxes and a submit button. The text boxes take name, year, and language of a movie and the submit button invokes the "createMovie" method of "movieSessionBean" and then render "show.xhtml". Create "show.xhtml" ("New" -> "Other..." -> "Other" -> "XHTML File") such that it looks like: <head> <title><h1>List of movies</h1></title> </head> <body> <h:form> <h:dataTable value="#{movieSessionBean.movies}" var="m" > <h:column><f:facet name="header">Name</f:facet>#{m.name}</h:column> <h:column><f:facet name="header">Year</f:facet>#{m.year}</h:column> <h:column><f:facet name="header">Language</f:facet>#{m.language}</h:column> </h:dataTable> </h:form> This page shows the name, year, and language of all movies stored in the database so far. The list of movies is returned by "movieSessionBean.movies" property. Now create the "Movie" class such that it looks like: import com.mongodb.BasicDBObject;import com.mongodb.BasicDBObject;import com.mongodb.DBObject;import javax.enterprise.inject.Model;import javax.validation.constraints.Size;/** * @author arun */@Modelpublic class Movie { @Size(min=1, max=20) private String name; @Size(min=1, max=20) private String language; private int year; // getters and setters for "name", "year", "language" public BasicDBObject toDBObject() { BasicDBObject doc = new BasicDBObject(); doc.put("name", name); doc.put("year", year); doc.put("language", language); return doc; } public static Movie fromDBObject(DBObject doc) { Movie m = new Movie(); m.name = (String)doc.get("name"); m.year = (int)doc.get("year"); m.language = (String)doc.get("language"); return m; } @Override public String toString() { return name + ", " + year + ", " + language; }} Other than the usual boilerplate code, the key methods here are "toDBObject" and "fromDBObject". These methods provide a conversion from "Movie" -> "DBObject" and vice versa. The "DBObject" is a MongoDB class that comes as part of the mongo-2.6.3.jar file and which we added to our project earlier.  The complete javadoc for 2.6.3 can be seen here. Notice, this class also uses Bean Validation constraints and will be honored by the JSF layer. Finally, create "MovieSessionBean" stateless EJB with all the business logic such that it looks like: package org.glassfish.samples;import com.mongodb.BasicDBObject;import com.mongodb.DB;import com.mongodb.DBCollection;import com.mongodb.DBCursor;import com.mongodb.DBObject;import com.mongodb.Mongo;import java.net.UnknownHostException;import java.util.ArrayList;import java.util.List;import javax.annotation.PostConstruct;import javax.ejb.Stateless;import javax.inject.Inject;import javax.inject.Named;/** * @author arun */@Stateless@Namedpublic class MovieSessionBean { @Inject Movie movie; DBCollection movieColl; @PostConstruct private void initDB() throws UnknownHostException { Mongo m = new Mongo(); DB db = m.getDB("movieDB"); movieColl = db.getCollection("movies"); if (movieColl == null) { movieColl = db.createCollection("movies", null); } } public void createMovie() { BasicDBObject doc = movie.toDBObject(); movieColl.insert(doc); } public List<Movie> getMovies() { List<Movie> movies = new ArrayList(); DBCursor cur = movieColl.find(); System.out.println("getMovies: Found " + cur.size() + " movie(s)"); for (DBObject dbo : cur.toArray()) { movies.add(Movie.fromDBObject(dbo)); } return movies; }} The database is initialized in @PostConstruct. Instead of a working with a database table, NoSQL databases work with a schema-less document. The "Movie" class is the document in our case and stored in the collection "movies". The collection allows us to perform query functions on all movies. The "getMovies" method invokes "find" method on the collection which is equivalent to the SQL query "select * from movies" and then returns a List<Movie>. Also notice that there is no "persistence.xml" in the project. Right-click and run the project to see the output as: Enter some values in the text box and click on enter to see the result as: If you reached here then you've successfully used MongoDB in your Java EE 6 application, congratulations! Some food for thought and further play ... SQL to MongoDB mapping shows mapping between traditional SQL -> Mongo query language. Tutorial shows fun things you can do with MongoDB. Try the interactive online shell  The cookbook provides common ways of using MongoDB In terms of this project, here are some tasks that can be tried: Encapsulate database management in a JPA persistence provider. Is it even worth it because the capabilities are going to be very different ? MongoDB uses "BSonObject" class for JSON representation, add @XmlRootElement on a POJO and how a compatible JSON representation can be generated. This will make the fromXXX and toXXX methods redundant.

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  • Organization &amp; Architecture UNISA Studies &ndash; Chap 5

    - by MarkPearl
    Learning Outcomes Describe the operation of a memory cell Explain the difference between DRAM and SRAM Discuss the different types of ROM Explain the concepts of a hard failure and a soft error respectively Describe SDRAM organization Semiconductor Main Memory The two traditional forms of RAM used in computers are DRAM and SRAM DRAM (Dynamic RAM) Divided into two technologies… Dynamic Static Dynamic RAM is made with cells that store data as charge on capacitors. The presence or absence of charge in a capacitor is interpreted as a binary 1 or 0. Because capacitors have natural tendency to discharge, dynamic RAM requires periodic charge refreshing to maintain data storage. The term dynamic refers to the tendency of the stored charge to leak away, even with power continuously applied. Although the DRAM cell is used to store a single bit (0 or 1), it is essentially an analogue device. The capacitor can store any charge value within a range, a threshold value determines whether the charge is interpreted as a 1 or 0. SRAM (Static RAM) SRAM is a digital device that uses the same logic elements used in the processor. In SRAM, binary values are stored using traditional flip flop logic configurations. SRAM will hold its data as along as power is supplied to it. Unlike DRAM, no refresh is required to retain data. SRAM vs. DRAM DRAM is simpler and smaller than SRAM. Thus it is more dense and less expensive than SRAM. The cost of the refreshing circuitry for DRAM needs to be considered, but if the machine requires a large amount of memory, DRAM turns out to be cheaper than SRAM. SRAMS are somewhat faster than DRAM, thus SRAM is generally used for cache memory and DRAM is used for main memory. Types of ROM Read Only Memory (ROM) contains a permanent pattern of data that cannot be changed. ROM is non volatile meaning no power source is required to maintain the bit values in memory. While it is possible to read a ROM, it is not possible to write new data into it. An important application of ROM is microprogramming, other applications include library subroutines for frequently wanted functions, System programs, Function tables. A ROM is created like any other integrated circuit chip, with the data actually wired into the chip as part of the fabrication process. To reduce costs of fabrication, we have PROMS. PROMS are… Written only once Non-volatile Written after fabrication Another variation of ROM is the read-mostly memory, which is useful for applications in which read operations are far more frequent than write operations, but for which non volatile storage is required. There are three common forms of read-mostly memory, namely… EPROM EEPROM Flash memory Error Correction Semiconductor memory is subject to errors, which can be classed into two categories… Hard failure – Permanent physical defect so that the memory cell or cells cannot reliably store data Soft failure – Random error that alters the contents of one or more memory cells without damaging the memory (common cause includes power supply issues, etc.) Most modern main memory systems include logic for both detecting and correcting errors. Error detection works as follows… When data is to be read into memory, a calculation is performed on the data to produce a code Both the code and the data are stored When the previously stored word is read out, the code is used to detect and possibly correct errors The error checking provides one of 3 possible results… No errors are detected – the fetched data bits are sent out An error is detected, and it is possible to correct the error. The data bits plus error correction bits are fed into a corrector, which produces a corrected set of bits to be sent out An error is detected, but it is not possible to correct it. This condition is reported Hamming Code See wiki for detailed explanation. We will probably need to know how to do a hemming code – refer to the textbook (pg. 188 – 189) Advanced DRAM organization One of the most critical system bottlenecks when using high-performance processors is the interface to main memory. This interface is the most important pathway in the entire computer system. The basic building block of main memory remains the DRAM chip. In recent years a number of enhancements to the basic DRAM architecture have been explored, and some of these are now on the market including… SDRAM (Synchronous DRAM) DDR-DRAM RDRAM SDRAM (Synchronous DRAM) SDRAM exchanges data with the processor synchronized to an external clock signal and running at the full speed of the processor/memory bus without imposing wait states. SDRAM employs a burst mode to eliminate the address setup time and row and column line precharge time after the first access In burst mode a series of data bits can be clocked out rapidly after the first bit has been accessed SDRAM has a multiple bank internal architecture that improves opportunities for on chip parallelism SDRAM performs best when it is transferring large blocks of data serially There is now an enhanced version of SDRAM known as double data rate SDRAM or DDR-SDRAM that overcomes the once-per-cycle limitation of SDRAM

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  • Can a partition table be edited from a LiveUSB of another architecture?

    - by Eliran Malka
    My purpose is to re-partition a dual-boot machine (running Ubuntu 13.04 / Windows 7), i.e. the current table is as follows: ----------------------------------------------------------- | | extended partition | | | windows |--------------------------------| recovery | | (NTFS) | swap | filesystem | (NTFS) | | | (swap) | (ext4) | | ----------------------------------------------------------- and I want to create an additional ext4 partition under the extended partition, and mount those (the one I created and the 'filesystem' partition) to root and home (/ and /home), such as the new layout will be: ----------------------------------------------------------- | | extended partition | | | windows |--------------------------------| recovery | | (NTFS) | swap | root | home | (NTFS) | | | (swap) | (ext4) | (ext4) | | ----------------------------------------------------------- As the installations on the system and on my Live USB differ in architecture, I want to know: Is it safe to use a 64bit GParted from a Live USB for partitioning a 32bit installation?

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  • ASP.NET MVC Portable Areas - Can they communicate and be used as a plugin-like architecture?

    - by Beton
    I'll get straight to the point: I was wondering if there is a common pattern to use portable areas as a components of a plugin-like architecture. Example: We've got 3 plugins (portable areas) packaged and distributed via NuGet feed. Each of them is following the standard MVC structure (has it own Models, Views and Controllers). Lets say login form, header and footer. What I was wondering if there is a way to make them communicate. For example: when user logs on, login plugin executes it own logic, logs the user and then it updates the state of the header plugin with changes it state accordingly. Thanks in advance.

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  • How do I sell Oracle? It all starts with the database

    - by swiesner
    Partner sales reps often ask me how they start a conversation with their customers around Oracle. The first question should be, "are you running an Oracle database?" Much of what we do at Oracle is intended to optimize our customers' investments in the Oracle database. Many of our acquisitions, new features in existing products, new applications, are often designed to improve the experience of the 400,000 Oracle database customers worldwide. Once you find an Oracle database customer, the next set of questions are much easier, but depend on your expertise: License Management, Upsell, and Services. Let's start with License Management: Have there been any changes to your infrastructure since you purchased the database licenses? Have you upgraded the servers on which the Oracle database is running? Have the number of users or employees increased since the last license purchase? Yes to any of these questions will lead to investigating correct licensing. The goal is to provide a "soft" license review. Oracle generally does not require any license keys to install our software, so we need to help our customers with compliance. Correct licensing is essential to managing costs, and can provide a great way to efficiently manage IT spend. You might want to contact your local Oracle Channel Manager or VAD for licensing assistance. Or, review the Software Investment Guide. Naturally, these questions can lead to upsell opportunities. If your customer has invested in Oracle technology to manage their data, that data is essential to running their business. We'll take a look at those upsell questions in a later blog post.

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  • Arguments of using WCF/OData as access layer instead of EF/L2S/nHibernate directly

    - by Carl Hörberg
    We develop mostly low traffic but highly specialized web applications. Normally we use L2S, EF or nHibernate as access layer and then throws Asp.Net MVC to it and in which for normal crud operations we query the ISession/DataContext directly but for more advanced functions/side effects we put it in a some kind of service layer. Now, i was think about publishing the data through OData (WCF Data Service) and query that from the controllers (or even from jQuery when the a good template engine shows up) and publish the service operations through a WCF service (or as custom methods on the WCF Data Service?). What advantages/disadvantages does this architecture poses? Do I gain something except higher complexity and latency? Better separations of concerns (or is it just a illusion)?

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  • WCF Data Services implementation strategies.

    - by Nix
    Microsoft has done a savvy job of not outlining the actual place for data services in the wonderful world of SOA/Web dev. So my question is simple, are WCF Data Services designed to be used via clients? Or has anyone ever heard of someone using them on the server side? Simple scenario a general layered architecture using BO business objects (parenthesis indicate what is being passed between layers) (XML) WCF Service - (BO)Business Logic - (BO) Dao - Entity Framework or using data services it would be where DS BO are modeled business entities to be used in data service. (XML) WCF Service -(BO) Business Logic - (BO) WCF Data Service - (DS BO)Server I can't see a use for the later, unless there are going to be a lot of cases people would be accessing your data via your Data Service Layer vs the Service layer? Thoughts anyone? I have not seen any mention of using DS from within a Service Layer....

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  • Expose url to webservice

    - by Patrick Peters
    In our project we want to query a document management system for a specific document or movie. The dms returns a URL with the document location (for example: http://mydomain.myserver1.share/mypdf.pdf or http://mydomain.myserver2.share/mymovie.avi). We want to expose the document to internet users and intranet users. The requested file can be large (large video files). Our architecture is like: request goes like: webapp1 - webapp2 - webapp3 - dms response goes like: dms - webapp3 - webapp2 - webapp1 webapp1 could be on the internet. I have have been thinking how we can obfusicate the real url from the dms, due to security issues. I have seen implementations from other webapps where the pdf URL was obfusicated by creating a temp file for the requested document that is specific for the session and user. So other users cannot easily guess the documentname of other users. My question: is there a pattern that deals with exposing company/user vulernable data to the public ? Our development is in C# 3.5.

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  • java enterprise project

    - by darko petreski
    Hi All, All the time we are hearing that java is enterprise. We have read many books about jpa, entity beans and other stuff. All this books explain this technology with some dummy examples. I have not seen a book that explains real problems with enterprise beans, java clients and security! I mean real book not some imaginated stupid examples . Is there any book that describes completely some enterprise system, Its architecture, communication, security, of course the client that uses the distributed components ? I need a book that will cover the flowing: server side components (ejb, jpa) client side java desktop application security (authentication and authorization) web services with complete authentication clustering (we can find for all of this a book, but there is no book that covers all this things in one piece. Also all the books are with dummy samples.) Or may be some project that is documented. Regards, Darko

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  • JBoss Seam - Jetty - Virtualhosting

    - by Walter White
    Hi all, I am trying to cutback on the memory usage of my server and would like to optimize the architecture. I currently deploy 2 separate web applications to Jetty 6.1.22 that correspond to different virtualhosts. They have pretty much the same application stack except one has fewer components and are styled differently (content, images, css, etc.). If I change my design pattern over to EJB / EAR + 2 WARS embedded, will that lower the memory consumption? Will that give me a single instance of JBoss Seam, Quartz, and all of my components? They must use a different datasource. Thanks, Walter

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  • Circular Dependency Solution

    - by gfoley
    Our current project has ran into a circular dependency issue. Our business logic assembly is using classes and static methods from our SharedLibrary assembly. The SharedLibrary contains a whole bunch of helper functions, such as a SQL Reader class, Enumerators, Global Variables, Error Handling, Logging and Validation. The SharedLibrary needs access to the Business objects, but the Business objects need access to SharedLibrary. The old developers solved this obvious code smell by replicating the functionality of the business objects in the shared library (very anti-DRY). I've spent a day now trying to read about my options to solve this but i'm hitting a dead end. I'm open to the idea of architecture redesign, but only as a last resort. So how can i have a Shared Helper Library which can access the business objects, with the business objects still accessing the Shared Helper Library?

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  • EF and design pattern

    - by kathy
    Hello, I’m working on a high volume transactional enterprise application(asp.net, windows app, oracle app as client) which has been designed using n-tire application and SOA architecture .The application was developed in the .NET platform utilizing C#,VB.NET, Framework 3.5 (I’m planning to upgrade to the , Framework 4.0), EF( EF in the data layer level) and WCF(WCF services in the service layer level) Since this is the first project using EF, and having read about using EF in n-tier and SOA applications, and the features available in the EF Feature, I have the following points: Which design pattern should I use in EF( Simple Entities, Change Set, Self-Tracking Entities and DTOs) in the data layer level In addition Which design pattern should I use in the other tier and layer to get the best practices of EF Thanks

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  • REST doesn't work with Sever-Client-Client setup

    - by drozzy
    I am having a problem with my current RESTful api design. What I have is a REST api which is consumed by Django web-server, which renders the HTML templates. REST api > Django webserver > HTML The problem I am encountering is that I have to reconstruct all the URLS like mysite.com/main/cities/<id>/streets/ into equivalent rest api urls on my web-server layer: api.com/cities/<id>/streets/ Thus I have a lot of mapping back and forth, but as far as I know REST says that the client (in this case my web-server) should NOT need to know how to re-construct the urls. Can REST be used for such a setup and how? Or is it only viable for Server-Client architecture. Thanks

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  • How to determine OS Platform with WMI?

    - by cary.wagner
    I am trying to figure out if there is a location in WMI that will return the OS Architecture (i.e. 32-bit or 64-bit) that will work across "all" versions of Windows. I thought I had figured it out looking at my Win2k8 system when I found the following: Win32_OperatingSystem / OSArchitecture I was wrong. It doesn't appear that this field exists on Win2k3 systems. Argh! So, is anyone aware of another field in WMI that "is" the same across server versions? If not, what about a registry key that is the same? I am using a tool that only allows me to configure simple field queries, so I cannot use a complex script to perform. Any help would be greatly appreciated! Cheers... Cary

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  • How to choose light version of databse system

    - by adopilot
    I am starting one POS (Point of sale) project. Targeting system is going to be written in C# .NET 2 WinForms and as main database server We are going to use MS-SQL Server. As we have a lot of POS devices in chain for one store I will love to have backend local data base system on each POS device. Scenario are following: When main server goes down!! POS application should continue working "off-line" with local database, until connection to main server come up again. Now I am in dilemma which local database is going to be most adoptable for me. Here is some notes for helping me point me in right direction: To be Light "My POS devices art usually old and suffering with performances" To be Free "I have a lot of devices and I do not wont additional cost beside main SQL serer" One day Ill love to try all that port on Mono and Linux OS. Here is what I've researched so far: Simple XML "Light but I am afraid of performance, My main table of items is average of 10K records" SQL-Expres "I am afraid that my POS devices is poor with hardware for SQLExpres, and also hard to install on each device and configure" Less known Advantage Database Server have free distribution of offline ADT system. DBF with extended Library,"Respect for good old DBFs but that era is behind Me with clipper and DBFs" MS Access Sqlite "Mostly like for now, but I am afraid how it is going to pair with MS SQL do they have same Data taypes". I know that in this SO is a lot of subjective data, but at least can someone recommended some others lite database system, or things that I shod most take attention before I choice database.

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  • Any exprience with Castle ActiveRecord?

    - by afsharm
    Hi all, I was searching for a light data access framework based on NHibernate. I needed simple CRUD and some simple HQL or LINQ-to-NHhibernate queries. Performance was not an important issue and applications which I'm working on have simple table structure but many tables. This data access framework is going to be used in a ASP.NET Webform application. Once a time I found S#harp architecture, but it was developed for ASP.NET MVC. Just today I found Castle ActiveRecord. But I'm wondering: If any one has any experience with it? Is it suitable for me? Should I consider any specific matter? What about its future? Is Castle ActiveRecord supposed to be developed and be active in coming years? Thanks in Advance

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  • Design Patterns: What's the antithesis of Front Controller?

    - by Brian Lacy
    I'm familiar with the Front Controller pattern, in which all events/requests are processed through a single centralized controller. But what would you call it when you wish to keep the various parts of an application separate at the presentation layer as well? My first thought was "Facade" but it turns out that's something entirely different. In my particular case, I'm converting an application from a sprawling procedural mess to a clean MVC architecture, but it's a long-term process -- we need to keep things separated as much as possible to facilitate a slow integration with the rest of the system. Our application is web-based, built in PHP, so for instance, we have an "index.php" and an IndexController, a "account.php" and an AccountController, a "dashboard.php" and DashboardController, and so on.

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  • Load vs Get in Nhibernate

    - by Quintin Par
    The master page in my web application does authentication and loads up the user entity using a Get. After this whenever the user object is needed by the usercontrols or any other class I do a Load. Normally nhibernate is supposed to load the object from cache or return the persistent loaded object whenever Load of called. But this is not the behavior shown by my web application. NHprof always shows the sql whenever Load is called. How do I verify the correct behavior of Load? I use the S#arp architecture framework.

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  • Hibernate: Check if object exists/changed

    - by swalkner
    Assuming I have an object Person with long id String firstName String lastName String address Then I'm generating a Person-object somewhere in my application. Now I'd like to check if the person exists in the database (= firstname/lastname-combination is in the database). If not = insert it. If yes, check, if the address is the same. If not = update the address. Of course, I can do some requests (first, try to load object with firstname/lastname), then (if existing), compare the address. But isn't there a simpler, cleaner approach? If got several different classes and do not like to have so many queries. I'd like to use annotations as if to say: firstname/lastname = they're the primary key. Check for them if the object exists. address is the parameter you have to compare if it stayed the same or not. Does Hibernate/JPA (or another framework) support something like that? pseude-code: if (database.containsObject(person)) { //containing according to compound keys if (database.containsChangedObject(person)) { database.updateObject(person); } } else { database.insertObject(person); }

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