Search Results

Search found 41907 results on 1677 pages for 'database programming'.

Page 45/1677 | < Previous Page | 41 42 43 44 45 46 47 48 49 50 51 52  | Next Page >

• Linux System Programming

  - by AJ

  I wanted to get into systems programming for linux and wanted to know how to approach that and where to begin. I come from a web development background (Python, PHP) but I also know some C and C++. Essentially, I would like to know: Which language(s) to learn and pursue (I think mainly C and C++)? How/Where to learn those languages specific to Systems Programming? Books, websites, blogs, tutorials etc. Any other good places where I can start this from basics? Any good libraries to begin with? What environment setup (or approx.) do I need? Assuming linux has to be there but I have a linux box which I rarely log into using GUI (always use SSH). Is GUI a lot more helpful or VI editor is enough? (Please let me know if this part of the question should go to serverfault.com) PS: Just to clarify, by systems programming I mean things like writing device drivers, System tools, write native applications which are not present on Linux platform but are on others, play with linux kernel etc.

  Read the article

• Aligning music notes using String matching algorithms or Dynamic Programming

  - by Dolphin

  Hi I need to compare 2 sets of musical pieces (i.e. a playing-taken in MIDI format-note details extracted and saved in a database table, against sheet music-taken into XML format). When evaluating playing against sheet music (i.e.note details-pitch, duration, rhythm), note alignment needs to be done - to identify missed/extra/incorrect/swapped notes that from the reference (sheet music) notes. I have like 1800-2500 notes in one piece approx (can even be more-with polyphonic, right now I'm doing for monophonic). So will I have to have all these into an array? Will it be memory overloading or stack overflow? There are string matching algorithms like KMP, Boyce-Moore. But note alignment can also be done through Dynamic Programming. How can I use Dynamic Programming to approach this? What are the available algorithms? Is it about approximate string matching? Which approach is much productive? String matching algos like Boyce-Moore, or dynamic programming? How can I assess which is more effective? Greatly appreciate any insight or suggestions Thanks in advance

  Read the article

• Big Data – Operational Databases Supporting Big Data – Columnar, Graph and Spatial Database – Day 14 of 21

  - by Pinal Dave

  In yesterday’s blog post we learned the importance of the Key-Value Pair Databases and Document Databases in the Big Data Story. In this article we will understand the role of Columnar, Graph and Spatial Database supporting Big Data Story. Now we will see a few of the examples of the operational databases. Relational Databases (The day before yesterday’s post) NoSQL Databases (The day before yesterday’s post) Key-Value Pair Databases (Yesterday’s post) Document Databases (Yesterday’s post) Columnar Databases (Tomorrow’s post) Graph Databases (Today’s post) Spatial Databases (Today’s post) Columnar Databases  Relational Database is a row store database or a row oriented database. Columnar databases are column oriented or column store databases. As we discussed earlier in Big Data we have different kinds of data and we need to store different kinds of data in the database. When we have columnar database it is very easy to do so as we can just add a new column to the columnar database. HBase is one of the most popular columnar databases. It uses Hadoop file system and MapReduce for its core data storage. However, remember this is not a good solution for every application. This is particularly good for the database where there is high volume incremental data is gathered and processed. Graph Databases For a highly interconnected data it is suitable to use Graph Database. This database has node relationship structure. Nodes and relationships contain a Key Value Pair where data is stored. The major advantage of this database is that it supports faster navigation among various relationships. For example, Facebook uses a graph database to list and demonstrate various relationships between users. Neo4J is one of the most popular open source graph database. One of the major dis-advantage of the Graph Database is that it is not possible to self-reference (self joins in the RDBMS terms) and there might be real world scenarios where this might be required and graph database does not support it. Spatial Databases  We all use Foursquare, Google+ as well Facebook Check-ins for location aware check-ins. All the location aware applications figure out the position of the phone with the help of Global Positioning System (GPS). Think about it, so many different users at different location in the world and checking-in all together. Additionally, the applications now feature reach and users are demanding more and more information from them, for example like movies, coffee shop or places see. They are all running with the help of Spatial Databases. Spatial data are standardize by the Open Geospatial Consortium known as OGC. Spatial data helps answering many interesting questions like “Distance between two locations, area of interesting places etc.” When we think of it, it is very clear that handing spatial data and returning meaningful result is one big task when there are millions of users moving dynamically from one place to another place & requesting various spatial information. PostGIS/OpenGIS suite is very popular spatial database. It runs as a layer implementation on the RDBMS PostgreSQL. This makes it totally unique as it offers best from both the worlds. Courtesy: mushroom network Tomorrow In tomorrow’s blog post we will discuss about very important components of the Big Data Ecosystem – Hive. Reference: Pinal Dave (http://blog.sqlauthority.com) Filed under: Big Data, PostADay, SQL, SQL Authority, SQL Query, SQL Server, SQL Tips and Tricks, T SQL

  Read the article

• Opening a password encrypted access database using DAO VB.NET

  - by prasoon99

  I create a database like this: Sub Main() Dim wrkDefault As Workspace Dim dbE As DBEngine Dim dbs As Database 'Get default Workspace. dbE = New DBEngine wrkDefault = dbE.Workspaces(0) 'Set the database filename Dim DBFilename As String DBFilename = "c:\mydb.mdb" 'Make sure there isn't already a file with the same name of 'the new database file. If Dir(DBFilename) <> "" Then MsgBox("File already exists!") Exit Sub End If 'Create a new encrypted database with the specified 'collating order. 'lock database with the password 'hello' dbs = wrkDefault.CreateDatabase(DBFilename, _ LanguageConstants.dbLangGeneral & ";pwd=hello;", DatabaseTypeEnum.dbEncrypt) dbs.Close() End Sub How do I open this database again in VB.NET using DAO?

  Read the article

• Catch database exception in Kohana

  - by danilo

  I'm using Kohana 2. I would like to catch a database exception to prevent an error page when no connection to the server can be established. The error displayed is system/libraries/drivers/Database/Mysql.php [61]: mysql_connect() [function.mysql-connect]: Lost connection to MySQL server at 'reading initial communication packet', system error: 110 The database server is not reachable at all at this point. I'm doing this from a model. I tried both public function __construct() { // load database library into $this->db try { parent::__construct(); } catch (Exception $e) { die('Database error occured'); } } as well as try { $hoststatus = $this->db->query('SELECT x FROM y WHERE z;'); } catch (Exception $e) { die('Database error occured'); } ...but none of them seemed to work. It seems as if no exception gets passed on from the main model. Is there another way to catch the database error and use my own error handling?

  Read the article

• Legacy Database, Fluent NHibernate, and Testing my mappings

  - by sdanna

  As the post title implies, I have a legacy database (not sure if that matters), I'm using Fluent NHibernate and I'm attempting to test my mappings using the Fluent NHibernate PersistenceSpecification class. My question is really a process one, I want to test these when I build locally in Visual Studio using the built in Unit Testing framework for now. Obviously this implies (I think) that I'm going to need a database. What are some options for getting this into the build? If I use an in memory database does NHibernate or Fluent NHibernate have some some mechanism for sucking the database schema from a target database or maybe the in memory database can do this? Will I need to manually get the schema to feed to an in memory database? Ideally I would like to get this this setup to where the other developers don't really have to think about it other than when they break the build because the tests don't pass.

  Read the article

• What is the point in using a "real" database modeling tool?

  - by cdeszaq

  We currently have a 10 year old nasty, spaghetti-code-style SQL Server database that we are soon looking to pretty much re-write from scratch as part of a re-write to a large web application. (The existing application will serve as the functional requirements for the next incarnation of the app). Some have suggested we use Visio to do all the diagramming and to generate the DDL, but others have suggested we use a dedicated database design tool, rather than a diagramming tool that is able to export DDL. Is there any benefit to using "real" DB design tools, such as ModelRight, over general tools like Visio? If so, what are those specific benefits? Edit: In a nutshell, what can real/dedicated tools do that something like Visio can't, and how much do these capabilities matter (from a best-practices standpoint, for example)

  Read the article

• What resources will help me understand the fundamentals of Relational Database Systems.

  - by Rachel

  This are few of the fundamental database questions which has always given me trouble. I have tried using google and wiki but I somehow I miss out on understanding the functionality rather than terminology. If possible would really appreciate if someone can share more insights on this questions using some visual representative examples. What is a key? A candidate key? A primary key? An alternate key? A foreign key? What is an index and how does it help your database? What are the data types available and when to use which ones?

  Read the article

• Database: relational/not relational/object oriented... What to choose?

  - by Damian

  I'm porting a website that I made for app engine to run on a dedicated server. It is coded in java and I'm looking for a database to replace google datastore. My first thougt was MySql because everybody uses it, but i dont like SQL and I think I would feel more comfortable using OODB or anything else. With google datastore I could modify my models and don't worry about the database definition at all. I know using MySql that isn't possible. And I don't want to miss that. And if I use a OODB, which should I use? What about performance compared to MySql? Well, any idea or tip will really help me since I know nothing about databases.

  Read the article

• YAGNI and database creation scripts

  - by Daniel Straight

  Right now, I have code which creates the database (just a few CREATE queries on a SQLite database) in my main database access class. This seems unnecessary as I have no intention of ever using the code. I would just need it if something went wrong and I needed to recreate the database. Should I... Leave things as they are, even though the database creation code is about a quarter of my file size. Move the database-creation code to a separate script. It's likely I'll be running it manually if I ever need to run it again anyway, and that would put it out-of-sight-out-of-mind while working on the main code. Delete the database-creation code and rely on revision control if I ever find myself needing it again.

  Read the article

• How secure is a PostgreSQL database if my server is stolen?

  - by orokusaki

  If I have a server with a database if top secret data in PostgreSQL and my password is practically impossible to crack (128 character string of all sorts of weird chars, generated by hand). The server password is also uncrackable in theory (basically, ignore the possibility of a password crack on the DB). Aside from a password crack, how easy is it to get the data out of this database? Assumptions: Only the DB exists on the server. There is no password in a PHP script or anything like that The person who has the server is a computer / DB / hard-drive recovery expert I'm not using any hard-drive encryption or anything out of the norm for protection I'm trying to understand the risks involved with somebody gaining physical access to my server's hard-drives.

  Read the article

• What resources will help me understand the fundamentals of Relational Database Design.

  - by Rachel

  This are few of the fundamental database questions which has always given me trouble. I have tried using google and wiki but I somehow I miss out on understanding the functionality rather than terminology. If possible would really appreciate if someone can share more insights on this questions using some visual representative examples. What is a key? A candidate key? A primary key? An alternate key? A foreign key? What is an index and how does it help your database? What are the data types available and when to use which ones?

  Read the article

• Do you think functional language is good for applications that have a lot of business rules but very

  - by StackUnderflow

  I am convinced that functional programming is an excellent choice when it comes to applications that require a lot of computation (data mining, AI, nlp etc). But is it wise to use functional programming for a typical enterprise application where there are a lot of business rules but not much in terms of computation? Please disregard the fact that there are very few people using functional programming and that it's kind of tough. Thanks

  Read the article

• How it is better to organise a large database of addresses?

  - by shurik2533

  How it is better to organise a large database of addresses? It is need to create mysql database of addresses. How it is better for organising? I have two variants: 1) cuontries id|name 1 |Russia cities id|name 1 |Moscow 2 |Saratov villages id|name streets id|name 1 |Lenin st. places id|name |country_id|city_id|village_id|street_id|building_number|office|flat_number|room_number 1 |somebuilding |1 |1 |NULL |1 |31 |12a |NULL |NULL For simplification I use not all making addresses. If any part does not participate in the address it is equal NULL 2) addressElements id|name 1 |country 2 |city 3 |village 4 |street 5 |office 6 |flat_number 7 |room_number addressValues id|addressElement_id|value 1 |1 |Russia 2 |2 |Saratov 3 |2 |Moscow 4 |3 |Prostokvashino 5 |4 |Lenin st. places id| name 1 | somebuilding places_has_addressValues place_id|addressValue_id 1 |1 1 |3 1 |5 UPD. I have decided to make as follows

  Read the article

• Copy of Access mdb database being updated by live database

  - by James

  I'm trying to compute statistics for data held in an Access .mdb database. In order to avoid interfering with the live database, I'm working from a copy which I made by simply using copy-paste in Windows Explorer. The copy resides in the same directory, but with a different name. I'm using R and RODBC to connect to the copy of the file. The strange thing is that new data that is being updated on the original live database is appearing in my queries. This is despite the file timestamps of the copy not changing at all. It is also causing some slowdown in the live database. My understanding is that the .mdb files are standalone, or is this not the case? Should I have copied the database in a different way?

  Read the article

• CREATE DATABASE permission denied in database 'master'.

  - by MuraliVijay CSK

  I have used this connection string to connect my database.... <connectionStrings> <add name="connectionString" connectionString="Data Source=.\SQLEXPRESS;AttachDbFilename=C:\Program Files\Microsoft SQL Server\MSSQL.1\MSSQL\Data\Taxi.mdf;Database=Taxi;Trusted_Connection=Yes;" providerName="System.Data.SqlClient"/> i got this error while running in IIS Exception Details: System.Data.SqlClient.SqlException: CREATE DATABASE permission denied in database 'master'. Cannot attach the file 'C:\Program Files\Microsoft SQL Server\MSSQL.1\MSSQL\Data\Taxi.mdf' as database 'Taxi'.

  Read the article

• database encryption questions

  - by 5YrsLaterDBA

  We are using Sybase SQL Anywhere 11. We need to encrypt some of our tables in our database. I followed the instruction and did it. We selected the "strong" option with encryptionKey and AES256_FIPS algorithm. But there are something I am not clear about them. It will require encryptonKey when we create the database, remove the database and start the database server but it will NOT require encryptionKey when we stop the database server and connect to the server to create tables and add data. Why there is NO encryptionKey asked when we connect to it or try to stop the server? I am doing something wrong? don't know how to test the encryption? I still can see all plain text in the encrypted tables when I use Sybase Central tool. If somebody knows the database user name and password, he/she can connect to the database and read the content without the encryptionKey. is this right?

  Read the article

• Won't connect to the database

  - by user1657958

  I'm confused...I'm using the same code in a different document and in there it's not a problem to get a connection to the database. But in the new document it's just not working...(password, username, database name...all is checked and correct) :-/ <?php define ("DB_HOST", "db1234567.db.hello.com"); // set database host define ("DB_USER", "db1234567"); // set database user define ("DB_PASS","password123"); // set database password define ("DB_NAME","db1234567"); // set database name $link = mysql_connect(DB_HOST, DB_USER, DB_PASS) or die("Couldn't make connection."); $db = mysql_select_db(DB_NAME, $link) or die("Couldn't select database"); ?> In the browser I get this: "Warning: mysql_connect() [function.mysql-connect]: Access denied for user 'db1234567'@'123.123.12.12 (using password: YES) in /homepages/12/1234567/test/test.php on line 8 Couldn't make connection." Would be cool if someone could help me :) I'm not seeing any error... Thx!

  Read the article

• SQL SERVER – What is Spatial Database? – Developing with SQL Server Spatial and Deep Dive into Spati

  - by pinaldave

  What is Spatial Database? A spatial database is a database that is optimized to store and query data related to objects in space, including points, lines and polygons. While typical databases can understand various numeric and character types of data, additional functionality needs to be added for databases to process spatial data types. (Source: Wikipedia) Today I will be talking about the same subject at Microsoft TechEd India. If you want to learn about how to spatial aspect of data and how to integrate them with SQL Server this is the perfect session for you. Spatial is very special concept of SQL Server and I really like how it is implemented in SQL Server. In general Performance Tuning and Query Optimization is something I always have enjoyed in my professional life. Index are my best friends and many time, by implementing and many time by removing I have improved the performance of the system. In this session, I will be talking about Index along with Spatial Data. As Spatial Database is very interesting concept, I will cover super short but very interesting 10 quick slides about this subject. I will make sure in very first 20 mins, you will understand following topics Introduction to Spatial Database One line definition Understanding Spatial Indexing Index Internals Query/Performance Tuning Query Hinting/Cost Analysis Spatial Index Catalog Views Performance Troubleshooting Finding Optimal Index using Spatial Index SP Common Errors Index Maintenance This slides decks will be followed by around 30 mins demo which will have story of geometry, geography, index internals and performance tuning. If you are interested in learning how GIS works and how SQL Server out of the box supports this wonderful tools, you will really like how the story is told. I am sure all people who attend the event will know how the Bangalore is positioned on the map of India. I will take example of Bangalore and Hyderabad and demonstrate how index can improve the performance. Well there are lots of story to tell in the session, and I will be opening this session with the beautiful script of Botticelli’s Birth of Venus created by Michael J. Swart. I will also demonstrate few real life scenario where I will be talking about Spatial Database and its usage. Do not miss this session. At the end of session there will be book awarded to best participant. My session details: Session 3: Developing with SQL Server Spatial and Deep Dive into Spatial Indexing Date: April 14, 2010 Time: 5:00pm-6:00pm Microsoft SQL Server 2008 delivers new spatial data types that enable you to consume, use, and extend location-based data through spatial-enabled applications. Attend this session to learn how to use spatial functionality in next version of SQL Server to build and optimize spatial queries. This session outlines the new geography data type to store geodetic spatial data and perform operations on it, use the new geometry data type to store planar spatial data and perform operations on it, take advantage of new spatial indexes for high performance queries, use the new spatial results tab to quickly and easily view spatial query results directly from within Management Studio, extend spatial data capabilities by building or integrating location-enabled applications through support for spatial standards and specifications and much more. Reference: Pinal Dave (http://blog.SQLAuthority.com) Filed under: Pinal Dave, SQL, SQL Authority, SQL Index, SQL Optimization, SQL Performance, SQL Query, SQL Server, SQL Tips and Tricks, SQLAuthority Author Visit, T SQL, Technology Tagged: Spatial Database

  Read the article

• Oracle Database Appliance Now Certified by SAP

  - by Bandari Huang

  All SAP products based on SAP NetWeaver 7.x that are also certified for Oracle Database 11g Release 2 (single node or RAC) can now be used with the Oracle Database Appliance. RAC One Node is NOT supported. Only Three-Tier SAP Installations. Only the Oracle database can run on the Oracle Database Appliance.  No SAP instance can be deployed on the Oracle Database Appliance. SAP instances have to run on different middle-tier machines of any hardware architecture and operating system. Central Services (ASCS and/or SCS) can be configured to run on the Oracle Database Appliance for Unicode installations of SAP. SAP BR*Tools support is now available for the Oracle Database Appliance. For more information about SAP on ODA, please refer: Using SAP NetWeaver with the Oracle Database Appliance New Nov2012 Note 1760737 - SAP Software and Oracle Database Appliance (ODA) Note 1785353 - ODA 11.2.0: Patches for 11.2.0.3  

  Read the article

• Would learning any (linguistic) language in particular further your programming career?

  - by Anonymous

  It seems apparent that English is the dominant international language for programming based on previous P.SE questions (though a highly upvoted comment correctly points out that asking a question like that on a predominantly English site will skew the results). However, is there benefit in learning a foreign language for software development? For example, do the Chinese have completely different software tools, languages, technologies, etc? How about Japanese, Russian, and other non-latin based languages? Is there an entire world of software development languages, tools and so on that only exist in these other languages? Or do people that know these languages use the tools and languages we know and love?

  Read the article

• Writing a new programming language - when and how to bootstrap datastructures?

  - by OnResolve

  I'm in the process of writing my own programming language which, thus far, has been going great in terms of what I set out to accomplish. However, now, I'd like to bootstrap some pre-existing data structures and/or objects. My problem is that I'm not really sure on how to begin. When the compiler begins do I splice in these add-ins so their part of the scope of the application? If I make these in some core library, my concern is how I distribute the library in addition to the compiler--or are they part of the compiler? I get that there are probably a number of plausible ways to approach this, but I'm having trouble with the setting my direction. If it helps, the language is on top of the .NET core (i.e it compiles to CLR code). Any help or suggestions are very much appreciated!

  Read the article

• Is Haskell's type system an obstacle to understanding functional programming?

  - by FarmBoy

  I'm studying Haskell for the purpose of understanding functional programming, with the expectation that I'll apply the insight that I gain in other languages (Groovy, Python, JavaScript mainly.) I choose Haskell because I had the impression that it is very purely functional, and wouldn't allow for any reliance on state. I did not choose to learn Haskell because I was interested in navigating an extremely rigid type system. My question is this: Is a strong type system a necessary by-product of an extremely pure functional language, or is this an unrelated design choice particular to Haskell? If it is the latter, I'm curious what would be the most purely functional language that is dynamically typed. I'm not particularly opposed to strong typing, it has its place, but I'm having a hard time seeing how it benefits me in this educational endeavor.

  Read the article

• What programming languages should every computer science student be taught?

  - by Anto

  What languages (or classes (as in paradigms) of programming languages, plus a recommended language of that class) should every computer science student be taught in college according to you? Motivate your answers; why that language? What use will one have from it? What concepts does it teach (better than language X does)? Note/clarification: This question is about computer science with heavy focus on software engineering, not pure computer science. It is still computer science education and not software engineering education which is the focus.

  Read the article

• Would learning any (linguistic) language imparticular further your programming career?

  - by Anonymous

  It seems apparent that English is the dominant international language for programming (in the West, at least!) based on previous P.SE questions. Or maybe not, given that a highly upvoted comment correctly points out that asking a question like that on a predominantly English site will skew the results. This question is about whether there is a benefit in learning a foreign language for software development. For example, do the Chinese have completely different software tools, langugages, technologies etc? How about Japanese, Russian, and other non-latin based languages? Am I/are we missing an entire world of software development languages, tools and so on that only exist in these other languages? Or do people that know these languages still learn and program using the tools and languages we all know and love?

  Read the article

< Previous Page | 41 42 43 44 45 46 47 48 49 50 51 52  | Next Page >