Search Results

Search found 40870 results on 1635 pages for 'database design'.

Page 126/1635 | < Previous Page | 122 123 124 125 126 127 128 129 130 131 132 133  | Next Page >

• database vs flat file, which is a faster structure for regex matching with many simultaneous request

  - by Jamex

  Hi, which structure returns faster result and/or less taxing on the host server, flat file or database (mysql)? Assume many users (100 users) are simultaneously query the file/db. Searches involve pattern matching using regex against a static file/db. File has 50,000 unique lines (same data type). There could be many matches. There is no writing to the file/db, just read. Is it possible to have a duplicate the file/db and write a logic switch to use the backup file/db if the main file is in use? Which language is best for the type of structure? Perl for flat and PHP for db? TIA

  Read the article

• database vs flat file, which is a faster structure for "regex" matching with many simultaneous reque

  - by Jamex

  Hi, which structure returns faster result and/or less taxing on the host server, flat file or database (mysql)? Assume many users (100 users) are simultaneously query the file/db. Searches involve pattern matching against a static file/db. File has 50,000 unique lines (same data type). There could be many matches. There is no writing to the file/db, just read. Is it possible to have a duplicate the file/db and write a logic switch to use the backup file/db if the main file is in use? Which language is best for the type of structure? Perl for flat and PHP for db? Addition info: If I want to find all the cities have the pattern "cis" in their names. Which is better/faster, using regex or string functions? Please recommend a strategy TIA

  Read the article

• Java init method

  - by Johan Sjöberg

  What's a good way to make sure an init method is invoked in java? The alternatives I see are Don't test it, let the method fail by itself, likely by a NullPointerException Test if method was initialized or throw public void foo() { if (!inited) { throw new IllegalArgumentException("not initalized"); } ... } Delagate public void foo() { if (!inited) { throw new IllegalArgumentException("not initalized"); } fooInternal(); } private void fooInternal(){ ... }; Always init, and make init a noop otherwise public void foo() { init(); ... } public void init() { if(!inited) { ... } } Silently init public void foo() { if (!inited) { init(); } ... } Most of these approaches are very verbose and decreases overall readability.

  Read the article

• Order database results by bayesian rating

  - by One Trick Pony

  I'm not sure this is even possible, but I need a confirmation before doing it the "ugly" way :) So, the "results" are posts inside a database which are stored like this: the posts table, which contains all the important stuff, like the ID, the title, the content the post meta table, which contains additional post data, like the rating (this_rating) and the number of votes (this_num_votes). This data is stored in pairs, the table has 3 columns: post ID / key / value. It's basically the WordPress table structure. What I want is to pull out the highest rated posts, sorted based on this formula: br = ( (avg_num_votes * avg_rating) + (this_num_votes * this_rating) ) / (avg_num_votes + this_num_votes) which I stole form here. avg_num_votes and avg_rating are known variables (they get updated on each vote), so they don't need to be calculated. Can this be done with a mysql query? Or do I need to get all the posts and do the sorting with PHP?

  Read the article

• Java library to partially export a database while respecting referential integrity constraints

  - by Mwanji Ezana

  My production database is several GB's uncompressed and it's getting to be a pain to download and run locally when trying to reproduce a bug or test a feature with real data. I would like to be able to select the specific records that interest me, then have the library figure out what other records are necessary to produce a dataset that respects the databases integrity constraints and finally print it out as a list of insert statements or dump that I can restore. For example: given Author, Blog and Comment tables when I select comments posted after a certain date I should get inserts for the Blog records the comments have foreign keys to and the Author records those Blogs have foreign keys to.

  Read the article

• What is the difference between the Facade and Addapter Pattern?

  - by devoured elysium

  I've been reading both definitions and they seem quite the same. Could anyone point out what are their differences? Thanks

  Read the article

• C# Importing Large Volume of Data from CSV to Database

  - by guazz

  What's the most efficient method to load large volumes of data from CSV (3 million + rows) to a database. The data needs to be formatted(e.g. name column needs to be split into first name and last name, etc.) I need to do this in a efficiently as possible i.e. time constraints I am siding with the option of reading, transforming and loading the data using a C# application row-by-row? Is this ideal, if not, what are my options? Should I use multithreading?

  Read the article

• what's the best practice to config Hibernate-Spring for multiple database relationship?

  - by nazila

  We have a main mysql database which all of the applications within our organization need the data within this database. How can I config my java web application to use this database with it's specific database when I use Spring and Hibernate within my application? How can I config JPA annotations for example between CONTRACT table within my database and COUNTRY table within our main database? what's the best practice to do this?

  Read the article

• Database indexes and their Big-O notation

  - by miket2e

  I'm trying to understand the performance of database indexes in terms of Big-O notation. Without knowing much about it, I would guess that: Querying on a primary key or unique index will give you a O(1) lookup time. Querying on a non-unique index will also give a O(1) time, albeit maybe the '1' is slower than for the unique index (?) Querying on a column without an index will give a O(N) lookup time (full table scan). Is this generally correct ? Will querying on a primary key ever give worse performance than O(1) ? My specific concern is for SQLite, but I'd be interested in knowing to what extent this varies between different databases too.

  Read the article

• C# ASP.NET Update database with datatable

  - by Sir Graystar

  Scenario: I'm just trying to update my database with the changes made by the user to their information. Here is my code: SqlCommandBuilder cb = new SqlCommandBuilder(da); dt.Rows[0][2] = txtname.Text; dt.Rows[0][3] = txtinterests.Text; dt.Rows[0][4] = txtlocation.Text; da.SelectCommand = new SqlCommand(sqlcommand, conn); da.Update(dt); I know its going to be something obvious, but what have I missed? There are no errors, everything compiles correctly, but nothing happens. The record remains unchanged.

  Read the article

• how to share a variable between two threads

  - by prmatta

  I just inherited some code, two threads within this code need to perform a system task. One thread should do the system task before the other thread. They should not be performing the system task together. The two threads do not have references to each other. Now, I know I can use some sort of a semaphore to achieve this. But my question is what is the right way to get both threads to access this semaphore. I could create a static variable/method a new class : public class SharedSemaphore { private static Semaphore s = new Semaphore (1, true); public static void performSystemTask () { s.acquire(); } public static void donePerformingSystemTask() { s.release(); } } This would work (right?) but this doesn't seem like the right thing to do. Because, the threads now have access to a semaphore, without ever having a reference to it. This sort of thing doesn't seem like a good programming practice. Am I wrong?

  Read the article

• UML - Object Method Returns a Collection

  - by derekerdmann

  How can I indicate that a method will return a collection of objects in UML? Is there a better way to explain the relationship than to have a collection class as a return type?

  Read the article

• Single database with multiple instances of Django

  - by jwesonga

  I have a Django project where the company will have a main site like www.ourcompany.org and a bunch of sub-domains like project.ourcompany.org. Content appearing in the sub-domains like case studies should also appear in the main site. I've decided to use multiple instances of Django BUT one database for each sub-domain so that I can have some flexibility and take advantage of the Sites framework. What I'm not sure of is how to access the models across the multiple instances. If I have a model: class CaseStudy(models.Model): title=models.CharField(max_length=100) site=models.ManyToMany(Site) Do I need to create this model in every instance so that I can have access to the object?

  Read the article

• Set database based on how the application was started

  - by AaronThomson

  I have two Rails applications (lets call them APP-1 and APP-2), each of them has a dependancy on a third Rails application (APP-3). I would like to be able to run the tests for APP-1 and APP-2 in parallel on my CI server. The problem is, both need to start up APP-3 and write to a DB via the APP-3. This causes conflicts and failures if the tests are run in parallel. My idea for a solution is for APP-1 and APP-2 to each start their own instance of APP-3 and to have each instance point to a different DB. Is there a way to dynamically set the DB in the database.yml of APP-3 so that it connects to a different DB depending on which APP starts it up? FYI. APP-1 and APP-2 currently start APP-3 via rake tasks.

  Read the article

• Can we create a class from a xml file ?

  - by panzerschreck

  Hello, Is it possible to create a class dynamically by reading an xml file ( in java preferably) ? if yes, please provide pointers on how to do it. In the process of development, we have come up with a class that has 5 attributes, all these attributes correspond to an entry in the xml file, now if the user adds/modifies the xml entry the object corresponding to it must change automatically, one approach would be generate the source code, before compile time.Is there any other way ? Is there any common pattern to model such changes in the system ? Thanks,

  Read the article

• Codeigniter database update

  - by Carry All

  The table is like this and I want to update DecryptionDate by specify ArchiveID and RecipientID this is my code $this->load->database(); $date = date("Y-m-d H:i:s"); $data = array('DecryptionDate' => $date); $array = array('ArchiveID'=>$archiveID.'','RecipientID'=>$userID.''); $this->db->where($array); $this->db->update('log', $data); if ($this->db->affected_rows() > 0) { echo "SUCCESS"; } else { echo "FAIL"; } my problem is I can update the data only when $archiveID is 911 and $userID is test01 but the program fail to update when $archiveID is 911 and $userID is test02

  Read the article

• What is the difference between the Facade and Adapter Pattern?

  - by devoured elysium

  I've been reading both definitions and they seem quite the same. Could anyone point out what are their differences? Thanks

  Read the article

• Create a service that connects to remote database and uses public key encryption

  - by Leedsoft Solutions

  I have been searching all day and reading many tutorials and still I am confused. I am working on a project that has the following requirements as specified by the client (customer - not to be confused with client app): Connect to a remote server and verify that connection was successful. Connect to Web service on said server via SOAP. Authenticate with service using public key encryption Upon successful authentication, push a list of products and categories to a MSSQL database on remote server via the Web service. The client is a Winforms application written in C#. So far, I have created a WCF Service Application with separate services for the products and categories but I cannot figure the rest out. Can anyone point me in the direction of a tutorial or tutorials that cover these requirements? Many thanks in advance! Joe

  Read the article

• Copying a mysql database from localhost to remote server using mysqldump.exe

  - by Ankur

  I want to copy a mysql database from my local computer to a remote server. I am trying to use the mysql dump command. All the examples on the internet suggest doing something like The initial mysql> is just the prompt I get after logging in. mysql> mysqldump -u user -p pass myDBName | NewDBName.out; But when I do this I get You have an error in your SQL syntax; check the manual that corresponds ... to use near 'mysqldump -u user -p pass myDBName | NewDBName.out' Since I have already logged in do I need to use -u and -p? Not doing so gives me the same error. Can you see what is wrong?

  Read the article

• Alternatives to static methods on interfaces for enforcing consistency

  - by jayshao

  In Java, I'd like to be able to define marker interfaces, that forced implementations to provide static methods. For example, for simple text-serialization/deserialization I'd like to be able to define an interface that looked something like this: public interface TextTransformable<T>{ public static T fromText(String text); public String toText(); Since interfaces in Java can't contain static methods though (as noted in a number of other posts/threads: here, here, and here this code doesn't work. What I'm looking for however is some reasonable paradigm to express the same intent, namely symmetric methods, one of which is static, and enforced by the compiler. Right now the best we can come up with is some kind of static factory object or generic factory, neither of which is really satisfactory. Note: in our case our primary use-case is we have many, many "value-object" types - enums, or other objects that have a limited number of values, typically carry no state beyond their value, and which we parse/de-parse thousands of time a second, so actually do care about reusing instances (like Float, Integer, etc.) and its impact on memory consumption/g.c. Any thoughts?

  Read the article

• Where are the readonly/const in .NET?

  - by acidzombie24

  In C++ you'll see void func(const T& t) everywhere. However, i havent seen anything similar in .NET. Why? I have notice a nice amount of parameters using struct. But i see no functions with readonly/const. In fact now that i tried it i couldnt use those keywords to make a function that promises to not modify a list being passed in. Is there no way to promise the caller that this function will never modify the contents of list? Is there no way to say to call code and say this list should never be modified? (I know i can clone the list or look at documentation but i like compile errors sometime)

  Read the article

• .NET Database application guidance.

  - by Wally

  Hello, I'm stumbling in the data wilderness and feel very lost, so i am asking for help. I have done some database apps in VS (C#) winforms for some time, wpf lately. These are small to medium apps (embedded dbs, a bit of sql server), like a restaurants, cash registers and similar. (15-20 tables) Until now, i have done all my datasets by drag and drop in Visual Studio designer. I spent weeks on web trying to find some complete solution how to write complete solution with typed datasets by hand from scratch (DAL, B.Objects) in hope to learn some architecture patterns along the way, but without success. So, finally question. Can someone recommend me what to learn for this type of applications, maybe move away from datasets , use some ORM ( maybe overkill, i dont know). Point me in some direction please.

  Read the article

• Storing millions of URLs in a database for fast pattern matching

  - by Paras Chopra

  I am developing a web analytics kind of system which needs to log referring URL, landing page URL and search keywords for every visitor on the website. What I want to do with this collected data is to allow end-user to query the data such as "Show me all visitors who came from Bing.com searching for phrase that contains 'red shoes'" or "Show me all visitors who landed on URL that contained 'campaign=twitter_ad'", etc. Because this system will be used on many big websites, the amount of data that needs to log will grow really, really fast. So, my question: a) what would be the best strategy for logging so that scaling the system doesn't become a pain; b) how to use that architecture for rapid querying of arbitrary requests? Is there a special method of storing URLs so that querying them gets faster? In addition to MySQL database that I use, I am exploring (and open to) other alternatives better suited for this task.

  Read the article

• designing multi module J2EE application

  - by user728947

  Might be my question is abstract or out of context, but i am asking here since i have little idea how this happens. I am wondering how big application/ platform break down there application in to multiple module and how they able to manage modules dependencies. For example in some E-commerce application they tend to break down it in various modules like pricing,promotions,shipping.import/export and many more. when we develop those application we hardly think about the underlying modules and how they have been designed to provides functionalists. Most of those module are not web-applications but are standalone module and not deployed in the web-app as jar files. can any one help me to understand how they break up things or is there any standard way to do this.any help/resources to get insight will really be helpful

  Read the article

• How to create initializeDB() method for java database

  - by Holly

  I am working on a Java project for class and have not worked much with incorporating databases into Java. I can't find much on the initializeDB() method, but if I could get some help I would really appreciate it. Below is the code being used for the intializeDB() method: private void initializeDB() { try { // Load the JDBC driver System.out.println("Driver loaded"); // Establish a connection System.out.println("Database connected"); // Create a statement // Create a SQL Query string // Execute the query to create a recordset } catch (Exception ex) { ex.printStackTrace(); } }

  Read the article

< Previous Page | 122 123 124 125 126 127 128 129 130 131 132 133  | Next Page >