Search Results

Search found 38931 results on 1558 pages for 'database testing'.

facebook twitter digg google delicious technorati stumbleupon myspace wordpress linkedin gmail igoogle windows live tumblr viadeo yahoo buzz yahoo mail yahoo bookmarks favorites email print

Page 16/1558 | < Previous Page | 12 13 14 15 16 17 18 19 20 21 22 23  | Next Page >

  • Book Review: Pro SQL Server 2008 Relational Database Design and Implementation

    - by Alexander Kuznetsov
    Investing in proper database design is a very efficient way to cut maintenance costs. If we expect a system to last, we need to make sure it has a good solid foundation - high quality database design. Surely we can and sometimes do cut corners and save on database design to get things done faster. Unfortunately, such cutting corners frequently comes back and bites us: we may end up spending a lot of time solving issues caused by poor design. So, solid understanding of relational database design is...(read more)

    Read the article

  • SQL University: What and why of database testing

    - by Mladen Prajdic
    This is a post for a great idea called SQL University started by Jorge Segarra also famously known as SqlChicken on Twitter. It’s a collection of blog posts on different database related topics contributed by several smart people all over the world. So this week is mine and we’ll be talking about database testing and refactoring. In 3 posts we’ll cover: SQLU part 1 - What and why of database testing SQLU part 2 - What and why of database refactoring SQLU part 2 – Tools of the trade With that out of the way let us sharpen our pencils and get going. Why test a database The sad state of the industry today is that there is very little emphasis on testing in general. Test driven development is still a small niche of the programming world while refactoring is even smaller. The cause of this is the inability of developers to convince themselves and their managers that writing tests is beneficial. At the moment they are mostly viewed as waste of time. This is because the average person (let’s not fool ourselves, we’re all average) is unable to think about lower future costs in relation to little more current work. It’s orders of magnitude easier to know about the current costs in relation to current amount of work. That’s why programmers convince themselves testing is a waste of time. However we have to ask ourselves what tests are really about? Maybe finding bugs? No, not really. If we introduce bugs, we’re likely to write test around those bugs too. But yes we can find some bugs with tests. The main point of tests is to have reproducible repeatability in our systems. By having a code base largely covered by tests we can know with better certainty what a small code change can break in other parts of the system. By having repeatability we can make code changes with confidence, since we know we’ll see what breaks in other tests. And here comes the inability to estimate future costs. By spending just a few more hours writing those tests we’d know instantly what broke where. Imagine we fix a reported bug. We check-in the code, deploy it and the users are happy. Until we get a call 2 weeks later about a certain monthly process has stopped working. What we don’t know is that this process was developed by a long gone coworker and for some reason it relied on that same bug we’ve happily fixed. There’s no way we could’ve known that. We say OK and go in and fix the monthly process. But what we have no clue about is that there’s this ETL job that relied on data from that monthly process. Now that we’ve fixed the process it’s giving unexpected (yet correct since we fixed it) data to the ETL job. So we have to fix that too. But there’s this part of the app we coded that relies on data from that exact ETL job. And just like that we enter the “Loop of maintenance horror”. With the loop eventually comes blame. Here’s a nice tip for all developers and DBAs out there: If you make a mistake man up and admit to it. All of the above is valid for any kind of software development. Keeping this in mind the database is nothing other than just a part of the application. But a big part! One reason why testing a database is even more important than testing an application is that one database is usually accessed from multiple applications and processes. This makes it the central and vital part of the enterprise software infrastructure. Knowing all this can we really afford not to have tests? What to test in a database Now that we’ve decided we’ll dive into this testing thing we have to ask ourselves what needs to be tested? The short answer is: everything. The long answer is: read on! There are 2 main ways of doing tests: Black box and White box testing. Black box testing means we have no idea how the system internals are built and we only have access to it’s inputs and outputs. With it we test that the internal changes to the system haven’t caused the input/output behavior of the system to change. The most important thing to test here are the edge conditions. It’s where most programs break. Having good edge condition tests we can be more confident that the systems changes won’t break. White box testing has the full knowledge of the system internals. With it we test the internal system changes, different states of the application, etc… White and Black box tests should be complementary to each other as they are very much interconnected. Testing database routines includes testing stored procedures, views, user defined functions and anything you use to access the data with. Database routines are your input/output interface to the database system. They count as black box testing. We test then for 2 things: Data and schema. When testing schema we only care about the columns and the data types they’re returning. After all the schema is the contract to the out side systems. If it changes we usually have to change the applications accessing it. One helpful T-SQL command when doing schema tests is SET FMTONLY ON. It tells the SQL Server to return only empty results sets. This speeds up tests because it doesn’t return any data to the client. After we’ve validated the schema we have to test the returned data. There no other way to do this but to have expected data known before the tests executes and comparing that data to the database routine output. Testing Authentication and Authorization helps us validate who has access to the SQL Server box (Authentication) and who has access to certain database objects (Authorization). For desktop applications and windows authentication this works well. But the biggest problem here are web apps. They usually connect to the database as a single user. Please ensure that that user is not SA or an account with admin privileges. That is just bad. Load testing ensures us that our database can handle peak loads. One often overlooked tool for load testing is Microsoft’s OSTRESS tool. It’s part of RML utilities (x86, x64) for SQL Server and can help determine if our database server can handle loads like 100 simultaneous users each doing 10 requests per second. SQL Profiler can also help us here by looking at why certain queries are slow and what to do to fix them.   One particular problem to think about is how to begin testing existing databases. First thing we have to do is to get to know those databases. We can’t test something when we don’t know how it works. To do this we have to talk to the users of the applications accessing the database, run SQL Profiler to see what queries are being run, use existing documentation to decipher all the object relationships, etc… The way to approach this is to choose one part of the database (say a logical grouping of tables that go together) and filter our traces accordingly. Once we’ve done that we move on to the next grouping and so on until we’ve covered the whole database. Then we move on to the next one. Database Testing is a topic that we can spent many hours discussing but let this be a nice intro to the world of database testing. See you in the next post.

    Read the article

  • ?Oracle Database Appliance???????????

    - by Norihito Yachita
    ?????????????????????????????·????????Oracle Database Appliance???????????????????????????? ?Oracle Database Appliance????Oracle Linux??????2?????Sun Fire?????·???????????Oracle Database 11g Release 2?????Oracle Real Application Clusters???????????????? ?Oracle Database Appliance????????????????????????????????????????????????????????????????OLTP??????????????·?????????????????????????????????????????????????????????????Oracle Real Application Clusters????????????Automatic Storage Management?????????????????

    Read the article

  • XML flat file vs. relational database backend

    - by donpal
    Most projects now need some form of a database. When someone says database, I usually think relational databases, but I still hear about flat file XML databases. What parameters do you take into consideration when deciding between a "real" database and a flat-file XML database. When should one be used over the other, and under what circumstances should I never consider using a flat file (or vice versa a relational) database?

    Read the article

  • sybase bcp import fails

    - by chromeplatedbanana
    We're trying to export some tables from our production database to our test database using bcp. The bcp export seems to work fine, but the import always fails with a data type error (see below). We tested on our test database exporting the table content to a file, then importing it in again immediately, but that failed too. e.g., bcp TABLENAME out ~/tempfile -S servername -U username generates a file as expected. If we use -c option then the number of lines is as expected. However, bcp TABLENAME in ~/tempfile -S servername -U username fails with CTLIB Message: - L0/0D/S0/N0/0/0: blk_int(): blk_layer: CT library error: Cannot find an equivalent CS_TYPE for this TDS data type 49 blk_init failed. We get this whenever we try to copy into TABLENAME, whether from the production or test table dump file. I don't understand why export and import for the same TABLENAME is generating a data type error. What am I doing wrong here? Thanks

    Read the article

  • SQL 2008 Database tuning advisor won’t start

    - by Andrew Hancox
    For some reason I can't get DTA to connect to my development machine. It connects to a remote DB just fine but when I point it to my dev machine I get an error saying: Failed to initialize MSDB database for tuning (exit code: -1073741819). I'm pretty sure it's not a permissions issue since I've used profiler to capture what it's doing and all of the commands it's run so far look fine and are being run under my account which is associated with the sysadmin role, when I run them in sql management studio they go through fine. I'm pretty convinced that the problem is related to creating the objects in MSDB that are used by DTA but I tried creating these manually (I found scripts on the web) and it just seems to push the problem along the line slightly. I'm going out of my mind - have even tried reinstalling SQL but that's not fixed it. I'm using SQL 2008 with SP1 (10.0.2531) on windows server 2008 (patched up to date). SAVE ME!!!!!

    Read the article

  • MSSQL Replace Database in Live Web App

    - by casoninabox
    I have a web app that is currently live. I had the need to make major modifications to the database and now I need to replace the current one. My dev SQL instance is not the live one. I usually just make a backup of the new DB, blow the old one away and Restore my updated one. But now I have data I need to preserve. Most of the current tables have changed, in that extra columns have been added, all existing columns are still there and unchanged. I have access to Management Studio. What is the right way to do this?

    Read the article

  • Regression testing for firewall changes

    - by James C
    We have a number of firewalls in place around our organisation and in some cases packets can pass through four levels of firewall limiting the flow TCP traffic. A concept that I'm used to from software testing is regression testing, allowing you to run a test suite against a changed application to verify that the new changes haven't affected any old features. Does anyone have any experience or an offer any solutions to being able to perform the same type of thing with firewall changes and network testing? The problem becomes a lot more complicated because you'd ideally want to be originating (and testing receipt) of packets across many machines.

    Read the article

  • How do we greatly optimize our MySQL database (or replace it) when using joins?

    - by jkaz
    Hi there, This is the first time I'm approaching an extremely high-volume situation. This is an ad server based on MySQL. However, the query that is used incorporates a lot of JOINs and is generally just slow. (This is Rails ActiveRecord, btw) sel = Ads.find(:all, :select = '*', :joins = "JOIN campaigns ON ads.campaign_id = campaigns.id JOIN users ON campaigns.user_id = users.id LEFT JOIN countries ON countries.campaign_id = campaigns.id LEFT JOIN keywords ON keywords.campaign_id = campaigns.id", :conditions = [flashstr + "keywords.word = ? AND ads.format = ? AND campaigns.cenabled = 1 AND (countries.country IS NULL OR countries.country = ?) AND ads.enabled = 1 AND campaigns.dailyenabled = 1 AND users.uenabled = 1", kw, format, viewer['country'][0]], :order = order, :limit = limit) My questions: Is there an alternative database like MySQL that has JOIN support, but is much faster? (I know there's Postgre, still evaluating it.) Otherwise, would firing up a MySQL instance, loading a local database into memory and re-loading that every 5 minutes help? Otherwise, is there any way I could switch this entire operation to Redis or Cassandra, and somehow change the JOIN behavior to match the (non-JOIN-able) nature of NoSQL? Thank you!

    Read the article

  • Data won't save to SQL database, getting error "close() was never explicitly called on database"

    - by SnowLeppard
    I have a save button in the activity where the user enters data which does this: String subjectName = etName.getText().toString(); String subjectColour = etColour.getText().toString(); SQLDatabase entrySubject = new SQLDatabase(AddSubject.this); entrySubject.open(); entrySubject.createSubjectEntry(subjectName, subjectColour); entrySubject.close(); Which refers to this SQL database class: package com.***.schooltimetable; import android.content.ContentValues; import android.content.Context; import android.database.Cursor; import android.database.SQLException; import android.database.sqlite.SQLiteDatabase; import android.database.sqlite.SQLiteOpenHelper; public class SQLDatabase { public static final String KEY_SUBJECTS_ROWID = "_id"; public static final String KEY_SUBJECTNAME = "name"; public static final String KEY_COLOUR = "colour"; private static final String DATABASE_NAME = "Database"; private static final String DATABASE_TABLE_SUBJECTS = "tSubjects"; private static final int DATABASE_VERSION = 1; private DbHelper ourHelper; private final Context ourContext; private SQLiteDatabase ourDatabase; private static class DbHelper extends SQLiteOpenHelper { public DbHelper(Context context) { super(context, DATABASE_NAME, null, DATABASE_VERSION); // TODO Auto-generated constructor stub } @Override public void onCreate(SQLiteDatabase db) { // TODO Auto-generated method stub db.execSQL("CREATE TABLE " + DATABASE_TABLE_SUBJECTS + " (" + KEY_SUBJECTS_ROWID + " INTEGER PRIMARY KEY AUTOINCREMENT, " + KEY_SUBJECTNAME + " TEXT NOT NULL, " + KEY_COLOUR + " TEXT NOT NULL);"); } @Override public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) { // TODO Auto-generated method stub db.execSQL("DROP TABLE IF EXISTS " + DATABASE_TABLE_SUBJECTS); onCreate(db); } } public SQLDatabase(Context c) { ourContext = c; } public SQLDatabase open() throws SQLException { ourHelper = new DbHelper(ourContext); ourDatabase = ourHelper.getWritableDatabase(); return this; } public void close() { ourHelper.close(); } public long createSubjectEntry(String subjectName, String subjectColour) { // TODO Auto-generated method stub ContentValues cv = new ContentValues(); cv.put(KEY_SUBJECTNAME, subjectName); cv.put(KEY_COLOUR, subjectColour); return ourDatabase.insert(DATABASE_TABLE_SUBJECTS, null, cv); } public String[][] getSubjects() { // TODO Auto-generated method stub String[] Columns = new String[] { KEY_SUBJECTNAME, KEY_COLOUR }; Cursor c = ourDatabase.query(DATABASE_TABLE_SUBJECTS, Columns, null, null, null, null, null); String[][] Result = new String[1][]; // int iRow = c.getColumnIndex(KEY_LESSONS_ROWID); int iName = c.getColumnIndex(KEY_SUBJECTNAME); int iColour = c.getColumnIndex(KEY_COLOUR); for (c.moveToFirst(); !c.isAfterLast(); c.moveToNext()) { Result[0][c.getPosition()] = c.getString(iName); Result[1][c.getPosition()] = c.getString(iColour); Settings.subjectCount = c.getPosition(); TimetableEntry.subjectCount = c.getPosition(); } return Result; } This class has other variables and other variations of the same methods for multiple tables in the database, i've cut out the irrelevant ones. I'm not sure what I need to close and where, I've got the entrySubject.close() in my activity. I used the methods for the database from the NewBoston tutorials. Can anyone see what I've done wrong, or where my problem is? Thanks.

    Read the article

  • Verfication vs validation again, does testing belong to verification? If so, which?

    - by user970696
    I have asked before and created a lot of controversy so I tried to collect some data and ask similar question again. E.g. V&V where all testing is only validation: http://www.buzzle.com/editorials/4-5-2005-68117.asp According to ISO 12207, testing is done in validation: •Prepare Test Requirements,Cases and Specifications •Conduct the Tests In verification, it mentiones. The code implements proper event sequence, consistent interfaces, correct data and control flow, completeness, appropriate allocation timing and sizing budgets, and error definition, isolation, and recovery. and The software components and units of each software item have been completely and correctly integrated into the software item Not sure how to verify without testing but it is not there as a technique. From IEEE: Verification: The process of evaluating software to determine whether the products of a given development phase satisfy the conditions imposed at the start of that phase. [IEEE-STD-610]. Validation: The process of evaluating software during or at the end of the development process to determine whether it satisfies specified requirements. [IEEE-STD-610] At the end of development phase? That would mean UAT.. So the question is, what testing (unit, integration, system, uat) will be considered verification or validation? I do not understand why some say dynamic verification is testing, while others that only validation. An example: I am testing an application. System requirements say there are two fields with max. lenght of 64 characters and Save button. Use case say: User will fill in first and last name and save. When checking the fields and Save button presence, I would say its verification. When I follow the use case, its validation. So its both together, done on the system as a whole.

    Read the article

  • How to verify the code that could take a substantial time to compile? [on hold]

    - by user18404
    As a follow up to my prev question: What is the best aproach for coding in a slow compilation environment To recap: I am stuck with a large software system with which a TDD ideology of "test often" does not work. And to make it even worse the features like pre-compiled headers/multi-threaded compilation/incremental linking, etc is not available to me - hence I think that the best way out would be to add the extensive logging into the system and to start "coding in large chunks", which I understand as code for a two-three hours first (as opposed to 15-20 mins in TDD) - thoroughly eyeball the code for a 15 minutes and only after all that do the compilation and run the tests. As I have been doing TDD for a quite a while, my code eyeballing / code verification skills got rusty (you don't really need this that much if you can quickly verify what you've done in 5 seconds by running a test or two) - so I am after a recommendations on how to learn these source code verification/error spotting skills again. I know I was able to do that easily some 5-10 years ago when I din't have much support from the compiler/unit testing tools I had until recently, thus there should be a way to get back to the basics.

    Read the article

  • How can I test linkable/executable files that require re-hosting or retargeting?

    - by hagubear
    Due to data protection, I cannot discuss fine details of the work itself so apologies PROBLEM CASE Sometimes my software projects require merging/integration with third party (customer or other suppliers) software. these software are often in linkable executables or object code (requires that my source code is retargeted and linked with it). When I get the executables or object code, I cannot validate its operation fully without integrating it with my system. My initial idea is that executables are not meant to be unit tested, they are meant to be linkable with other system, but what is the guarantee that post-linkage and integration behaviour will be okay? There is also no sufficient documentation available (from the customer) to indicate how to go about integrating the executables or object files. I know this is philosophical question, but apparently not enough research could be found at this moment to conclude to a solution. I was hoping that people could help me go to the right direction by suggesting approaches. To start, I have found out that Avionics OEM software is often rehosted and retargeted by third parties e.g. simulator makers. I wonder how they test them. Surely, the source code will not be supplied due to IPR rgulations. UPDATE I have received reasonable and very useful suggestions regarding this area. My current struggle has shifted into testing 3rd party OBJECT code that needs to be linked with my own source code (retargeted) on my host machine. How can I even test object code? Surely, I need to link them first to even think about doing anything. Is it the post-link behaviour that needs to be determined and scripted (using perl,Tcl, etc.) so that inputs and outputs could be verified? No clue!! :( thanks,

    Read the article

  • SQL SERVER – List of All the Samples Database Available to Download for FREE

    - by Pinal Dave
    It is pretty much very common to have a sample database for any database product. Different companies keep on improving their product and keep on coming up with innovation in their product. To demonstrate the capability of their new enhancements they need the sample database. Microsoft have various sample database available for free download for their SQL Server Product. I have collected them here in a single blog post. Download an AdventureWorks Database The AdventureWorks OLTP database supports standard online transaction processing scenarios for a fictitious bicycle manufacturer (Adventure Works Cycles). Scenarios include Manufacturing, Sales, Purchasing, Product Management, Contact Management, and Human Resources. Coconut Dal Coconut Dal is a lightweight data access layer, for use in projects where the Entity Framework cannot be used or Microsoft’s Enterprise Library Data Block is unsuitable. Anyone who is handwriting ADO.NET should use a library instead and Coconut Dal might be the answer.  DataBooster – Extension to ADO.NET Data Provider The dbParallel DataBooster library is a high-performance extension to ADO.NET Data Provider, includes two aspects: 1) A slimmed down API encapsulation which simplified the most common data access operations (DbConnection -> DbCommand -> DbParameter -> DbDataReader) into a single class DbAccess, to help application with a clean DAL, avoid over-packing and redundant-copy of data transfer. 2) A booster for writing mass data onto database. Base on a rational utilization of database concurrency and a effective utilization of network bandwidth. Tabular AMO 2012 The sample is made of two project parts. The first part is a library of functions to manage tabular models -AMO2Tabular V2-. The second part is a sample to build a tabular model -AdventureWorks Tabular AMO 2012- using the AMO2Tabular library; the created model is similar to the ‘AdventureWorks Tabular Model 2012. SQL Server Analysis Services Product Samples SQL Server Analysis Services provides, a unified and integrated view of all your business data as the foundation for all of your traditional reporting, online analytical processing (OLAP) analysis, Key Performance Indicator (KPI) scorecards, and data mining. Analysis Services Samples for SQL Server 2008 R2 This release is dedicated to the samples that ship for Microsoft SQL Server 2008R2. For many of these samples you will also need to download the AdventureWorks family of databases. SQL Server Reporting Services Product Samples This project contains Reporting Services samples released with Microsoft SQL Server product. These samples are in the following five categories: Application Samples, Extension Samples, Model Samples, Report Samples, and Script Samples. If you are interested in contributing Reporting Services samples, please let us know by posting in the developers’ forum. Reporting Services Samples for SQL Server 2008 R2 This release is dedicated to the samples that ship for Microsoft SQL Server 2008 R2 PCU1. For many of these samples you will also need to download the AdventureWorks family of databases. SQL Server Integration Services Product Samples This project contains Integration Services samples released with Microsoft SQL Server product. These samples are in the following two categories: Package Samples and Programming Samples. If you are interested in contributing Integration Services samples, please let us know by posting in the developers’ forum. Integration Services Samples for SQL Server 2008 R2 This release is dedicated to the samples that ship for Microsoft SQL Server 2008R2. For many of these samples you will also need to download the AdventureWorks family of databases. Windows Azure SQL Reporting Admin Sample The SQLReportingAdmin sample for Windows Azure SQL Reporting demonstrates the usage of SQL Reporting APIs, and manages (add/update/delete) permissions of SQL Reporting users. Windows Azure SQL Reporting ReportViewer-SOAP API usage sample These sample projects demonstrate how to embed a Microsoft ReportViewer control that points to reports hosted on SQL Reporting report servers and how to use SQL Reporting SOAP APIs in your Windows Azure Web application. Enterprise Library 5.0 – Integration Pack for Windows Azure This NuGet package contains a zip file with the source code for the Enterprise Library Integration Pack for Windows Azure.  Reference: Pinal Dave (http://blog.sqlauthority.com) Filed under: PostADay, SQL, SQL Authority, SQL Download, SQL Query, SQL Server, SQL Tips and Tricks, T SQL, Technology Tagged: SQL Sample Database

    Read the article

  • New Whitepaper: Advanced Compression 11gR1 Benchmarks with EBS 12

    - by Steven Chan
    In my opinion, if there's any reason to upgrade an E-Business Suite environment to the 11gR1 or 11gR2 database, it's the Advanced Compression database option.  Oracle Advanced Compression was introduced in Oracle Database 11g, and allows you to compress structured data (numbers, characters) as well as unstructured data (documents, spreadsheets, XML and other files).  It provides enhanced compression for database backups and also includes network compression for faster synchronization with standby databases.In other words, the promise of Advanced Compression is that it can make your E-Business Suite database smaller and faster.  But how well does it actually deliver on that promise?Apps 12 + Advanced Compression Benchmarks now availableThree of my colleagues, Uday Moogala, Lester Gutierrez, and Andy Tremayne, have been benchmarking Oracle E-Business Suite Release 12 with Advanced Compression 11gR1.  They've just released a detailed whitepaper with their benchmarking results and recommendations.This whitepaper is available in two locations:Oracle E-Business Suite Release 12.1 with Oracle Database 11g Advanced Compression (Note 1110648.1) (requires My Oracle Support access)Oracle E-Business Suite Release 12.1 with Oracle Database 11g Advanced Compression (Applications Benchmark website, PDF, 500K)

    Read the article

  • how to do database updates in each release

    - by Manoj R
    Our application uses database (mostly Oracle), and database is at the core. Each customer has its own database, with its own copy of application. Now with each new release of our product, we also need to update the database schema. These changes are adding new tables, removing columns, manipulating data etc. How do the people handle this? Are there any standard processes for this? EDIT:- The main issue is the databases are huge with many tables and more of huge amount of data. We provide the scripts and some utilities to manipulate the data. How to handle the failures and false negatives? More of looking for this kind articles. http://thedailywtf.com/Articles/Database-Changes-Done-Right.aspx

    Read the article

  • Amazon SOA: database as a Service

    - by Martin Lee
    There is an interesting interview with Werner Vogels which is partly about how Amazon does Service Oriented Architecture: For us service orientation means encapsulating the data with the business logic that operates on the data, with the only access through a published service interface. No direct database access is allowed from outside the service, and there’s no data sharing among the services. I do not understand that. Why do they need to 'wrap' a database into some layer if it already can be consumed as a service by other service through database adaptors? Does Amazon do that just because they need to expose the database to third parties or because of anything else? Why "no direct database access is allowed"? What are the advantages of such an architectural decision?

    Read the article

  • Which database to use and system/db administration by layman [closed]

    - by blah
    So my friend and I got briliant ;) idea for a business. Since it is not predictable whether it will work out or not, we decided to keep cost as low as possible to start with, in particular not to hire anyone. If it will work out as expected it will generate enough profit to hire professionals in few months. But for the first few months we'll be doing everything by ourselfs. He's a business/finance major, and I'm a software developer, so obviously I have to take care of IT :) It will be a webapp, written in python/django. My questions regarding this project: 1) What database should I choose? I'm experienced with oracle, and have been working with SQL Server for a while, but both of them are too expensive(at least now). It's a developer experience, I've never done any dba stuff. I'm looking for something free(as in beer). Looks like MySql or PostgreSQL are most popular in this sector. I would appreciate any comments on which db to choose. I'm open to any suggestions(it doesn't have to be MySql or Postgre). Here's what I know about data: It will be almost dates and numbers, a little bit of text. Searched mainly by dates. Data will almost never be updated, mostly inserted and browsed. From 30k to 300k new records/month. 2) Servers. My idea is to rent two dedicated servers. During normal operation one would be a web server(debian/apache), other would be a db server(debian/?). My recovery plan is to install everything on both, and in case of trouble with one of machines just run everything on the other one. Does it even makes sense? Any other tips appreciated. Thanks.

    Read the article

  • When should we use weak entities when modelling a database?

    - by Songo
    This is basically a question about what are weak entities? When should we use them? How should they be modeled? What is the main difference between normal entities and weak entities? Does weak entities correspond to value objects when doing Domain Driven Design? To help keep the question on topic here is an example taken from Wikipedia that people can use to answer these question: In this example OrderItem was modeled as a weak entity, but I can't understand why it can't be modeled as a normal entity. Another question is what if I want to track the order history (i.e. the changes in it status) would that be a normal or weak entity?

    Read the article

facebook twitter digg google delicious technorati stumbleupon myspace wordpress linkedin gmail igoogle windows live tumblr viadeo yahoo buzz yahoo mail yahoo bookmarks favorites email print

< Previous Page | 12 13 14 15 16 17 18 19 20 21 22 23  | Next Page >