Database design is the process of specifying the logical and/or physical parts of a database. The goal of database design is to make a representation of some "universe of discourse" - the types of facts, business rules and other requirements that the database is intended to model.

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Referring to super parent or as a separate entity?

I have this person table as super parent, id firstname lastname email telephone ... ... and user table as a child id person_id (FK) password username screenname ... ... They must be 1:1 ...
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2k views

how to enable temporal database capability in mysql.?

How to enable the temporal database compatibility in mysql database? Is there any library or a plug-in to enable the temporal upward compatibility? I want to keep the past records whenever a current ...
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955 views

Database redesign opportunity: What table design to use for this sensor data collection?

Background I have a network of approximately 2000 sensors, each of which has about 100 data points that we collect on 10 minute intervals. These data points are typically int values, but some are ...
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660 views

Why shouldn't I have one table for multiple relationships?

Assuming I have multiple relations in my database, for example Store, Employee and Sale, and I want to connect pairs with a simple binary relationship. Personally I would create tables named ...
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2answers
101 views

Adding Security to a legacy DB with Schema

I am working on a DB where almost every technical user has full read / write permissions on all tables. We are working towards removing permissions, gradually, from certain users, and I had hoped that ...
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4answers
805 views

Are there any good reasons for keeping date and time in separate columns?

I'm trying to understand our software vendor's decision to keep date and time in separate columns. For example, when the row was created or updated. Both time and date are DateTime columns. We are ...
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2answers
742 views

How to design a schema to store search keywords

I am doing a database design that stores search keywords of a search form, used to generate the most popular search keyword reports by date, month and year. I have made a simple schema: CREATE TABLE ...
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3answers
3k views

Plural vs Singular Table Name

How should I name my Tables when creating a new database? Singular: Client or Plural: Clients?
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1k views

Database for building a realtime analytics system

I want to build a system similar to Google Analytics (only used for internal use, less traffic and less feature), and mainly focus on Real time counting of unique URI visit/PV by different ...
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3answers
2k views

SQL Server Primary key / clustered index design decision

Looking for some advice regarding a table / index design decision I've got to make on some tables that I've got to port into SQL server from an existing 4GL based database. I've got a product history ...
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4answers
1k views

How to store data in a database without tables?

All I learned in school was SQL which saves data to tables. Right now I am working on a project where data is stored in XML-files. Additionally every XML contains a reference to visual files (JPEG). ...
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330 views

Would it be considered as a bad practice to have multiple nullable FKs on a table in SQL Server

On my database structure in SQL Server, I have 3 types of products which requires different information about the order. So, I created one Customers table and three different orders tables: ...
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3answers
240 views

How do I add a time dimension to this forecasting database without having to duplicate every data point @ each reforecast?

I have a database designed to facilitate revenue forecasting. Revenue forecasting consists of tracking Orders which are recognized into Revenue at multiple points in time (each, a revenueDate). There ...
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2answers
434 views

Using 100's of schemas in a database SQL2008R2?

We are in SSAS type of environment with 100's of clients. Currently each client gets a database and we have 200 per instance on SQL Server 2008R2. This presents limitations with snapmanager being ...
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3answers
465 views

How do I model data from arbitrary CSV's in a database?

I am setting up a web interface for data management. Users upload CSV or similarly structured files, and I want to store these in the database so they can do manipulations on them -- filtering, ...
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2answers
746 views

Is to possible to forbid access to tables in own schema - Oracle?

Lets assume that we have the following situation: We have an Oracle schema/user: USER_TEST (with the "create session" privilege). SYS as SYSDBA creates couple Tables on schema USER_TEST. Is it ...
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2answers
156 views

How to implement Draft functionality, with attached files?

Should allow for: User can save an entity as a draft, that would normally not be valid in its table (ie some missing values) User can attach files to the draft User can find, sort, and discard their ...
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2answers
1k views

How to implement soft deletes?

What is your method of implementing soft deletes in a database? Ideally the solution would allow for decent performance on large tables take relationships into account take unique keys into account ...
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1answer
2k views

Generating Invoices and Tracking

Every 2 weeks, the system will generate the invoices for the companies. Company will receive an invoice on the 1st and 16th every month. (It will run via Cron Job every 2 week. It scan through the ...
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1answer
637 views

Table structure/schema for spreadsheet-like web app (ex: Google Docs)?

I'm a front-end developer/designer who is trying to branch out and learn more about the back-end world. I've chosen Python, Django, and Postgres as my starting place. My goal is to build a personal ...
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4answers
2k views

Is it a good idea to use Synonyms to avoid creating a duplicate table?

We have 3 copies of the exact same database. All 3 databases have a Users table, and a User will always exist in all 3 databases with the exact same settings. Anytime we want to add or edit a User we ...
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2answers
1k views

Ready-to-Use Database models example

Where can I find ready-to-use database models ? I don't need a database with data in it, but only schemas (UML diagrams). Perhaps something like the data models at this link, but much more complex ...
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5answers
249 views

Enforcing database integrity

Would this ever make sense to have application enforce the database integrity instead of having foreign keys, check constraints, etc? How much of a performance improvement one can expect for not ...
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1answer
159 views

Tick boxes and Dropdown

Have a look at the image below: This is "Plain Buger" item - customer can select sauces and extras with it. There are different sizes for Plain Burger. I need to translate this UI into database ...
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2answers
1k views

Having a unique ID for 2 different tables

We would like to use two different tables, one will hold an object when it is 'Active', and the other will hold the object once it becomes'Non-Active'. The ID is therefore unique per both tables ...
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1answer
416 views

Some Ideas In Database Design

I am creating a site where users can sell their products(let say a little version of eBay, just assumption). Concerning the database design am a little bit stuck and looking for some ideas how it is ...
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1answer
200 views

Do you feel like DBA/DBD Is a “secure Field” still? [closed]

I noticed recently alot of Database jobs/Development have kind been pushed onto general developers, not to mention with NoSQL Solutions (Which IMO are probably a little easier for Non-DBA's to throw ...
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674 views

Multiple child tables

I would like to know what is the best solution for making a parent table with multiple children? I have to make multiple children table. One for each profile. Is there a better idea than having 3 ...
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1answer
57 views

Want to add a “variable” to a table

I'm using PostgreSQL 8.4 and I have a table that is cleared out and refilled with new data every so often. I want to be able to store the date that the table was last filled, but I'm not sure where to ...
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2answers
363 views

Is it more secure to go through a 3rd database to connect two databases using the same login?

We have the following setup: Multiple production database containing private data which is used by desktop software A web database for a public website which needs some data from the private ...
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3answers
367 views

Express union which is dependent on other results

I would like to make a union of two tables that are actually in a hierarchical constellation. How would I write that in relational algebra? Say table A is the parent of B in a 1:n relationship. ...
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1answer
436 views

Design problem with auto-increment fields

I've made this design similar to my problem, it's not exact but it close enough to understand my problem: http://i42.tinypic.com/bhbp5.jpg Some cellular client frequently send their GPS position and ...
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2answers
1k views

What are the penalties of using many (thousands) of column families or keyspaces in Cassandra?

I am in the process of evaluating the best design for our Cassandra installation. There is not so much information out there on the Internet about using the first two levels of access that Cassandra ...
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1answer
2k views

What is a basic model for making a database with users and groups?

I'm trying to find the best way for a basic security system for a website. I know I want users and groups. I thought I'd have: user_table user_id user_name ... group_type group_id group_name ...
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1answer
499 views

SSAS Modelling - many to many with one dimension

I'm having bit of a hard time modelling an OLAP cube. My analogy is this: I have a list of students. Each one has one Major subject of study, and zero or more minors, up to five in total. The raw ...
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6answers
5k views

Splitting Tables in MySQL. Good practice?

I have started working on an existing project and the previous developer had split up a table into 10 separate tables with identical schemas but different data. The tables look like this: ...
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1answer
64 views

Reading and writing the common data

I have a couple tables and application service that intensively inserts, updates its. From the other hand some client application have to read data using those tables. Sometimes client application ...
9
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2answers
393 views

How many Sproc Parameters is too many?

I've just started writing a Stored Procedure in SQL Server 2008 and have 30+ parameters. I've never written one with more than ~10 parameters, and that got me thinking... At what point are there too ...
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2answers
5k views

Questionnaire database design - which way is better?

I have ONE long html page, several sets of questions divided into small sections (approx. 15 sub-sections in one page), the total of questions are about 100 questions: varies from input, multiple ...
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1answer
134 views

Help me to better design my query so I can gain more performance

I need to find so called first entry in database for items regarding their partners. I wrote query and it is giving me correct results but it sucks with performances. I suspect that I have missed ...
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1answer
297 views

ERDs: How do you indicate mutually-exclusive encounters?

If you have a character_instance and character entity in an ERD for a video game, and you want to indicate that something happens when a character entity encounters a character_instance entity, how do ...
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2answers
514 views

Database Modelling of Type, Subtype Relation

I'm trying to model the type and subtype relationship described here. The best approach I could come up with would look like this: CREATE TABLE Card_Types ( card_type varchar(12) PRIMARY KEY ...
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2answers
231 views

Design: How do you decide when items are related vs when they are attributes?

I've been trying to figure this out for a while. Let's say you have a person, for example. An attribute of a person is his or her social security number, right? But a person also has a social ...
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2answers
727 views

Database normalization: Describing trait - foreign key to table, or varchar field with value?

My colleagues and I are having a discussion about the normalization of descriptive traits in the database, such as "status" or "type". Let's call the central table of the discussion "Order". In my ...
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1answer
317 views

Could Stack Overflow run on SQL Server Web Edition?

I am starting a new web venture that may need to scale to a high number of users. I am confident with the SPLA licencing for SQL Server Web edition, but want to know if I will need to factor in ...
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2answers
168 views

design of maintenance database

Lets say i am designing a database that tracks maintenance of equipment. Each piece of equipment has various fields that usually don't change eg. ID, model, serial number etc. Some fields change ...
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1answer
305 views

Implementing Pub/Sub initiated from the database

I have a number of state-full Windows Services that currently poll the database looking for new or changed records in specific Tables and/or Views. For obvious reasons this limits scalability and is ...
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1answer
1k views

ERD via Chen's notation: How do I organize multiple 'last done' entries?

I'm having an issue creating a little practice ERD. I'm trying to do some more difficult stuff, and I'm not sure what the standard way to organize it is. Basically, I don't know which of these is ...
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1answer
2k views

Storing XML in varchar(MAX) or use SQL-XML

I am defining a schema for a new set of resources using SQL Server 2008... In this case, each record (e.g. row) will need to store XML fragments. From time-to-time; although not frequently; I'll need ...
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2answers
393 views

Decision criteria on when to use a non-dbo schema vs a new Database

I'm mostly an application developer but find myself having to do all the up-front database work for my current project (btw... its MS SQL Server 2008). As a first decision, I'm trying to figure out ...