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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Table design for child tables with multiple many-to-many relationships

We are working on designing tables for a new Networking application, and have been having some problems with finding the best design for the top level tables. Network is the top level table. Under ...
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31 views

For alignment optimized table is bigger than original table - why?

In another question I learned that I should optimize the layout from one of my tables to save space and have better performance. I did this, but ended up with a larger table than before and ...
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37 views

How to design a database that tracks sports player's positions

I'm building a database for a sports (ultimate) tracking program. Basically, the "raw data" for the program will be the positions and IDs for all the players on the field at one time. But the way I'm ...
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19 views

Relying on expected data

I'm relatively new to Database Design and I wanted to know the disadvantages to a particular decision I have made in the design of a database for a project. I don't think it will have an effect on the ...
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56 views

DB table design [on hold]

Sl_no Details of operation units rate Amount 1 Registration Fee input input input 2 Travel ...
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1answer
40 views

Database design suggestions for a data scraping/warehouse application?

I'm looking into the database design for a data warehouse kind of project which involves a large number of inserts daily. The data archives will be further used to generate reports. I will have a ...
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1answer
19 views

Optional oneToOne relations and criteria field

Introduction: Visitors can fill reports on my website. Those report can either be filled by a legalPerson or a naturalPerson. Constraint: I don't like empty fields and I would like to normalize as ...
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27 views

Conceptual model vs Logical model vs Physical model

I'm doing a work about database, and now I need to show three different images, one image with the conceptual model, other with logical model and other with physical model of a database. I'm looking ...
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25 views

Lookup tables with long lookup values? [on hold]

If I have a table with long lookup values, like 50 characters for example, is it better to put those in a descriptive column and come up with shorter names for the actual values, possibly to show in a ...
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1answer
42 views

Conditionally join table

I'm new to database design and have designed a database that seems fine for the application but looks like it has a major red flag to me. I have a master table which is then joined to another table ...
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1answer
25 views

Parent/Child table design?

Lets say I have a table to hold Tasks and then I have a table to hold Sub Tasks, is it better to break Tasks and Sub Tasks into separate tables or keep them both in the same table with a possible ...
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2answers
30 views

Store n:m data with most n:1 tuples

I have these tables: create table data ( id int identity not null, ref int not null ); create table reference ( refid int not null ); with ~2 million rows in data and ~200k rows in ...
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1answer
28 views

DBMS database management system [on hold]

How are derived attributes stored in tables?
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1answer
38 views

Database Design for classifieds site [on hold]

I'm creating a classifieds site where there are many categories and subcategories. 1) Each category has different fields. 2) Each listing has one or more images I need help with the database design. ...
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2answers
31 views

Auto increment char varying column prefixed with some characters

I have a table in PostgreSQL for hospital patients and I want to make a primary key for it as PAT0000001 (char varying) and to keep that field as auto-increment as well. Is there a way to achieve ...
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2answers
31 views

Mysql replication with c

I have huge database on MySql and It's become more and more huge. So, Now I am facing performance issues with my database. Some of tables has millions of records in it. like my login detail table ...
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2answers
51 views

Database Design Help: MySql/PostgreSQL Single Database/Multiple Databases

We are planning to build a web based custom business analytics tool using PHP and MySQL/PostgreSQL. In our application, we are planning to upload customer’s data using a Excel sheet and these data ...
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49 views

Need Advice on Normalizing Database

I have a group of database tables that lack normalization. They all have a similar primary key called 'doc_index', which is either a PK by itself or part a composite PK. As you can see below, there ...
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5answers
230 views

Using Timestamp plus Integer as Primary Key

In Sql Server, what would the drawbacks and disadvantages be of using a primary key that is: Two Character Table Identifier + YEAR + MONTH + DAY + HOUR + MINUTE + MILLISECOND + random integer between ...
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2answers
53 views

How to change schema so that account_id reference is unique among 3 tables

Original image: Updated to have more-correct terminology and an 'is_debit' column: I am designing a (PostgreSQL) schema for a lottery website that uses double-entry accounting. 'jackpots', ...
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2answers
23 views

Database design for tracking referral dollars and referred dollars

Dropbox has a great referral incentive program that gives a storage bonus based on whether a person is referred to Dropbox or refers others to Dropbox. What data base design is good for managing ...
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25 views

How to handle multiple hierarchies in a data model?

In Sql Server, there is a datatype called HIERARCHYID which helps with hierarchies. In our environment, we have patient data that needs to be classified under multiple hierarchies. Example 1: ...
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2answers
32 views

Dimension or Degenerate Dimension?

I am taking a course on data warehousing. Currently, I am reading through Ralph Kimball's Data Warehouse Toolkit. I understand that a degenerate dimension is a dimension key that is stored in a fact ...
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1answer
53 views

Setting up a new database [on hold]

I'm setting up a new basic database and wanted some on advice on the best approach to do this with. This would be a database in SQL Server 2012 and would be a reservation system for a customer. I have ...
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2answers
63 views

How to find usage of each object in other objects from a database?

I am with the task of taking an old SQL Server database and identify all of it's objects and their relationships, because the one who made it did not bother to use any foreign key, he just made all ...
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1answer
95 views

Database revision needed for sports events database

This is not a code review but more of a database schema review. I have a sports events website that I am doing in my spare time. I need assistance with the database design. I am about 80% completed. ...
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26 views

I got a database in CSV file and would like to create a ERD diagram [closed]

I got a database in CSV file and would like to create a ERD diagram, what is the best approach for this? The CSV file comes from a 20 tab Excel spread sheet and hence, so far, I am selecting each tab ...
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1answer
55 views

Inserting data into multiple tables

For my system, students are required to create a user account by completing a registration form (personal, contact and course details; also username and password). I need to collect registration data ...
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10 views

When there is a Type 1 and type 2 SCD in a dimension table, how are updates to the type 1 column handled after the type 2 column is updated?

Eg: ID Type1SCD Type2SCD FromDate todate 1000 100 ABC 01-JUL-2014 NULL Now, Type2SCD is updated ID Type1SCD Type2SCD FromDate todate 1000 100 ABC 01-JUL-2014 12-JUL-2014 ...
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1answer
34 views

pass data from deleted table to another

This is the situation: I have a table, with name TABLE_1 I would like delete TABLE_1 and then create another table with the same name and some of its columns. TABLE_1 has records, but I need to pass ...
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34 views

performance questions in database design

I need to describe a set of studies that are practiced to a patient, every patient have a "Clinical History", that are described in another table called "Clinical History Lines"(hclines) Every visit ...
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3answers
207 views

Heterogeneous ordered list of value

I have the following object model: class A { List<Thing> orderedListOfThings; } interface Thing { } class X implements Thing { int attr; } class Y implements Thing { String ...
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1answer
24 views

DBF corrupted database

I'm in great trouble here. I'm using Microsoft Visual FoxPro 9.0 on my Windows 7 machine. I had some DBF files which was created in MS Visual FoxPro. The files were undoubtedly valuable since they ...
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14 views

What is the optimal way to get a tabular view from an Entity-Attribute-Model table?

Following up on my previous question, I have created a table for storing measurements of different physical quantities. The schema looks like this: CREATE TABLE sensorreadings ( time TIMESTAMP, ...
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12 views

A better database model for level of product-information in service and maintenance environment

This is a tough question and rewriting it now for a couple of times. I have a question about a good, more solid way to design my database model about service and maintenance. My main problem are the ...
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38 views

Database design for large incoming data

I've been tasked to design a database to handle a large volume of incoming traffic from sensor readings, possibly 1,000s an hour when it's at full strength. Each reading will be relatively short - ...
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23 views

How to model when you could have many (thousands of) attributes to a table (product)?

We have a main table, let's say, Product. It has several general attributes like 'Product Name', Manufacturer ID, etc. As of now, all these attributes are implemented in the data model as columns to ...
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1answer
47 views

Handling a chat room in a database

I have been searching all day to find a better answer to my question but those I found was useful but do not critically analyse my question. I am building a chat room using php, mysql, jquery and ...
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53 views

How to share Users table between Clients and Customers?

I have a rental system where the system admin can add clients and their users. Each client's user can manage products, categories, orders etc., as well as their own customers. However, while ...
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1answer
25 views

Mixed search in multiple columns

I have a table which has a particular column of type JSON, where some user's contact information are stored. I can alter the table and add new columns with cached values to increase search performance ...
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14 views

employees Evaluation System database

I am new to database designing I want to design an Employees Evaluation System for a company. Based on Competencies Rating Each Manager will rate his/her employees at the end of each year for 6 ...
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2answers
20 views

getting one day timestamp in mysql

Please consider the following stored procedure I have: ORIGINAL Stored Procedure: -- -------------------------------------------------------------------------------- -- Routine DDL -- Note: comments ...
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1answer
67 views

Enforce referential integrity between two groups of data

I have two sets of records: A collection of rules. A collection of actions to perform based on those rules. What I'm trying to model is something like this: Multiple rules can be grouped ...
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2answers
29 views

primary_key problem in MySql view

I have 3 tables. and I want to create a view. There is no problem about generating SQL qeury and creating a view. but when I want to use this view in my web app it says me (LIKE THIS): "your view's ...
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1answer
34 views

SQL or NoSQL for structured clinical data [closed]

I'm designing a database for a primary health center, the idea We basically have a Patient with many Encounters, also the Encounters have to be entered from different Users (Health Professionals). ...
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1answer
72 views

Optimizing large MySQL SELECT WHERE IN clauses

How can the following SELECT WHERE IN case be optimized? I have a table with over 100 million rows with only 3 columns. The primary key (col1) is a 127 varchar. I am performing a SELECT col1 WHERE ...
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1answer
43 views

database normalization to 3NF [closed]

I am just at a complete lost. I need help with this. There should be 12 tables (or perhaps 11 since one table has just a single attribute) when you are finished with the normalization and merging of ...
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0answers
27 views

How do I design a database for different sets of measurements on different subjects?

I'm conducting a research project that consists in sampling different physical quantities on about 30 buildings, most of them single-family houses. Some of those physical quantities will be common to ...
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1answer
16 views

Datatype for different categories in a database

I have got the following categories for accounting and cash flow purposes: Equity Contribution Distribution Valuation Debt Issuance Payment Valuation Allowance Interest ...
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2answers
27 views

Design for table with multiple links to other table

I am designing a database to keep track of our network equipment. My db has 2 tables: sites & circuits (circuit = cable) & (site = property location) Each circuit runs between two sites, so ...