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.

learn more… | top users | synonyms (2)

2
votes
0answers
69 views

Covering Index - Insert Performance

We are running some performance tuning on our database in SQL Server. The database in itself is pretty small with around 13 tables. But there are multi-level relationships between tables. When I try ...
0
votes
1answer
27 views

Using part of a compound key as foreign key

We have the following situation, in which we have three tables: Article ------- - Id (PK) - Supplier_Id - Supplier_Contactperson_Id - Name Supplier --------- - Id (PK) - Name SupplierContactperson ...
0
votes
0answers
19 views

Database systems with users and sub users accessing the data

I am making a database for school student maintenance. Below is the basic description. There are schools. One school has many staff (i.e: Principles,Teachers, Section Head, Office Staff etc) These ...
0
votes
1answer
28 views

Daisy chaining two is-a relationships?

I'm currently dabbling in ER modeling and wondering if it is possible to create a chain of is-a relationships. Example: Here I'm basically trying to model specific in-stock items available for rent ...
0
votes
1answer
102 views

Transpose MySQL rows as column names - DYNAMIC

My goal is to be able to calculate the time difference between the ticket timestamp being created and closed and if reopened Add time from being reopened to closed again etc.. I have an existing mySQL ...
1
vote
1answer
38 views

mongo: how should I layout my data

I have 2TB of data currently spread across many CSV files that looks like: { 'rec_date': "2010-01-29", 'rec_time': "09:15:00", 'site_no': '46', 'data_owner': '1', 'flow_period': '5', ...
0
votes
1answer
38 views

How to reference categories table in products table?

I am using modified preorder traversal algorithm to store product categories in database (like image shown above). But i don't understand how to reference it in my products table. Here is my ...
0
votes
0answers
31 views

Designing a correct table structure

We are trying to save the Family History of a particular foreign job applicant. Below are the details we have to save. Familiy Member: Father|Mother|1st Brother| 2nd Brother| 1st Sister| etc etc ...
1
vote
2answers
73 views

Design: how to store lots of booleans?

What is the most optimal way to store lots (up to 300) of properties about an object? All properties determinate presence of a factor. Like, "has dog", "has cat", "has garden", "has N". Initially I ...
1
vote
2answers
38 views

Table design for linking pictures to a place

Could someone give me some advice on designing a table for a system that has to store x picture for 1 place? Is it better to have something like this: place table: id_place / reference 100 ...
2
votes
1answer
209 views

Why do/should DBMS cache at the application layer?

This article describes DBMS as caching data at the application layer, which is why they often use Direct IO to bypass the file buffer cache. My question is: what benefits are provided by the DBMS ...
1
vote
1answer
227 views

Designing a High Score/Leaderboard table

I'm looking for input on how to design a highscore table for a game I'm creating. The database I'm using is postgres. That's not really something I can or want to change (unless there's very good ...
0
votes
0answers
72 views

ER diagram to tables

Consider the following exam question: Translation: The INCORRECT transformation from the diagram at the right to tables is... This is what I think: a) is incorrect (the column es_C (is_C) does ...
2
votes
1answer
97 views

How to return a record from function, executed by INSERT/UPDATE rule (trigger)?

I'm having some issue when I'm trying to join two tables in a single view (for migrating code we want to split one big record into two records). I'm using Postgres 9.4! Here is an SQL fiddle. The ...
0
votes
1answer
33 views

What does normalization say about storing data from objects that use a decorator pattern?

I am just curious as to what the best practices are for storing the data from objects built using decorator design. I have a base class and can decorate it with A, B, and/or C, with A B and C having ...
0
votes
0answers
16 views

Modeling attributes relations in RDBMS/NOSQL?

I have a table to hold the relationship between attributes and documents: I need to support the following queries : give all documents where attrib X='value' give me all documents where attib ...
0
votes
2answers
82 views

Database structure for hierarchical quiz?

I'm doing a personal project where I have a quiz with a number of boolean questions. Each question will have a two answer choices "true" and "false". Based on the selected answer, a new question will ...
2
votes
1answer
81 views

I can't create relationship in my database sql server

I have designed a database for my website. It has 3 tables: user, topic and comment. A user has many topics (or articles) A topic (or article) has many comments A user has many comments I ...
0
votes
0answers
21 views

How to have a relation applied only to all entities related to another given entity?

Let's say I'm trying to design an online server for judging a bunch of submissions to several problems. Firstly, each problem has many subtasks (which must go to one problem alone). For each ...
2
votes
1answer
44 views

Does SQL Server redistribute data after adding an additional data file?

Imagine a database about 30GB in size using 3 data files on the same disk. Someone told me to have one data file per processor implemented to get full performance on all cpus. So if I now add three ...
0
votes
1answer
62 views

What's the best database if i want save data temporally? [closed]

I want to create a datalog system so I need to store some int data temporally. What would be the best database (Relational, NO-SQL or some specific) for that purpose? And what would be the best way to ...
0
votes
0answers
42 views

Design a database with test table with different answer format

I am designing a database with tables: For each test,there should be a template and one test has many product code and each product code has or has no attribute. tb_template(id,name) ...
1
vote
1answer
50 views

Clarification for database creation and relations

I've trying to make database with few tables and relations between them. As I'm not very good in databases at all I need some clarifications. The idea is to connect table with table_1, table_2 and ...
2
votes
2answers
114 views

What's worse, too many entities or too many tables?

I just had a question about database design, I am in fairly early learning stages of this so bear with me. Suppose I have a parent table called "Projects" each "Project" Entity can have any number of ...
0
votes
0answers
24 views

Data modeling question on Cassandra DB

I'm trying to save events of a month for a user to my Cassandra DB instance. Each month the data will expire and will be removed. The data I try to model will contain user id, date of event and event ...
0
votes
0answers
16 views

Should I install hadoop on a single node

I just bought a desktop computer with 16GB RAM and 1TB drive, i7-quad core. I will be partitioning off 800GB for Ubuntu so I can do some data science type tasks. Is there any advantage to installing ...
1
vote
1answer
36 views

ER-Model for Borrowing-Lending-Network?

I plan on creating my first database so this is going to be a newbie question. My database is supposed to be for a Borrowing-Lending-Network where users can borrow products from other users. Creating ...
2
votes
3answers
437 views

Which design to choose

Suppose I have a website that communicates with a database. In some page of my site i want to exhibit a list with all the students in my database. There are two kinds of students: regular ...
0
votes
2answers
56 views

what is a good use case for splitting user table by role

I have a requirement where there are primarily 5 roles in the system. Each of these roles increase in hierarchy from junior to senior most role. Each junior role is a subset of its immediate next ...
3
votes
1answer
55 views

How to create a Relation between a table and a many-to-many relation table

I am buildng a new database inside an Sql server 2008 r2.I have the following tables & business rules:- Skill that have predefined levels assigned to it, such as junior, senior, manager. Staff ...
1
vote
1answer
40 views

Duplicate table structure with different data [closed]

I am looking for a way to resolve a design issue with a Microsoft Access project that is being converted to use SQL Server 2014 as a backend. We have several Access backend files, two of them have ...
1
vote
2answers
42 views

Separate login for user / administrators using mongodb

I have 2 separate groups of users on my website. One is user and the other one is admin. Currently I put them in 2 different collections user and admin and login respectively. My questions is: ...
0
votes
1answer
42 views

Schema design for storing item combination with order

What I need: Three types of items, and user can add/delete items. Use will select some items from those three packs, and arrange an order according to his/her preference. The number of records ...
1
vote
1answer
88 views

Optimize large table design

First, I am a complete novice when it comes to databases, but have been given the task to speed up queries on a large set of data. (Hundreds of millions of records) The current implementation is a ...
1
vote
1answer
70 views

Best way to document Dwh views [closed]

I works in a company that provide Dwh views as an API for external Customers (We use MS-SQL 2008 & 2012). every once in a while we release new views and updates the existing views. We have ...
1
vote
0answers
43 views

Nosql multiple database design to handle sharing scenarios

This question is regarding design of a database in mongodb. The scenario: A user has a drive which he can share with others. Drive has two categories: docs and others. The user has three choices in ...
3
votes
1answer
47 views

Best Design for this “Sweepstakes” Project?

Hello there fellow developers, Merry Christmas first aff all, and i hope you will have a happy new year soon. :) I was having more or less a problem with an idea that came to my mind. I am currently ...
2
votes
0answers
68 views

Storing URLs in a database

I am thinking about storing URL's in my database, but I am not sure whether the way I use is an efficient way to do things or not. Table name : url url_id (Primary Key & Auto Increment) url_value ...
1
vote
0answers
38 views

What are the different types of binary relationship types?

I'm new to databases and while studying questions on it, I've come across one that I can't find the answer to. Define the three different binary relationship types that are common in relational ...
1
vote
2answers
54 views

Should running number be separated column from primary key in database?

I have questions that blogged my mind on separating member number and member id. Suppose that we have a database with member id primary key of Guid type. Then, normally, when we view the profile (on ...
0
votes
1answer
31 views

tables relationships in database

Just a basic question here but it's been bothering me for a while. Do all tables have to be related to another? I'm trying to design a database so far I have 15 tables, 13 of them have relationships ...
1
vote
1answer
80 views

database design for simple comment

I have a following given scenario. A user can have zero or more item. A user can comment on the item. (Just simple comment listing with name of people who comment, no need hierarchical structure for ...
1
vote
1answer
47 views

MySQL column type to boost performance

I'll have a table where: userid (link to user's id in users table) foldername (a varchar, max. 260 char) entry (varchar, max. 1024) data (varchar, max. 20kb) Single user will have several ...
0
votes
1answer
27 views

Design for periodic data cuts

I've been building an application that has a 6-monthly update schedule, i.e. a cut of the data for H1 & H2 of each year. The previous version of this application implemented this by making a copy ...
0
votes
0answers
27 views

Advice on MYSQL DELETE on CASCADE, UPDATE on CASCADE features

I have 2 tables called copyrigihtinfo and sourceinfo and many to many to relationship table cp_src_junction with following data. copyrightinfo table cp_pk cp_info 1 copyright (c) 1991-2000, ...
1
vote
1answer
106 views

optimize design for a table with 50 columns [closed]

I have a table with 50 column and one of my friend has told me to split the table in 4 different table to save 12 column in each table. He proposed a design to have Master table and refer the PK of ...
0
votes
1answer
34 views

What Is the Next Best Ingredient to Add?

I am building a program that allows users to optimize their grocery shopping so they can make the most recipes using the fewest ingredients. One of the features of this program is a function I’m ...
0
votes
2answers
41 views

when to put a business rule in the business application layer or into a database constraint

I need you wisdom, I am debating with another person when is it recommended to put the code of a business rule into a database constraints or inside of the application business layer? There is a ...
2
votes
1answer
49 views

How to store a 64-digit key of alpha numerical values into MySQL Database

I am student studying in Database Administration (first year), one of our task requires a to design a login form for corporate and regular users. Below are the requirements for the username and ...
1
vote
1answer
38 views

Need Help in building database

I am developing an app that send messages (email and sms) to users. The db must also maintains the list of messages send to users. And also the status of messages send to user like send or failed. I ...