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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13
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6answers
2k views

Is database normalization dead? [closed]

I've been brought up old school - where we learned to design the database schema BEFORE the application's business layer (or using OOAD for everything else). I've been pretty good with designing ...
6
votes
2answers
1k views

Bitmask Flags with Lookup Tables Clarification

I've received a dataset from an outside source which contains several bitmask fields as varchars. They come in length as low as 3 and as long as 21 values long. I need to be able to run SELECT queries ...
0
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1answer
37 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 ...
0
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1answer
53 views

Normalization of Time Series Data

I have a table containing various a/b test experiment performance on a daily basis. The table structure looks something like this: date | experiment | user_count | user_attr | sales ...
1
vote
2answers
109 views

Does this medical database look correct?

I'm pretty new to databases and I'm trying to create some schemas. I've been working away at this one for a while, but I can't help feeling that it doesn't look right. Essentially I have the ...
0
votes
1answer
127 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 ...
0
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0answers
22 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 ...
1
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1answer
36 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 ...
0
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0answers
38 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 ...
0
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0answers
69 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 ...
1
vote
1answer
322 views

Add a column contains a photo

I installed PostgreSQL 9.1 under Ubuntu 12.10 And now I have a table called property I want to add a field that can be used to store photo(link to the photo or import a photo into a column?) But I ...
0
votes
1answer
31 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 ...
0
votes
0answers
18 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, ...
0
votes
0answers
44 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 - ...
0
votes
0answers
15 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 ...
0
votes
0answers
23 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 ...
1
vote
2answers
40 views

getting one day timestamp in mysql

Please consider the following stored procedure I have: ORIGINAL Stored Procedure: -- -------------------------------------------------------------------------------- -- Routine DDL -- Note: comments ...
15
votes
3answers
4k views

How Does Table Partitioning Help?

I am having difficulty to grab the idea of pros and cons of table partitioning. I am about to start work on a project which would have 8 tables and one of them will be the main data table which will ...
2
votes
3answers
169 views

Database design for excel-like data

The task I need to store the some values in sequence in the database. The data looks just like a sequence of numbers. Here is an example of the data: Val_1 Val_2 Val_3 ... ...
1
vote
2answers
132 views

Oracle 11.2 using too few memory

it is about one year that I have changed my server from Oracle 10g to 11.2g (and also changed the hardware and Windows from 2003R2 to 2012). The problem is that with more than doubled cpu power, ...
0
votes
2answers
31 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 ...
0
votes
1answer
55 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). ...
-1
votes
1answer
67 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 ...
2
votes
3answers
101 views

Entity Relationship Model - double one to many

ERD A customer submits one or many leads. A lead belongs to one customer. A lead is a request or an inquiry. A lead belongs to one manufacturer. A manufacturer has one or many leads. Tables ...
0
votes
2answers
28 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 ...
0
votes
0answers
37 views

set error message on out variable in mysql stored procedure

I have a stored procedure: fill_DATA (serial varchar(20), OUT oError) I am doing an Insert operation here. so what I want is to SET value of oError for any error message in case the query fails to ...
1
vote
1answer
76 views

Update new column with value from old columns for all the rows

I've got an odd db design in place that was here when I got on my new work space. We have a column named params which contains some string data which appears that it belongs in more than one column, ...
1
vote
1answer
19 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 ...
2
votes
0answers
29 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 ...
1
vote
1answer
67 views

Data modeling with many attributes where few apply to each record [closed]

I'm pretty new to data modeling, so please excuse me if I've missed something obvious. I'm trying to decide on a schema (or possibly a DBMS) to work with some data where there are quite a few possible ...
1
vote
2answers
4k views

Multiple parents and multiple children in product categories

I am making a ecommerce site. In this site I want to categorise the items into three different layers primary category sub category sub category >>electronic ...
0
votes
0answers
45 views

MySQL Table with 568 columns: 1118, 'Row size too large…'

I'm currently migrating a database from Oracle to MySQL5.6. One table consists of 568 columns. When atempting to create the table I received this Error 1118, 'Row size too large..' I already ...
4
votes
2answers
143 views

Database instance and database

I did some research and finally came to this conclusion: Database instance = processes + memory Database = (physical) log files + control files + data files. Is this understanding correct? ...
4
votes
2answers
2k views

How to choose a collation for international database?

I'm designing a database which will store data in different languages (using UTF-8), so I think the best way to display the queries results is ordering it according to the user's language during the ...
0
votes
1answer
57 views

Pros and cons of master status table vs private status table?

I am the only DBA at our company and am relatively new in the profession (having 2.5 years of experience now). The developers and I are currently having a discussion about how to properly design the ...
1
vote
1answer
166 views

Functional dependencies and candidate key example [closed]

Hi there I'm still learning for my examination and I got this exercise: A table is given: F-Name, F-Nation, Team-Name, Team-Nation ...
0
votes
0answers
73 views

Uploaded files corrupted except txt/csv

I have an ASP.NET MVC 4 Application with standard CRUD functionality plus a file Upload capability. Currently I am struggling with the files being corrupted after the download. I created a ...
0
votes
2answers
69 views

Are #tables and #procedures 'not best practice' or 'bad practice'?

I am working on a project and part of it is an interface tool that executes SQL code stored in a xml file to import/export files. In the file, temp procedures and temp tables are used quite heavily ...
1
vote
3answers
91 views

Relational Database design best practice

I am a student and I am trying to design a simple database, so if the ideas seem bad please let me know how to improve. I have three tables in my mind, one for Professors and one for Students. Both ...
0
votes
0answers
35 views

Having a Table to store information about “Feedback”/“Enquiry”/“Complain”

I am creating a database for an application and I want to be able to capture feedback information (Enquiry, complains or comments) from users using a form. My question is : Do I have to create a ...
4
votes
1answer
3k views

Product Attribute List Design Pattern

I am working on updating our website's product database. It’s built in MySQL but this is more of a general database design pattern question. I’m planning on switching to a Supertype/Subtype pattern. ...
1
vote
5answers
5k views

Coding an accounting database from scratch?

My new medical practice is picking up fast and my homemade Libreoffice Calc spreadsheet is quickly becoming cumbersome to track patient visits, accounts receivable, overhead reconciliation, etc. Most ...
0
votes
1answer
58 views

Optimization for 100 GB Real-time info table

I have a table of device information feed which is filled by data from remote device units. There will be like 1000 units each sending an update per minute which will be stored as a row in that ...
0
votes
1answer
26 views

single table or different tables [closed]

I am very new to PHP & Mysql. I am currently working on database structure of website. I have been a keen follower of this website. I have found that many posts have discouraged use of multiple ...
2
votes
3answers
378 views

How can I improve my table design for different types of an entity?

Consider an accounting system as an example. I have an Entity called Client. Client can be of different types, with different fields applicable to different types. I consider creating separate tables ...
1
vote
1answer
52 views

Personal and Global messaging database design

I am trying to implement a database design system that will be sending messages to a person(thus 1 to 1) or many persons (1 to many). table --users |u_id | Name | | ...
-1
votes
2answers
25 views

query multiple unrelated tables

Just learning mysql and db so guess this is a general schema design question. Say i have 10 different types of widgets and each widget transaction has a date, amount and 8 other unique columns to that ...
0
votes
2answers
51 views

One table with a flag or two tables

I have a problem with the design of a database: In my Android application i need to store the upload (the status, so if the file is in upload it will report the % of the upload) of a file and a list ...
1
vote
1answer
29 views

Understanding how relationship sides works

So, I have this relations on my tables (see image) and I need to understand some things. I'll enumerate what I understand and what I need from yours is to say if I'm right or not and in case I'm not ...
0
votes
1answer
581 views

How do you query supertypes to get subtype data?

I'm a bit of a DBA newbie here (coming from a programming background having to fill the role of a DBA), so please excuse by blantant and somewhat basic ignorance. Using a simple relationship between ...