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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98 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 ...
2
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2answers
34 views

Fetch all words from column with like

I have a column with description and inside it can contain # value . what I want is all the words searched from that column with #tag This is my query SELECT description FROM photo where ...
0
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2answers
151 views

Relational Model vs. Database Products [on hold]

The formal Relational Model (logical level) for databases is not exactly the same thing as you get with MySQL, Oracle or other major products / implementations of ‘relational’ database management ...
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36 views

DB Design: Looking for Performance improvement with a Column used in all SQL Queries

I recently got added to a new ASP .NET Project(A web application) .There were recent performance issues with the application, and I am in a team with their current task to Optimize some slow running ...
0
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2answers
61 views

Train Fare Database Normalisation

I have a database to normalize. The database has details of train ticket fares. The trains have different fares depending on the distance and I have to store these fares in the database It is not an ...
0
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1answer
38 views

When to use a multidimensional relationship in an ERD?

When to use a multidimensional relationship in an ERD? My textbook is in Dutch, and the two paragraphs that explain about multidimensional relationships is too vague and brief. I don't understand when ...
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0answers
17 views

SQL query to fetch results for multiple many to many relationship tables

We are developing a database for storing licensedetails of source code, archives, shareobjects, binary. We parse a detailed build and extract list of source files that make objects, list of objects ...
0
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1answer
18 views

Design for an Asset Management System

I'm attempting to design a database to track IT Fixed Assets and Consumable Parts; what is the best practice for this? Should I design separate tables for Fixed Assets and Consumables, or should I ...
0
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3answers
21 views

What's the proper design for the table that will hold the processor load stats?

Let's say that I need to implement a widget on the site that allows the user to view the processor load stats via a chart. The user will be allowed to choose how detailed the statistics are: with ...
7
votes
1answer
305 views

Designing Simple Schema for Disaggregation of Demand Forecast

I am doing a simple database design task as a training exercise where I have to come up with a basic schema design for the following case: I have a parent-child hierarchy of products (example, Raw ...
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2answers
216 views

Separate table for 'scheduled payments' and 'completed payments'?

In a previous financial payments related database I'd worked on, it just had one large transactions table. We would insert scheduled transactions for the future, and when that time came, we'd execute ...
0
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0answers
16 views

use of crows foot or chens notation to draw an extended ER diagram

I am trying to understand if we can use crows foot or chens notation to get an extended ER diagram. or does extended ER diagram has its own notations that should be used ? From what i understand, ...
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2answers
32 views

DB for storing simple time-stamped values

I don't have that much experience in databases but I need to accomplish this as best as I can. It is rather specific. Database will contain only data structured like this: dataID-timestamp-value ...
1
vote
1answer
159 views

NoSQL approach: design table “scheme”

We need to store simple log data in a database, but we also need to get and filter data in realtime, based on 'user', simple 'tag' (ie. redis, memcache, php, mysql, etc.) and timestamp. We need to ...
1
vote
1answer
64 views

How to improve this product rental schema?

I have a rental system where each product's stock item can be rented from a location and returned to a different location (think Alamo, Hertz etc.). When saving an order, first an inventory event is ...
0
votes
0answers
8 views

Design and queries for analysis of event-sequences

I will have to store sequences of events with certain properties in a database (MariaDB preferably) and I have some issues regarding the design and queries. The crucial part is the analysis of the ...
1
vote
1answer
102 views

Peer Review of Database Design

I'm working on a movie inventory database. This is a personal side project for me. I can use what I have, but I would like to make it the best design that I can while learning more about databases and ...
1
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1answer
51 views

Calculating a running balance to store with transactions

I need to put a read-only copy of balance and transaction data from a legacy system, which will only be used to view/print statements. Balance | id | member_id | product_id | balance | | 1 | ...
0
votes
1answer
45 views

Suitable database to store GPS track data

I have a network of vehicles. Each vehicle is equipped with a GPS sensor sending data over 3G to my FTP server. As a first solution to test the sensors, each vehicle sensor sends a .csv file to the ...
1
vote
1answer
57 views

“Transitive” keys

I have a central table, A, which will have a key that I'll call A_ID. Now, I have a table B in a "one to many" relationship with A (many B's map to one A). Each link will, of course, have a link ...
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2answers
34 views

How to represent foreign key in an ER diagram?

Suppose I have a 'Transactions' table which has a column 'Customer ID' (Foreign Key) and a Customer Table having 'ID' (Primary key). How do I show the relation between the two tables and showing that ...
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0answers
16 views

Peer Review of ER Diagram for Flight information

This is the first ER diagram I have made. I am hoping that some of you will have valuable information and criticism about my design.
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0answers
10 views

Architecture for huge catalog of products

I need to upgrade my current system of product catalog. For currently I have a 12 000 items in catalog, it's not a lot, but I need to improve them for feature. I have a task to reorganize my database ...
1
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1answer
57 views

CRM Address table and it relation

Hi I want to ask about I have this DBD for my CRM I am trying to have the addresss in one table(customer and Employee Address) and both customerID and Employee ID are guid I have in address table FK ...
2
votes
1answer
237 views

How to normalize my db schema for a quiz application?

I am putting together a quiz application. (I'm calling each quiz a "challenge") I have a "challenge" table and a "challenge_question" table which is pretty straightforward. challenge table: id ...
1
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1answer
82 views

Execution plan index suggestion - difference between similar queries

I am trying to analyze queries on this table: CREATE TABLE [dbo].[Values]( [tid] [smallint] NOT NULL, [t] [datetime2](3) NOT NULL, [v] [real] NOT NULL, CONSTRAINT [PK_Values_Unique] ...
2
votes
1answer
36 views

Best way to design a database with one person with different roles

We've been browsing for a while looking for an answer to this, but any of them suited exactly my needs, I hope is a relevant question. We have a database for managing books. In this database, a same ...
1
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1answer
50 views

MySQL - varchar length and performance

Is declaring VARCHAR size make sense for performance? Is there any difference (in speed) between VARCHAR(50) and VARCHAR(255)? Or defining length is logic/design constraint?
0
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1answer
2k views

MySQL count multiple columns and sum the total occurrence

I have the following table, say, MyDRAW ... DRAWNO PRIZENO FIRSTD SECONDD THIRDD FOURTHD M123/14 8458 8 4 5 8 M123/14 7214 7 2 1 4 M123/14 1640 1 6 4 0 ...
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2answers
118 views

How to make a better Data model

I am creating a database system using MySQL for a group in my school (a University). I am new to MySQL and its usage.I have started with the data modelling process, since this process will be the main ...
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1answer
198 views

Should I save “document ID” as a String or Number in MongoDB

So I'm importing about a 100,000 documents into mondoDB. MongoDB already generates an Object hash but the data has a documentID that was used to identify records in the previous database. The IDs ...
0
votes
1answer
333 views

Storing multidimensional array in MongoDB

I am attempting to convert a large MySQL database of product information (dimensions, specifications, etc) to MongoDB for flexibility and to move away from the restriction of a column based table. I ...
0
votes
1answer
102 views

Duplicate Relationships in Rails/MySQL Healthcare Application

Overview of the Application I am building a Ruby on Rails application to organize medications, using MySQL. The goal of this application is to provide dosage specific treatment recommendations, and ...
0
votes
1answer
20 views

Fetch data from database from multiple tables matching condition

I want to fetch data from the database. I have three tables in my database like listing_master_residential and listing_master_condo and listing_master_commercial. There are three tables and there is ...
0
votes
1answer
64 views

Text Storage and Database Design Optimization in a SQL Server Database

Given a database with a number of columns (c), where some of these columns contain text that is one of multiple values due to a set CONSTRAINT on the columns, what is the most efficient way to ...
0
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1answer
153 views

facebook group alike database scheme

Here are my requirements: one user can have many tasks one group can have many task one group can have many users only invited user by a user can be added into a group Does this db design appear ...
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vote
1answer
92 views

Proper implementation of child (derived) table PK/FK during single and multiple inheritance hard coded generalization physical data model

Below is an image of hard coded generalization UML logical model of entities. I'd like to implement these classes as tables in a physical data model. Two derived classes/entities (Class2 and ...
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1answer
68 views

Reviewing relational database tables

I am building a database, but I am a little bit confused with my table relationships. I wish someone could help review my table relationships below for me and tell me where I am going wrong. I have ...
4
votes
1answer
436 views

Database table design question

Firstly, database novice here. I'm trying to create a system for processing Sales Orders into Purchase Orders and then split the Purchase Order into Shipping Containers. The systems needs to be able ...
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votes
3answers
48 views

Completion of ERD, uncertainties about generalization/specialization and primary keys

I'm practicing making conceptual databases and I would like to know of I'm on the right track. I've been trying to create an ERD for a scenario as follows: A hotel can take bookings for weddings, ...
2
votes
2answers
83 views

SQL order by query results in any arbitrary (but reproducible) manner

For testing purposes I need to get some data from a set of database tables in any arbitrary (but reproducible) order. The idea being that I can later compare two runs using a textual diff tool. Is ...
0
votes
1answer
36 views

Need Help for Update Syntax [closed]

How can i create a single query to answer this question: Update amount_withdraw to 200 where less than 500 and amount_withdraw to 330 where greater than 700.
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2answers
50 views

Database Design for Preserving Values and Additional columns

My colleague and I are having some trouble coming up with a database design, and I am doing my best to stay away from EAV for now. We have an entity called Preparation that stores configuration data ...
1
vote
1answer
22 views

Building dependence between regional data (Street -> City -> PostalCode -> Country)

I'm in the process of designing a database to contain regional data to be used inside a CRM system. So, a user suspects that things like the city or country are automatically filled (or maybe just ...
0
votes
0answers
12 views

Need a database and server suggestion for android application [closed]

I need a suggestion for the best server and a database for a android application that will send the real time GPS information and Images captured from the mobile to the server, the images will be ...
3
votes
1answer
253 views

Removing “duplicates” within a time range

I have a table that contains number plate data with a date and time stamp, collected by a plate-reading CCTV camera at a site entrance. Vehicles stopping at the site entrance will create multiple ...
0
votes
0answers
32 views

Completion of ERD, uncertainties about generalization/specialization and primary keys [duplicate]

I'm practicing making conceptual databases and I would like to know of I'm on the right track. I've been trying to create an ERD for a scenario as follows: A hotel can take bookings for weddings, ...
0
votes
1answer
26 views

Naming for status attributes [closed]

How to name status fields in the database, for example if in products table exist field for marking removed items should field name be remove or removed, should it be in the past tense? remove ...
1
vote
2answers
34 views

Need database design advise

I attached the DB schema, so it will be simple. Problem: Need to get the item records from the company e.g. 'A'. Should I add to the item table company_id field? Will it be a redundancy info as we ...
0
votes
0answers
46 views

Context diagram and Data flow diagram for online booking system [closed]

Hi Every one, so far i have created context diagram and DFD for online booking system for hotel. please go through these diagrams and tell me if you find any error. Regards