The logical model and/or physical design of a database.

learn more… | top users | synonyms (4)

0
votes
0answers
63 views

Table design for optimum performance

For example let's say I have to create a table called Employee with columns EmployeeID, Name, DOB, Address, DepartmentID[FK]. So I create the table as follows with a primary key and a nonclustered ...
2
votes
0answers
78 views

With SSD's and in memory tables, does a snowflake schema become preferred over a star?

With SSD's being very fast (reducing the overhead of joins), while more expensive (increasing the cost of redundancy due to de-normalization), along-with a focus on in memory tables (again reducing ...
1
vote
1answer
78 views

When using underscores, should they be reserved to junction tables? [closed]

Say you have the following tables company (contains companies) industry (contains industries) company_type (contains company types, e.g., Public, Private) company_status (contains company statuses, ...
3
votes
3answers
455 views

Can't convert this type of ER diagram into SQL or relational tables

I have stumbled upon a problem during database design. Let me explain what it is all about: Contract has some simple attributes that describe him, and may have annexes and dynamics of payment. ...
0
votes
0answers
137 views

Looking for a recipe to merge multiple rows to single row

I have a aggregation table that is written by multiple processors (around 20). Each row has a composite key - location-id, campaign-id,... and aggregate stats about it. I need to merge the ...
1
vote
1answer
119 views

Will switching from Concrete Table Inheritance to Single Table Inheritance improve the performance of my queries?

I currently have an application that allows people to view and share 10 different types of posts (ex SportsPost, WorldNewsPost, TechnologyPost, etc). All posts types are conceptually the same, but ...
0
votes
3answers
423 views

Autoincrement Primary Key For Constants

We are having an issue that is probably due to some poor design choice or lack of understanding of how to use primary keys. We have a simple constants table CREATE TABLE IF NOT EXISTS `constants` ( ...
1
vote
2answers
127 views

Need help designing a database

We are designing a system which holds statistical parameters about a particular user. As the users use the system the statistics change and the updated statistics are stored in the database. So for a ...
1
vote
1answer
112 views

Should I create a Factless Fact Table or Denormalise my table

I am creating a data warehouse from a store database and I have a question regarding the design of my dimensions and facts. In the store database a table exists for Person, Person_Address and ...
1
vote
1answer
159 views

How can I design this database?

So I have a ton of transaction logs in pipe-separated format spread across a few dozen files. Concatenated into one file, it's around 2.4 million lines. Each transaction has a store number and a ...
1
vote
2answers
95 views

A simple question regarding database design that has always bothered me

Say I have a table of schools, and each school is either Public, Private, or For-Profit. As well, each school is either '2-4 Year,' '4+ Year', or 'Graduate'. My initial instinct in this situation is ...
5
votes
2answers
529 views

How to store immutable, unique, ordered, lists?

I have an entity with millions of instances. Each instance has to reference an ordered list of items. The lists have to be unique so no list will be stored more than once. But once created, both lists ...
0
votes
1answer
66 views

Design: Fitting variable hierarchy of text files into a relational db

I have a large data corpus (several TB) made up of data gathered through customer support queries. I've been asked to set up a database to make this data more accessible, but as I'm kind of new to ...
0
votes
0answers
93 views

Using triggers or php code

I have a table called Salons, which has over 15k Salon names. I have another table which takes count of the pageviews of each salon. My question is that if I want to update reputation of the Salons ...
0
votes
1answer
184 views

Division Email Template DB Design [closed]

First question for me on the DBA SA site! This is for an Java email notification app using MySQL for backend. I have a small number of groups in our organization, [Marketing, Commerce, ...
0
votes
0answers
41 views

Tables with same schema in DB for different sources. Bad pattern?

The main purpose of the system being developed is to collect data from different sources, process and standardize it, and then add it to the DB. After information from all sources is collected it ...
0
votes
1answer
63 views

How can I quantify the business value of normalization?

My company is developing an internal application with a SQL server database which was started earlier by another developer. Now I am Looking at the model,the developer has stopped at 1NF. I proposed ...
1
vote
1answer
206 views

Date model for commenting system stored in a key-value NoSQL DB?

I'm trying to leverage Cassandra's strong support for time series data to build a commenting system. So far I'm thinking that each row would be a particular topic, and each comment would be a new ...
1
vote
1answer
49 views

Financial Inst - Model Role+Relationships b/w Person and Account

A Person can be on one-or-more Accounts. For each Account a Person is on, Person has a certain role on that account i.e. Person 1 is primary on Account 1 Person 1 is joint on Account 2 Person 1 is ...
1
vote
1answer
663 views

Postgres JSON field for many to many relationships

I'm designing a schema that has a many-to-many relationship as such: A lead can have several stages and each stage can have several leads. I currently have three tables, with one of them as being a ...
0
votes
0answers
79 views

Best way to handle multiple query keys

I am designing a postgresql database for an online card game. I want to provide users with the option to access their play history - users can see log of their games. The data I want to save has the ...
4
votes
2answers
5k views

Check whether empty strings are present in character-type columns

I have an application that (as part of its logic) trims strings and replaces empty strings with NULL prior to insertion in the database. I guess one way to ensure that this is enforced would be to ...
0
votes
1answer
120 views

creating a multi table “identity” column (faux identity)

I am currently designing a job execution engine and have run into a problem I am looking for some advice on. I am converting some processes to a new system and need to define the table structure. ...
-3
votes
1answer
162 views

Best design to handle multiple query keys [closed]

I am designing a postgresql database for an online card game. I want to provide users with the option to access their play history - users can see log of their games. The data I want to save has the ...
0
votes
1answer
123 views

modeling data dimensions as columns - some dimensions are highly variable while others have low variability

Please excuse my question if it is a bad one - I am not a DBA... I would like to model the following data: Let's say that I have one column that is the row id as generated by a sequence. Let's also ...
1
vote
1answer
99 views

A many-to-many relationship

I'm designing a simple database and have a question regarding a relationship. So far, I have users, books, highlights and bookmarks. The relationship rules are as follows: Each user may 'subscribe' ...
1
vote
3answers
468 views

Oracle static lookup table

What is the best approach (or what options am I not aware of) to creating a static table or view where the data rarely, if ever, changes? An example use-case is a list of US states, where my ...
1
vote
1answer
375 views

Composite Foreign key to single primary key [duplicate]

How do I create a composite foreign key to a table with a single primary key? For example suppose I have the following tables: CREATE TABLE Branches ( BranchId UniqueIdentifier DEFAULT ...
0
votes
1answer
62 views

Time Series data for controllers connected to other devices [closed]

We have a relatively large number of controllers deployed to the field (4500). Each of these controllers have multiple other devices connected to them. These controllers are now going to be able to ...
2
votes
2answers
110 views

PostgreSQL and storing configs

The problem is to store and use global configs such as currency/date format etc. Since this functions are commonly called I'm concerned with the performance impact. Lets take currency as an example. ...
0
votes
3answers
142 views

Database Design for Paper Submission System

I am learner of Database design, I want to design a database for a journal paper submission system in which one paper can be submitted by one or more author. I have initially two tables Author and ...
5
votes
2answers
3k views

How to insert values in junction table for many to many relationships?

I have three tables in database: trips(trip_id(pk), trip_name(unique), user_id(fk)) places(place_id(pk), place_name(unique)) trips_places_asc(trip_id(fk), place_id(fk)) Since many trips can ...
0
votes
1answer
876 views

How to create a relationship between one table and multiple other entities

(PLEASE NOTE: I am aware that in a few cases there are one-to-one relationships where one-to-many should be present. It's not intentional, it's just a mistake on my side. Take no notice.) I am ...
0
votes
2answers
115 views

Need help about giving relationships in database design

I am developing a simple blog application in which users can write posts and others can like, comment, share etc. i am facing difficulty in designing database. What I have tried is: user (user_id(pk),...
0
votes
2answers
260 views

How does one know when to stop normalizing?

Alright, so basically I feel that I tend to over-normalize things, and maybe I am doing it at the cost of performance. So, to illuminate on the problem, I have created the following schema to use as ...
0
votes
1answer
41 views

Effects of monolothic databases on performance and security?

Please note: although I'm specifically calling out MySQL here, I would also appreciate/entertain generic answers that apply to all/most relational systems. As a developer I don't see the design ...
1
vote
2answers
85 views

Preventing duplicate data when usual normalization only makes sense for some of the records

Background I have two tables, one called issues and the other called status_checks, which both contain (among others) the field comment (VARCHAR). An issue is raised by a user when something needs ...
1
vote
0answers
35 views

What does a high level overview of the logic backing database queries look like? [closed]

explanation i.e. At the database driver level of abstraction you may invoke API methods for compiling and executing some kind of query language, which can be expressed as a string sometimes (SQL e.g.)...
0
votes
0answers
97 views

Last synchronization time between master and slave (replication)

During replication process where a Master is connected with slave. Some times connection between these two goes down. Any options to get the details of the last synchronization time?
4
votes
3answers
669 views

How to achieve many to many relationship in this database design?

I am currently working on small travel application in which users can add other users' trips in their wishlist. I am facing difficulty in designing database for wishlist. What I have tried so far is: ...
1
vote
1answer
113 views

Different kinds of pricing PostgreSQL

I would like to hear your opinion about handling different kinds of pricing. We have a product table which looks almost like this: +----+------+-----------+-----------+ | ID | Name | price_old | ...
1
vote
2answers
194 views

Need help about normalizing database to 3NF

I am currently working on a city travel guide application which let users explore places and plan trip. In the account module, the following functions are to be considered: User can register by ...
7
votes
4answers
2k views

What exactly is overlapping candidate key?

Can some one please explain to me in simple terms what is overlapping candidate key ? What is overlapping as the name suggests? Consider the below relation R(L,M,N,O,P) { M -> O NO -> ...
2
votes
3answers
930 views

Database design: 4 types of users but have different functionality , separate or one table?

I have 4 types of users: Admins , normal user , company , service provider Admins and normal user share some attributes (id .first name ,last name ,phone ,mail) company and service provider share ...
0
votes
3answers
198 views

Confused about Primary Keys, and Foreign Keys

Im brand new to database design and, I'm slightly confused about Primary Keys, and Foreign Keys and my database design. Context: I'm working on a database of museums and Categories will be one way ...
0
votes
1answer
125 views

Trying to map postal codes to their respective cities, but running into some issues

The Problem I am creating a database of Countries, Regions, Cities and Postal Codes. Here's an example to give an idea of the database structure as it is now: Now, let's take Tuskegee University ...
0
votes
1answer
77 views

Database design: Which will perform better, auto incremented column or a composite key for appointments

The schema of table is : appointment(date,time,patientID,...) pateint(patientID,PName,age,...) PS: two or more patient can came at the same time . The number of appointments per day up to 500 . ...
0
votes
1answer
140 views

Copy database from one mysql sever to another mysql server

Following are the details of the database and server: Server1: Host Name: abc Port Num: 01 database: test Server2: Host Name: xyz Port Num 02 database: spareparts userid: spts password: abcdefgh@123 ...
1
vote
1answer
352 views

No-SQL Database Design for restaurant app

I've been working with SQL databases all my life and I am now trying to get into the NoSQL world. I am a looking for a piece of advice on whats the best practice in order to achieve this. Suppose I ...
8
votes
4answers
524 views

Don't know how to transform variable entity into relational table

INTRODUCTION AND RELEVANT INFORMATION: The following example illustrates the problem I face: Animal has a race, which can be a cat or a dog. Cat can be either Siamese or Persian. Dog can be a German ...