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

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4
votes
6answers
320 views
+50

Database design for an exam

I am designing database for an exam, and I am stuck. I do not know how to do it. Here is the relevant information: Student answers 10 questions. Each question has 3 options (answers) and student ...
0
votes
1answer
1k views

Allow access to enter data through forms, but not full database access

Using Access 2013 or Sharepoint 2013 is it possible to give someone access to data entry forms that work with a back end database whether Access database or Sharepoint SQL. But from everything I've ...
0
votes
2answers
870 views

How to build a table for a private messaging system that supports replies?

I'm writing a private messaging web application in PHP, the application allows replies such that when you view a message, you also get to see to what was that a reply to, and to what was that a reply ...
1
vote
1answer
51 views

Questions and answers database design for Core Data

I am designing database for a question and answer projects , and I am stuck. I do not know how to do it. Here is information: There will be many users There will be many questions Each question ...
0
votes
1answer
24 views

How to use a table when the user identifier can be one of two fields

Recently we've started developing Github like organisation system for our service. We have both free and payed plans. There are users. Also there should be the owner for organisation and the owner ...
9
votes
1answer
553 views

CouchDB and document versioning

I'm currently working on a wiki-esque application using CouchDB and am trying to implement a document versioning scheme. The way I see it there are two ways of doing this: Store each version as a ...
2
votes
3answers
2k views

Is it worth to separate columns into multiple tables for one-to-one relational table

I need to make a decision for database structure on whether to separate one-to-one relational columns into multiple tables and link with one relationship id or just add all columns into one table. ...
0
votes
1answer
123 views

MySQL Circular Replication

I have this scenario where I have 4 MySQL servers (A,B,C,D), as this: Server (A) is always online, and serves as the main website. Servers (B,C and D) are online on random periods of the day, and ...
1
vote
1answer
28 views

Design: How to account for a custom product in a transaction item table

This question is related to Database Design: inventory and sales system? So for example a burger is a Product which is made up of Component bun, meat, cheese, pickles etc. When this burger is sold it ...
1
vote
1answer
21 views

SQL Server Table Design for Report - Is OLAP Schema Suitable

A work colleague is developing SQL Server database tables for a reporting project. Basically, the only activity on the table will be populating it from a ETL process (SSIS). He insists on creating a ...
0
votes
1answer
33 views

Database extensions vs migrations [on hold]

When using of database specific features (instead of 3rd party solutions) is justified, especially on the beginning stage of the project? Example: Postgres has full-text search, which do not support ...
0
votes
1answer
41 views

I Need Help With My Database Design for Product Management

I'm designing a MySQL database and the front end for my work. The database will store all of the products that we sell on our marketplaces and their relevant data. We will be able to lookup products ...
3
votes
0answers
98 views

Inputting auto-incrementing, grouped, unique hashes?

Alright, here's what I've come up with so far: SET @id=(SELECT IFNULL(MAX(id) + 1, 0) FROM leads); UPDATE leads SET id=@id WHERE id IN ( SELECT id FROM (SELECT * FROM leads) AS something WHERE ...
1
vote
0answers
32 views

Anchoring values for a rating or likert scale

I am designing a schema for an interview system as per the suggestion in this answer. I need to store several different types of questions: Questions with a free-text response Multiple choice text-...
2
votes
1answer
41 views

Database design - summary table vs always counting over tables

Imagine a system where a user can make a whole lot of different actions, like: Making a purchase Liking something Opening a specific view (pretty much every click) Inviting a friend ... The ...
4
votes
2answers
39 views

Database Design (how to handle subclass & superclass)

I'm wondering what is the best approach to this type of problem (I'm a highschooler so don't have practical knowledge on the subject): Let's say I want to store information about employees at a zoo. ...
0
votes
1answer
150 views

How to/Where to find MySQL templates for Toad Data Modeler

I have recently install Toad Data Modeler 5.3.4 and it only has Oracle data model templates. Where can I find and import the MySQL data templates so that I can create MySQL database models. I have ...
1
vote
1answer
47 views

How to deal with a chain of several linked 1:n:n*m:n*m*k “join” explosion?

I have a domain model, where I have a "manager" which has 1:n relation with another resource (A). A has 1:n with B, and B has 1:n with C (it makes sense as a relation). However I'll need a lot of ...
1
vote
2answers
136 views

Efficient workflow/queries to save unique information?

I am saving company information in a database. There is a single table with an auto-incrementing key that is unique to each company. There are separate tables for emails, websites, phone numbers, and ...
-4
votes
1answer
67 views

How does indexes work in a database? [on hold]

If I have a list of name that are all different and I have to find a specific name,how could indexes help.thi research?How does index work in a database?I have read other discussion but I haven't ...
1
vote
3answers
295 views

Working NoSQL scheme for a betting app

I'm building an app where a user can bet on the result of a sports game. Basically, we feed the database with competitions and games, and the users can place their bet in the form of a score ...
0
votes
0answers
15 views

Build EER from requirement specifications [on hold]

As a newbie for database, how to build a EER from requirements specifications, and what does it mean actually.Hard to find any resources from internet!
0
votes
1answer
43 views

Set indexes for database used for login and register actions

I am thinking on how to set indexes to improve performance of a database for register and login actions.I have seen that alphabetical indexes are not good so I don't know how to do...Can you help me?...
3
votes
3answers
167 views

Database architecture

I am in the early stages of designing a database, and I have little (none) database design/planning experience. The database is part of a job tracking engine.. As jobs are created, they are assigned ...
1
vote
2answers
31 views

Best practice for parent child relation

Suppose, there are some tasks and some sub-tasks under those tasks For example: Task 1 Sub task 1.1 Sub task 1.2 Sub task 1.3 Sub task 1.4 Task 2 Sub task 2.1 Sub ...
1
vote
1answer
33 views

Simple Database Design - Many to many? - First database (newbie)

This is my first database I am designing. However I am getting confused on the many to many relationships. I have a products table, each product can have inventories in many different warehouses. So ...
1
vote
2answers
34 views

How to model that several variants of a merchandise item may affect its price?

I am an absolute beginner to relational data modelling. I hope my question will be acceptable here nevertheless. Let’s say there’s a merchandise. An item of merchandise may have variants. (While it ...
1
vote
1answer
21 views

Using Case with no column result

I made this solution but it continues not returning any value If the user not exists. select case when TypeId = 1 then 1 when TypeId = 0 then 2 when count(1) < 1 then 3 ...
0
votes
0answers
21 views

single Small Table with more rows or single large table with less rows [closed]

I need to design a table to hold an various records coming from the source. The records are such that they have around 20 fixed columns that are common to all. There are another 10 to 15 columns which ...
2
votes
1answer
46 views

What is the cardinality of entity relationship between Employee and Department?

Recently, a friend of mine asked me this question about the cardinality between a Department and Employee entities, I replied many to many, then he, my friend, showed me drawings from the internet ...
1
vote
1answer
132 views

How to efficiently design MongoDB database for Uber-like application?

I'm designing a MongoDB database for an Uber-like application, but since I'm new to NoSQL concept, I have several doubts. I have three main collections - users, requests and messages. User can post a ...
1
vote
0answers
52 views

How does one map nested multi valued attributes?

Let's say one has an Entity E. E has a multivalue Attribute M1 and a simple attribute A1. However M1 consists again of a multivalue Attribute M2 and a simple Attribute A2. How would one map this ...
3
votes
1answer
1k views

Database design for Magazine website

I need to design a CMS based website using asp.net web form (c#) and MS SQL Server as backend database for a magazine website which will have monthly issue. I am finding it hard to design a database ...
1
vote
1answer
38 views

Booking database design with a twist

I'm wanting to find a way to how I can implement a booking system that lets users put a start date on the booking and generate the end date whenever. Lets take a house renting example. Say I wanted ...
-3
votes
0answers
31 views

What is the optimized query to get max id from a table? [closed]

I have this query: select max(id) from myTable As myTable has one million rows, sometimes the query throws this error Transaction TransactionImple < ac, BasicAction: 0:ffff0acb10a4:126a:...
3
votes
0answers
17 views

How to decipher entity relationships in a Physical Data Model given the corresponding Logical Data Model

Can someone use the entity relationships in this Logical Data Model (LDM): to explain the entity relationships in this Physical Data Model (PDM): and how to specify the foreign keys in the PDM?
-4
votes
1answer
31 views

Relational model 1:1 relationship [closed]

Can a one to one relationship exist without the primary key- foreign key tie up? Please give an example.
3
votes
1answer
41 views

How would i create a report involving multiple many to many relationships

Lets say table A has a many to many relationship with table B, and table B has a many to many relationship with C. Two junction tables are created for AB and BC to form the many to many relationships. ...
1
vote
0answers
11 views

does insert “logs or traces” into RDBMS (example log4j) makes sense? What are pros and cons?

Our developers are inserting Java logs into a table. This table can grow very much (for example debug logging enabled) and I need to to truncate table. Our database is for OLTP. > desc ...
0
votes
0answers
28 views

In DB2 , what steps need to be followed to improve bufferpool hit ratio for particular table? [closed]

I have read Scott's article on Bufferpool hit ratios and folly . I am more interested in experts views on steps they follow when the bufferpool hit ratio drops down, to say, 60%. Also, any specific ...
0
votes
0answers
31 views

Final Unique Index for Person and Companies?

I am creating a persons schema where the the person table must be very simple because it will be father of other tables that completes it, but a person can be fisical or legal, so I wont put any ...
0
votes
0answers
22 views

one Comment table for all content types or many tables for each content type

I have a very similar question with this stack overflow link but since its not answered I had to post it again. I have many place which people can place comment: file download, biography, blog and etc....
1
vote
2answers
30 views

Bridge table question

Should be a simple questions, I just want to make sure. If I had 2 tables I want to bridge, for example food (food_id, foodname, ...) and a plate (plate_id, platetype, ..). When the tables are ...
1
vote
1answer
42 views

Multiple person roles in database(how to define if same person)

I have the following data structure: For internal purposes I can register my outside partner. In this case I don't know his/her identify card number. So I add my partner to database but without id ...
2
votes
1answer
340 views

PizzaShop - DB - Normalized Schema

I am trying to make a simple DB in Access for a theoretical pizza shop(the db is for an assignment). What I am trying to do is link one type of pizza to one or more types of toppings. I just wanted a ...
0
votes
1answer
162 views

Database design for products with multiple units

I am designing a database for retail business. There are some products that can be sold in multiple units, for example, pencils can be sold in ea and dozen, paper can be sold in sheet, ream, and ...
9
votes
1answer
242 views

Overcoming the SQL Server Express Edition limitation

Microsoft SQL Server 2014 Express edition has a database size limit to 10GB. Now, is that just for a single instance or the overall size that the edition will allow? Or does that means that I can have ...
1
vote
2answers
71 views

How to decide that a new table is needed?

This might seem a vague question but I am going through a bit of a dilemma here. How do you people decide when a new table will be need? For example, when creating a table for storing user ...
2
votes
2answers
76 views

How do I guarantee inventory numbers are unique across all tables?

I have an assortment of physical objects which need to be inventoried and each type of object has it's own table. For two example objects, let's use 'swords' for the table containing different swords ...
2
votes
1answer
56 views

SQL Server 2008: how do I hide data from a DB Maintainance User?

Our organisation employs a third party company to do maintenance on our database. To be honest, currently they act as our DBA's since we do not have one. In order to do the maintenance work, they ...