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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Architecting table with multiple paths to common parent tables

I'm wondering how to architect a database when there are multiple paths (via foreign keys) to a common parent table. For example I have the following tables: Table: Students PK StudentId Table: ...
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1answer
2k views

Many to Many and Weak Entities

I have an entity that cannot exist without being defined by another, and I want this entity to participate in a many-to-many relationship. Example: An artist has an album (the album cannot exist ...
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3answers
50 views

Column A or Column B required MS Access DB

I'm in the situation where I would like to enforce the requirement where a record must contain either one column or another at a data level, I'm not sure whether it's achievable. I've got an Enquiry ...
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1answer
76 views

Friendship and Messages in a MySQL table relational schema problem (concerning big data manipulation)

Before you start suggesting this question for duplicate read it, I have searched and i haven't found any proper solution. So, i'm building a social networking site (I know that you are laughing ...
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1answer
57 views

Enterprise database design [closed]

we have customer who want to make some product like this or more specifically she needs replica of this product which is a generic inventory,product,customer etc management system. And the reqirement ...
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1answer
30 views

Cyclic relationships in ER Diagrams

I am trying to draw an generic entity-relationship diagram to model a software object (Let's say a xml file). This xml file has references to other xml files. Also if a xml file (say "file-A") is ...
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3answers
504 views

What are the pros and cons of using my customer codes as a primary key?

I am designing a database for one of my sales teams. Right now, the goal is to get a master list of customers and their mailing addresses, but the DB will eventually expand to track some other ...
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4answers
84 views

SqlServer: can one table's PK be the FK of other two table's? [duplicate]

I have three tables project, users and proj_user. The PK of proj_user table is the FK of project and users table's pk e.g.(project_id,user_id) My question is, is it possible for the project_id and ...
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1answer
111 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 ...
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2answers
47 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 ...
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2answers
183 views

Relational Model vs. Database Products [closed]

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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0answers
61 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 ...
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1answer
63 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
32 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
43 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 ...
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3answers
31 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 ...
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2answers
270 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 ...
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2answers
36 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 ...
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1answer
87 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 ...
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0answers
14 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 ...
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1answer
65 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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0answers
38 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 ...
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1answer
170 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] ...
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1answer
39 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 ...
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1answer
107 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?
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1answer
36 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 ...
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3answers
118 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, ...
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2answers
121 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 ...
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2answers
62 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 ...
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1answer
36 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 ...
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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, ...
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2answers
35 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
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3answers
81 views

Best way to create relationship between multiple tables

I have a question about how to best handle a table that would be shared among multiple relationships, but shouldn't really be joined with all these tables. For example, suppose I have a table that has ...
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2answers
137 views

Data Modeling for different roles

This is my first post here, so I hope its clear enough. I want to make an application for people who sell, buy, rent and fix a certain product. I need to create a database that would keep the data of ...
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2answers
227 views

Best practice database design - user rating tables

I want to create a table to store user ratings of items for collaborative filtering algorithms. So far my table looks like this: IID | UID | Rating i.e. item ID |user id |rating. From ...
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28 views

many to many relationship tables for four or more master 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 ...
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1answer
59 views

Multiple User Types - DB Design Advice

I'm developing a web application that will support user authentication with corresponding roles for each user. Also, my users can be of different types and have different fields associated with them. ...
3
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2answers
373 views

Disable all constraints and table checks while restoring a dump

I've obtained a dump of my PostgreSQL database with: pg_dump -U user-name -d db-name -f dumpfile which I then proceed to restore in another database with: psql X -U postgres -d db-name-b -f ...
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2answers
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Is a composite index also good for queries on the first field?

Let's say I have a table with fields A and B. I make regular queries on A+B, so I created a composite index on (A,B). Would queries on only A also be fully optimized by the composite index? ...
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4answers
9k views

What is an audit table?

What are audit tables? How are they useful? I came across them reading this article.
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which role-permission database design?

I want to manage roles and permissions. Most of designs on web look like this tables: Users Roles UserRoles Permissions RolePermissions Here, what is permissions? I am thinking for such a design ...
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1answer
1k views

Designing An ACL Based Permission System

I am trying to create a permissions system where everything is going to be stored in MySQL (or some database) and pulled using PHP for a project management system I am building.  I am right now trying ...
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0answers
2k views

Schema for an RBAC (Role-based Access Control System)

I want to implement an RBAC, Flat based. I've decided to base my system on the NIST standardization model. Although all fine and well, I have an inclusion to that design. Instead of a hierarchy ...
5
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2answers
3k views

Designing a user authenication (Roles & Rights) module

I am trying to model a User Authentication module for a MS SQL Server database that will be the back end to a Delphi UI Application. Basically, I want to have user accounts where the user belongs to ...
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297 views

Need Help in DFD Diagram for online hotel booking system

Hi friends, I am creating a data flow diagram for online hostel booking system. not sure if i created a correct diagram or not any help would be appreciated. thanks in advance
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2answers
117 views

Database design suggestions for a data scraping/warehouse application?

I'm looking into the database design for a data warehouse kind of project which involves a large number of inserts daily. The data archives will be further used to generate reports. I will have a ...
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3answers
62 views

Best approach for Legal/Natural can have many Orders

I'm working on this model: where as you may see one NaturalPerson can have many Order and the same for LegalPerson the only difference between NaturalPerson and LegalPerson are a few so in that ...
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1answer
92 views

Database analysis

I have database which that store the sold products in Orders Table and another table called Transaction to set the time and the total price for the individual order ,my question is: How to combined ...
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1answer
104 views

Difference between Relational database and time series database?

I have a bit stupid question maybe. I recently came across a term "time-series database". I would like to ask what is time series database and is it same as relational database? Thanks,
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2answers
628 views

Online Hostel Management System ER Diagram

I have created an ER diagram for an online hostel management system. Please advise me if this diagram makes sense or needs improvement.