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.

learn more… | top users | synonyms (3)

1
vote
1answer
34 views

Alternative approaches to “primary” record in child table

I have a database with a Customers table, and two child tables Addresses and Contacts, as customers often have multiple locations and contacts. However we also need a "primary address" and a "primary ...
2
votes
2answers
59 views

unusual relation, binary aspect

I have question very unusual for databases. I’m not a good English speaker, but good English reader :) so for explanation I’ll give you examples. Part1 In MySQL, I have two tables with relations ...
-1
votes
2answers
22 views

How can I create Data Base on phpMyAdmin?

I have a serious problem here. I am not able to create data bases as the option is not to be found on my phpMyAdmin, but it only shows 'No Privilege' in red font. I even tried to create data base ...
0
votes
0answers
4 views

SSMA not moving partition info from MySQL to MSSQL

I am trying to convert my existing database from MySQL5.x to MSSQL 2014. While all the table schemas gets ported from MySQL into MSSQL, table partition info are not being carried over. ...
0
votes
1answer
44 views

Ternary Relationship in ERD , What would the cardinalities look like in this situation?

I have 4 entities USER , COURSE , MODULE , TOPIC The Constraints go something like this. A Course contains one or more Modules and each Module contains one or more Topics Now, a User can study ...
1
vote
1answer
48 views

Database design import massive csv files is there a more efficient way?

I need to let users import huge csv files varied between 200k - 1.5m lines. For this I use LOAD DATA INFILE which is the fastest way to import those files. Thing is however that I can't check the user ...
0
votes
1answer
32 views

Big lists in a relational DB

I need to store a list of items and that list belongs to a single user. The lists are going to be huge, so this has to be done as efficiently as possible. The lists also have to be modifiable to a ...
0
votes
0answers
13 views

Dummy Objects vs. NULLs: optionality for three-way relationship

In a nutshell, I'm trying to model a relationship and can't decide whether to allow NULLs or to require values and use dummy objects (in place of NULL). Here are the details. I have three classes: ...
2
votes
0answers
15 views

Filegroup design for Document Table for BLOB Storage

I have a table for storing documents as VARBINARY types in my database (I'm not using filestream). My database is setup with only one data file, but I am wondering if there is a benefit to creating a ...
0
votes
3answers
157 views

What is the term for a “wide”, non-normalized view/query?

A well-designed relational DB schema tends to have a relatively large count of relatively small, normalized tables — a cluster of snowflakes, I think, describes the situation. In order to ...
1
vote
1answer
77 views

How to manage many-to-many relationships when there is also a hierarchy among the many?

I have these entities – employee, task, phase, project – and these relationships: project 1:m phase phase 1:m task employee m:m task, phase, project The first two relationships form a ...
2
votes
1answer
60 views

Scalable Relational Database Design

I'm designing a web application (using Django) for a client that will need a fairly large database behind it. I've never worked with databases that handle large amounts of data before so I'm hoping to ...
2
votes
1answer
23 views

Attribute-Attribute Dependency

So as part of our college project, I'm working on CENSUS Database. I stumbled upon a problem wherein if an individual is below the age of 18, his/her marital status should only allow 'NA' and anyone ...
0
votes
1answer
44 views

Need help on a database model design

I am creating a small booking application with Laravel. It lists some centers. Each center has its own unique rooms. Each room may be booked several times (with dates). From my application, I post the ...
0
votes
1answer
46 views

How should I store changes to items in the database?

I have items (tracked with itemid) that have attributes assigned to them (field1,field1 for example). At any given time, field1=val1, field2=val1, ..., fieldn=valn where val1,val1,...,valn = 1..100. ...
0
votes
1answer
27 views

Usage of non standardized queries

So this is more of a theory question than practical but I'd appreciate any help. My friend and I are doing a project to learn new stuff and have fun. He's a coder and I like to think that I'm good ...
1
vote
2answers
56 views

Schema to make a Payment History/Viewing History

On some websites I have seen two history of events: Payment History and View/Watched History. I want to have both payment and viewing histories in my app, but I got stuck when I started thinking ...
0
votes
0answers
29 views

Unique indexes on table with multiple columns

I have a table called organogram: SHOW CREATE TABLE organogram: CREATE TABLE `organogram` ( `organogram_id` int(11) NOT NULL AUTO_INCREMENT, `locatie_id` int(11) NOT NULL, `afdeling_id` int(11) ...
-1
votes
2answers
215 views

How to run multiple select statements in Data flow task in SSIS [closed]

I am migrating data from one database to another database using SSIS package and i need to write multiple select statements for same table depending on conditions as mentioned below. Actual Queries i ...
2
votes
1answer
50 views

In SQL Server would misc pages be pushed out when an object grows within a mixed extent?

In SQL Server 2008-2012, objects (including tables) are first put in a mixed extent. An extent can accommodate up to 8 pages and accommodates more than one type of page (meaning: pages from more than ...
-2
votes
1answer
64 views

Design database for tournaments

I'm looking around since few days on how should I build my database to support full flexible tournaments. Let me explain my specs. As a user I want to : Create a tournament Let other users register ...
0
votes
1answer
25 views

sub and sub-sub item organization system [duplicate]

So I am looking to find the best database design for the following situation. I will refer to my entities as 'articles' as that would best/most-easily describe them. So the articles have already ...
1
vote
1answer
66 views

Make 3 separate tables, or 1 combined table for similar data?

When designing a database's structure, if we have multiple tables with similar data, should these tables be combined, with an added ENUM field to denote the table type; or should 3 separate tables be ...
0
votes
0answers
43 views

Database design trouble for survey application

I'm having trouble figuring out how to design database tables. I'm going to have a table employees which has the employees' information such as names, age, email, etc. It is going to be an ...
1
vote
1answer
25 views

Drill Down Functionality for Data Entry in Database

I am building a database that houses financial statement data. Within the database and to maintain the relational model and data integrity the fields are standardized. However, I do not want to lose ...
0
votes
0answers
29 views

Two id columns in one detail table

Let's I have two tables(I have removed some columns for brevity): ADULTS -> ID CHILDS -> ID And I have one table which includes detials about these persons like that: USERS-> ADULT_ID, ...
-2
votes
1answer
78 views

how many database tables is too much?

I'm working on a project for a school and so far I have 91 tables! Everything is linked to the student table, is it normal to have this many tables in one database? or do i need to make multiple ...
0
votes
1answer
37 views

Finding the same value in a column and only returning rows without the same value

I have a query that i have to find the DiscountPercent that are the same and not show the rows with the same DiscountPercent. I have tryd this and it brings back the values that are the same SELECT ...
0
votes
0answers
22 views

Multiple M-M relationships between tables

I am working on the design of a new database. In this database, we track equipment corrective actions (repair). We have three personnel fields in each Equipment Corrective Action record: initiated ...
0
votes
0answers
25 views

How do I define a 'flexible' relationship in my table?

I'm working on a large application, with tons of tables and a huge codebase. It's a system in which people have rights to use functionality X and/or functionality Y and/or functionality Z. ...
0
votes
0answers
28 views

Use ID from another mysql database?

I have a mysql database for form submission (written in PHP) data and a mysql database for CRM (using X2CRM) on the same server. When a form is submitted on my website the POSTed data of the form ...
0
votes
0answers
23 views

Help in Designing a CBT database

Please i need help in modifying or remaking the database so that i can mark answers to questions immediately. The problem is some courses have 50 questions, while others have 100. How can i design ...
0
votes
1answer
56 views

Normalization for three somehow identical tables

These three tables are nearly identical. But, there are some exceptions. But, I can't find best normalized structure. Could you please help me? Here is the informations must be hold in database: ...
0
votes
1answer
137 views

document and edges in orientdb

I was playing around with OrientDB lately and was create some classes and edges. I was able to create edges between documents, is this something that is expected from OrientDB when edges are ...
0
votes
1answer
15 views

GROUP BY parentId and MAX childId

My tables are below: crm_conversions crm_messages_of_conversions crm_receivers_of_messages I want to get all of conversions of an user with only last message. I'm trying to get with the query: ...
0
votes
1answer
203 views

Trigger function check if all NEW.* fields exist in another table

In PostgreSQL I need to code a trigger function that checks if all the fields in NEW.* exist in another table that has the exact same name as the table that fired the trigger but appended with "_hv". ...
0
votes
0answers
10 views

Access 2010 Forms not seeing imported data

I created a form that has several sub-forms. During testing with sample data everything works great. I can switch between sub-forms and all the data is correct. I deleted the sample data and imported ...
0
votes
0answers
72 views

how to enable powerdesigner 16.5 auto increment primary key for MySQL database

I am using powerdesigner 16.5 to model my MySQL database. Anybody knows how to enable its auto-increment primary key feature?
1
vote
0answers
28 views

how to resolve this insurance company database

Company offers 3 types of personal motor insurance to vehicle owners. It includes the third party insurance, fire and theft, and comprehensive cover. All vehicle owners need to purchase a motor ...
0
votes
1answer
54 views

Store data of feedback form

I am a novice at database management and doing a small project on Feedback System. My question is that I want to know that how i should store the data of feedback form. Suppose i have different ...
0
votes
1answer
85 views

Most efficient way to set up a database handling millions of links? [closed]

I'm looking at making a site that will potentially have up to a million users, and each user will have hundreds/thousands of links connected to a set of sites, as well as other info. I'm using mysql ...
0
votes
1answer
56 views

Maximum Partitioning PostgreSQL

I have 400,000 records I need to partition. The records will increase 100,000 per year and those new records might need to have 1000 new partitions added. Here are some of my concerns: How many ...
1
vote
2answers
150 views

How to enforce data consistency across one-to-one relationship in an inheritance hierarchy

Consider this design for a typical school database: Person: ----------------- FirstName LastName SocialSecurityNumber Phone Email Student: ----------------- Grade Teacher: ----------------- ...
1
vote
0answers
24 views

Finding missing_index_details in MySQL

MS SQL Server apparently can tell you what indexes would be useful for your query. Is there anything similar in MySQL? This article (scroll to "Find missing indexes") says that in Microsoft SQL ...
1
vote
1answer
68 views

Automatic deduplication (normalization) of strings in MySQL

The question is whether MySQL can use separate physical storage for strings transparently, but with the same operations that are applicable to varchar, including %. I have a large number of ...
4
votes
1answer
68 views

Does MySQL exectution plan depend on available indexes?

Does MySQL choose an execution plan for a given query taking into account what indexes are available, or does it first choose an execution plan and then uses indexes if they are available? ...
2
votes
2answers
81 views

Unique across tables

I have a table containing users. Each user has a primary email and a flag indicating if the user is deleted or not (we never hard-delete users). However, each user can also have additional emails. ...
0
votes
0answers
49 views

Relationships for database tables in HR/Compliance Database using MS Access

I am designing a dual HR and Compliance Database and am stuck on how to relate 3 specific tables. I have an Incidents table that tracks incidents, a Review table that shows data collected from reviews ...
2
votes
0answers
12 views

Counting daily distinct records [duplicate]

I have a table that looks like this in Google Big Query: custID InteractionDate Purchased? Sales 1 20150312 F 0 1 20150312 T 200 1 ...
1
vote
1answer
37 views

Should my application utilize database credentials for user login?

I'm working on an application that has an ASP front end and a SQL Server database. The way credential management is currently performed is there is a custom built User Table in the database that ...