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

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0answers
112 views

Unable to decompose this relation to BCNF

I have a relation R = { A, B, C, D, E, F, G, H, I } And functional dependencies F ={ ABC -> DE E -> C AB -> F C -> G F -> H H -> IJ F -> B } I am able to do simple BCNF ...
28
votes
6answers
33k views

In what data type should I store an email address in database?

I understand that an 254 character email address is valid, but implementations I have researched tend to use a varchar(60) to varchar(80) or equivalent. For example: this SQL Server recommendation ...
2
votes
1answer
813 views

Best practice around sys.dm_db_missing_index_group_stats in SQL Server

I have a fairly simple query using sys.dm_db_missing_index_group_stats that identifies missing indexes in my SQL Server database. This is pretty commonly used. My question is how do I identify which ...
6
votes
1answer
179 views

What is a good way to determine the performance I should expect from a PostgreSQL server?

Trying to figure out how I should expect my database to perform. Basically, I need to determine when the server I have set up is reaching its performance limits - which would help me plan server ...
1
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1answer
129 views

big db for managing user files and settings

Hi im about to start a project that will hopefully eventually hit milion+ users which is some kind of a site managment, problem is how to set the db in mysql, some people suggest way 1 and others way ...
7
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2answers
659 views

Best relational database structure for this data

I'm in the process of creating a database scheme for the following scenario: There are users Users have roles (such as "Developer" or "CEO") Roles have applications (such as "Topdesk") Applications ...
2
votes
3answers
2k views

Database Design Relationship for Patient Visit in MS Access

I am designing a database to store records for research purposes, and I am having trouble picturing how I can create a relational database based on the information I have. There are a total of 6 ...
1
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1answer
717 views

Structuring data in MongoDB for a to-do list type application

This is a fairly high level question as I am in the initial stages of planning this application, and am also very new to MongoDB and document-based databases in general. Disclaimer aside, I am ...
10
votes
4answers
911 views

Arbitrarily ordering records in a table

A common need when using a database is to access records in order. For example, if I have a blog, I want to be able to reorder my blog posts in arbitrary order. These entries often have lots of ...
1
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1answer
233 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 ...
0
votes
2answers
95 views

Adding a bool column; tracking untouched vs. false

[backstory] I have a simple database of our current Widget inventory. It averages just dozen columns across five or six tables, but has a huge number of records already. Some Widgets came with ...
1
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2answers
207 views

Database design that handles data growth with time

I have a big table that stores video rental data with the following columns: id, title, language, duration, owner, remarks, closing_date_for_loan Assuming every day there are thousands of data ...
3
votes
4answers
291 views

PRIMARY KEY CONSTRAINT fundamentals

Can you explain why "primary key constraint" exists if, as you know, it is possible to create relationships between tables using unique indexes only ? The RDBMS that is used is SQL Server. In fact, ...
1
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3answers
587 views

Rent weekly cost database design

I have a database which contains a table BUILDING with in each row details about some building, another table BUILDING_UNIT contains rows with details about a single building unit which refers with a ...
1
vote
2answers
589 views

Database Design question, calculate or save financial positions

As the question states i'm currently internally strugling witha database design question. I work as a software developer (and i tend to do everything database related aswell since we're rather small) ...
5
votes
1answer
1k views

Does PgBouncer create a separate pool for every database config entry?

If I set up a pgbouncer.ini config file with several database entries, does pgBouncer create a separate pool for each one? I would think so, but have not been able to confirm this. For example, ...
5
votes
1answer
812 views

Enforce data integrity with a recursive table

I have an existing oracle 11g database schema that works with a web application. I am planning an expansion to the application so a web service can do data operations on the database. As part of the ...
5
votes
2answers
892 views

How to properly configure PostgreSQL RAM usage?

Using PostgreSQL, we have several hundred concurrent processes doing regular database access. We have our data spread out through several database servers, each of which houses a connection pool with ...
3
votes
0answers
531 views

How to properly configure pgBouncer transaction level pooling?

What is a good way to determine the number of available transaction connections when using pgBouncer to pool database connections? Also, how should I determine the number of max_connections and ...
1
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1answer
404 views

Database Relational Design for Multiple Categories

I am building a database for participants who are grouped into studies. There's a total of 5 different studies - A, B, C, D, and E. The participants may be in more than one studies, and participants ...
1
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1answer
184 views

Approach to Analyzing Database Requirements

When presented with requirements for a database driven system, I always find it useful to imagine a world with no computers, where data records were kept in filing cabinets and data was collected by ...
2
votes
0answers
127 views

Digital asset management

I'm working in a company that currently develops Media Asset Management system and now we want to improve our system for document files. I have to search nearly thousand .doc and .pdf files and index ...
1
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1answer
143 views

Public Database for Mobile Application

What are the proper steps to hosting a public database. Currently I a building a mobile application with Adobe Flash Builder. I have used Microsoft SQL Server, My SQL as well as WAMP Server. All of ...
2
votes
1answer
478 views

IP Address lookup star schema design

I am working on a project in which we need to do IP Address lookups. So for this we have got the datasets and now the next steps is to populate this datasets in to the table. And then have some ...
1
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2answers
274 views

Use single table with foreign key or two twin tables for text entries?

I have a table answers that has several columns including the content iself such as ID | q_id | list_id | user_module_id | content | updated_timestamp The content column is a varchar since we want ...
1
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2answers
432 views

Extensible Asset Database Schema

Background I work for a decent sized company in the hardware sector. Currently, we have a number of varying assets that need to be tracked. Until recently, this was done by hand as was an ...
3
votes
2answers
6k views

Database design for an E-commerce website

I am new to database design. I am designing a database for an E-commerce website, there are a lot of products to be updated, but while designing for product specification table I do not understand ...
5
votes
3answers
14k views

How to model inheritance of two tables mysql

I have some tables where I store data and depending on the type of person (worker,civil) that did a job I want to store it a table 'event', now these guys rescue an animal (thereis a table animal). ...
2
votes
3answers
3k views

Simple scenario needs to go from Unnormalized Data to 3NF - Review Please

NOTE: The Question has been updated. View Edit Revisions to view original question. The scenario. An animal charity that at the moment, track their establishment's costs via a spreadsheet like so: ...
1
vote
1answer
378 views

table design to track significant events associated with an item

An Orders table I'm dealing with at present in design phase has about 10 or more columns. Each OrderID in the Orders table will have certain significant events or milestones. The number of Orders ...
6
votes
1answer
3k views

Schema design: Use of association (aka: bridge/junction) table vs foreign key constraint with composite index containing a non-key field

This is an inventory database for IT assets. The models used are trimmed in order to focus on the problem at hand. Using SQL Server 2008. Thanks for taking the time to read and for any input you can ...
1
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1answer
621 views

Possible reasons for slow BLOB updates in Oracle?

We have an application that transfers .bmp images as BLOBs to an Oracle table. One of the users of the app has complained that it is taking 2-3 seconds to transfer each image. Each image is ~1.2Mb. ...
0
votes
1answer
34 views

mySQL Quickly find rows linked to another row

For example if I have a posts table with id and a likes table width id post_id user_id, how can I set up the database to organize the likes table by post_id in order so queries are faster? I can't ...
0
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1answer
39 views

Automatically create linked row in a different table

What I mean is that for example if I have a table user with id name prefId, and a second table preferences with id etc..., is it possible that when I add a row to user, it would automatically create a ...
0
votes
1answer
906 views

Efficient way to move rows across the tables?

This is somewhat long question as I would like to explain all details of the problem. System Description We have a queue of incoming messages from external system(s). Messages are immediately stored ...
2
votes
2answers
544 views

Relational database for address model

I want to design an "Address" model for all types of entities like users, businesses, etc. I have two types of main models: one is User and the other is Business. Each one has different address types ...
2
votes
1answer
834 views

SQL Uniqueness Across Multiple Tables

I have two SQL tables: Users and clients. Every row in the users table has a set of clients in the clients table, linked by the users table id field and the clients table user_id field. The users ...
0
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0answers
787 views

Postgresql Retrieve / Find Primary Key Serial Autonumber field for Audit logs

I need to find the Primary Key field name in each of a number (approx 70) of tables to create audit logs. All the primary keys are type serial (auto incrementing integer) and all have the name in the ...
2
votes
1answer
182 views

Will a primary key be added as a clustered index?

I've inherited a database where no primary keys were defined on the tables. There are also no clustered indexes assigned to the tables. If I perform an alter table to assign a primary key will this ...
3
votes
0answers
185 views

Database describing databases and references to tables

Context The company I work for makes a number of different softwares each with its own database. As they're all about related things (accounting) a good amount of data is theoretically the same among ...
4
votes
1answer
185 views

Adding an ID column to a join table (many-to-many) so that it can be targeted

I'm building a web application for a company that sells cars. They buy leads (personal details of people interested in buying cars) and try to turn them into customers. The company has a number of ...
0
votes
1answer
130 views

Implementation of stack in MySQL

I had an abstract idea of implementing a stack in MySQL. Tried a lot of Google work but couldn't reach to any logical conclusion. The Stack must be a collection of tables with the stack top pointing ...
0
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0answers
146 views

UML class diagramm for database design?

I used to make database designs using a french method called MERIS that uses mainly two diagrams to create the database (MCD and MLD), then i heard about UML and that is used also for databases and ...
0
votes
0answers
417 views

Error in creating trigger in phpMyAdmin

I have 4 tables: event: event_id(p.k) | uid | circle_id(f.k) activity: uid | performed_activity_id(f.k->event_id) | activity_type_id follow: follower_id | circle_id(f.k) notification: sender_id ...
8
votes
4answers
1k views

Database Design - different objects with shared tagging

My background is more in web programming rather than database administration, so please correct me if I'm using the wrong terminology here. I'm trying to figure out the best way to design the ...
4
votes
1answer
114 views

Should I always make an attribute id that's an primary key?

I was thinking, sometimes several columns in a table uniquely specify the whole row. In that case, is there a need to create a special column for a primary key? Is that good for something?
7
votes
3answers
6k views

Best practices for history/temporal tables?

Suppose I have an object, with certain fields which I want to track history, and certain fields which I do not want to track history. From a normalization perspective, is the following schema alright: ...
1
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2answers
224 views

Suggestion for storing a lot of simple data

I'm looking to crawl a lot of webpages (500,000,000,000) records and be able to store the linking structure for a later date. The way I planned on laying out the database was as follows: 2 Tables ...
5
votes
2answers
1k views

What are the advantages of a database design with single table for MtM relationships?

The database that backs our software product has a table design like the following: Positions ID Name Parts 1 One 12345 2 Two 12346 3 Three 12347 Collections ID ...
3
votes
2answers
2k views

Should I create a separate user table for different web products within the same platform?

We have a web product for young professional that gives them the possibility to create their page to show their professional identity. So a table users that has both information about the user (email, ...