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

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2
votes
1answer
957 views

How to store several lists and their items

The app I'm working on revolves around projects. Each project can contain several lists, and each list is made up of several items. Each list relates to a single project. Is it better to have one ...
4
votes
1answer
241 views

How to set constraints on UDT in SQL Server 2005 - 2012

I'm creating my UDT: CREATE TYPE [dbo].[Code] FROM VARCHAR(20) NOT NULL As RULES and DEFAULTS are considered deprecated, what is the recommended way to set constraint on my type to make sure that ...
3
votes
1answer
241 views

Database Relationships overview appreciated

I am helping to create a database via salesforce for storing information about Non-profit organizations. It has primarily 4 entities in the schema: Agency, Program, Project, and Contact, where Agency ...
2
votes
2answers
318 views

Proper use of NULL, and utilizing CHECK constraints for business logic vs stored procedures

This question regards the proper use of NULL and utilizing CHECK constraints for business logic vs stored procedures. I have the following tables setup. I normalized the tables to avoid using ...
7
votes
1answer
261 views

How can I make my database more concise?

I am writing an application for Android using SQLite (backed by ORMlite if it matters). So far I'm in the conceptual stage and working on the database design. The database is being designed to contain ...
5
votes
1answer
819 views

Denormalized table designs in normalized database?

There was a discussion between the developers and DBA's last week on set of tables that the developers were creating with more than 400 columns in our OLTP environment with combinations of VARCHARs, ...
1
vote
1answer
616 views

Is PostgreSQL 9.2 autovacuum sufficient for a busy table?

I have one table on a PostgreSQL 9.2/PostGIS 2.0.1 database: CREATE TABLE ch02.markers ( ff_id SERIAL PRIMARY KEY, col1 boolean, col2 smallint, created_at timestamp, lat double precision, ...
0
votes
3answers
553 views

Is adding rows better then adding columns in case their value is not consistent?

In my project I have a table of customers, each customer has his own special price for each product, It's a small business and there are currently about 5 products. The manager says there might be ...
4
votes
1answer
618 views

Using indexes to create multiple relationships to a table in order to enforce data integrity and add meaning

I'm working on an inventory database that uses supertype/subtype model. My question regards creating multiple relationships with the same tables using the primary key and composite indexes that also ...
6
votes
2answers
15k views

Efficient way of changing VARCHAR to NVARCHAR fields in a large table in SQL Server 2008?

I am aware of when adding new fields to large tables, it is recommended to add them to the end of the fields rather than somewhere in the middle, and wondering if something like this applies when ...
4
votes
3answers
2k views

Primary key should be chosen so as attributes never change?

I was reading about keys in this DatabaseSystems book - The primary key should be chosen such that its attributes are never, or very rarely, changed. For instance, the address field of a person ...
1
vote
2answers
1k views

How do I normalize a database with lots of many-to-many relationships?

I am building a database that is based around a business project, in this case called a "Program." Each Program will have multiple Reports, Clients, and Partners. My first thought was to place each ...
2
votes
2answers
583 views

Help with Vehicle Service database

I am using the Desktop Vehicle Maintenance template in access, but i am trying to cater it towards our farms needs. We will be keeping track of the service's done on Trucks, Tractors, Equipment, etc. ...
5
votes
2answers
5k views

Does order matter for composite primary key in Oracle or any database?

I have a Composite Primary key which is combination of Column1, and Column2. What would be the difference if I have Composite key with Column2, and Column1. Does it even really matter which order ...
2
votes
2answers
121 views

Long JOINS Returns No result all tables have one to many relationship with a particular table [closed]

I have a Table Enterpries with Primary Key 'RCNO'. All other tables have a one to many relationship with Enterprise via it's RCNO column. I make a Join of all the tables and i get nothing. Below is ...
2
votes
4answers
285 views

What free database software support sequences [closed]

I have a requirement that a database must support sequences. I know oracle and PostgreSQL support it. Are there any other free database software that support database sequences? it would be great if ...
3
votes
2answers
1k views

Optimizing real-time Database table in Microsoft SQL server 2008

We are using a web interface to monitor our jobs state and its started and completed timestamps. We have >200,000 job instances running on each day for different job run-users. We maintain the state ...
4
votes
3answers
259 views

Database tables design

If I have, in my Java code, the following classes: Patient :contains instance of anther classes (mentioned bellow) PatientBasicInformation: contains PatientId, phoneNumber, Name, Gender, Age. ...
3
votes
1answer
213 views

Database design - many to many

I have one MySQL table which contains: a question 4 possible answers separated by a comma a number (0-3) representing the correct answer. unique id with about 2000 entries. I also have another ...
5
votes
2answers
544 views

Help with good RDBMS transactional schema design that mimicks a sports league

I need to design a data model for a typical RDBMS that will mimic the structure of your typical sports league. Architecturally my requirements are: Well normalized Transactional Application ...
2
votes
1answer
313 views

Best approach to design a database model for this situation? Clients and records

We need to store the following information for each client: Three types of record per file, for example (obviously, with real data): HDR2007022399999900000000000Soft/XX 0.0 XXX ...
1
vote
2answers
630 views

MySQL table design / architecture, table is too big

I have a MySQL DB that contains a lot of text, I'm fetching data from a website and inserting it into a table. I'm using a SSD HD (100GB) for the DB and I'm out of space, I think that something in ...
54
votes
5answers
9k views

Is there a name for this database structure?

Noob question, sorry if it's too basic for this exchange. We process a routine data feed from a client who just refactored their database from a form that seems familiar (one row per entity, one ...
4
votes
1answer
697 views

Table structure for keeping track of multiple similar accounts

I'm creating a database to keep track financial information for about 30 different accounts. So far this has all been handled with each account as its own Excel table with the different years across ...
3
votes
1answer
644 views

Simple survey database design [closed]

I'm creating a survey for visitors of my event. However it's been a while since I created a database. So I need some help. I found some solutions but they are way too extensive and that is something ...
4
votes
1answer
3k views

Under what conditions are polymorphic associations used? What are the alternatives?

As I understand it, polymorphic relationships among tables in a database allow one table to have one foreign key that references many tables. I have found that tags are a common application of this ...
3
votes
1answer
280 views

Serialized objects vs multiple tables

What would be the best way to store several entries in a database, each containing a list of other entries? An example of this would be a table of receipts, where each receipt has some information ...
5
votes
2answers
548 views

What is the primary key on a temporal table?

If I use the following table design to capture history...: CREATE TABLE MyTable ( insertion_timestamp TIMESTAMP, deleted_flag BOOLEAN, natural_key INT, attribute VARCHAR ); ... then ...
227
votes
15answers
98k views

Can MySQL reasonably perform queries on billions of rows?

I am planning on storing scans from a mass spectrometer in a MySQL database and would like to know whether storing and analyzing this amount of data is remotely feasible. I know performance varies ...
2
votes
2answers
278 views

creating a database scheme for storing information about an item, which option is better?

I have a database which stores information about various items. In particular, for each item I need to store the name, type and color. Each type can have a various amount of different colors. For ...
0
votes
3answers
627 views

Name of the product price, line-item database pattern?

What is the database pattern called where (for example) the current price of a product is stored in one table, and when someone makes a purchase the current price of the product is copied to a line ...
2
votes
2answers
102 views

which option is better for not slow down the performance of queries?

I am developing a system that records customer payments, when a customer makes a payment, the system must update the account and show the payment made and all previous payments, is here when the ...
4
votes
1answer
159 views

How can I improve this design?

I'm creating an event planning PHP/MySQL web application as a learning project. The whole app revolves around the idea of the event and its various components (participants, groups, lists, etc.) I ...
-3
votes
1answer
3k views

How to Create a Trigger in SQL Server to Update Cascade When @@RowCount > 1?

I Have 2 Table Table1 | column name | type | |-------------+-------------| | ID1 | Int | | Name | NVARCHAR(50)| Table2 | column name | type | |------------...
5
votes
1answer
1k views

How to use a relational database to store all users who belong to a group, and all groups which a user belongs to?

This is a beginner question: A user can belong to many groups, and a group can contain many users. Let's say the two tables look something like this: user_id user_name user_email group_id ...
1
vote
1answer
575 views

designing server side database to store user-specific data

I have a database with a number of quiz questions and answers. My basic design consists of these two tables questions (question_id, question_string); answers (answer_id, answer_string, ...
2
votes
2answers
476 views

Is a trade-in its own purchase order, or an adjustment on a sales order?

Let's say you're a car dealer, selling cars. When a customer buys a new car, he often trades in his existing car. What data model makes more sense? A) create a sales order record for the sale, and ...
15
votes
6answers
3k views

Is database normalization dead? [closed]

I've been brought up old school - where we learned to design the database schema BEFORE the application's business layer (or using OOAD for everything else). I've been pretty good with designing ...
0
votes
1answer
163 views

Review my logical model for gaps

We need to centralize our ability to manage the various schedules that our banking centers keep since it is a manual nightmare right now. Do you see any obvious gaps in this? A schedule is ...
6
votes
1answer
1k views

What should every DBA know? [closed]

As a SysAdmin who "wears all the hats", I find myself increasingly pulled into database projects. I took one database course back in college and since then I've always scoured resources online (like ...
1
vote
1answer
59 views

delimited values in a column value

I have a table which have a * to * relationship with another table. Lets say the first table is T1 and the second table is T2. So I need to keep the T2 Pks linked with single row in T1. I really like ...
0
votes
2answers
5k views

How can primary keys in a Netezza table be indexed?

What is the best way to index a Netezza fact table with lots of primary keys. For now, let's suppose we have 10 primary keys. This table is mainly used to store meta data about our database. =====...
0
votes
2answers
81 views

Best practice for entry position indicators

My problem is, that I have no idea how I could cleanly make an index (not a real Table index, just an indicator) for each table row representing the entries position while each position must be unique ...
7
votes
2answers
33k views

Add a new Column and define its position in a table

I have Table A with 5 columns: TableA -- Name Tel Email Address I want to add a new column (mobile) in between Tel & Email: TableA -- Name Tel Mobile Email Address If I use ALTER TABLE ...
3
votes
2answers
8k views

Tool for Reverse Engineering of PostgreSQL Database on Linux (Ubuntu) [closed]

Please suggest a tool to reverse engineer a PostgreSQL DB into an entity-relationship-diagram (ERD) or equivalent ?? Ideally, I'm looking for a simple ERD or UML class diagram in a format that is ...
5
votes
1answer
365 views

Database structure, relational or data warehouse?

Good morning, Im having some issues with how my database should be laid out and would appreciate some guidance. I have several tables (rainfall data), each containing the following columns: Date (...
3
votes
4answers
3k views

One table with many rows or many tables with a few rows

I'm having a question rounding my mind. It's better to create one table and store a lot of rows there or create various tables and have a few rows on them? What's the performance and the I/O saved at ...
0
votes
3answers
4k views

Will using bigint vs mediumint have a performance impact?

I'm considering using mediumint or bigint for an ID column. I prefer to use bigint, because that way I'm very sure that the huge numbers that the client sometimes uses are stored just fine. However, I ...
3
votes
2answers
1k views

Design best practices for last tracking with indexed view

My tables structure is below : TbDoc (ID int , ...) TbDocActions( ID Int, DocID Int, Date DateTime, col1 int, col2 int, ...) I want to have indexed view to get last TbDocActions columns for ...
2
votes
1answer
74 views

Creating a schema for various sizes of varchar

I am redesigning a database schema for an application I am working on, and one of the major changes I am adding is the ability to dynamicly add new "fields" into a form based administration area. ...