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 (2)

5
votes
2answers
936 views

How to design a schema to store search keywords

I am doing a database design that stores search keywords of a search form, used to generate the most popular search keyword reports by date, month and year. I have made a simple schema: CREATE TABLE ...
5
votes
1answer
494 views

Can filtered indexes help improve queries that are based on a time entered or should this be avoided?

I'm just learning about the new filtered indexes in MS SQL 2008 and I'm trying to understand where they would hurt and where they would help. I can see that adding a filtered index to an employees ...
5
votes
1answer
113 views

Many-to-many relationship with attributes

I'm working on a project where I need a book database. The problem is as follows: A book can be related to multiple people (authors, editors, traslators, etc.). Then a person may contribute to ...
5
votes
2answers
53 views

How to enforce the structural constraints of rectangularly arrayed data?

(I'm particularly interested in answers that view the question below as a special case of the question: how should a RDBMS enforce structural constraints that are more specific than "one-to-many" and ...
5
votes
1answer
685 views

Full text search through many tables in MySQL

We have high traffic NEWS websites, I want to add a feature that every user can search through over all content of site, such as news, polls, comments, galleries,etc . Each of contents type has its ...
5
votes
1answer
540 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
504 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 ...
5
votes
1answer
90 views

Database Design: Linking 'vague' entries to associations?

Experienced developer, inexperienced DBA here. I'm currently working on a project that lets users input the names of freight vehicles for particular packages. Eg: Company: White Star Line Vehicle: ...
5
votes
1answer
1k views

Survey database design: first version. Are there errors?

I have to represent surveys with questions like these ones: Studying those groups of questions I found these rules: A survey has questions' groups. A questions' group has a name and questions ...
5
votes
2answers
2k views

how to enable temporal database capability in mysql.?

How to enable the temporal database compatibility in mysql database? Is there any library or a plug-in to enable the temporal upward compatibility? I want to keep the past records whenever a current ...
5
votes
1answer
249 views

HStore vs. multiple tables with inheritance - do I have a good use case for HStore?

My broader question here has to do with when it is appropriate to use HStore vs. multiple tables vs. one table for storing document-like objects. Now, for my localized example: I’m designing a ...
5
votes
1answer
309 views

Temporal Validity and Primary/Foreign Key Relationships

I've read through several of the oracle tutorials that show temporal validity and time features. However, in the examples I'v read, there is no primary key used in the demo tables. ...
5
votes
1answer
3k views

Could too many idle connections affect PostgreSQL 9.2 performance?

Some queries on my database server seem to take a long time to respond, and I believe the CPU usage is high. When running ps aux, I see ~250 "idle" connections (which I believe to be too many). I ...
5
votes
1answer
656 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
140 views

To Foreign Key or not to Foreign Key… (inet -> cidr)

Below is a very abridged version of a project I am working on. CREATE TABLE cidr_block ( id serial not null unique, block_def cidr primary key, dhcp_server_id int not null references ...
5
votes
3answers
2k views

Partition pruning with multiple date columns

I have a large table in Oracle 11g database that holds historical data from several years, so I would like to partition it by year. The problem is that the table has multiple date columns and they are ...
5
votes
2answers
901 views

Vehicle spare parts inventory datadase model

I am modeling a database to be used for vehicle spare parts inventory management and I am stuck... Some spare parts can be broken down from a kit into component parts. I would like to create a model ...
5
votes
4answers
16k 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 ...
5
votes
1answer
366 views

Design for file based with many events

I'm not a database guy but I need to design a database to store events for our application. Our client app connects to remote hardware and syncs count data. The count data are csv files split into ...
5
votes
1answer
653 views

How to handle “reference tables” in CouchDB?

What's the best way to handle "reference tables", tables that contain static data, for example a list with various kinds of ingredients for food? Multiple documents, one for each ingredient One ...
5
votes
1answer
674 views

In MongoDB, is having lots of small collections better than having one huge collection?

Huge collections have huge indexes that may not fit into RAM. Is that problem entirely solved with sharding ? If I have lots of small collections with small indexes, what are the options for storing ...
5
votes
1answer
847 views

Designing a database for a site that stores content from multiple services?

I'm building a site that implements David Allen's Getting Things Done that pulls in your email, Facebook newsfeed, tweets from those you follow on Twitter, and more services are planned. The problem ...
4
votes
8answers
2k views

Should you ever not assign an unique ID to each row in a table? [duplicate]

Possible Duplicate: Should every table have a single-field surrogate/artificial primary key? I can't imagine ever not using a unique ID with every table, which is why I'm asking this ...
4
votes
6answers
3k views

Any way around unique index 16 column max

According to the CREATE INDEX documentation: Up to 16 columns can be combined into a single composite index key. We've got a table with ~18 columns that need to form a unique combination. This ...
4
votes
3answers
632 views

Is a surrogate key better than a natural key in this case

I copied this code from here: CREATE TABLE records( email TEXT REFERENCES users(email), lat DECIMAL, lon DECIMAL, depth TEXT, upload_date TIMESTAMP, comment TEXT, PRIMARY ...
4
votes
1answer
1k views

PostgreSQL versus MySQL for EAV structures storage

Is there any practical difference or what are the advantages of using Postgres 9.x versus MySQL 5.x for storing EAV (Entity-Attribute-Value) structures, especially in terms of read performance?
4
votes
3answers
357 views

Database Design Issues

My question consists of three parts: When can I be sure that my database design is perfect? Is returning to the database design to change some issues (i.e, adding new column, deleting a column, ...
4
votes
2answers
3k views

Create table group sub-folders in Management Studio

When I was exploring the master database in SSMS I noticed that under the Tables folder there is another folder called Systems Tables that houses a bunch of tables. Is it possible for us to create a ...
4
votes
4answers
338 views

DB Optimization with 2 to the power of N - Approach clarification

This is a request for analysis and better performance approaches, one of my colleague has come up with an approach in optimizing the DB and it looks very impressive too. Can someone please let us know ...
4
votes
4answers
2k views

Examples of SQL transaction procedures for sales tracking or a financial database

I am making a database for an accounting/sales type system similar to a car sales database and would like to make some transactions for the following real world actions: salesman creates new product ...
4
votes
2answers
3k views

How to choose a collation for international database?

I'm designing a database which will store data in different languages (using UTF-8), so I think the best way to display the queries results is ordering it according to the user's language during the ...
4
votes
3answers
6k 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). ...
4
votes
3answers
1k views

Lookup table for a one-to-many relationship

I have a tickets table with an id that I need to associate to a lookup table where the counterpart of that data is another id that is controlled from an outside source. tickets - id - sutff lookup - ...
4
votes
1answer
4k views

Product Attribute List Design Pattern

I am working on updating our website's product database. It’s built in MySQL but this is more of a general database design pattern question. I’m planning on switching to a Supertype/Subtype pattern. ...
4
votes
2answers
1k views

Ready-to-Use Database models example

Where can I find ready-to-use database models ? I don't need a database with data in it, but only schemas (UML diagrams). Perhaps something like the data models at this link, but much more complex ...
4
votes
4answers
809 views

Speed problem with a simple select statement

I'm having a problem with a select statement taking way too long to run. I would like to know if I'm doing something wrong or if it taking this long makes sense. I am using Microsoft SQL 2005 ...
4
votes
2answers
1k views

Data validity and accuracy according to database integrity

What does it mean that data is valid and accurate according to database integrity?
4
votes
3answers
1k views

What is a common way to save 'debit' and 'credit' information?

I'm working on an accounting system, and for each transaction I need to save if this is either debit or credit. I can think of two ways (MySQL database): METHOD 1 Amount (decimal) Type (enum, ...
4
votes
2answers
362 views

Best way to design this mileage table?

I will be populating a Miles Per Gallon (MPG) table. It's coming from an odometer source. It's currently set up as so: id (primary_key) , truck_num , start_date , end_date , ...
4
votes
2answers
169 views

Database instance and database

I did some research and finally came to this conclusion: Database instance = processes + memory Database = (physical) log files + control files + data files. Is this understanding correct? ...
4
votes
2answers
432 views

Is it ever a good idea to denormalize for integrity?

I'm using Postgres 9.2 to develop a quiz app, in which I present the user with a series of problems and record their answers. These problems can take a variety of forms - they might be multiple ...
4
votes
2answers
2k views

Index max row size error

Is there a upper bound for an array column? I am getting this error when inserting into the array field - PG::Error: ERROR: index row size 3480 exceeds maximum 2712 for index "ix_data" Here's my ...
4
votes
1answer
221 views

What is the correct way to ensure unique entries in a temporal database design?

I'm having trouble with the design of a temporal database. I need to know how to make sure I have only one active record for any given timeframe for a store. I have read this answer, but I'm afraid I ...
4
votes
2answers
94 views

StackExchange clone: where should I add my indexes?

I'm creating an open source stack exchange clone and the following is my schema. What should I add indexes on for it to be optimal? Here is the schema in Rails format (SQL format below as well): ...
4
votes
3answers
978 views

Are there any tools to go from ERD to DB design and vice versa?

I'm learning DB design and looking for some tools, preferably open source software, that could help go from an ERD to a DATABASE and vice versa. For the record, the database i'm using is MySQL.
4
votes
1answer
2k views

Proper tuning for 30GB InnoDB table on server with 48GB RAM

I have a 30GB 15M rows InnoDB MySQL 5.5.15 table. It is running on a server with many other MyISAM tables (300GB db). The system has 48GB RAM. Besides the default configurations, I've changed the ...
4
votes
2answers
476 views

Table contains multiple names for same company

I have a table of monetary transactions that has a field for who the money was paid to or received from. Transactions are recorded using info from paper invoices, paper reciepts, internet reciepts, ...
4
votes
1answer
97 views

How do you manage a list for particular object. for eg. user comments on specific object(user post etc.)

I am new to database and web application development. I want to know how to store a list for a particular object in a database. For example, user comments for a particular post(object), or the ...
4
votes
1answer
165 views

How can i prevent decryption in SQL Server procedures

I came across in internet tool to decrypt procedures, I checked my database with this tool to decrypt my procedures and it works fine, now the problem is I wish to prevent this kind of tools from ...
4
votes
2answers
642 views

Recommendations for building a big search engine

I am creating a image search engine that would probably have millions of images tagged with keywords. Basically it would be something like Google Image search. So I want to ask for any tips on ...