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

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3
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1answer
131 views

Help to create indexes to improve query performance and reduce report generation time

The database in SQL Server 2008 has these tables below - the main table being the Master: Master A_ID (PK) SYSSerialNumber Bootlog SequenceNumber FileName Cfg Unique(serialnumber,sequencenumber) ...
0
votes
1answer
169 views

What MySQL storage engine and table schema should I use?

I am making a web project and I created necessary and the most important table, but I am not sure that I did it right. In this site users will post data like text, picture, text's category, etc. I ...
2
votes
2answers
454 views

Please review my first thought-out attempt at a database schema

I am researching database design and theory and have finally made a thoughtful attempt at creating a schema that would be based upon SQL. I would like, if someone has time, to review my layout and ...
1
vote
2answers
165 views

How to store massive quantities of machine generated data?

I am tasked with developing a system that stores massive quantities of machine generated data (syslogs) from a number of server farms and I am wondering what tools you fine folks use such instances. ...
3
votes
2answers
1k views

Save history editable data RDBMS

I want to make application like testing system. Every question has one or many variant of answers (and one or many can be right). I apologize that tutors and students use my testing system. It means ...
1
vote
1answer
314 views

Does my design adhere to 3NF?

I created this schema with OpenOffice. Does this design adhere to 3NF ? (A relationship link between Equipment and Supplier_Equipment , Customer and Membership should be created but OpenOffice ...
1
vote
2answers
79 views

How to Handle Database for Application which Starts from Scratch Annually

I am working on an application which will be used by an organisation annually, however each year they will be starting from a clean sheet. Which of the following two approaches (or any other approach) ...
2
votes
1answer
6k views

Derive Attributes in Tables?

I have designed my ERD. It has derived attributes. When it comes to relational data modeling using relational schema, I've designed my tables and linked everything properly. I don't know if I should ...
5
votes
3answers
426 views

Storing date increments in tables

I'm working on a ASP/MS SQL project that performs a lot of calculations based on dates and time. In one case, the system will lookup a value based on the nearest half hour increment throughout the ...
3
votes
3answers
3k views

Empty LONGTEXT or NULL?

In my MySQL DB I have one field called html_contents that contains all the html to be shown in a webpage. Obviously the html could be huge, and certaintly bigger than 64KB, therefore I decided to use ...
4
votes
1answer
673 views

Writing a database analysis document

I've been tasked with writing an analysis of a database that is currently used on a small scale. The intent of the document is to show to the business (as well as technically) that the database can ...
1
vote
1answer
32 views

Stroring a type of an entry

There is a table estate with numeric fields districtru and districthe (for a name of a district in Russian and Hebrew), which refer to primary keys of the table districts. The districts table has the ...
1
vote
1answer
99 views

Tables of a huge database

When I work on a huge database, and after following normalization rules, I found that I have many tables for each part of my huge database. That makes me worry about the final number of tables, it ...
2
votes
2answers
353 views

How to properly design outgoing/incoming mailserver configuration per user?

I'd like to store incoming and outcoming mailserver configuration per user, it's not a real live project, but to learn database-design (never done before). Let's say I have a ...
-1
votes
1answer
73 views

Can I make that connection?

If I have a column with data type varchar(max) in a table that contains a big piece of text, can I make a connection between a word or a sentence in that text with another word or a sentence in ...
0
votes
1answer
364 views

Patients profiles database

I am making software for patients in hospitals. I want to make an option that if a doctor has prescribed a drug that interacts with another drug that the patient already uses, a warning will appear ...
0
votes
1answer
73 views

How to design this kind of relations in a database

I have a conceptual problem and I would like to get your ideas on how I'll be able to do what I am aiming. My goal is to create a database with information of persons who work at a place depending on ...
3
votes
1answer
638 views

Applying user-defined fields to arbitrary entities

Currently we have an old (rather crude) system that has user-defined fields, which are mapped against rows in arbitrary tables. This was an after-the-fact modification based on a customer request, and ...
6
votes
2answers
785 views

How should I best design the tables and relationships, given the following rules?

In a Pawnshop business, customers pawn, sell or buy items. A contract which specifies the customers information, the items, and the terms and conditions is created whenever customers pawn, sell or buy ...
4
votes
1answer
127 views

Set the primary key for many to many relationship

For the two relations, Customer and Equipment: There is a limited number of equipments (stock) and upon hiring I need to store the date of hire and the expected return date. I sketched this: ...
3
votes
2answers
277 views

Finding violations of the symmetry constraint

Suppose I have a table Friends with columns Friend1ID, Friend2ID. I chose to represent each friendship with two records, say (John, Jeff) and (Jeff, John). Thus, each pair of friends should show up ...
0
votes
1answer
113 views

Is it acceptable to have a surrogate/primary key of one table be the primary/foreign key of another table?

For my purposes I'm trying to apply this to Microsoft SQL, but would like to know if there are restrictions for other DBMS regarding this. I don't know how to represent UML as ascii characters so if ...
1
vote
3answers
127 views

Storing summed values

I'm trying to create a database to store values for Profit & Loss statements and I'm wondering what the best way to structure this would be. Specifically, amounts that are are equated from other ...
1
vote
1answer
374 views

Are these database tables normalized?

I am developing a webapp for an institute and I designed these tables: Are these tables normalized?
0
votes
1answer
71 views

Several variants of a string in tables

I need: a table containing keyword phrases; a table containing URLs; a table (or maybe a view) with keyword-URL pairs (referring to IDs of the two previous tables); tables holding keywords/URLs for ...
33
votes
2answers
12k views

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? ...
2
votes
1answer
723 views

Database design with different user roles connected by different relationships to one organizaiton table

An user is connected to an organization by some role. Lets say there are 2 roles freelancer and employee. One employee can only be a part of one organization and if he is an employee then he can't be ...
0
votes
1answer
125 views

unenforced constraints/possible duplication in my database design?

I am trying to store information about a school and the class timetable in a database. The outline is as follows: 'A subject has ~20 lessons, each of which needs to have it's description stored in ...
0
votes
1answer
364 views

Users database to store access levels, can I move the non-essential information to another table?

I would like some advice on the best database structure for my system. I have different kinds of users with different access levels, and different information of course. I created a users table with ...
3
votes
1answer
2k views

How would I build a data model for parking lot hours and respective parking fees?

Say a parking lot has the following hours and associated costs... Mon-Fri 7am - 5pm parking is $5/2hrs Mon-Fri 5pm - 7am parking is $1/hr Sat and Sun - 12am - 12pm parking is free How would you ...
5
votes
1answer
348 views

MySQL table design of logging tables

I'm not a DBA by any means, but I have a basic understanding of some of the underlying principles of database optomization. Currently we have a table that logs session data, it writes about 1....
8
votes
1answer
28k views

What happens when you modify (reduce) a column's length?

Lets say I have two columns of type NUMBER (without precision, and scale) and VARCHAR(300). I saw that these columns are way too large for my data, so I want to modify them to NUMBER(11) and VARCHAR(...
1
vote
1answer
1k views

Issues on defining a PK on a nvarchar column and indexing the FK referring this PK

Someone from the team, has defined two reference tables with a few records in each, and has defined the PK of these tables on a column of type nvarchar(255). The value exists in this columns are ...
3
votes
1answer
622 views

Model with variable number of “properties” of different types.

I would like to have a table of microscope slides, where on top of the basic id, name,date_created would each slide also have a number of editable "properties". Imagine one slide having ...
3
votes
1answer
1k views

Database design for Magazine website

I need to design a CMS based website using asp.net web form (c#) and MS SQL Server as backend database for a magazine website which will have monthly issue. I am finding it hard to design a database ...
2
votes
1answer
7k views

What is the best database design for multi-language data?

I am designing a multi-language database for a piece of software with the following features: data used in every country differs from other countries data used in every country will be in 2 ...
4
votes
4answers
193 views

Database design: where do I put this data?

EventCategory ============= EventCategoryId PK, Name Event ===== EventId PK, EventCategoryId FK, Name This is what I've got now. However, events of some event category type need extra data fields. ...
1
vote
1answer
151 views

Regularly import tab-seperated log file to MySQL

I'm looking to keep arpwatch entries in a MySQL database to crossreference with other information I'm storing based on mac addresses. I've manually imported the arpwatch database into my mysql ...
2
votes
4answers
394 views

Does my table violate normalization rules?

I am developing an emulator for a game. My item table looks like this: -- ---------------------------- -- Table structure for `items` -- ---------------------------- DROP TABLE IF EXISTS `items`; ...
-1
votes
0answers
450 views

Synchronising SQL tables in two locations [closed]

We have a bit of a conundrum at the moment. ANSI SQL solutions please. We have two databases located at two different geographic locations and will be using the web for all traffic between the two ...
-2
votes
1answer
165 views

Need help in DB design?

software will used in many countries ..each country products differ from others and these products will be available in 2 languages: english, the native language . i start designing a DB for each ...
7
votes
2answers
2k views

Should a log table get an id field or primary key?

I have a log table that captures the datetime stamp of when certain files were exported to another system. The exportedLog table currently has three fields: id (primary key) messageId ...
1
vote
3answers
269 views

Does this design satisfy 3NF, and can any improvements be made?

Does this design satisfy 3NF, and can any improvements be made? If it does not satisfy 3NF - why? By improvements, I only care if it will seriously affect scalability, efficiency, etc - I'm not ...
2
votes
1answer
433 views

Null Values and Performance

I always try to build the database avoiding any NULL values in my tables, and I have successfully had done this so far. (Hey, I am very new to database design.) But still there are times when saving ...
0
votes
1answer
269 views

Trouble in Multi-Language DB

I'm working on a DB design for medicines in many countries with different languages. I created a table for the different languages I want and link it to another table of chemicals. But I find that ...
3
votes
3answers
646 views

Merging tables with a 1 to 1 relationship in a database

Is it a good idea to merge two tables that have a 1..1 relationship together? I have inherited a database with too many tables linked together in a 1..1 relationship. I'd like to evaluate the ...
-1
votes
1answer
281 views

Selecting the right data type for text

In my database, I have columns that should contain text pieces. What is the best data type used for texts in SQL? How can I show that text as a numbered or bullet list? Can I search for a certain ...
2
votes
2answers
453 views

Implementation Idea for login structure (login id with two different tables)

I am creating a sample web application for a business and I am stuck at the login implementation. There is supposed to be two different users (login types?). I will have employees and customers. I ...
7
votes
3answers
3k views

Separate archive tables or soft delete for inventory database

I'm building an inventory database that tracks computer equipment and other hardware devices. At some point in any device's life it is retired and gets archived. After it becomes archived it needs to ...
1
vote
2answers
3k views

help in multi-language medical database?

My project is to design a medical database for many countries. This database contains many parts: medicines, medical centers, patients, etc. for every country with its own language. I started my ...