In my MySQL database I have a table with 4 columns, the PRIMRAY KEY, two columns with a FOREIGN KEY CONSTRAINT and one UNIQUE index on all fields except for the PRIMARY KEY. The SHOW CREATE TABLE: ...
I want to use SQLite as file format for my app, a reporting program. Below is an idea of the kind of schema I'll use (just the first few tables). There will be one report per file and all tables are ...
Inspecting a rather critical database that is used by some software on my system, I found that one of the tables had a primary key on the column Id, where Id is calculated using checksum(newid()). ...
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?
I am running PostgreSQL 9.1.4. I have a table with many existing rows, and a bunch of other tables with foreign keys pointing to it, for which I am trying to : 1 - Remove the pkey constraint on the ...
What are the major differences between Unique Key and Primary Key in MySQL?
Creating a table with composite PRIMARY KEY or using UNIQUE INDEX for two columns guarantee uniqueness of col1, col2. Is there a tricky approach to make the reverse order of two columns UNIQUE too ...
What are the performance considerations between using a broad PK vs a separate synthetic key and UQ?
I have several tables where records can be uniquely identified with several broad business fields. In the past, I've used these fields as a PK, with these benefits in mind: Simplicity; there are no ...