MySQL primary/foreign key size?

Posted by David on Stack Overflow See other posts from Stack Overflow or by David
Published on 2010-05-15T17:58:35Z Indexed on 2010/05/15 18:04 UTC
Read the original article Hit count: 312

Filed under:

mysql

|

primary-key

|

foreign-key

|

length

|

size

I seem to see a lot of people arbitrarily assigning large sizes to primary/foreign key fields in their MySQL schemas, such as INT(11) and even BIGINT(20) as WordPress uses.

Now correct me if I'm wrong, but even an INT(4) would support (unsigned) values up to over 4 billion. Change it to INT(5) and you allow for values up to a quadrillion, which is more than you would ever need, unless possibly you're storing geodata at NASA/Google, which I'm sure most of us aren't.

Is there a reason people use such large sizes for their primary keys? Seems like a waste to me...

© Stack Overflow or respective owner

Related posts about mysql

How to remove MySQL completely with config and library files on ubuntu 12.04 gnome 3.0

as seen on Ask Ubuntu - Search for 'Ask Ubuntu'
I tried everything till now: sudo apt-get remove mysql-server mysql-client mysql-common sudo apt-get purge mysql-server mysql-client mysql-common sudo apt-get autoremove and even more commands... But whenever I am trying to locate mysql. I get a no. of files related to mysql command: shell>>… >>> More
mysql: Cannot load from mysql.proc. The table is probably corrupted

as seen on Server Fault - Search for 'Server Fault'
Mysql was started: /usr/bin/mysqld_safe --datadir=/srv/mysql/myDB --log-error=/srv/mysql/logs/mysqld-myDB.log --pid-file=/srv/mysql/pids/mysqld-myDB.pid --user=mysql --socket=/srv/mysql/sockets/mysql-myDB.sock --port=3700 but when I'm trying to do something: ERROR 1548 (HY000) at line 1: Cannot… >>> More
Why is there a /etc/init.d/mysql file on this Slackware machine? How could it have gotten there?

as seen on Server Fault - Search for 'Server Fault'
A client of my IT-consulting service owns a web-development shop. He's been having problems with a Slackware 12.0 server running MySQL 5.0.67. The machine was set up by the client's sysadmin, who left on bad terms. My client no longer employs a sysadmin. As far as I can tell, the only copy of MySQL… >>> More
mysql: Bind on unix socket: Permission denied

as seen on Server Fault - Search for 'Server Fault'
Can't start mysql with: sudo /usr/bin/mysqld_safe --datadir=/srv/mysql/myDB --log-error=/srv/mysql/logs/mysqld-myDB.log --pid-file=/srv/mysql/pids/mysqld-myDB.pid --user=mysql --socket=/srv/mysql/sockets/mysql-myDB.sock --port=3700 120222 13:40:48 mysqld_safe Starting mysqld daemon with databases… >>> More
MySQL – Learning MySQL Online in 6 Hours – MySQL Fundamentals in 320 Minutes

as seen on SQL Authority - Search for 'SQL Authority'
MySQL is one of the most popular database language and I have been recently working with it a lot. Data have no barrier and every database have their own place. I have been working with MySQL for quite a while and just like SQL Server, I often find lots of people asking me if I have a tutorial which… >>> More

Related posts about primary-key

How to explain to users the advantages of dumb primary key?

as seen on Stack Overflow - Search for 'Stack Overflow'
Primary key attractiveness I have a boss(and also users) that wants primary key to be sophisticated/smart/attractive control number(sort of like Social Security number, or credit card number format) I just padded the primary key(in Views) with zeroes to appease their desire to make the control number… >>> More
Can a Compound key be set as a primary key to another table?

as seen on Stack Overflow - Search for 'Stack Overflow'
Can a compound key be set as a primary key to another table? For instance i have the tables: Books -with Primary Key:Product_ID Client -with Primary key: Client_ID Clients_Books -with Compound Primary Key:Product_Id and Client_ID I want to set this compound Primary key from Clients_Books as… >>> More
Setting the primary key of a object type table in Oracle

as seen on Stack Overflow - Search for 'Stack Overflow'
I have two Oracle questions. How can I set the primary key of a table when the table is made up of an object type? e.g. CREATE TABLE object_names OF object_type I have created a Varray type, CREATE TYPE MULTI_TAG AS VARRAY(10) OF VARCHAR(10); but when I try to do SELECT p.tags… >>> More
use of EntityManagerFactory causing duplicate primary key exceptions

as seen on Stack Overflow - Search for 'Stack Overflow'
Hey guys, my goal is create an EntityManager using properties dependent on which database is in use. I've seen something like this done in all my Google searches(I made the code more basic for the purpose of this question): @PersistenceUnit private EntityManagerFactory emf; private EntityManager… >>> More
Mapping a child collection without indexing based on database primary key or using bag

as seen on Stack Overflow - Search for 'Stack Overflow'
I have a existing parent-child relationship I am trying to map in Fluent Nhibernate: [RatingCollection] -- [Rating] Rating Collection has: ID (database generated ID) Code Name Rating has: ID (database generated id) Rating Collection ID Code Name I have been trying to figure out which permutation… >>> More