How to store an IP in mySQL

Use PostgreSQL, there's a native data type for that.

More seriously, I would fall into the "one 32-bit integer" camp. An IP address only makes sense when all four octets are considered together, so there's no reason to store the octets in separate columns in the database. Would you store a phone number using three (or more) different fields?

I would suggest looking at what type of queries you will be running to decide which format you adopt.

Only if you need to pull out or compare individual octets would you have to consider splitting them up into separate fields.

Otherwise, store it as a 4 byte integer. That also has the bonus of allowing you to use the MySQL built-in INET_ATON() and INET_NTOA() functions.

Performance vs. Space

Storage:

If you are only going to support IPv4 addresses then your datatype in MySQL can be an UNSIGNED INT which only uses 4 bytes of storage.

To store the individual octets you would only need to use UNSIGNED TINYINT datatypes, not SMALLINTS, which would use up 1 byte each of storage.

Both methods would use similar storage with perhaps slightly more for separate fields for some overhead.

More info:

• Numeric Type Overview
• Integer Types (Exact Value) - INTEGER, INT, SMALLINT, TINYINT, MEDIUMINT, BIGINT

Performance:

Using a single field will yield much better performance, it's a single comparison instead of 4. You mentioned that you will only run queries against the whole IP address, so there should be no need to keep the octets separate. Using the INET_* functions of MySQL will do the conversion between the text and integer representations once for the comparison.

A BIGINT is 8 bytes in MySQL.

To store IPv4 addresses, an UNSINGED INT is enough, which I think is what you shoud use.

I can't imagine a scenario where 4 octets would gain more performance than a single INT, and the latter is much more convenient.

Also note that if you are going to issue queries like this:

SELECT  *
FROM    ips
WHERE   ? BETWEEN start_ip AND end_ip

, where start_ip and end_ip are columns in your table, the performance will be poor.

These queries are used to find out if a given IP is within a subnet range (usually to ban it).

To make these queries efficient, you should store the whole range as a LineString object with a SPATIAL index on it, and query like this:

SELECT  *
FROM    ips
WHERE   MBRContains(?, ip_range)

See this entry in my blog for more detail on how to do it:

• Banning IPs