maximum length of INSERT query string?

[Florin Andrei]

I am doing an INSERT with multiple rows:

INSERT INTO tbl_name (a,b,c) VALUES(1,2,3),(4,5,6),(7,8,9) ....

The INSERT statement is generated by a PHP script.
What is the maximum length allowed for this string? I.e., how do I know when to stop adding more rows?
Is this related to any of the following variables?

max_allowed_packet
bulk_insert_buffer_size
key_buffer_size

I am using MySQL-5.0.22 and PHP-5.1.6 on Linux CentOS 5 x86_64

--
Florin Andrei

http://florin.myip.org/