Maximum length of text primary key?

[El_Pablo]

Hi,

Is there a maximum length for a text primary key?

The table create a primary which merge a serial number field with the computer MAC address. The relationship between the child table and the parent works on a PC with a 48-bit address but not on the UMPC which seems to have a longer address.

On the UMPC, a problem occur when I created a child data from the parent. Whenever I create a record from a portal in the parent layout all the records from the child table where showing. This problem was not occuring on the PC.

Is there any reason?

BTW, on the UMPC it's an offline version of the server. It's the reason why I use the MAC address as the key.

[corn]

100 characters per documentation; 109 characters in observation

You should look into Ray Cologon's UID technique available on his website which can help create unique keys.