Maximum size of row in SQL

It will depend on which RDBMS you're using.

In SQL Server 2000 there was a maximum row size of 8094 bytes which is the size of a memory page (8K) less some overhead.

However, in SQL Server 2005 or later, there isn't really a maximum size because pointers can be added to the first page to point to other pages, if the limit would otherwise be exceeded.

There's a link here which explains how all this works behind the scenes:

http://codebetter.com/raymondlewallen/2005/12/30/how-sql-server-2005-bypasses-the-8kb-row-size-limitation/