Hi Matthew,
This falls into the category of a "more general" Clarion question- and hopefully someone here with SQL knowledge can respond - but you may have more joy posting in the normal Clarion newsgroups. Phrase it as a "general" Clarion question, not mentioning the NetTalk bit (which is irrelevant to your problem) and you might get something useful.
I am definitely _not_ a SQL expert, but as I understand it, this is a problem for Clarion programs in general. But it may be solved in some Clarion version, or there may be techniques to use, or whatever.
cheers
Bruce