>> What is 'jointure' ?

I came across this question under database section in a written test at an interview for a French company --

What is 'jointure' ?

I left the answer blank. However, came back from the interview, I did quite a bit of search with google but still failed to find the answer (with much of the search results came only in French, a language I wish I knew).

Any answer or hint to the question would be very much appreciated. Please cc your post to jerry_at_smartbridges.com

Much thanks in advance.

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Regards,
Jerry