Appending DB Connection String with prepareSQL=0

Question

What does this do?

Answer 1

Assuming jTDS here:

"prepareSQL=0 is only intended for testing (as it actually replaces the parameter placeholders with string representations of the values and submits everything as a regular query) and it's also kind of beta. It should never be used in production.

Also, as you have seen, the performance penalty is quite severe compared to the other prepare modes." (from Eric Pugh's Weblog).