Paradox _qsq files

I'm working on Delphi 3 and Paradox 5.0...

When I execute my application, some files with names starting with "_qsq"
(like
_qsq1.db) are generated.
I'd like to know why or when they are generated and if it could be
prevented, because some of this files are very large (100 Mb).

Another question : what about Paradox and Paradox newsgroups : are they to
disappear ?