On Thu, 2002-03-14 at 19:43, Bruce Momjian wrote:
> Kyle wrote:
> > On the subject on client/server compression, does the server
> > decompress toast data before sending it to the client? Is so, why
> > (other than requiring modifications to the protocol)?
> >
> > On the flip side, does/could the client toast insert/update data
> > before sending it to the server?
>
> It has to decrypt it so the server functions can process it too. Hard
> to avoid that. Of course, in some cases, it doesn't need to be
> processed on the server, just passed, so it would have to be done
> conditionally.
>
Along those lines, it occurred to me if the compressor somehow knew the
cardinality of the data rows involved with the result set being
returned, a compressor data dictionary (...think of it as a heads up on
patterns to be looking for) could be created using the unique
cardinality values which, I'm thinking, could dramatically improve the
level of compression for data being transmitted.
Just some food for thought. After all, these two seem to be somewhat
related as you wouldn't want the communication layer attempting to
recompress data which was natively compressed and needed to be
transparently transmitted.
Greg