On Thu, 3 Apr 2003, Jan Wieck wrote:
> "Nigel J. Andrews" wrote:
> > B64 would still require a bytea storage type to avoid any character encoding
> > issue between client and server though, right?
>
> I don't think so, since it uses characters from the 7-Bit ASCII set
> exclusively and IIRC those map to the same codes in almost every
> encoding except EBCDIC (though, I'm not an encoding expert).
>
> What might have slowed down bytea as it would text is TOAST's attempt to
> compress the data. As image data usually is compressed already (if not
> using PPM or such), this will be a waste of time. For that reason alone,
> TOAST offers you to disable the compression attempt on a per attribute
> base.
>
Now that is interesting, I didn't try that. I might have another test run to
see what difference it makes, if I find the time.
There was a definite relationship between data size increase through escaping
and speed. Some of which would be down to the escape/unescape process itself,
some down to the transmission between client and server and then there'd be
some impact from the server's operations as well. I didn't quantify the split.
--
Nigel J. Andrews