New to oracle, but I'm coming from the sybase side.

I took over one of our oracle production databases (1.5 Tb) while the
regular dba is out. I got errors (unable to extend temp segment) for two
user tablespaces which I took care of by adding a datafile to each. While
reviewing the other tablespaces, I was surprised to see the system
tablespace at 99%. I checked with app folks. No new
objects were added accidentally to it. I panicked and resized the
system tablespace by an additional 33%. Upon review, I forgot to notice
that the system tablespace was set to autoextend. My question is this:
even with the autoextend option set, is there a performance hit or crash
potential by not resizing the system (or any other) tablespace before it
hits 100%? On the sybase side, I take care of the logical devices before
it reaches 85%.

~newbie appreciates any comments
thanks,
gecho

gecho <gecho (AT) hawaii (DOT) rr.com> wrote

Gecho, by extending the system tablespace manually you eliminated the
additional overhead that would have occurred when Oracle attempted to
expand an object and then discovered that the file space necessary to
hold the extent did not exist but could be obtained by expanding the
file. Depending on what operation would have taken the extent that
resulted in the file auto-extending this overhead may or may not have
been noticable to the end user. But taking it early did not hurt and
may have prevented a performance hit.

IMHO -- Mark D Powell --