Oracle 10.2.0.5/HPUX 11.23 (no flames please, upgrading next month)
Recently, to improve performance, our Data Warehouse folks implemented
'nologging' loads as well as amending their table, index and partition
creations to include the 'nologging' modifier. This of course caused the
controlfile updates to go nuts with CF Enqueue waits which slowed the whole
process to a crawl. To alleviate this, we set Oracle event 10356 (per Doc
ID 1380939.1) which by-passes the controlfile updates. Loads are working
quite well now but what are the recoverability ramifications?
My what happens with backups? I understand nologging=norecovery and was
planning on implementing RMAN using BCT and incremental backups following
the completion of the nightly load cycle.
Checkpoints occur at log switches, at specified intervals or on request and
update datafile headers as well as the control files. They write
information about modifications from the SGA buffer cache.
Is there a danger of either having these age out of the buffer cache or
consuming so much space that it reduces the efficacy of the cache?
Should we increase checkpoint intervals? Will external BCT capture the
changes so we can get a good incremental backup?
