gzip

[Fred Ruffet]

You can't speed up pipes. HP-UX pipes are using a block size that are breaking big IOs in multiple tiny Ios. And you cannot do anything about that.

I've been involved in a porting problem where programmers were using pipes on a 32 bit SUN OS to read/write big files. Porting this on a brand new system, this programs where *very* much slower. As long as we were on a 64 bits OS, we could remove the pipes, read the big files and speed up the programs. But pipes are slow.

In order to improve your export, you have 2 ways :
. OS one could be, as said before, to use files. But thois mean you will need sapce for uncompressed export...
. Oracle exports can be speed up by using different buffer sizes or direct path exports.

Regards,

Fred

[mangor]

ok well that's a lot of responses.
1. 8k is the size of the pipe file. 8k worth of data only appears to go through the pipe file at a time. I was looking to increase this amount. Yes I have already tried changing the compress rate. That still isn't fast enough for me.

[Alzhy]

Mangor,

Have you tried compress with split and with a big record size? it's given us better results than gzip:

/etc/mknod ${EXPORT_DIR}/${ORACLE_SID}_export.dmp p

compress < ${EXPORT_DIR}/${ORACLE_SID}_export.dmp | split -b 2048m - ${EXPORT_DMP}/${ORACLE_SID}_full_${CUR_DATE}.dmp.Z&

exp \
FILE=${EXPORT_DMP}/${ORACLE_SID}_export.dmp \
LOG=${EXPORT_LOG}/${ORACLE_SID}_full_${CUR_DATE}.log \
DIRECT=Y \
RECORDLENGTH=65536 \
COMPRESS=N \
CONSISTENT=Y \
FULL=Y < ${CTL_FILE_DIR}/logexp.ctl

[mangor]

Thanks fred I'll have to try the split.