Re: HPF is it really faster than a simple unload/load
From: "Donald Leclerc" <dl@novertech.com> >I have some big tables with over 1M records and some with 15M with some >indexes. >I would like to know if it is really faster to use HPF instead of >load/unload, I saw in informix guide that it's a lot of configuration to >use >HPF, but if it's worth it! I assume you mean HPL? How long does a 1M row table unload/load take on your box? I did a simple test unload / load / reindex of 2M unfragmented 70 byte rows with 3 indexes on my dev box and timex reported < 10 minutes for the whole lot. (The unload file was 118MB and I'm on a RAID5 array :-(((( , so OS access would have been a non-trivial component of this.) >Actually, I am not the DBA, but want to know because the DBA is not >interested in using HPF but I really need a faster way to load the data. >By >the way, if you can tell me the difference in speed between the "deluxe" >and >"express" mode. I am more intersted in the "deluxe" mode because I saw in >the manual that we must take a level 0 to reset a readonly flag. Most of >the time (not to say all) we need to load the data when the system is >online >because 24x7. Well, if you've already found the manual... :-) >The other point of interest, what about the checkpoint time during the load >with HPF ??? It depends. :-) >Actually we have dynamic server 7.3 and no logging, dirty read. It is wickedly fast, even in deluxe mode. Express mode disables and re-enables (rebuilds) indexes. The only downside of HPL is that it can take up to 30 seconds to fire up, which may be expensive in the total time to do your particular job. I can't remember if you can run multiple jobs within the same session, which means it could cost up to 1 minute per table. Also, you might get better throughput with your current environment by fragmenting your tables across multiple dbspaces and using PDQ and PSORT for the current process. _____________________________________________________________________________________ Get more from the Web. FREE MSN Explorer download : http://explorer.msn.com