RE: how informix archive works?

Actually I was doing some testing on my test server after observing some abnormality of database archive running on my production server. I have a cron job to run database archive once a day at my production server. The first observation I noticed is the duration of archive will become longer and longer. I can assure that this was not caused by the surge of data volume in the database as total used chunks size was still the same. The archive will take more than 3 hours to complete when the database is running more than few weeks. The duration of the archive is increase gradually. However, after i did a dbexport-import, the archive was back to normal which is only take ~20 min to complete on the entire database. I think this could be caused by the bug that you all mentioned. The second observation I noticed is if I run second archive again on the same day, it will usually take faster than the first archive. The first archive might take up to 3 hours, however, the second run will not take more than 90 min. As I mentioned earlier, i have a cron job to run the archive once a day. Sometime i will need to perform another archive on the same day due to ad-hoc reqeust (sometime the gap between the first and second archive is about 3-4 hours). This symptom does not happen one time only. In fact, I'm able to reproduce it at my test server. This is the doubt that i have, Why the second archive will run faster than the first archive? --- Ravi T <ravit29@yahoo.com> wrote: > Yes Miyaki, > > Keith is correct. > > Provide us more information please ! > > 1. Is this a one time deal or does this happen each > time you perform this archive ? > > 2. What is the reason for you to run 2 archives one > after the other ? > > 3. What is the time difference between the two > archives ? > > etc. > > Thanks. > > "Simmons, Keith" <keith.simmons@office2office.biz> > wrote: > Miyaki > > I have absolute confidence in the Informix archive. > I too back up using > ontape and have restored (to a test machine) on > numerous occasions with no > problems. > Do you have some very old data in your database? It > could be you are > encountering the 'archive very old page' bug which > slows the archive while > it updates the timestamp on very old pages. Once > they have been updated (and > if there is no other activity on the system) they > will not need to be > updated if you archive again immediately after. > You do not say what the normal length of time of an > archive is, or is this > the first archive for some days (weeks, months)? > A bit more information. > > Keith > > -> -----Original Message----- > -> From: miyaki [mailto:lcib@yahoo.com] > -> Sent: Thursday, May 20, 2004 4:27 AM > -> To: ids@iiug.org; informix-list@iiug.org > -> Subject: how informix archive works? > -> > -> > -> Hi all, > -> > -> I have some doubt on the informix backup. I'm > using > -> ontape command to perform level 0 backup on my > Test > -> database (7.31.UC2). The first level 0 backup > took > -> around 2 hours to complete and the second time of > -> level 0 backup only took ~45min. The second time > of > -> the backup begin right after the first backup > -> completed. There's no other transactions running > on > -> the database during the backup. Which means that > the > -> data for both archive is exactly identical. My > -> question is why second backup take shorter > duration to > -> complete compare to the first backup > -> > -> Does any one of us know where can i obtain the > -> documentation to describe how informix archive > works? > -> > -> TIA, > -> miyaki > -> > -> > -> > -> > -> __________________________________ > -> Do you Yahoo!? > -> Yahoo! Domains - Claim yours for only $14.70/year > -> http://smallbusiness.promotions.yahoo.com/offer > -> sending to informix-list > -> > > > ******************************************************************************** ** > This message is sent in strict confidence for the > addressee only. It may > contain legally privileged information. The contents > are not to be disclosed > to anyone other than the addressee. Unauthorised > recipients are requested > to preserve this confidentiality and to advise the > sender immediately of any > error in transmission. > This footnote also confirms that this email message > has been swept for the > presence of computer viruses, however we cannot > guarantee that this message > is free from such problems. > ******************************************************************************** ** > > > > --------------------------------- > Do you Yahoo!? > Yahoo! Domains - Claim yours for only $14.70/year > __________________________________ Do you Yahoo!? Yahoo! Domains – Claim yours for only $14.70/year http://smallbusiness.promotions.yahoo.com/offer