Re: Q: Level0 & Level1 bkup

sanjeev sagar wrote: > > Informix server : XPS 8.21.uc1 > Backup Mgr : Onbar > Storage Manager : Alexandria > Databse size : 30gb[test size] > > I was taking Level0 & Level1 bakup which took almost > same time which seem to me no sense b'coz it lost the > meaning of Incremental bakup. > > I was having dialouges with some Oracle DBA, they > told me that in Oracle it keep the bit flag for > modified pages. So if you want Level1 bakup, server > only look for modified pages and make process faster. > > In Informix how it goes? > > As per my edjucation it scan the full data page and > it consider the timestamp factor for taking bakup. > In brief it scan all the data pages, even for taking > Level1 backup. > > Please correct me. And tell me that how it implement > Level1 & Level2 backup and why it take same amount of > time. If you have a relatively small instance and relatively fast archive device, versus the speed of the database disks, then a level 1 or 2 will take nearly as long as a level 0. For larger installations with faster disk farms (say large stripe sets) there can be significant gains in speed of a level1 -vs- a level 0. Yes Informix does indeed scan all ALLOCATED disk pages to determine which pages to archive. There is really no better scheme. Art S. Kagel