Re: dbexport and BYTE datatypes

In article <884362121.1965293581@dejanews.com>, jjtest@ismi.net writes >While porting thru the park one day, I ran into an interesting and scary >Informix data migration problem. > >The move was from a Solaris Sparc10 V5 Online Engine to a Solaris >UltraEnterprise 3000 V7.2.0.UC3 Online engine. > >I found that onload/onunload wouldn't work and various sources explained >that architectural differences were probably to blame in this case. Yes, onunload dump does a binary dump of the pages. > >Okay then. Use dbimport/dbexport right!? Well, KINDA. > >dbexport seems to work GREAT, as long as you are not using BYTE datatypes. > ?? It should be ok all the time. >Our one table stores pointers to our scanned images in a BYTE field. >(nope, not using 'blobspace') > ?? How do you mean pointers to scanned images. Do you mean blobs? >After dbexport/dbimport, these byte pointers were GARBAGE!! After taking >a little time to figure this out, I was fortunate enough to have the disk >space to use dbaccess and unload the pointers manually and load them back >where I needed them and I was okay, BUT, isn't this weird?? It's not an >architecture thing, because I tried dbexporting one row to disk, then >comparing it to a row I had unloaded. DIFFERENT! So the problem is >obviously in dbexport, right?? What gives here?? I always assumed that >dbexport was actually performing an action similar to a dbaccess/unload >sequence, as pipe-delimited data files are the result in both cases... >This is obviously NOT the case. Why not? This could potentially be a BIG >problem/suprise to someone in a similar situation who did not have disk >space to play with! > remember that a BYTE field is a 56 byte descriptor to where the actual pages are for the blob. If ou reload the blobs they will be on different pages hence the 56 byte descriptors will be different. YOu are not using your own pointers to pages containing blobs are you? >Anyone out there run into this before? I'd like to hear about it, or any >solutions that have been found. Thanks in advance. jj. > >-------------------==== Posted via Deja News ====----------------------- > http://www.dejanews.com/ Search, Read, Post to Usenet -- David Williams Maintainer of the Informix FAQ Primary site (Beta Version) http://www.smooth1.demon.co.uk Official site http://www.iiug.org/techinfo/faq/faq_top.html I see you standin', Standin' on your own, It's such a lonely place for you, For you to be If you need a shoulder, Or if you need a friend, I'll be here standing, Until the bitter end... So don't chastise me Or think I, I mean you harm... All I ever wanted Was for you To know that I care