[Zope-DB] Unpickling data from OracleStorage

Matthew T. Kromer matt@zope.com
Mon, 14 Oct 2002 10:24:23 -0400

Randy Jay Yarger wrote:

>I'm trying to 'manually' unpickle some objects from OracleStorage and am
>not having much luck. Here is the situation in brief:
>* A bad block on a disk caused part of the ZODB_RECORD table to become
>* Oracle allowed me to export all of the rest of the tables and at least
>part of ZODB_RECORD

Randy, I dont have much experience probing the possible failure modes 
after you lose data out of OracleStorage due to disk corruption.  With 
FileStorage, you could usually roll back the DB to a point in time 
before the corruption with truncation, with Oracle Storage, there is no 
linearity involved, so just unwinding the TIDs or OIDs may not help.

Clearly my best advice is to restore from whatever backup you have. 
 Guessing that you don't have a backup ...

Well, the ZODB_RECORD table maps objects to transactions to versions, 
and may contain pointers to other records -- this is pretty much a key 
table; anything that loses pages out of this table is going to goof up 
objects, randomly.

Matt Kromer
Zope Corporation  http://www.zope.com/