| Martin Mueck 2005-04-18, 7:23 am |
| We are using the Sybase SQL Anywhere 9.0.1.4339 in a
healthcare environment.
Recently a very critical problem arised at a customer
system.
The database reported a missing index entry.
Error: General error: Unable to find in index 'XXX' for
table 'XXX'
NativeError: State:S1000,Native:- 189,Origin:[Sybase][
ODBC
Driver][Adaptive Server Anywhere]
The validation tool dbvalid reported:
Foreign key "XXX" has missing index entries.
A database rebuild did repair the corrupt index.
But the root cause, how the index got corrupted is not found
yet.
Within our test environment this problem cannot be
reproduced until now.
The problem arised on two different customer databases
within the same timeframe.
On each database two indices got corrupt.
Q1: What is the cause that an entry in an index gets lost ?
Q2: How can this be prevented ?
Further background:
Both indices are foreign keys.
They have rolenames that are used also by other foreign keys
in other tables but referencing the same table.
The uniqueness of the rolename is only forced per table.
Q3: Can those rolenames cause that entries in indices get
lost ?
Q4: What can we do to prevent the customer from getting into
that situation ?
The database having the corrupt index is available for
futher tests.
Are there any hints regarding this problem?
Thanks.
|