We have many sites running Oracle (in the hundreds) and it is rare to see
corruption. I have seen it once in the last 4 years where it was not
clearly due to a hardware problem. When it occurs you get an error if the
query uses an index. The solution is to drop and rebuild the index. If the
database block has corruption then you will get an error in the sidalrt.log.
You can test for corruption is several ways.
1. Export the table involved - this does a full table scan and if you have
db block corruption this is likely to find it.
2. Run dbverf, on NT or Netware you have to have the database closed, and
this will tell you on a file basis if you have a problem.
3. run analyze table table_name validate structure cascade;
You can log in as sys and spool to a file
select 'analyze table '||owner||'.'||table_name||' validate structure
cascade;' from dba_tables order by ower,tablename;
then run the resulting file. Saves you a lot of typing.
Also do backups and run in archivelog mode. Then if you have to you can
recover from an old backup and roll the database forward.
Jim
ajh_at_rtk.com wrote in message <7afgbu$s79$1_at_nnrp1.dejanews.com>...
>We've been making light use of Oracle at our site for about three years
>without any problems, but we're thinking about finally putting it to the
test
>and we've started to be concerned about corruptions.
>
>We're thinking about building a little warehouse to store our transaction
>information. We'd have one large table which would grow by about 15M
>transactions/week, would probably start out with around a billion records,
and
>would have probably two or three indices on it.
>
>Data will be updated in a batch once per week, and peak usage will probably
be
>three or four queries running on it concurrently.
>
>Should we be taking any precautions to avoid corrupted tables or indices?
Is
>it unavoidable, or are we being excessively paranoid even thinking about
it?
>
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Received on Thu Feb 18 1999 - 07:42:33 CST
