Re: Please Help

: In article: <3i466h$i01_at_news.cis.nctu.edu.tw> Vinay
: <vinay_at_wslvax1.wipsys.soft.net> writes:
: >
: > Each day while exporting
: > the error comes on different tables not on the same table
: > which was errored out by previous export.

In article <97109968wnr_at_artemis.demon.co.uk>

           tim_at_artemis.demon.co.uk "C:DEMONSPOOLMAIL" writes:
:
: question 1
:
: seem to be some serious corruption here, because you
: are doing an export at the time, and the table causing
: the corruption changes, the corruption could be in the temporary
: tablespace, if you are lucky :-)
:

Seconded, only it could be worse.
The 1578 means that there is an internal 'formatting' type of problem with a block that Oracle is trying to read: this does not necessarily mean that the error has been caused by a physically bad block: it is much more likely to be the result of some sort of s/w problem damaging (or replacing) the expected content of a block.

Given that the error does not occur on the same table every time, then I would worry about two possibilities: there are SYS tables that are used in tracking the exports (particularly revelant for incremental exports). Since these are updated during the course of exports I would assume that either they have become damaged, or that there are some blocks in your rollback area that are damaged.)

If I were you, I would:

1. tablescan the table next referenced by the ORA-01578 to see if it is damaged: if so, then it will ora-01578 again.
2. tablescan tables like VIEW$, TAB$, FET$, (basically anything in sys come to think of it). If anything gives you ORA-01578 start thinking about a total rebuild of your database.

If nothing shows as bad:

    c) Drop and recreate your TEMP tablespaces (following Tim's note)

    d) Drop and recreate any tablespaces that hold rollback segments.

        (excluding the SYSTEM rollback in the SYSTEM tablespace).

If no further 1578s come up, you may be okay If further 1578s come up, I guess (and it _is_ a guess) the next thing to worry about is the SYSTEM rollback segment: which is another indicator for rebuilding the database.

-- 
Jonathan Lewis