All Oracle Error Codes
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Frequent Oracle Errors

TNS:could not resolve the connect identifier specified
Backtrace message unwound by exceptions
invalid identifier
PL/SQL compilation error
internal error
missing expression
table or view does not exist
end-of-file on communication channel
TNS:listener unknown in connect descriptor
insufficient privileges
PL/SQL: numeric or value error string
TNS:protocol adapter error
ORACLE not available
target host or object does not exist
invalid number
unable to allocate string bytes of shared memory
resource busy and acquire with NOWAIT specified
error occurred at recursive SQL level string
ORACLE initialization or shutdown in progress
archiver error. Connect internal only, until freed
snapshot too old
unable to extend temp segment by string in tablespace
Credential retrieval failed
missing or invalid option
invalid username/password; logon denied
unable to create INITIAL extent for segment
out of process memory when trying to allocate string bytes
shared memory realm does not exist
cannot insert NULL
TNS:unable to connect to destination
remote database not found ora-02019
exception encountered: core dump
inconsistent datatypes
no data found
TNS:operation timed out
PL/SQL: could not find program
existing state of packages has been discarded
maximum number of processes exceeded
error signaled in parallel query server
ORACLE instance terminated. Disconnection forced
TNS:packet writer failure
see ORA-12699
missing right parenthesis
name is already used by an existing object
cannot identify/lock data file
invalid file operation
quoted string not properly terminated

Re: Reusing UNEXPIRED UNDO blocks

Stephen Barr


Hi Daniel,

 Answers below.
 My theory based on how I think it all works - we
have a high undo_retention (9 hours) because we are
performing a migration.

 The unexpired blocks look normal considering our
undo_retention. However, because one of the files was
marked as autoextensible, then instead of steal one of
the other unexpired blocks it just tried to extend the
datafile and failed when it couldn't.

 Also, would this explain why we are seeing some
statements fail quite quickly even though the undo
usage from v$transaction was only hovering ~6GB (we
have a 67GB UNDO).

 Does the above scenario sound realistic?

>> 1) Is the autoextended datafile at/near it's limit?

Yes - the filesystem that the datafile sits on is full
- this file cannot extend.

>> 2) How many undo segments do you have?

I assume I just get this info from dba_undo_extents?

2 from dba_undo_extents
3 /


>> 3) What version of Oracle?

>> 4) Is undo_retention guaranteed?

--- Daniel Fink <danielwfink@(protected):

> Stephen,
> Several questions come to mind.
> 1) Is the autoextended datafile at/near it's limit?
> 2) How many undo segments do you have?
> 3) What version of Oracle?
> 4) Is undo_retention guaranteed?
> In terms of expired/unexpired, it is supposed to
> mark the block as expired after the last commit time
> + undo_retention > current time. However, in
> practice, this is usually not the case. In testing,
> I (and others) have seen blocks expire almost
> immediately after a commit and other blocks not
> expire even days after the last commit time +
> undo_retention.
> If a block is not being used by a current
> transaction, not part of the undo segment minimum,
> unexpired and undo_retention is not guaranteed, a
> current transaction should steal it (and you can see
> that stealing is occurring in the query you ran).
> Regards,
> Daniel Fink

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