Oracle DBA Forum
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


2004-08-25       - By -not available-

Reply:     <<     171     172     173     174     175     176     177     178     179     180     >>  

IMHO -- Mark D Powell --

-- --Original Message-- --
From: oracle-l-bounce@(protected)
[mailto:oracle-l-bounce@(protected)]On Behalf Of Daniel W. Fink
Sent: Wednesday, August 25, 2004 10:00 AM
To: oracle-l@(protected)
Subject: Re: SET TRANSACTION statements within PL/SQL?

Fewer, but larger, undo segments (auto or rbs) can actually cause other
problems. If you have many processes running at the same time, you may
run into contention for the transaction table (undo header waits). If
you have very few processes running in parallel (but many transactions
running sequentially), you may run into space management issues (unable
to extend).

For this process only, you might look at creating 1 undo segment per
parallel transaction and size them to 2x the largest transaction. This
reduces the risk of header waits and space management issues.

Of course, no matter which approach you adopt, you always need to
consider ORA-1555 (See If you intend to reuse undo blocks as quickly as
possible, you increase the risk. You can minimize the risk by
'partitioning ' the data so that each process does not try to query data
that may have been changed by another process.

Daniel Fink

Powell, Mark D wrote:

>Mark, from within pl/sql you should probably consider using
>dbms_transaction.use_rollback_segment( 'segname ') to assign DML activity to
>specific rollback segment.
>Remember that the assignment is only maintained until a commit or rollback
>is issued and the assignment will have to be reset immediately after each
>transaction prior to doing any other work or the re-assignment will fail.
>You might want to consider re-creating your RBS segments so that you have
>fewer but larger segments available at all times. This would eliminate the
>need to try to assign segments to begin with.
>DDL statements are generally very small and do not require assignment which
>is a good thing considering that every DDL statement is preceeded and
>followed by an implicit commit making assignment a practical
>Just some thoughts on the matter.
>-- Mark D Powell --
>-- --Original Message-- --
>From: oracle-l-bounce@(protected)
>[mailto:oracle-l-bounce@(protected)]On Behalf Of Mark Richard
>Sent: Wednesday, August 25, 2004 12:07 AM
>To: oracle-l@(protected)
>Subject: SET TRANSACTION statements within PL/SQL?
>Dear List,
>I am working on some large data conversion scripts and we would like to
>assign specific Rollback Segments to the queries. I have done some testing
>in standard SQL using "set transaction use rollback segment blah " and the
>results have been positive.
>Typically, however, we write most conversion scripts in PL/SQL to provide a
>standard mechanism for exception handling and also to deal nicely with
>various tests / reporting. My concern is how to combine the set
>transaction statement with PL/SQL. The PL/SQL blocks are simply anonymous
>blocks within a script - Can I put a "set transaction " statement before the
>DECLARE line or does it need to be within the PL/SQL itself?
>Also, sometimes the queries are just placed within the PL/SQL and other
>times EXECUTE IMMEDIATE is used (particularly when the same PL/SQL block
>first adds a new column to be populated) - I at least have the freedom to
>use either approach if it matters. Does this confuse the issue at all?
>Unfortunately I 'm not clear on how the parsing of PL/SQL and calling of
>EXECUTE IMMEDIATE fit amongst a "set transaction " statement. Suggestions
>Thanks in advance,

-- ---- ---- ---- ---- ---- ---- ---- ---- ---- ---- ---- ------
Please see the official ORACLE-L FAQ:
-- ---- ---- ---- ---- ---- ---- ---- ---- ---- ---- ---- ------
To unsubscribe send email to: oracle-l-request@(protected)
put 'unsubscribe ' in the subject line.
Archives are at
FAQ is at
-- ---- ---- ---- ---- ---- ---- ---- ---- ---- ---- ---- ---- --