If you're going the PDML route, don't forget to increase the initrans of 
the tables and indices, since each Parallel Execution slave will have its 
own entry into the block transaction list, and this in itself could result 
in that annoying ORA-01555 error we see.

Regards :

Ferenc Mantfeld

-----Original Message-----
From:   Deshpande, Kirti [SMTP:[EMAIL PROTECTED]]
Sent:   Tuesday, November 26, 2002 11:19 AM
To:     Multiple recipients of list ORACLE-L
Subject:        RE: Mass updates to production tables (NULL to non-NULL)

I would consider PDML to get the job done faster, provided there are enough 
resources.
Using a cursor seems like a good idea, but avoid fetching across commits. 
We are going through a similar exercise, adding 10000000 to a cust_id field 
to denote the source of the data, and Developers complained about ORA-1555. 
Asked them not to commit as existing rollback segments and space were 
adequate ;)

Good Luck,

- Kirti

-----Original Message-----
Sent: Monday, November 25, 2002 3:04 PM
To: Multiple recipients of list ORACLE-L


I've got a real hot project (8.1.7.2 on HP/UX 11.0) that needs to have 
NULLs
converted to spaces on three different columns.  Each is a CHAR, so I
shouldn't need to worry about chaining, since that column's full size has
already been allocated in the block, right?  But the first column has 1.2M
NULLs out of 1.45M rows.

My first test was to just UPDATE mytable SET mycol = ' ' WHERE mycol IS
NULL, after removing the index on that column.  Seeing as there were many
more rows updated than I had anticipated, I was going to test the UPDATE
using a cursor, and committing at every 10K rows (~120 total commits) to
reduce rollback and locking issues.

Thoughts?  Since this table is used for time-and-attendance and directly
affects payroll, downtime isn't possible.

TIA!

Rich


Rich Jesse                           System/Database Administrator
[EMAIL PROTECTED]              Quad/Tech International, Sussex, WI 
USA
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