ALTER TABLE ADD columns in parallel?

From: Rich Jesse <>
Date: Wed, 5 Mar 2014 09:44:01 -0600 (CST)
Message-ID: <>

Hey all,

In, our ERP migration is adding 14 columns with default values to a populated table:

ALTER TABLE erptbl ADD (newcol1 NCHAR(1) DEFAULT ' ',...

  • This is running single-threaded, taking 4+ hours over the 16.5M rows (~42GB).
  • I tried altering the table with PARALLEL=8 (server has 16 logical CPUs) and even ALTER SESSION FORCE PARALLEL DDL, but no luck.
  • There are 254 columns with a mix of NCHAR and NUMBER (no LOBs, which could prevent parallel).
  • The ERP software (JDEdwards) is generating the SQL, and AFAIK this can't be changed.

I've been trying to search on MOS, but even though they thankfully fixed the right-click-on-link issue, it only lets me look at about the first 60 results of a query. I've also scanned the docs, but nothing seems to stick out.



Received on Wed Mar 05 2014 - 16:44:01 CET

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