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Creating Partitioned table faster than Non-partitioned [message #188412] Fri, 18 August 2006 07:52 Go to next message
a_developer
Messages: 194
Registered: January 2006
Senior Member
I am using CTAS to create a table of 50M records. I noticed that when I include the partitions while creating:

CREATE TABLE TabA
partition by range (TRXN_DATE)

. . .
as SELECT . . .

it is faster than creating it without the partitions:

CREATE TABLE TabA
as SELECT . . .

I don't quite understand why.. can anyone explain??
Re: Creating Partitioned table faster than Non-partitioned [message #188523 is a reply to message #188412] Sat, 19 August 2006 00:44 Go to previous message
rleishman
Messages: 3724
Registered: October 2005
Location: Melbourne, Australia
Senior Member
You'd have to show us the SQL and the EXPLAIN PLAN of both. It is likely that the faster one is using parallelism of some kind, because they have to do the same amount of I/O.

If the source table is also partitioned, then Oracle could probably parallelise that very efficiently.

Ross Leishman
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