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On Fri, 15 Jun 2001 18:02:16 +0800, E_at_E.COM (steve) wrote:
>Hi,
>yes I just found out.
>
>
>I was under tha assumption that i could partition my data on a given
>col,then if I changed that col oracle would automatically move the data
>to another partition. But that is not the case.
>
You can do this with partitioned tables. You have to alter the table
to enable row movement, the default is for it to be disabled.
Obviously, if you are updating the key you want to partition on, this
isn't going to be good for performance. The row has to be deleted,
from the old partition, then inserted to the new one, whenever an
update results in a row needing to move partitions.
>
>I want to devide the data up into descrete areas so that oracle knows
>where to find all the col1=n and does nto check the full 10k records.
>steve
>
>
This sounds like range partitioning could help. As long as your query
includes 'where col1 = n' then it will be possible to eliminate
partitions that cannot hold that value of n. The results can be
dramatic in terms of performance, but to be honest, I wouldn't know
whether it was worth it for 10k rows. Perhaps there's something else
that needs tuning.
Received on Sat Jun 16 2001 - 16:05:58 CDT