Re-partition

ahmedwaseem2000 · Post by **ahmedwaseem2000** » Mon Jun 02, 2008 3:59 am

Hi,

Scenario:

I partition the data in my first step using hash partition. after which, i would want to rename the the key columns on which i have partitioned the data upon. so, when i rename the columns does the partition is lost or the same partitions can be continued with?

PS: I know that i can always rename the column before partitioning the data. but thats not my answer.

Thanks,
Waseem

ArndW · Post by **ArndW** » Mon Jun 02, 2008 4:12 am

The partition will remain the same until you explicitly change the partitioning method; i.e. the default will be "same".

ahmedwaseem2000 · Post by **ahmedwaseem2000** » Mon Jun 02, 2008 4:27 am

thanks - However, will the change in the key names will have any impact on that?

ameyvaidya · Post by **ameyvaidya** » Mon Jun 02, 2008 5:24 am

Change in metadata should not trigger re-partitioning; once done, logically speaking, only explicit repartitioning and (this section may be incorrect) stage-driven auto re-partitioning can change the partitioned data.

ag_ram · Post by **ag_ram** » Mon Jun 02, 2008 5:32 am

However, will the change in the key names will have any impact on that?

No. You can certainly do an experiment to confirm this.

ray.wurlod · Post by **ray.wurlod** » Mon Jun 02, 2008 6:13 am

No even without an experiment. Key-based partitioning is driven by VALUES in the data fields, not the names of the data fields. Non-key partitioning is driven simply by the order of rows in the data - again not the name(s) of anything.