> Here are my questions:
> 1) Is this correct? Will it really reduce the amount of data it loads in
It will only reduce memory usage if you currently have multiple
versions of the same cell.
> 2) How do I do this in production? I know that HBase shell supports alter
> statement. Do you recommend using that?
> If I execute an alter statement, will it immediately start lot of activity
> there by degrading our real time performance?
Yes, you should use the shell. You'll need to disable the table first.
No activity should happen immediately. If you currently have multiple
version of any cells, they will disappear during the next major
> 3) Do we need to do anything else before or after we run alter command?
You can run a full compaction if you want to make sure that additional
versions are deleted right away.