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From: Ian Varley <ivarley@salesforce.com>
To: "user@hbase.apache.org" <user@hbase.apache.org>
Date: Thu, 12 Jan 2012 11:03:33 -0800
Subject: Re: does increasing region filesize followed by major compactions
 supposed to reduce number of regions?
Thread-Topic: does increasing region filesize followed by major compactions
 supposed to reduce number of regions?
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Vinod,

The answers to your questions (and so many more!) are easily found in the H=
Base Reference Guide:

http://hbase.apache.org/book.html#schema.versions

"Excess versions are removed during major compactions."

 - Ian "Doug Meil" Varley ;)

On Jan 12, 2012, at 10:59 AM, T Vinod Gupta wrote:

Thanks ill take a look.. meanwhile, i just decreased the versions for my
column families from 3 to 1 and triggered another compaction. does this
make hbase delete the previous versions and keep only the latest one?

thanks

On Thu, Jan 12, 2012 at 10:57 AM, kisalay <kisalay@gmail.com<mailto:kisalay=
@gmail.com>> wrote:

Vinod,

U will have to do merge of the regions after the major compact to decrease
the number of regions that you have. You can do either an online or an
offline merge.

You can pickup the online merge jruby script from the jira
https://issues.apache.org/jira/browse/HBASE-1621

~Kisalay

On Fri, Jan 13, 2012 at 12:13 AM, T Vinod Gupta <tvinod@readypulse.com<mail=
to:tvinod@readypulse.com>
wrote:

so there is no way to make the regions merge since they are much below
region max size?

On Thu, Jan 12, 2012 at 10:40 AM, Doug Meil
<doug.meil@explorysmedical.com<mailto:doug.meil@explorysmedical.com>>wrote:


Major compactions don't change the number of regions.


On 1/12/12 1:35 PM, "T Vinod Gupta" <tvinod@readypulse.com<mailto:tvinod@re=
adypulse.com>> wrote:

this is probably a rookie question. but my understanding is that if i
increase the region max file size and then initiate major compaction
manually, the number of regions should ideally go down by the factor
by
which i increased the region max file size. isn't that true? im not
seeing
that happening. ofcourse, my compaction is still underway - so i don't
know
if ill see region count decrease at the very end of it. major
compaction
does do region merging right?

thanks


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