What Zhou said only I'd add that there is no snappy support in 0.90 hbase. Its in TRUNK (0.92). Only lzo (with some work) and gzip are supported in 0.90. See: http://hbase.apache.org/book/compression.html St.Ack
On Mon, Jul 11, 2011 at 4:06 AM, Zhoushuaifeng <zhoushuaif...@huawei.com> wrote: > Yes, you can change the compressor as you want(use alter table), it will not > break the existing data. > > Zhou Shuaifeng(Frank) > > -----Original Message----- > From: Frédéric Fondement [mailto:frederic.fondem...@uha.fr] > Sent: Monday, July 11, 2011 5:05 PM > To: user@hbase.apache.org > Subject: Change compressor on existing tables > > Another related question: is there a mean to change compressor (or > enable compressor) on an existing column family without breaking > existing data (e.g. from LZO to snappy) ? > > Le 10/07/11 10:21, Weiwei Xiong a écrit : >> Now I applied the major_compact on a table with BLOOMFILTER enabled. But how >> can I make sure if the row-keys have really been added into the bloomfilter? >> >> >> I profiled the cost of<HTable>.exists(<Get>) but it seems to me BF didn't >> give me speedup comparing with the execution without BLOOMFILTER enabled. >> >> Am I missing anything here? >> >> Thanks >> ww >> >> On Sat, Jul 9, 2011 at 1:32 PM, Weiwei Xiong<xion...@gmail.com> wrote: >> >>> Thanks Andrew. I will give it a try. >>> >>> ww >>> >>> >>> On Fri, Jul 8, 2011 at 6:45 PM, Andrew Purtell<apurt...@apache.org>wrote: >>> >>>> Sorry that is: >>>> >>>> major_compact 'tablename' >>>> >>>> Typing too fast... >>>> >>>> Best regards, >>>> >>>> >>>> - Andy >>>> >>>> Problems worthy of attack prove their worth by hitting back. - Piet Hein >>>> (via Tom White) >>>> >>>> >>>> ----- Original Message ----- >>>>> From: Andrew Purtell<apurt...@apache.org> >>>>> To: "user@hbase.apache.org"<user@hbase.apache.org> >>>>> Cc: >>>>> Sent: Friday, July 8, 2011 6:42 PM >>>>> Subject: Re: Enable BLOOMFILTER on existing tables >>>>> >>>>> You can update existing data through manually triggering compaction. >>>> After you >>>>> make a change like this, go to the hbase shell and execute: >>>>> >>>>> major_compaction 'yourtablename' >>>>> >>>>> After major compaction all of the store files for the table will abide >>>> the most >>>>> recent schema settings. >>>>> >>>>> Best regards, >>>>> >>>>> >>>>> - Andy >>>>> >>>>> >>>>> Problems worthy of attack prove their worth by hitting back. - Piet Hein >>>> (via >>>>> Tom White) >>>>> >>>>> >>>>> ----- Original Message ----- >>>>>> From: Weiwei Xiong<xion...@gmail.com> >>>>>> To: user@hbase.apache.org >>>>>> Cc: >>>>>> Sent: Friday, July 8, 2011 6:02 PM >>>>>> Subject: Enable BLOOMFILTER on existing tables >>>>>> >>>>>> Hi all, >>>>>> >>>>>> I want to enable the bloomfilter on some existing tables to speed-up >>>>> row-key >>>>>> existence checking. I altered the BLOOMFILTER from "NONE" to >>>>>> "ROW" for this >>>>>> purpose. >>>>>> >>>>>> But one think I am not clear is, will the setting change also take >>>> effect >>>>> on >>>>>> pre-existing rows? Or only rows to be inserted in future get the >>>>> BLOOMFILTER >>>>>> property? >>>>>> >>>>>> If bloomfilter change won't be applied to existing rows, is there any >>>>> other >>>>>> way to speed up the row-key existence checking? >>>>>> >>>>>> Thanks, >>>>>> ww >>>>>> >>> > >
