thanks thats helpful
On Thu, Aug 22, 2013 at 5:16 PM, Vladimir Rodionov <vrodio...@carrieriq.com>wrote: > Yes, number of tables must be reasonable as well. Region Servers operates > on 'regions' . > Each Table can have multiple CFs, each CF can have multiple regions. The > more regions you have per Region Server - > the more data you will need to keep in memory, the more time it will take > to recover from Region Server failure, therefore > there is a practical limit on number of regions per one Region Server > (hundreds - not thousands). It is recommended > to keep the number of regions per server much less than 1000 (say , 100- > 500 max). > > > Best regards, > Vladimir Rodionov > Principal Platform Engineer > Carrier IQ, www.carrieriq.com > e-mail: vrodio...@carrieriq.com > > ________________________________________ > From: Koert Kuipers [ko...@tresata.com] > Sent: Thursday, August 22, 2013 12:30 PM > To: user@hbase.apache.org; Vladimir Rodionov > Subject: Re: one column family but lots of tables > > if that is the case, how come people keep warning about limiting the > number of column families to only a handful (with more hbase performance > will degrade supposedly), yet there seems to be no similar warnings for > number of tables? see for example here: > http://comments.gmane.org/gmane.comp.java.hadoop.hbase.user/27616 > > if a table means at least one column family then the number of tables > should also be kept to a minumum, no? > > > > > On Thu, Aug 22, 2013 at 1:58 PM, Vladimir Rodionov < > vrodio...@carrieriq.com<mailto:vrodio...@carrieriq.com>> wrote: > Nope. Column family is per table (its sub-directory inside your table > directory in HDFS). > If you have N tables you will always have , at least, N distinct CFs (even > if they have the same name). > > Best regards, > Vladimir Rodionov > Principal Platform Engineer > Carrier IQ, www.carrieriq.com<http://www.carrieriq.com> > e-mail: vrodio...@carrieriq.com<mailto:vrodio...@carrieriq.com> > > ________________________________________ > From: Koert Kuipers [ko...@tresata.com<mailto:ko...@tresata.com>] > Sent: Thursday, August 22, 2013 8:06 AM > To: user@hbase.apache.org<mailto:user@hbase.apache.org> > Subject: one column family but lots of tables > > i read in multiple places that i should try to limit the number of column > families in hbase. > > do i understand it correctly that when i create lots of tables, but they > all use the same column family (by name), that i am just using one column > family and i am OK with respect to limiting number of column families ? > > thanks! koert > > Confidentiality Notice: The information contained in this message, > including any attachments hereto, may be confidential and is intended to be > read only by the individual or entity to whom this message is addressed. If > the reader of this message is not the intended recipient or an agent or > designee of the intended recipient, please note that any review, use, > disclosure or distribution of this message or its attachments, in any form, > is strictly prohibited. If you have received this message in error, please > immediately notify the sender and/or notificati...@carrieriq.com<mailto: > notificati...@carrieriq.com> and delete or destroy any copy of this > message and its attachments. > >
