Hi Marcelo, Truncate also removes the regions boundaries. You can use truncate_preserve if you want to keep your region splits. Not sure if it's available in 0.96...
Also, I don't think you can look at the splits from the shell command... JM 2015-02-25 10:09 GMT-05:00 Marcelo Valle (BLOOMBERG/ LONDON) < [email protected]>: > Hi, > > I have created an HBase table just like that: > > t = create 'HBaseSerialWritesPOC', 'user_id_ts', {NAME => 'alnfo'}, > {SPLITS => ['100000000000000000000000', '200000000000000000000000', > '300000000000000000000000', '400000000000000000000000', > '500000000000000000000000', '600000000000000000000000', > '700000000000000000000000', '800000000000000000000000', > '900000000000000000000000', 'a00000000000000000000000', > 'b00000000000000000000000', 'c00000000000000000000000', > 'd00000000000000000000000', 'e00000000000000000000000', > 'f00000000000000000000000']} > > After some tests, I truncated the table. > > Then I inserted 1 million rows, just to test. I was expecting to have 16 > regions for this table, but when I checked admin UI, I saw two regions: > > Table Regions > Name Region Server Start Key End Key Requests > HBaseSerialWritesPOC,,1424873821297.cf92656f68a16e9696d0fbfe2494219b. > host1 800000190000125396f3f2bb 500625 > HBaseSerialWritesPOC,800000190000125396f3f2bb,1424873821297.696a25e590e3248005c638c0f86c0564. > host2 800000190000125396f3f2bb 500621 > > I am new to HBase, so it really means just 2 regions have been created, > right? It seems keys have been split in a half, 0000.. To ffff... > > I disabled, dropped and created the table again using the same command > bellow, then I saw 16 regions, as expected. > > Question 1: Is it possible to check the same thing using hbase shell? > > Question 2: Is it expected behavior the truncate messing up the splits? > What kind of DML operations could change the splits in my table? I am using > HBase 0.96.1.2.0.10.0-1-hadoop2 > > -Marcelo
