How small is small? If it is bytes, then setting the value to 50 is not so much different from 1, I suppose. If 50 rows fit in one block, it will just fetch one block whether the setting is 1 or 50. You might want to try a larger value. It should be fine if the records are small and you need them all on the client side anyway.
It also depends on the block size, of course. When you only ever do full scans on a table and little random access, you might want to increase that. Friso On 11 nov 2010, at 12:15, Oleg Ruchovets wrote: > Hi , > To improve client performance I changed > hbase.client.scanner.caching from 1 to 50. > After running client with new value( hbase.client.scanner.caching from = 50 > ) it didn't improve execution time at all. > > I have ~ 9 million small records. > I have to do full scan , so it brings all 9 million records to client . > My assumption -- this change have to bring significant improvement , but it > is not. > > Additional Information. > I scan table which has 100 regions > 5 server > 20 map > 4 concurrent map > Scan process takes 5.5 - 6 hours. As for me it is too much time? Am I write? > and how can I improve it > > > I changed the value in all hbase-site.xml files and restart hbase. > > Any suggestions.
