Reg:delete performance on HBase table

[Manoj Babu <ma...@gmail.com>]

Hi All,

I am having doubt on delete performance inHBase table.

I have 190 million rows in oracle table it hardly took 4hours to delete it,
If i am having the same 190 million rows in HBase table how much time by
approx Hbase will take to delete the rows(based on row key range) and
how internally HBase handles delete?


Thanks in advance!

Cheers!
Manoj.

Re: Reg:delete performance on HBase table

[Mohammad Tariq <do...@gmail.com>]

Hello Manoj,

     When a Delete command is issued , no data is actually deleted
instantaneously. Instead a tombstone marker is set, making the deleted
cells effectively invisible.

The tombstone markers are only deleted during major compactions (which
compacts all store files to a single one), because in order to prove that a
tombstone marker has no effect HBase needs to look at all cells.

HBase periodically removes deleted cells during compactions.

HTH

Regards,
    Mohammad Tariq



On Wed, Dec 5, 2012 at 6:33 PM, Manoj Babu <ma...@gmail.com> wrote:

> Hi All,
>
> I am having doubt on delete performance inHBase table.
>
> I have 190 million rows in oracle table it hardly took 4hours to delete it,
> If i am having the same 190 million rows in HBase table how much time by
> approx Hbase will take to delete the rows(based on row key range) and
> how internally HBase handles delete?
>
>
> Thanks in advance!
>
> Cheers!
> Manoj.
>

Re: Reg:delete performance on HBase table

[Leonid Fedotov <lf...@hortonworks.com>]

do you want to delete just subset of the rows, or delete whole table?
if whole, then use "drop" it should be almost instant.
Same as in oracle, you can do "delete * from table;" and it may take forever, even give errors on rollback segment too small…
if you use "drop table" it mark it as deleted instantly, and then delete actual data during the next major compaction.

Thank you!

Sincerely,
Leonid Fedotov

On Dec 5, 2012, at 5:03 AM, Manoj Babu wrote:

> Hi All,
> 
> I am having doubt on delete performance inHBase table.
> 
> I have 190 million rows in oracle table it hardly took 4hours to delete it,
> If i am having the same 190 million rows in HBase table how much time by
> approx Hbase will take to delete the rows(based on row key range) and
> how internally HBase handles delete?
> 
> 
> Thanks in advance!
> 
> Cheers!
> Manoj.