GitHub user eowhadi opened a pull request:
https://github.com/apache/incubator-trafodion/pull/284
[TRAFODION-1420] Use ClientSmallScanner for small scans to improve
performance
Hbase implements an optimization for small scan (defined as scanning less
than a data block ie 64Kb) resulting in 3X performance improvement. The
underlying trick is about cutting down RPC calls from 3 (OpenScan/Next/Close)
to 1, and use pread stateless instead of seek/read state-full and locking
method to read data. This JIRA is about improving the compiler who can be aware
if a scan will be acting on single data block (small) or not, and pass this
data to executor so that it can use the right parameter for scan.
(scan.setSmall(boolean)).
reference:
https://issues.apache.org/jira/browse/HBASE-9488
https://issues.apache.org/jira/browse/HBASE-7266
You can merge this pull request into a Git repository by running:
$ git pull https://github.com/eowhadi/incubator-trafodion smallScanner
Alternatively you can review and apply these changes as the patch at:
https://github.com/apache/incubator-trafodion/pull/284.patch
To close this pull request, make a commit to your master/trunk branch
with (at least) the following in the commit message:
This closes #284
----
commit 49a06f8be5f2c35b4f6ea20fd4220143addddc7a
Author: Eric Owhadi <[email protected]>
Date: 2016-01-25T17:40:50Z
Implement TRAFODION-1420 Use ClientSmallScanner for small scans to improve
perdormance
Hbase implements an optimization for small scan (defined as scanning less
than a data block ie 64Kb) resulting in 3X performance improvement. The
underlying trick is about cutting down RPC calls from 3 (OpenScan/Next/Close)
to 1, and use pread stateless instead of seek/read state-full and locking
method to read data. This JIRA is about improving the compiler who can be aware
if a scan will be acting on single data block (small) or not, and pass this
data to executor so that it can use the right parameter for scan.
(scan.setSmall(boolean)).
reference:
https://issues.apache.org/jira/browse/HBASE-9488
https://issues.apache.org/jira/browse/HBASE-7266
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