Home | About | Sematext search-lucene.com search-hadoop.com
NEW: Monitor These Apps!
elasticsearch, apache solr, apache hbase, hadoop, redis, casssandra, amazon cloudwatch, mysql, memcached, apache kafka, apache zookeeper, apache storm, ubuntu, centOS, red hat, debian, puppet labs, java, senseiDB
 Search Hadoop and all its subprojects:

Switch to Threaded View
HBase >> mail # user >> Scan with Filter


Copy link to this message
-
RE: Scan with Filter
The API shows one row per next() call but the number of rows fetched per RPC can be configured much higher with Scan.setCaching().

Filters are basically just server-side predicates that will dictate which rows/columns/values will be returned to the client.  This does not relate to the number of rows sent per RPC.  See http://hbase.apache.org/docs/current/api/org/apache/hadoop/hbase/filter/package-summary.html for more information about filters.

JG

> -----Original Message-----
> From: Weishung Chung [mailto:[EMAIL PROTECTED]]
> Sent: Tuesday, January 18, 2011 8:31 AM
> To: [EMAIL PROTECTED]
> Subject: Scan with Filter
>
> I have some questions about the way Hbase returns results. When we use
> HTable getScanner(Scan), it looks like it only retrieves 1 row per next() call
> which is different from how jdbc returns the resultset. If I set the Filter on
> the Scan, could it return a set of rows in one connection call? It looks like the
> ClientScanner does not make use of the Filter. Only the Scan uses the Filter in
> the readFields method. Please correct me if i am wrong about this.
>
> Thank you so much.
NEW: Monitor These Apps!
elasticsearch, apache solr, apache hbase, hadoop, redis, casssandra, amazon cloudwatch, mysql, memcached, apache kafka, apache zookeeper, apache storm, ubuntu, centOS, red hat, debian, puppet labs, java, senseiDB