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https://issues.apache.org/jira/browse/HBASE-9316?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=13748143#comment-13748143
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Ted Yu commented on HBASE-9316:
-------------------------------

+1 on this idea.
                
> Use JoinedHeap between MUST_PASS_ALL filters to better leverage essential 
> column family feature 
> ------------------------------------------------------------------------------------------------
>
>                 Key: HBASE-9316
>                 URL: https://issues.apache.org/jira/browse/HBASE-9316
>             Project: HBase
>          Issue Type: Bug
>            Reporter: James Taylor
>
> Currently, all column families in a MUST_PASS_ALL filter list are loaded in 
> advance of filtering. Instead, only the essential column family from the 
> first filter should be loaded and then its heap joined with subsequent 
> essential column family from the next filter in the list (probably up to some 
> reasonable/configurable limit).
> One particular Phoenix use case for this is when a SQL query is trying to 
> detect the absence of a KeyValue (though a <column> IS NULL clause). Our 
> workaround for a Phoenix TABLE is to insert a known, empty key value with 
> every row, or for a Phoenix VIEW (mapping to an existing HBase table) to 
> project everything. With this feature, we could instead use a filter per 
> column family and prevent the loading of the corresponding Store in many 
> cases.

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