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https://issues.apache.org/jira/browse/HBASE-4532?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=13128253#comment-13128253
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jirapos...@reviews.apache.org commented on HBASE-4532:
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This is an automatically generated e-mail. To reply, visit:
https://reviews.apache.org/r/2393/
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Review request for hbase, Dhruba Borthakur, Michael Stack, Pritam Damania, 
Prakash Khemani, Amitanand Aiyer, Kannan Muthukkaruppan, Jerry Chen, Liyin, 
Karthik Ranganathan, and Nicolas Spiegelberg.


Summary
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HBASE-4469 avoids the top row seek operation if row-col bloom filter is 
enabled. 
This jira tries to avoid top row seek for all the cases by creating a dedicated 
bloom filter only for row with empty column.

Previous solution is to create the dedicated bloom filter for delete family, 
which does not work if there is a row with empty column.
For example, 
we are interested in row1/cf1:/1/put.
So we seek to the top row: row1/cf1:/MAX_TS/MAXIMUM. And the delete family 
bloom filter will say there is NO delete family.
Then it will avoid the top row seek and return a fake kv, which is the last kv 
for this row (createLastOnRowCol).
In this way, we have already missed the real kv we are interested in.

The root cause is that even there is no delete family at top row, we still 
cannot avoid the top row seek.
We can ONLY avoid the top row seek when there is no row with empty column, no 
matter what kind of kv type (delete/deleteCol/deleteFamily/put).
So the current solution is to create the dedicate bloom filter for row with 
empty column.

This patch is rebased on 0.89-fb. But it should be the same for apache-trunk as 
well. I will submit the patch for apache-trunk later.


This addresses bug HBASE-4532.
    https://issues.apache.org/jira/browse/HBASE-4532


Diffs
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  src/main/java/org/apache/hadoop/hbase/KeyValue.java 93538bb 
  src/main/java/org/apache/hadoop/hbase/io/hfile/BlockType.java 9a79a74 
  src/main/java/org/apache/hadoop/hbase/io/hfile/HFile.java 5d9b518 
  src/main/java/org/apache/hadoop/hbase/io/hfile/HFilePrettyPrinter.java 
6cf7cce 
  src/main/java/org/apache/hadoop/hbase/io/hfile/HFileReaderV1.java 1f78dd4 
  src/main/java/org/apache/hadoop/hbase/io/hfile/HFileReaderV2.java 3c34f86 
  src/main/java/org/apache/hadoop/hbase/io/hfile/HFileWriterV1.java 2e1d23a 
  src/main/java/org/apache/hadoop/hbase/io/hfile/HFileWriterV2.java c4b60e9 
  src/main/java/org/apache/hadoop/hbase/regionserver/ScanQueryMatcher.java 
a1d7de5 
  src/main/java/org/apache/hadoop/hbase/regionserver/StoreFile.java e4dfc2e 
  src/main/java/org/apache/hadoop/hbase/regionserver/StoreFileScanner.java 
ebb360c 
  src/main/java/org/apache/hadoop/hbase/regionserver/StoreScanner.java 8814812 
  src/main/java/org/apache/hadoop/hbase/util/BloomFilterFactory.java fb4f2df 
  src/test/java/org/apache/hadoop/hbase/regionserver/TestBlocksRead.java 
c88b23f 
  
src/test/java/org/apache/hadoop/hbase/regionserver/TestCompoundBloomFilter.java 
48e9163 
  src/test/java/org/apache/hadoop/hbase/regionserver/TestStoreFile.java 0eca9b8 

Diff: https://reviews.apache.org/r/2393/diff


Testing
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Running all the unit tests now


Thanks,

Liyin


                
> Avoid top row seek by dedicated bloom filter for delete family bloom filter
> ---------------------------------------------------------------------------
>
>                 Key: HBASE-4532
>                 URL: https://issues.apache.org/jira/browse/HBASE-4532
>             Project: HBase
>          Issue Type: Improvement
>            Reporter: Liyin Tang
>            Assignee: Liyin Tang
>
> HBASE-4469 avoids the top row seek operation if row-col bloom filter is 
> enabled. 
> This jira tries to avoid top row seek for all the cases by creating a 
> dedicated bloom filter only for delete family
> The only subtle use case is when we are interested in the top row with empty 
> column.
> For example, 
> we are interested in row1/cf1:/1/put.
> So we seek to the top row: row1/cf1:/MAX_TS/MAXIMUM. And the delete family 
> bloom filter will say there is NO delete family.
> Then it will avoid the top row seek and return a fake kv, which is the last 
> kv for this row (createLastOnRowCol).
> In this way, we have already missed the real kv we are interested in.
> The solution for the above problem is to disable this optimization if we are 
> trying to GET/SCAN a row with empty column.

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