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https://issues.apache.org/jira/browse/HBASE-2794?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=13117615#comment-13117615
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[email protected] commented on HBASE-2794:
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This is an automatically generated e-mail. To reply, visit:
https://reviews.apache.org/r/2084/
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(Updated 2011-09-29 21:05:20.334849)
Review request for hbase.
Changes
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Addressing Jonathan's comments.
Summary
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Previously we only used row-column Bloom filters for scans that only requested
one column. We have seen production queries that request up to 200 columns, and
with say ~6 store files per store (region / column family combination) this
might have resulted in 1200 block read operations in the worst case. With this
diff we will be avoiding seeks on store files that we know don't contain the
row/column of interest when using an ExplicitColumnTracker. The performance
should remain the same for column range queries.
This addresses bug HBASE-2794.
https://issues.apache.org/jira/browse/HBASE-2794
Diffs (updated)
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src/main/java/org/apache/hadoop/hbase/KeyValue.java 585c4a8
src/main/java/org/apache/hadoop/hbase/io/hfile/AbstractHFileReader.java
f5173c4
src/main/java/org/apache/hadoop/hbase/io/hfile/HFile.java a3d778e
src/main/java/org/apache/hadoop/hbase/regionserver/AbstractKeyValueScanner.java
PRE-CREATION
src/main/java/org/apache/hadoop/hbase/regionserver/HRegion.java 7cbdb98
src/main/java/org/apache/hadoop/hbase/regionserver/KeyValueHeap.java 9d9895c
src/main/java/org/apache/hadoop/hbase/regionserver/KeyValueScanner.java
6cdada7
src/main/java/org/apache/hadoop/hbase/regionserver/MemStore.java 4aa72de
src/main/java/org/apache/hadoop/hbase/regionserver/ScanQueryMatcher.java
68cdac5
src/main/java/org/apache/hadoop/hbase/regionserver/StoreFile.java fd9e7ef
src/main/java/org/apache/hadoop/hbase/regionserver/StoreFileScanner.java
08d3ba4
src/main/java/org/apache/hadoop/hbase/regionserver/StoreScanner.java ac2348e
src/main/java/org/apache/hadoop/hbase/util/CollectionBackedScanner.java
32f88fb
src/test/java/org/apache/hadoop/hbase/regionserver/TestKeyValueHeap.java
a5d13f7
src/test/java/org/apache/hadoop/hbase/regionserver/TestMultiColumnScanner.java
baee696
src/test/java/org/apache/hadoop/hbase/regionserver/TestScanWithBloomError.java
PRE-CREATION
Diff: https://reviews.apache.org/r/2084/diff
Testing
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Existing unit tests. A new unit test (TestScanWithBloomError). Load testing
using HBaseTest.
Thanks,
Mikhail
> ROWCOL bloom filter not used if multiple columns within same family are
> requested in a Get
> ------------------------------------------------------------------------------------------
>
> Key: HBASE-2794
> URL: https://issues.apache.org/jira/browse/HBASE-2794
> Project: HBase
> Issue Type: Improvement
> Components: performance
> Reporter: Kannan Muthukkaruppan
> Fix For: 0.92.0
>
>
> Noticed the following snippet in StoreFile.java:Scanner:shouldSeek():
> {code}
> switch(bloomFilterType) {
> case ROW:
> key = row;
> break;
> case ROWCOL:
> if (columns.size() == 1) {
> byte[] col = columns.first();
> key = Bytes.add(row, col);
> break;
> }
> //$FALL-THROUGH$
> default:
> return true;
> }
> {code}
> If columns.size > 1, then we currently don't take advantage of the bloom
> filter. We should optimize this to check bloom for each of columns and if
> none of the columns are present in the bloom avoid opening the file.
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