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Hudson commented on HBASE-25972: -------------------------------- Results for branch branch-2.6 [build #120 on builds.a.o|https://ci-hbase.apache.org/job/HBase%20Nightly/job/branch-2.6/120/]: (/) *{color:green}+1 overall{color}* ---- details (if available): (/) {color:green}+1 general checks{color} -- For more information [see general report|https://ci-hbase.apache.org/job/HBase%20Nightly/job/branch-2.6/120/General_20Nightly_20Build_20Report/] (/) {color:green}+1 jdk8 hadoop2 checks{color} -- For more information [see jdk8 (hadoop2) report|https://ci-hbase.apache.org/job/HBase%20Nightly/job/branch-2.6/120/JDK8_20Nightly_20Build_20Report_20_28Hadoop2_29/] (/) {color:green}+1 jdk8 hadoop3 checks{color} -- For more information [see jdk8 (hadoop3) report|https://ci-hbase.apache.org/job/HBase%20Nightly/job/branch-2.6/120/JDK8_20Nightly_20Build_20Report_20_28Hadoop3_29/] (/) {color:green}+1 jdk11 hadoop3 checks{color} -- For more information [see jdk11 report|https://ci-hbase.apache.org/job/HBase%20Nightly/job/branch-2.6/120/JDK11_20Nightly_20Build_20Report_20_28Hadoop3_29/] (/) {color:green}+1 source release artifact{color} -- See build output for details. (/) {color:green}+1 client integration test{color} > Dual File Compaction > -------------------- > > Key: HBASE-25972 > URL: https://issues.apache.org/jira/browse/HBASE-25972 > Project: HBase > Issue Type: Improvement > Reporter: Kadir Ozdemir > Assignee: Kadir Ozdemir > Priority: Major > Labels: pull-request-available > Fix For: 2.7.0, 3.0.0-beta-2, 2.6.1, 2.5.9 > > > HBase stores tables row by row in its files, HFiles. An HFile is composed of > blocks. The number of rows stored in a block depends on the row sizes. The > number of rows per block gets lower when rows get larger on disk due to > multiple row versions since HBase stores all row versions sequentially in the > same HFile after compaction. However, applications (e.g., Phoenix) mostly > query the most recent row versions. > The default compactor in HBase compacts HFiles into one file. This Jira > introduces a new store file writer which writes the retained cells by > compaction into two files, which will be called DualFileWriter. One of these > files will include the live cells. This file will be called a live-version > file. The other file will include the rest of the cells, that is, historical > versions. This file will be called a historical-version file. DualFileWriter > will work with the default compactor. > The historical files will not be read for the scans scanning latest row > versions. This eliminates scanning unnecessary cell versions in compacted > files and thus it is expected to improve performance of these scans. -- This message was sent by Atlassian Jira (v8.20.10#820010)