> On Feb. 22, 2017, 3:30 a.m., Sahil Takiar wrote: > > common/src/java/org/apache/hadoop/hive/common/StringInternUtils.java, line > > 29 > > <https://reviews.apache.org/r/56687/diff/1/?file=1633965#file1633965line29> > > > > How will this class relate to the intern utils provided in > > `HiveStringUtils`? > > Misha Dmitriev wrote: > The string interning methods in HiveStringUtils, that use a custom Google > interner for strings, are now obsolete. This code was likely created in the > old days of JDK6, when the standard String.intern() didn't scale well. But > since JDK7, several improevements were made to String.intern(), and now it > works very well. So there is no need for this custom code anymore. > > Now, the code from my new class StringInternUtils code be moved to > HiveStringUtils - it's not against logic. The main reason I don't want to do > that is that HiveStringUtils.java is already huge. My new interning methods > need some static fields and other intitialization. It's easy enough to > understand and maintain when this stuff is all close together in its own > class. But not so good if it gets spread across several places in > HiveStringUtils.java.
Ok sounds good, thanks for the info. - Sahil ----------------------------------------------------------- This is an automatically generated e-mail. To reply, visit: https://reviews.apache.org/r/56687/#review166298 ----------------------------------------------------------- On Feb. 22, 2017, 7:54 p.m., Misha Dmitriev wrote: > > ----------------------------------------------------------- > This is an automatically generated e-mail. To reply, visit: > https://reviews.apache.org/r/56687/ > ----------------------------------------------------------- > > (Updated Feb. 22, 2017, 7:54 p.m.) > > > Review request for hive, Chaoyu Tang, Mohit Sabharwal, and Sergio Pena. > > > Bugs: https://issues.apache.org/jira/browse/HIVE-15882 > > https://issues.apache.org/jira/browse/https://issues.apache.org/jira/browse/HIVE-15882 > > > Repository: hive-git > > > Description > ------- > > See the description of the problem in > https://issues.apache.org/jira/browse/HIVE-15882 Interning strings per this > review removes most of the overhead due to duplicate strings. > > Also, where maps in several places are created from other maps, use the > original map's size for the new map. This is to avoid the situation when a > map with default capacity (typically 16) is created to hold just 2-3 entries, > and the rest of the internal 16-entry array is wasted. > > > Diffs > ----- > > common/src/java/org/apache/hadoop/hive/common/StringInternUtils.java > PRE-CREATION > ql/src/java/org/apache/hadoop/hive/ql/exec/Utilities.java > e81cbce3e333d44a4088c10491f399e92a505293 > ql/src/java/org/apache/hadoop/hive/ql/hooks/Entity.java > 08420664d59f28f75872c25c9f8ee42577b23451 > ql/src/java/org/apache/hadoop/hive/ql/io/CombineHiveInputFormat.java > e91064b9c75e8adb2b36f21ff19ec0c1539b03b9 > ql/src/java/org/apache/hadoop/hive/ql/io/HiveInputFormat.java > 51530ac16c92cc75d501bfcb573557754ba0c964 > ql/src/java/org/apache/hadoop/hive/ql/io/SymbolicInputFormat.java > 55b3b551a1dac92583b6e03b10beb8172ca93d45 > ql/src/java/org/apache/hadoop/hive/ql/lockmgr/HiveLockObject.java > 82dc89803be9cf9e0018720eeceb90ff450bfdc8 > ql/src/java/org/apache/hadoop/hive/ql/metadata/Partition.java > c0edde9e92314d86482b5c46178987e79fae57fe > ql/src/java/org/apache/hadoop/hive/ql/metadata/Table.java > c6ae6f290857cfd10f1023058ede99bf4a10f057 > ql/src/java/org/apache/hadoop/hive/ql/optimizer/GenMapRedUtils.java > 24d16812515bdfa90b4be7a295c0388fcdfe95ef > > ql/src/java/org/apache/hadoop/hive/ql/optimizer/physical/GenMRSkewJoinProcessor.java > ede4fcbe342052ad86dadebcc49da2c0f515ea98 > > ql/src/java/org/apache/hadoop/hive/ql/optimizer/physical/NullScanTaskDispatcher.java > 0882ae2c6205b1636cbc92e76ef66bb70faadc76 > > ql/src/java/org/apache/hadoop/hive/ql/plan/ConditionalResolverMergeFiles.java > 68b0ad9ea63f051f16fec3652d8525f7ab07eb3f > ql/src/java/org/apache/hadoop/hive/ql/plan/MapWork.java > d4bdd96eaf8d179bed43b8a8c3be0d338940154a > ql/src/java/org/apache/hadoop/hive/ql/plan/MsckDesc.java > b7a7e4b7a5f8941b080c7805d224d3885885f444 > ql/src/java/org/apache/hadoop/hive/ql/plan/PartitionDesc.java > 73981e826870139a42ad881103fdb0a2ef8433a2 > > Diff: https://reviews.apache.org/r/56687/diff/ > > > Testing > ------- > > > Thanks, > > Misha Dmitriev > >
