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Posted to dev@hive.apache.org by "Phabricator (Updated) (JIRA)" <ji...@apache.org> on 2012/04/12 21:19:21 UTC

[jira] [Updated] (HIVE-2950) Hive should store the full table schema in partition storage descriptors

     [ https://issues.apache.org/jira/browse/HIVE-2950?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel ]

Phabricator updated HIVE-2950:
------------------------------

    Attachment: HIVE-2950.D2769.1.patch

travis requested code review of "HIVE-2950 [jira] Hive should store the full table schema in partition storage descriptors".
Reviewers: JIRA

  When adding a partition, copy the full table schema into the partition storage descriptor. The table storage descriptor may not contain the full schema when using a serde that reports its schema. This change makes partitions with serde-reported schema behave the same as partitions without a serde-reported schem.

  Hive tables have a schema, which is copied into the partition storage descriptor when adding a partition. Currently only columns stored in the table storage descriptor are copied - columns that are reported by the serde are not copied. Instead of copying the table storage descriptor columns into the partition columns, the full table schema should be copied.

  DETAILS

  This is a little long but is necessary to show 3 things: current behavior when explicitly listing columns, behavior with HIVE-2941 patched in and serde reported columns, and finally the behavior with this patch (full table schema copied into the partition storage descriptor).

  Here's an example of what currently happens. Note the following:

  	the two manually-defined fields defined for the table are listed in the table storage descriptor.
  	both fields are present in the partition storage descriptor

  This works great because users who query for a partition can look at its storage descriptor and get the schema.

  hive> create external table foo_test (name string, age int) partitioned by (part_dt string);
  hive> describe extended foo_test;
  OK
  name	string
  age	int
  part_dt	string

  Detailed Table Information	Table(tableName:foo_test, dbName:travis_test, owner:travis, createTime:1334256062, lastAccessTime:0, retention:0, sd:StorageDescriptor(cols:[FieldSchema(name:name, type:string, comment:null), FieldSchema(name:age, type:int, comment:null), FieldSchema(name:part_dt, type:string, comment:null)], location:hdfs://foo.com/warehouse/travis_test.db/foo_test, inputFormat:org.apache.hadoop.mapred.TextInputFormat, outputFormat:org.apache.hadoop.hive.ql.io.HiveIgnoreKeyTextOutputFormat, compressed:false, numBuckets:-1, serdeInfo:SerDeInfo(name:null, serializationLib:org.apache.hadoop.hive.serde2.lazy.LazySimpleSerDe, parameters:{serialization.format=1}), bucketCols:[], sortCols:[], parameters:{}, primaryRegionName:, secondaryRegions:[]), partitionKeys:[FieldSchema(name:part_dt, type:string, comment:null)], parameters:{EXTERNAL=TRUE, transient_lastDdlTime=1334256062}, viewOriginalText:null, viewExpandedText:null, tableType:EXTERNAL_TABLE)
  Time taken: 0.082 seconds

  hive> alter table foo_test add partition (part_dt = '20120331T000000Z') location 'hdfs://foo.com/foo/2012/03/31/00';
  hive> describe extended foo_test partition (part_dt = '20120331T000000Z');
  OK
  name	string
  age	int
  part_dt	string

  Detailed Partition Information	Partition(values:[20120331T000000Z], dbName:travis_test, tableName:foo_test, createTime:1334256131, lastAccessTime:0, sd:StorageDescriptor(cols:[FieldSchema(name:name, type:string, comment:null), FieldSchema(name:age, type:int, comment:null), FieldSchema(name:part_dt, type:string, comment:null)], location:hdfs://foo.com/foo/2012/03/31/00, inputFormat:org.apache.hadoop.mapred.TextInputFormat, outputFormat:org.apache.hadoop.hive.ql.io.HiveIgnoreKeyTextOutputFormat, compressed:false, numBuckets:-1, serdeInfo:SerDeInfo(name:null, serializationLib:org.apache.hadoop.hive.serde2.lazy.LazySimpleSerDe, parameters:{serialization.format=1}), bucketCols:[], sortCols:[], parameters:{}, primaryRegionName:, secondaryRegions:[]), parameters:{transient_lastDdlTime=1334256131})

  CURRENT BEHAVIOR WITH HIVE-2941 PATCHED IN

  Now let's examine what happens when creating a table when the serde reports the schema. Notice the following:

  	The table storage descriptor contains an empty list of columns. However, the table schema is available from the serde reflecting on the serialization class.
  	The partition storage descriptor does contain a single "part_dt" column that was copied from the table partition keys. The actual data columns are not present.

  hive> create external table travis_test.person_test partitioned by (part_dt string) row format serde "com.twitter.elephantbird.hive.serde.ThriftSerDe" with serdeproperties ("serialization.class"="com.twitter.elephantbird.examples.thrift.Person") stored as inputformat "com.twitter.elephantbird.mapred.input.HiveMultiInputFormat" outputformat "org.apache.hadoop.hive.ql.io.HiveIgnoreKeyTextOutputFormat";
  OK
  Time taken: 0.08 seconds
  hive> describe extended person_test;
  OK
  name	struct<first_name:string,last_name:string>	from deserializer
  id	int	from deserializer
  email	string	from deserializer
  phones	array<struct<number:string,type:struct<value:int>>>	from deserializer
  part_dt	string

  Detailed Table Information	Table(tableName:person_test, dbName:travis_test, owner:travis, createTime:1334256942, lastAccessTime:0, retention:0, sd:StorageDescriptor(cols:[], location:hdfs://foo.com/warehouse/travis_test.db/person_test, inputFormat:com.twitter.elephantbird.mapred.input.HiveMultiInputFormat, outputFormat:org.apache.hadoop.hive.ql.io.HiveIgnoreKeyTextOutputFormat, compressed:false, numBuckets:-1, serdeInfo:SerDeInfo(name:null, serializationLib:com.twitter.elephantbird.hive.serde.ThriftSerDe, parameters:{serialization.class=com.twitter.elephantbird.examples.thrift.Person, serialization.format=1}), bucketCols:[], sortCols:[], parameters:{}, primaryRegionName:, secondaryRegions:[]), partitionKeys:[FieldSchema(name:part_dt, type:string, comment:null)], parameters:{EXTERNAL=TRUE, transient_lastDdlTime=1334256942}, viewOriginalText:null, viewExpandedText:null, tableType:EXTERNAL_TABLE)
  Time taken: 0.147 seconds
  hive> alter table person_test add partition (part_dt = '20120331T000000Z') location 'hdfs://foo.com/foo/2012/03/31/00';
  OK
  Time taken: 0.149 seconds
  hive> describe extended person_test partition (part_dt = '20120331T000000Z');
  OK
  part_dt	string

  Detailed Partition Information	Partition(values:[20120331T000000Z], dbName:travis_test, tableName:person_test, createTime:1334257029, lastAccessTime:0, sd:StorageDescriptor(cols:[FieldSchema(name:part_dt, type:string, comment:null)], location:hdfs://foo.com/foo/2012/03/31/00, inputFormat:com.twitter.elephantbird.mapred.input.HiveMultiInputFormat, outputFormat:org.apache.hadoop.hive.ql.io.HiveIgnoreKeyTextOutputFormat, compressed:false, numBuckets:-1, serdeInfo:SerDeInfo(name:null, serializationLib:com.twitter.elephantbird.hive.serde.ThriftSerDe, parameters:{serialization.class=com.twitter.elephantbird.examples.thrift.Person, serialization.format=1}), bucketCols:[], sortCols:[], parameters:{}, primaryRegionName:, secondaryRegions:[]), parameters:{transient_lastDdlTime=1334257029})
  Time taken: 0.106 seconds
  hive>

  PROPOSED BEHAVIOR

  I believe the correct thing to do is copy the full table schema (serde-reported columns + partition keys) into the partition storage descriptor. Notice the following:

  	Table storage descriptor does not contain any columns, because they are reported by the serde.
  	Partition storage descriptor now contains both the serde-reported schema, and full table schema.

  hive> create external table travis_test.person_test partitioned by (part_dt string) row format serde "com.twitter.elephantbird.hive.serde.ThriftSerDe" with serdeproperties ("serialization.class"="com.twitter.elephantbird.examples.thrift.Person") stored as inputformat "com.twitter.elephantbird.mapred.input.HiveMultiInputFormat" outputformat "org.apache.hadoop.hive.ql.io.HiveIgnoreKeyTextOutputFormat";
  OK
  Time taken: 0.076 seconds
  hive> describe extended person_test;                                                                                                                                     OK                                                                                                                                                                       name    struct<first_name:string,last_name:string>      from deserializer
  id	int	from deserializer
  email	string	from deserializer
  phones	array<struct<number:string,type:struct<value:int>>>	from deserializer
  part_dt	string

  Detailed Table Information	Table(tableName:person_test, dbName:travis_test, owner:travis, createTime:1334257489, lastAccessTime:0, retention:0, sd:StorageDescriptor(cols:[], location:hdfs://foo.com/warehouse/travis_test.db/person_test, inputFormat:com.twitter.elephantbird.mapred.input.HiveMultiInputFormat, outputFormat:org.apache.hadoop.hive.ql.io.HiveIgnoreKeyTextOutputFormat, compressed:false, numBuckets:-1, serdeInfo:SerDeInfo(name:null, serializationLib:com.twitter.elephantbird.hive.serde.ThriftSerDe, parameters:{serialization.class=com.twitter.elephantbird.examples.thrift.Person, serialization.format=1}), bucketCols:[], sortCols:[], parameters:{}, primaryRegionName:, secondaryRegions:[]), partitionKeys:[FieldSchema(name:part_dt, type:string, comment:null)], parameters:{EXTERNAL=TRUE, transient_lastDdlTime=1334257489}, viewOriginalText:null, viewExpandedText:null, tableType:EXTERNAL_TABLE)
  Time taken: 0.155 seconds
  hive> alter table person_test add partition (part_dt = '20120331T000000Z') location 'hdfs://foo.com/foo/2012/03/31/00';
  OK                                                                                                                                                                       Time taken: 0.296 seconds
  hive> describe extended person_test partition (part_dt = '20120331T000000Z');                                                                                            OK                                                                                                                                                                       name    struct<first_name:string,last_name:string>      from deserializer
  id	int	from deserializer
  email	string	from deserializer
  phones	array<struct<number:string,type:struct<value:int>>>	from deserializer
  part_dt	string

  Detailed Partition Information	Partition(values:[20120331T000000Z], dbName:travis_test, tableName:person_test, createTime:1334257504, lastAccessTime:0, sd:StorageDescriptor(cols:[FieldSchema(name:name, type:struct<first_name:string,last_name:string>, comment:from deserializer), FieldSchema(name:id, type:int, comment:from deserializer), FieldSchema(name:email, type:string, comment:from deserializer), FieldSchema(name:phones, type:array<struct<number:string,type:struct<value:int>>>, comment:from deserializer), FieldSchema(name:part_dt, type:string, comment:null)], location:hdfs://foo.com/foo/2012/03/31/00, inputFormat:com.twitter.elephantbird.mapred.input.HiveMultiInputFormat, outputFormat:org.apache.hadoop.hive.ql.io.HiveIgnoreKeyTextOutputFormat, compressed:false, numBuckets:-1, serdeInfo:SerDeInfo(name:null, serializationLib:com.twitter.elephantbird.hive.serde.ThriftSerDe, parameters:{serialization.class=com.twitter.elephantbird.examples.thrift.Person, serialization.format
 =1}), bucketCols:[], sortCols:[], parameters:{}, primaryRegionName:, secondaryRegions:[]), parameters:{transient_lastDdlTime=1334257504})
  Time taken: 0.133 seconds
  hive>

TEST PLAN
  empty

REVISION DETAIL
  https://reviews.facebook.net/D2769

AFFECTED FILES
  ql/src/java/org/apache/hadoop/hive/ql/exec/DDLTask.java

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> Hive should store the full table schema in partition storage descriptors
> ------------------------------------------------------------------------
>
>                 Key: HIVE-2950
>                 URL: https://issues.apache.org/jira/browse/HIVE-2950
>             Project: Hive
>          Issue Type: Bug
>            Reporter: Travis Crawford
>            Assignee: Travis Crawford
>         Attachments: HIVE-2950.D2769.1.patch
>
>
> Hive tables have a schema, which is copied into the partition storage descriptor when adding a partition. Currently only columns stored in the table storage descriptor are copied - columns that are reported by the serde are not copied. Instead of copying the table storage descriptor columns into the partition columns, the full table schema should be copied.
> DETAILS
> This is a little long but is necessary to show 3 things: current behavior when explicitly listing columns, behavior with HIVE-2941 patched in and serde reported columns, and finally the behavior with this patch (full table schema copied into the partition storage descriptor).
> Here's an example of what currently happens. Note the following:
> * the two manually-defined fields defined for the table are listed in the table storage descriptor.
> * both fields are present in the partition storage descriptor
> This works great because users who query for a partition can look at its storage descriptor and get the schema.
> {code}
> hive> create external table foo_test (name string, age int) partitioned by (part_dt string);
> hive> describe extended foo_test;
> OK
> name	string	
> age	int	
> part_dt	string	
> 	 	 
> Detailed Table Information	Table(tableName:foo_test, dbName:travis_test, owner:travis, createTime:1334256062, lastAccessTime:0, retention:0, sd:StorageDescriptor(cols:[FieldSchema(name:name, type:string, comment:null), FieldSchema(name:age, type:int, comment:null), FieldSchema(name:part_dt, type:string, comment:null)], location:hdfs://foo.com/warehouse/travis_test.db/foo_test, inputFormat:org.apache.hadoop.mapred.TextInputFormat, outputFormat:org.apache.hadoop.hive.ql.io.HiveIgnoreKeyTextOutputFormat, compressed:false, numBuckets:-1, serdeInfo:SerDeInfo(name:null, serializationLib:org.apache.hadoop.hive.serde2.lazy.LazySimpleSerDe, parameters:{serialization.format=1}), bucketCols:[], sortCols:[], parameters:{}, primaryRegionName:, secondaryRegions:[]), partitionKeys:[FieldSchema(name:part_dt, type:string, comment:null)], parameters:{EXTERNAL=TRUE, transient_lastDdlTime=1334256062}, viewOriginalText:null, viewExpandedText:null, tableType:EXTERNAL_TABLE)	
> Time taken: 0.082 seconds
> hive> alter table foo_test add partition (part_dt = '20120331T000000Z') location 'hdfs://foo.com/foo/2012/03/31/00';
> hive> describe extended foo_test partition (part_dt = '20120331T000000Z');
> OK
> name	string	
> age	int	
> part_dt	string	
> 	 	 
> Detailed Partition Information	Partition(values:[20120331T000000Z], dbName:travis_test, tableName:foo_test, createTime:1334256131, lastAccessTime:0, sd:StorageDescriptor(cols:[FieldSchema(name:name, type:string, comment:null), FieldSchema(name:age, type:int, comment:null), FieldSchema(name:part_dt, type:string, comment:null)], location:hdfs://foo.com/foo/2012/03/31/00, inputFormat:org.apache.hadoop.mapred.TextInputFormat, outputFormat:org.apache.hadoop.hive.ql.io.HiveIgnoreKeyTextOutputFormat, compressed:false, numBuckets:-1, serdeInfo:SerDeInfo(name:null, serializationLib:org.apache.hadoop.hive.serde2.lazy.LazySimpleSerDe, parameters:{serialization.format=1}), bucketCols:[], sortCols:[], parameters:{}, primaryRegionName:, secondaryRegions:[]), parameters:{transient_lastDdlTime=1334256131})	
> {code}
> CURRENT BEHAVIOR WITH HIVE-2941 PATCHED IN
> Now let's examine what happens when creating a table when the serde reports the schema. Notice the following:
> * The table storage descriptor contains an empty list of columns. However, the table schema is available from the serde reflecting on the serialization class.
> * The partition storage descriptor does contain a single "part_dt" column that was copied from the table partition keys. The actual data columns are not present.
> {code}
> hive> create external table travis_test.person_test partitioned by (part_dt string) row format serde "com.twitter.elephantbird.hive.serde.ThriftSerDe" with serdeproperties ("serialization.class"="com.twitter.elephantbird.examples.thrift.Person") stored as inputformat "com.twitter.elephantbird.mapred.input.HiveMultiInputFormat" outputformat "org.apache.hadoop.hive.ql.io.HiveIgnoreKeyTextOutputFormat";
> OK
> Time taken: 0.08 seconds
> hive> describe extended person_test;
> OK
> name	struct<first_name:string,last_name:string>	from deserializer
> id	int	from deserializer
> email	string	from deserializer
> phones	array<struct<number:string,type:struct<value:int>>>	from deserializer
> part_dt	string	
> 	 	 
> Detailed Table Information	Table(tableName:person_test, dbName:travis_test, owner:travis, createTime:1334256942, lastAccessTime:0, retention:0, sd:StorageDescriptor(cols:[], location:hdfs://foo.com/warehouse/travis_test.db/person_test, inputFormat:com.twitter.elephantbird.mapred.input.HiveMultiInputFormat, outputFormat:org.apache.hadoop.hive.ql.io.HiveIgnoreKeyTextOutputFormat, compressed:false, numBuckets:-1, serdeInfo:SerDeInfo(name:null, serializationLib:com.twitter.elephantbird.hive.serde.ThriftSerDe, parameters:{serialization.class=com.twitter.elephantbird.examples.thrift.Person, serialization.format=1}), bucketCols:[], sortCols:[], parameters:{}, primaryRegionName:, secondaryRegions:[]), partitionKeys:[FieldSchema(name:part_dt, type:string, comment:null)], parameters:{EXTERNAL=TRUE, transient_lastDdlTime=1334256942}, viewOriginalText:null, viewExpandedText:null, tableType:EXTERNAL_TABLE)	
> Time taken: 0.147 seconds
> hive> alter table person_test add partition (part_dt = '20120331T000000Z') location 'hdfs://foo.com/foo/2012/03/31/00'; 
> OK
> Time taken: 0.149 seconds
> hive> describe extended person_test partition (part_dt = '20120331T000000Z');
> OK
> part_dt	string	
> 	 	 
> Detailed Partition Information	Partition(values:[20120331T000000Z], dbName:travis_test, tableName:person_test, createTime:1334257029, lastAccessTime:0, sd:StorageDescriptor(cols:[FieldSchema(name:part_dt, type:string, comment:null)], location:hdfs://foo.com/foo/2012/03/31/00, inputFormat:com.twitter.elephantbird.mapred.input.HiveMultiInputFormat, outputFormat:org.apache.hadoop.hive.ql.io.HiveIgnoreKeyTextOutputFormat, compressed:false, numBuckets:-1, serdeInfo:SerDeInfo(name:null, serializationLib:com.twitter.elephantbird.hive.serde.ThriftSerDe, parameters:{serialization.class=com.twitter.elephantbird.examples.thrift.Person, serialization.format=1}), bucketCols:[], sortCols:[], parameters:{}, primaryRegionName:, secondaryRegions:[]), parameters:{transient_lastDdlTime=1334257029})	
> Time taken: 0.106 seconds
> hive> 
> {code}
> PROPOSED BEHAVIOR
> I believe the correct thing to do is copy the full table schema (serde-reported columns + partition keys) into the partition storage descriptor. Notice the following:
> * Table storage descriptor does not contain any columns, because they are reported by the serde.
> * Partition storage descriptor now contains both the serde-reported schema, and full table schema.
> {code}
> hive> create external table travis_test.person_test partitioned by (part_dt string) row format serde "com.twitter.elephantbird.hive.serde.ThriftSerDe" with serdeproperties ("serialization.class"="com.twitter.elephantbird.examples.thrift.Person") stored as inputformat "com.twitter.elephantbird.mapred.input.HiveMultiInputFormat" outputformat "org.apache.hadoop.hive.ql.io.HiveIgnoreKeyTextOutputFormat";
> OK
> Time taken: 0.076 seconds
> hive> describe extended person_test;                                                                                                                                     OK                                                                                                                                                                       name    struct<first_name:string,last_name:string>      from deserializer
> id	int	from deserializer
> email	string	from deserializer
> phones	array<struct<number:string,type:struct<value:int>>>	from deserializer
> part_dt	string	
> 	 	 
> Detailed Table Information	Table(tableName:person_test, dbName:travis_test, owner:travis, createTime:1334257489, lastAccessTime:0, retention:0, sd:StorageDescriptor(cols:[], location:hdfs://foo.com/warehouse/travis_test.db/person_test, inputFormat:com.twitter.elephantbird.mapred.input.HiveMultiInputFormat, outputFormat:org.apache.hadoop.hive.ql.io.HiveIgnoreKeyTextOutputFormat, compressed:false, numBuckets:-1, serdeInfo:SerDeInfo(name:null, serializationLib:com.twitter.elephantbird.hive.serde.ThriftSerDe, parameters:{serialization.class=com.twitter.elephantbird.examples.thrift.Person, serialization.format=1}), bucketCols:[], sortCols:[], parameters:{}, primaryRegionName:, secondaryRegions:[]), partitionKeys:[FieldSchema(name:part_dt, type:string, comment:null)], parameters:{EXTERNAL=TRUE, transient_lastDdlTime=1334257489}, viewOriginalText:null, viewExpandedText:null, tableType:EXTERNAL_TABLE)	
> Time taken: 0.155 seconds
> hive> alter table person_test add partition (part_dt = '20120331T000000Z') location 'hdfs://foo.com/foo/2012/03/31/00';
> OK                                                                                                                                                                       Time taken: 0.296 seconds                                        
> hive> describe extended person_test partition (part_dt = '20120331T000000Z');                                                                                            OK                                                                                                                                                                       name    struct<first_name:string,last_name:string>      from deserializer
> id	int	from deserializer
> email	string	from deserializer
> phones	array<struct<number:string,type:struct<value:int>>>	from deserializer
> part_dt	string	
> 	 	 
> Detailed Partition Information	Partition(values:[20120331T000000Z], dbName:travis_test, tableName:person_test, createTime:1334257504, lastAccessTime:0, sd:StorageDescriptor(cols:[FieldSchema(name:name, type:struct<first_name:string,last_name:string>, comment:from deserializer), FieldSchema(name:id, type:int, comment:from deserializer), FieldSchema(name:email, type:string, comment:from deserializer), FieldSchema(name:phones, type:array<struct<number:string,type:struct<value:int>>>, comment:from deserializer), FieldSchema(name:part_dt, type:string, comment:null)], location:hdfs://foo.com/foo/2012/03/31/00, inputFormat:com.twitter.elephantbird.mapred.input.HiveMultiInputFormat, outputFormat:org.apache.hadoop.hive.ql.io.HiveIgnoreKeyTextOutputFormat, compressed:false, numBuckets:-1, serdeInfo:SerDeInfo(name:null, serializationLib:com.twitter.elephantbird.hive.serde.ThriftSerDe, parameters:{serialization.class=com.twitter.elephantbird.examples.thrift.Person, serialization.format=1}), bucketCols:[], sortCols:[], parameters:{}, primaryRegionName:, secondaryRegions:[]), parameters:{transient_lastDdlTime=1334257504})	
> Time taken: 0.133 seconds
> hive> 
> {code}

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