[HIVE-10206] Improve Alter Table to not initialize Serde unnecessarily

• Type: Improvement
• Status: Closed
• Priority: Minor
• Resolution: Fixed
• Affects Version/s: 1.1.0
• Fix Version/s: 1.2.0
• Component/s: Serializers/Deserializers
• Assignee: Szehon Ho
• Reporter: Szehon Ho
• Created: 02/Apr/15 23:43
• Updated: 18/May/15 19:50
• Resolved: 09/Apr/15 19:15

Description

Create an avro table with an external avsc file like:

CREATE  TABLE test(...)
ROW FORMAT SERDE 
  'org.apache.hadoop.hive.serde2.avro.AvroSerDe' 
STORED AS INPUTFORMAT 
  'org.apache.hadoop.hive.ql.io.avro.AvroContainerInputFormat' 
OUTPUTFORMAT 
  'org.apache.hadoop.hive.ql.io.avro.AvroContainerOutputFormat'
TBLPROPERTIES (
  'avro.schema.url'='file:///Users/szehon/Temp/test.avsc', 
  'kite.compression.type'='snappy', 
  'transient_lastDdlTime'='1427996456')

Delete test.avsc file.

Try to modify the table properties:

alter table test set tblproperties ('avro.schema.url'='file:///Users/szehon/Temp/test2.avsc');

Will throw an exception like AvroSerdeException:

  at org.apache.hadoop.hive.serde2.avro.AvroSerdeUtils.determineSchemaOrThrowException(AvroSerdeUtils.java:119)
	  at org.apache.hadoop.hive.serde2.avro.AvroSerDe.determineSchemaOrReturnErrorSchema(AvroSerDe.java:163)
	  at org.apache.hadoop.hive.serde2.avro.AvroSerDe.initialize(AvroSerDe.java:101)
	  at org.apache.hadoop.hive.serde2.avro.AvroSerDe.initialize(AvroSerDe.java:78)
	  at org.apache.hadoop.hive.serde2.SerDeUtils.initializeSerDe(SerDeUtils.java:520)
	  at org.apache.hadoop.hive.metastore.MetaStoreUtils.getDeserializer(MetaStoreUtils.java:377)
	  at org.apache.hadoop.hive.ql.metadata.Table.getDeserializerFromMetaStore(Table.java:274)
	  at org.apache.hadoop.hive.ql.metadata.Table.getDeserializer(Table.java:256)
	  at org.apache.hadoop.hive.ql.metadata.Table.getCols(Table.java:595)
	  at org.apache.hadoop.hive.ql.exec.DDLTask.alterTableOrSinglePartition(DDLTask.java:3383)
	  at org.apache.hadoop.hive.ql.exec.DDLTask.alterTable(DDLTask.java:3340)
	  at org.apache.hadoop.hive.ql.exec.DDLTask.execute(DDLTask.java:332)
	  at org.apache.hadoop.hive.ql.exec.Task.executeTask(Task.java:160)
	  at org.apache.hadoop.hive.ql.exec.TaskRunner.runSequential(TaskRunner.java:88)
	  at org.apache.hadoop.hive.ql.Driver.launchTask(Driver.java:1638)
	  at org.apache.hadoop.hive.ql.Driver.execute(Driver.java:1397)
	  at org.apache.hadoop.hive.ql.Driver.runInternal(Driver.java:1181)
	  at org.apache.hadoop.hive.ql.Driver.run(Driver.java:1047)
	  at org.apache.hadoop.hive.ql.Driver.run(Driver.java:1037)
	  at org.apache.hadoop.hive.cli.CliDriver.processLocalCmd(CliDriver.java:207)
	  at org.apache.hadoop.hive.cli.CliDriver.processCmd(CliDriver.java:159)
	  at org.apache.hadoop.hive.cli.CliDriver.processLine(CliDriver.java:370)
	  at org.apache.hadoop.hive.cli.CliDriver.executeDriver(CliDriver.java:754)
	  at org.apache.hadoop.hive.cli.CliDriver.run(CliDriver.java:675)
	  at org.apache.hadoop.hive.cli.CliDriver.main(CliDriver.java:615)
	  at sun.reflect.NativeMethodAccessorImpl.invoke0(NativeMethodAccessorImpl.java:-1)
	  at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57)
	  at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
	  at java.lang.reflect.Method.invoke(Method.java:606)
	  at org.apache.hadoop.util.RunJar.run(RunJar.java:221)
	  at org.apache.hadoop.util.RunJar.main(RunJar.java:136)