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https://issues.apache.org/jira/browse/HIVE-15995?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=15942022#comment-15942022
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Pengcheng Xiong commented on HIVE-15995:
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Hello, I am deferring this to Hive 3.0 as we are going to cut the first RC and
it is not marked as blocker. Please feel free to commit to the branch if this
can be resolved before the release.
> Syncing metastore table with serde schema
> -----------------------------------------
>
> Key: HIVE-15995
> URL: https://issues.apache.org/jira/browse/HIVE-15995
> Project: Hive
> Issue Type: Bug
> Components: Metastore
> Affects Versions: 1.2.1, 2.1.0
> Reporter: Michal Ferlinski
> Assignee: Michal Ferlinski
> Fix For: 2.1.0
>
> Attachments: cx1.avsc, cx2.avsc, HIVE-15995.patch
>
>
> Hive enables table schema evolution via properties. For avro e.g. we can
> alter the 'avro.schema.url' property to update table schema to the next
> version. Updating properties however doesn't affect column list stored in
> metastore DB so the table is not in the newest version when returned from
> metastore API. This is problem for tools working with metastore (e.g. Presto).
> To solve this issue I suggest to introduce new DDL statement syncing
> metastore columns with those from serde:
> {code}
> ALTER TABLE user_test1 UPDATE COLUMNS
> {code}
> Note that this is format independent solution.
> To reproduce, follow the instructions below:
> - Create table based on avro schema version 1 (cxv1.avsc)
> {code}
> CREATE EXTERNAL TABLE user_test1
> PARTITIONED BY (dt string)
> 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'
> LOCATION
> '/tmp/schema-evolution/user_test1'
> TBLPROPERTIES ('avro.schema.url'='/tmp/schema-evolution/cx1.avsc');
> {code}
> - Update schema to version 2 (cx2.avsc)
> {code}
> ALTER TABLE user_test1 SET TBLPROPERTIES ('avro.schema.url' =
> '/tmp/schema-evolution/cx2.avsc');
> {code}
> - Print serde columns (top info) and metastore columns (Detailed Table
> Information):
> {code}
> DESCRIBE EXTENDED user_test1
> {code}
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