jiangxingbo 01e14bf303 [SPARK-17910][SQL] Allow users to update the comment of a column ... ## What changes were proposed in this pull request? Right now, once a user set the comment of a column with create table command, he/she cannot update the comment. It will be useful to provide a public interface (e.g. SQL) to do that. This PR implements the following SQL statement: ``` ALTER TABLE table [PARTITION partition_spec] CHANGE [COLUMN] column_old_name column_new_name column_dataType [COMMENT column_comment] [FIRST | AFTER column_name]; ``` For further expansion, we could support alter `name`/`dataType`/`index` of a column too. ## How was this patch tested? Add new test cases in `ExternalCatalogSuite` and `SessionCatalogSuite`. Add sql file test for `ALTER TABLE CHANGE COLUMN` statement. Author: jiangxingbo <jiangxb1987@gmail.com> Closes #15717 from jiangxb1987/change-column.		2016-12-15 10:09:42 -08:00
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benchmarks	[SPARK-17335][SQL] Fix ArrayType and MapType CatalogString.	2016-09-03 19:02:20 +02:00
src	[SPARK-17910][SQL] Allow users to update the comment of a column	2016-12-15 10:09:42 -08:00
pom.xml	[SPARK-18695] Bump master branch version to 2.2.0-SNAPSHOT	2016-12-02 21:09:37 -08:00