Dilip Biswal 4a486d6716 [SPARK-26982][SQL] Enhance describe framework to describe the output of a query. ... ## What changes were proposed in this pull request? Currently we can use `df.printSchema` to discover the schema information for a query. We should have a way to describe the output schema of a query using SQL interface. Example: DESCRIBE SELECT * FROM desc_table DESCRIBE QUERY SELECT * FROM desc_table ```SQL spark-sql> create table desc_table (c1 int comment 'c1-comment', c2 decimal comment 'c2-comment', c3 string); spark-sql> desc select * from desc_table; c1 int c1-comment c2 decimal(10,0) c2-comment c3 string NULL ``` ## How was this patch tested? Added a new test under SQLQueryTestSuite and SparkSqlParserSuite Closes #23883 from dilipbiswal/dkb_describe_query. Authored-by: Dilip Biswal <dbiswal@us.ibm.com> Signed-off-by: Wenchen Fan <wenchen@databricks.com>		2019-03-02 11:21:23 +08:00
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benchmarks	[SPARK-26584][SQL] Remove spark.sql.orc.copyBatchToSpark internal conf	2019-01-10 08:42:23 -08:00
compatibility/src/test/scala/org/apache/spark/sql/hive/execution	Revert [SPARK-19355][SPARK-25352]	2018-09-20 20:18:31 +08:00
src	[SPARK-26982][SQL] Enhance describe framework to describe the output of a query.	2019-03-02 11:21:23 +08:00
pom.xml	[SPARK-26306][TEST][BUILD] More memory to de-flake SorterSuite	2019-01-04 15:35:23 -06:00