From 5ff17aee94575b08c59dc149891b334560f718da Mon Sep 17 00:00:00 2001
From: Pavithra Ramachandran <pavi.rams@gmail.com>
Date: Tue, 17 Dec 2019 10:44:33 +0530
Subject: [PATCH] the column statistics received from hive is compared in a
 case sensitive manner.Converting the column name which is the key to lower
 case and searching using lower case whatever may be the input value.

---
 .../spark/sql/execution/command/tables.scala  |  5 +-
 .../inputs/describe-table-column.sql          | 13 +++++
 .../results/describe-table-column.sql.out     | 51 ++++++++++++++++++-
 3 files changed, 66 insertions(+), 3 deletions(-)

diff --git a/sql/core/src/main/scala/org/apache/spark/sql/execution/command/tables.scala b/sql/core/src/main/scala/org/apache/spark/sql/execution/command/tables.scala
index 71500c304bd48..8dc07b7b3ce6b 100644
--- a/sql/core/src/main/scala/org/apache/spark/sql/execution/command/tables.scala
+++ b/sql/core/src/main/scala/org/apache/spark/sql/execution/command/tables.scala
@@ -34,7 +34,7 @@ import org.apache.spark.sql.catalyst.catalog.CatalogTypes.TablePartitionSpec
 import org.apache.spark.sql.catalyst.expressions.{Attribute, AttributeReference}
 import org.apache.spark.sql.catalyst.plans.DescribeTableSchema
 import org.apache.spark.sql.catalyst.plans.logical._
-import org.apache.spark.sql.catalyst.util.{escapeSingleQuotedString, quoteIdentifier}
+import org.apache.spark.sql.catalyst.util.{escapeSingleQuotedString, quoteIdentifier, CaseInsensitiveMap}
 import org.apache.spark.sql.execution.datasources.{DataSource, PartitioningUtils}
 import org.apache.spark.sql.execution.datasources.csv.CSVFileFormat
 import org.apache.spark.sql.execution.datasources.json.JsonFileFormat
@@ -720,7 +720,8 @@ case class DescribeColumnCommand(
     }
 
     val catalogTable = catalog.getTempViewOrPermanentTableMetadata(table)
-    val colStats = catalogTable.stats.map(_.colStats).getOrElse(Map.empty)
+    val colStatsMap = catalogTable.stats.map(_.colStats).getOrElse(Map.empty)
+    val colStats = if (conf.caseSensitiveAnalysis) colStatsMap else CaseInsensitiveMap(colStatsMap)
     val cs = colStats.get(field.name)
 
     val comment = if (field.metadata.contains("comment")) {
diff --git a/sql/core/src/test/resources/sql-tests/inputs/describe-table-column.sql b/sql/core/src/test/resources/sql-tests/inputs/describe-table-column.sql
index 2d180d118da7a..821cb473751eb 100644
--- a/sql/core/src/test/resources/sql-tests/inputs/describe-table-column.sql
+++ b/sql/core/src/test/resources/sql-tests/inputs/describe-table-column.sql
@@ -49,3 +49,16 @@ DROP VIEW desc_col_temp_view;
 DROP TABLE desc_col_table;
 
 DROP TABLE desc_complex_col_table;
+
+--Test case insensitive
+
+CREATE TABLE customer(CName STRING);
+
+INSERT INTO customer VALUES('Maria');
+
+ANALYZE TABLE customer COMPUTE STATISTICS FOR COLUMNS cname;
+
+DESC EXTENDED customer cname;
+
+DROP TABLE customer;
+
diff --git a/sql/core/src/test/resources/sql-tests/results/describe-table-column.sql.out b/sql/core/src/test/resources/sql-tests/results/describe-table-column.sql.out
index 6ef8af6574e98..a5471c0f1c8ec 100644
--- a/sql/core/src/test/resources/sql-tests/results/describe-table-column.sql.out
+++ b/sql/core/src/test/resources/sql-tests/results/describe-table-column.sql.out
@@ -1,5 +1,5 @@
 -- Automatically generated by SQLQueryTestSuite
--- Number of queries: 23
+-- Number of queries: 28
 
 
 -- !query 0
@@ -264,3 +264,52 @@ DROP TABLE desc_complex_col_table
 struct<>
 -- !query 22 output
 
+
+
+-- !query 23
+CREATE TABLE customer(CName STRING)
+-- !query 23 schema
+struct<>
+-- !query 23 output
+
+
+
+-- !query 24
+INSERT INTO customer VALUES('Maria')
+-- !query 24 schema
+struct<>
+-- !query 24 output
+
+
+
+-- !query 25
+ANALYZE TABLE customer COMPUTE STATISTICS FOR COLUMNS cname
+-- !query 25 schema
+struct<>
+-- !query 25 output
+
+
+
+-- !query 26
+DESC EXTENDED customer cname
+-- !query 26 schema
+struct<info_name:string,info_value:string>
+-- !query 26 output
+col_name	cname
+data_type	string
+comment	NULL
+min	NULL
+max	NULL
+num_nulls	0
+distinct_count	1
+avg_col_len	5
+max_col_len	5
+histogram	NULL
+
+
+-- !query 27
+DROP TABLE customer
+-- !query 27 schema
+struct<>
+-- !query 27 output
+