MDEV-307 Add functionality for database comments

This commit adds a new feature to the server to add comments at the database
level. 1024 bytes is the maximum comment length allowed. If the comment length
exceeds this limit, a new error/warning code 4144 is thrown, based on whether
thd->is_strict_mode() is true/false. The database comment is also added to the
db.opt file, as well as to the information_schema.schemata table.

6 files changed, 176 insertions, 30 deletions

diff --git a/mysql-test/main/comment_database.result b/mysql-test/main/comment_database.result
new file mode 100644
index 00000000000..02dd24574db
--- /dev/null
+++ b/mysql-test/main/comment_database.result
@@ -0,0 +1,78 @@
+#
+# MDEV-307: Add functionality for database comments
+#
+CREATE DATABASE db1 COMMENT=;
+ERROR 42000: You have an error in your SQL syntax; check the manual that corresponds to your MariaDB server version for the right syntax to use near '' at line 1
+CREATE DATABASE db1
+COMMENT='abcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcd';
+SHOW CREATE DATABASE db1;
+Database	Create Database
+db1	CREATE DATABASE `db1` /*!40100 DEFAULT CHARACTER SET latin1 */ COMMENT 'abcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcd'
+SELECT schema_comment, char_length(schema_comment)
+FROM information_schema.schemata
+WHERE schema_name='db1';
+schema_comment	char_length(schema_comment)
+abcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcd	1024
+DROP DATABASE db1;
+SET SQL_MODE='';
+CREATE DATABASE db1
+COMMENT='abcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcde';
+Warnings:
+Warning	4144	Comment for database 'db1' is too long (max = 1024)
+SHOW CREATE DATABASE db1;
+Database	Create Database
+db1	CREATE DATABASE `db1` /*!40100 DEFAULT CHARACTER SET latin1 */ COMMENT 'abcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcd'
+SELECT schema_comment, char_length(schema_comment)
+FROM information_schema.schemata
+WHERE schema_name='db1';
+schema_comment	char_length(schema_comment)
+abcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcd	1024
+DROP DATABASE db1;
+SET SQL_MODE='TRADITIONAL';
+CREATE DATABASE db1
+COMMENT='abcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcde';
+ERROR HY000: Comment for database 'db1' is too long (max = 1024)
+SELECT schema_comment, char_length(schema_comment)
+FROM information_schema.schemata
+WHERE schema_name='db1';
+schema_comment	char_length(schema_comment)
+CREATE DATABASE db1 COMMENT 'db1';
+SHOW CREATE DATABASE db1;
+Database	Create Database
+db1	CREATE DATABASE `db1` /*!40100 DEFAULT CHARACTER SET latin1 */ COMMENT 'db1'
+ALTER DATABASE db1 COMMENT = "db1 comment";
+SELECT * FROM information_schema.schemata
+WHERE schema_name='db1';
+CATALOG_NAME	SCHEMA_NAME	DEFAULT_CHARACTER_SET_NAME	DEFAULT_COLLATION_NAME	SQL_PATH	SCHEMA_COMMENT
+def	db1	latin1	latin1_swedish_ci	NULL	db1 comment
+DROP DATABASE db1;
+CREATE DATABASE db1;
+USE db1;
+ALTER DATABASE COMMENT 'db1 comment' CHARACTER SET 'utf8';
+SHOW CREATE DATABASE db1;
+Database	Create Database
+db1	CREATE DATABASE `db1` /*!40100 DEFAULT CHARACTER SET utf8 */ COMMENT 'db1 comment'
+ALTER DATABASE db1 COMMENT 'this is db1 comment';
+SHOW CREATE DATABASE db1;
+Database	Create Database
+db1	CREATE DATABASE `db1` /*!40100 DEFAULT CHARACTER SET utf8 */ COMMENT 'this is db1 comment'
+ALTER DATABASE CHARACTER SET 'latin1';
+SHOW CREATE DATABASE db1;
+Database	Create Database
+db1	CREATE DATABASE `db1` /*!40100 DEFAULT CHARACTER SET latin1 */ COMMENT 'this is db1 comment'
+DROP DATABASE db1;
+CREATE DATABASE comment COMMENT 'comment' CHARACTER SET 'latin2';
+SHOW CREATE DATABASE comment;
+Database	Create Database
+comment	CREATE DATABASE `comment` /*!40100 DEFAULT CHARACTER SET latin2 */ COMMENT 'comment'
+ALTER DATABASE comment COMMENT 'comment comment';
+SHOW CREATE DATABASE comment;
+Database	Create Database
+comment	CREATE DATABASE `comment` /*!40100 DEFAULT CHARACTER SET latin2 */ COMMENT 'comment comment'
+USE comment;
+ALTER DATABASE COMMENT 'comment';
+SELECT * FROM information_schema.schemata
+WHERE schema_name='comment';
+CATALOG_NAME	SCHEMA_NAME	DEFAULT_CHARACTER_SET_NAME	DEFAULT_COLLATION_NAME	SQL_PATH	SCHEMA_COMMENT
+def	comment	latin2	latin2_general_ci	NULL	comment
+DROP DATABASE comment;
diff --git a/mysql-test/main/comment_database.test b/mysql-test/main/comment_database.test
new file mode 100644
index 00000000000..3fe1c7b205c
--- /dev/null
+++ b/mysql-test/main/comment_database.test
@@ -0,0 +1,63 @@
+--echo #
+--echo # MDEV-307: Add functionality for database comments
+--echo #
+
+# Check an error state
+--error ER_PARSE_ERROR
+CREATE DATABASE db1 COMMENT=;
+
+# 1024 bytes
+CREATE DATABASE db1
+COMMENT='abcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcd';
+SHOW CREATE DATABASE db1;
+SELECT schema_comment, char_length(schema_comment)
+FROM information_schema.schemata
+WHERE schema_name='db1';
+DROP DATABASE db1;
+
+# 1025 bytes (warning)
+SET SQL_MODE='';
+CREATE DATABASE db1
+COMMENT='abcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcde';
+SHOW CREATE DATABASE db1;
+SELECT schema_comment, char_length(schema_comment)
+FROM information_schema.schemata
+WHERE schema_name='db1';
+DROP DATABASE db1;
+SET SQL_MODE='TRADITIONAL';
+
+# 1025 bytes (error)
+--error ER_TOO_LONG_DATABASE_COMMENT
+CREATE DATABASE db1
+COMMENT='abcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcde';
+SELECT schema_comment, char_length(schema_comment)
+FROM information_schema.schemata
+WHERE schema_name='db1';
+
+CREATE DATABASE db1 COMMENT 'db1';
+SHOW CREATE DATABASE db1;
+ALTER DATABASE db1 COMMENT = "db1 comment";
+SELECT * FROM information_schema.schemata
+WHERE schema_name='db1';
+DROP DATABASE db1;
+
+CREATE DATABASE db1;
+USE db1;
+ALTER DATABASE COMMENT 'db1 comment' CHARACTER SET 'utf8';
+SHOW CREATE DATABASE db1;
+ALTER DATABASE db1 COMMENT 'this is db1 comment';
+SHOW CREATE DATABASE db1;
+ALTER DATABASE CHARACTER SET 'latin1';
+SHOW CREATE DATABASE db1;
+DROP DATABASE db1;
+
+# Test the case when the database is named 'comment'
+CREATE DATABASE comment COMMENT 'comment' CHARACTER SET 'latin2';
+SHOW CREATE DATABASE comment;
+ALTER DATABASE comment COMMENT 'comment comment';
+SHOW CREATE DATABASE comment;
+USE comment;
+ALTER DATABASE COMMENT 'comment';
+SELECT * FROM information_schema.schemata
+WHERE schema_name='comment';
+DROP DATABASE comment;
diff --git a/mysql-test/main/information_schema.result b/mysql-test/main/information_schema.result
index b4d2d065d4a..9e9c92e31be 100644
--- a/mysql-test/main/information_schema.result
+++ b/mysql-test/main/information_schema.result
@@ -10,11 +10,11 @@ grant select, update on test.* to mysqltest_1@localhost;
 create user mysqltest_3@localhost;
 create user mysqltest_3;
 select * from information_schema.SCHEMATA where schema_name > 'm';
-CATALOG_NAME	SCHEMA_NAME	DEFAULT_CHARACTER_SET_NAME	DEFAULT_COLLATION_NAME	SQL_PATH
-def	mtr	latin1	latin1_swedish_ci	NULL
-def	mysql	latin1	latin1_swedish_ci	NULL
-def	performance_schema	utf8	utf8_general_ci	NULL
-def	test	latin1	latin1_swedish_ci	NULL
+CATALOG_NAME	SCHEMA_NAME	DEFAULT_CHARACTER_SET_NAME	DEFAULT_COLLATION_NAME	SQL_PATH	SCHEMA_COMMENT
+def	mtr	latin1	latin1_swedish_ci	NULL	
+def	mysql	latin1	latin1_swedish_ci	NULL	
+def	performance_schema	utf8	utf8_general_ci	NULL	
+def	test	latin1	latin1_swedish_ci	NULL	
 select schema_name from information_schema.schemata;
 schema_name
 information_schema
@@ -1575,14 +1575,14 @@ id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	SIMPLE	b	ALL	NULL	NULL	NULL	NULL	NULL	Using where; Open_frm_only; Scanned all databases; Using join buffer (flat, BNL join)
 SELECT * FROM INFORMATION_SCHEMA.SCHEMATA
 WHERE SCHEMA_NAME = 'mysqltest';
-CATALOG_NAME	SCHEMA_NAME	DEFAULT_CHARACTER_SET_NAME	DEFAULT_COLLATION_NAME	SQL_PATH
+CATALOG_NAME	SCHEMA_NAME	DEFAULT_CHARACTER_SET_NAME	DEFAULT_COLLATION_NAME	SQL_PATH	SCHEMA_COMMENT
 SELECT * FROM INFORMATION_SCHEMA.SCHEMATA
 WHERE SCHEMA_NAME = '';
-CATALOG_NAME	SCHEMA_NAME	DEFAULT_CHARACTER_SET_NAME	DEFAULT_COLLATION_NAME	SQL_PATH
+CATALOG_NAME	SCHEMA_NAME	DEFAULT_CHARACTER_SET_NAME	DEFAULT_COLLATION_NAME	SQL_PATH	SCHEMA_COMMENT
 SELECT * FROM INFORMATION_SCHEMA.SCHEMATA
 WHERE SCHEMA_NAME = 'test';
-CATALOG_NAME	SCHEMA_NAME	DEFAULT_CHARACTER_SET_NAME	DEFAULT_COLLATION_NAME	SQL_PATH
-def	test	latin1	latin1_swedish_ci	NULL
+CATALOG_NAME	SCHEMA_NAME	DEFAULT_CHARACTER_SET_NAME	DEFAULT_COLLATION_NAME	SQL_PATH	SCHEMA_COMMENT
+def	test	latin1	latin1_swedish_ci	NULL	
 select count(*) from INFORMATION_SCHEMA.TABLES where TABLE_SCHEMA='mysql' AND TABLE_NAME='nonexisting';
 count(*)
 0
@@ -1627,7 +1627,7 @@ CONSTRAINT_CATALOG	CONSTRAINT_SCHEMA	CONSTRAINT_NAME	UNIQUE_CONSTRAINT_CATALOG	U
 select * from `information_schema`.`REFERENTIAL_CONSTRAINTS` where `TABLE_NAME` = NULL;
 CONSTRAINT_CATALOG	CONSTRAINT_SCHEMA	CONSTRAINT_NAME	UNIQUE_CONSTRAINT_CATALOG	UNIQUE_CONSTRAINT_SCHEMA	UNIQUE_CONSTRAINT_NAME	MATCH_OPTION	UPDATE_RULE	DELETE_RULE	TABLE_NAME	REFERENCED_TABLE_NAME
 select * from information_schema.schemata where schema_name = NULL;
-CATALOG_NAME	SCHEMA_NAME	DEFAULT_CHARACTER_SET_NAME	DEFAULT_COLLATION_NAME	SQL_PATH
+CATALOG_NAME	SCHEMA_NAME	DEFAULT_CHARACTER_SET_NAME	DEFAULT_COLLATION_NAME	SQL_PATH	SCHEMA_COMMENT
 select * from `information_schema`.`STATISTICS` where `TABLE_SCHEMA` = NULL;
 TABLE_CATALOG	TABLE_SCHEMA	TABLE_NAME	NON_UNIQUE	INDEX_SCHEMA	INDEX_NAME	SEQ_IN_INDEX	COLUMN_NAME	COLLATION	CARDINALITY	SUB_PART	PACKED	NULLABLE	INDEX_TYPE	COMMENT	INDEX_COMMENT
 select * from `information_schema`.`STATISTICS` where `TABLE_NAME` = NULL;
diff --git a/mysql-test/suite/funcs_1/r/is_columns_is.result b/mysql-test/suite/funcs_1/r/is_columns_is.result
index 386b0f07f98..00f9f347067 100644
--- a/mysql-test/suite/funcs_1/r/is_columns_is.result
+++ b/mysql-test/suite/funcs_1/r/is_columns_is.result
@@ -326,6 +326,7 @@ def	information_schema	ROUTINES	SQL_PATH	22	NULL	YES	varchar	64	192	NULL	NULL	NU
 def	information_schema	SCHEMATA	CATALOG_NAME	1	''	NO	varchar	512	1536	NULL	NULL	NULL	utf8	utf8_general_ci	varchar(512)			select		NEVER	NULL
 def	information_schema	SCHEMATA	DEFAULT_CHARACTER_SET_NAME	3	''	NO	varchar	32	96	NULL	NULL	NULL	utf8	utf8_general_ci	varchar(32)			select		NEVER	NULL
 def	information_schema	SCHEMATA	DEFAULT_COLLATION_NAME	4	''	NO	varchar	32	96	NULL	NULL	NULL	utf8	utf8_general_ci	varchar(32)			select		NEVER	NULL
+def	information_schema	SCHEMATA	SCHEMA_COMMENT	6	''	NO	varchar	1024	3072	NULL	NULL	NULL	utf8	utf8_general_ci	varchar(1024)			select		NEVER	NULL
 def	information_schema	SCHEMATA	SCHEMA_NAME	2	''	NO	varchar	64	192	NULL	NULL	NULL	utf8	utf8_general_ci	varchar(64)			select		NEVER	NULL
 def	information_schema	SCHEMATA	SQL_PATH	5	NULL	YES	varchar	512	1536	NULL	NULL	NULL	utf8	utf8_general_ci	varchar(512)			select		NEVER	NULL
 def	information_schema	SCHEMA_PRIVILEGES	GRANTEE	1	''	NO	varchar	190	570	NULL	NULL	NULL	utf8	utf8_general_ci	varchar(190)			select		NEVER	NULL
@@ -870,6 +871,7 @@ NULL	information_schema	ROUTINES	LAST_ALTERED	datetime	NULL	NULL	NULL	NULL	datet
 3.0000	information_schema	SCHEMATA	DEFAULT_CHARACTER_SET_NAME	varchar	32	96	utf8	utf8_general_ci	varchar(32)
 3.0000	information_schema	SCHEMATA	DEFAULT_COLLATION_NAME	varchar	32	96	utf8	utf8_general_ci	varchar(32)
 3.0000	information_schema	SCHEMATA	SQL_PATH	varchar	512	1536	utf8	utf8_general_ci	varchar(512)
+3.0000	information_schema	SCHEMATA	SCHEMA_COMMENT	varchar	1024	3072	utf8	utf8_general_ci	varchar(1024)
 3.0000	information_schema	SCHEMA_PRIVILEGES	GRANTEE	varchar	190	570	utf8	utf8_general_ci	varchar(190)
 3.0000	information_schema	SCHEMA_PRIVILEGES	TABLE_CATALOG	varchar	512	1536	utf8	utf8_general_ci	varchar(512)
 3.0000	information_schema	SCHEMA_PRIVILEGES	TABLE_SCHEMA	varchar	64	192	utf8	utf8_general_ci	varchar(64)
diff --git a/mysql-test/suite/funcs_1/r/is_schemata.result b/mysql-test/suite/funcs_1/r/is_schemata.result
index 6db6ac8f150..18ee8d01147 100644
--- a/mysql-test/suite/funcs_1/r/is_schemata.result
+++ b/mysql-test/suite/funcs_1/r/is_schemata.result
@@ -33,6 +33,7 @@ SCHEMA_NAME	varchar(64)	NO
 DEFAULT_CHARACTER_SET_NAME	varchar(32)	NO			
 DEFAULT_COLLATION_NAME	varchar(32)	NO			
 SQL_PATH	varchar(512)	YES		NULL	
+SCHEMA_COMMENT	varchar(1024)	NO			
 SHOW CREATE TABLE information_schema.SCHEMATA;
 Table	Create Table
 SCHEMATA	CREATE TEMPORARY TABLE `SCHEMATA` (
@@ -40,7 +41,8 @@ SCHEMATA	CREATE TEMPORARY TABLE `SCHEMATA` (
   `SCHEMA_NAME` varchar(64) NOT NULL DEFAULT '',
   `DEFAULT_CHARACTER_SET_NAME` varchar(32) NOT NULL DEFAULT '',
   `DEFAULT_COLLATION_NAME` varchar(32) NOT NULL DEFAULT '',
-  `SQL_PATH` varchar(512) DEFAULT NULL
+  `SQL_PATH` varchar(512) DEFAULT NULL,
+  `SCHEMA_COMMENT` varchar(1024) NOT NULL DEFAULT ''
 ) ENGINE=MEMORY DEFAULT CHARSET=utf8
 SHOW COLUMNS FROM information_schema.SCHEMATA;
 Field	Type	Null	Key	Default	Extra
@@ -49,6 +51,7 @@ SCHEMA_NAME	varchar(64)	NO
 DEFAULT_CHARACTER_SET_NAME	varchar(32)	NO			
 DEFAULT_COLLATION_NAME	varchar(32)	NO			
 SQL_PATH	varchar(512)	YES		NULL	
+SCHEMA_COMMENT	varchar(1024)	NO			
 SELECT catalog_name, schema_name, sql_path
 FROM information_schema.schemata
 WHERE catalog_name IS NOT NULL or sql_path IS NOT NULL
@@ -77,9 +80,9 @@ GRANT SELECT ON db_datadict_1.* to 'testuser2'@'localhost';
 GRANT SELECT ON db_datadict_2.* to 'testuser2'@'localhost';
 SELECT * FROM information_schema.schemata
 WHERE schema_name LIKE 'db_datadict_%' ORDER BY schema_name;
-CATALOG_NAME	SCHEMA_NAME	DEFAULT_CHARACTER_SET_NAME	DEFAULT_COLLATION_NAME	SQL_PATH
-def	db_datadict_1	latin1	latin1_swedish_ci	NULL
-def	db_datadict_2	latin1	latin1_swedish_ci	NULL
+CATALOG_NAME	SCHEMA_NAME	DEFAULT_CHARACTER_SET_NAME	DEFAULT_COLLATION_NAME	SQL_PATH	SCHEMA_COMMENT
+def	db_datadict_1	latin1	latin1_swedish_ci	NULL	
+def	db_datadict_2	latin1	latin1_swedish_ci	NULL	
 SHOW DATABASES LIKE 'db_datadict_%';
 Database (db_datadict_%)
 db_datadict_1
@@ -87,17 +90,17 @@ db_datadict_2
 connect  testuser1, localhost, testuser1, , db_datadict_1;
 SELECT * FROM information_schema.schemata
 WHERE schema_name LIKE 'db_datadict_%' ORDER BY schema_name;
-CATALOG_NAME	SCHEMA_NAME	DEFAULT_CHARACTER_SET_NAME	DEFAULT_COLLATION_NAME	SQL_PATH
-def	db_datadict_1	latin1	latin1_swedish_ci	NULL
+CATALOG_NAME	SCHEMA_NAME	DEFAULT_CHARACTER_SET_NAME	DEFAULT_COLLATION_NAME	SQL_PATH	SCHEMA_COMMENT
+def	db_datadict_1	latin1	latin1_swedish_ci	NULL	
 SHOW DATABASES LIKE 'db_datadict_%';
 Database (db_datadict_%)
 db_datadict_1
 connect  testuser2, localhost, testuser2, , db_datadict_2;
 SELECT * FROM information_schema.schemata
 WHERE schema_name LIKE 'db_datadict_%' ORDER BY schema_name;
-CATALOG_NAME	SCHEMA_NAME	DEFAULT_CHARACTER_SET_NAME	DEFAULT_COLLATION_NAME	SQL_PATH
-def	db_datadict_1	latin1	latin1_swedish_ci	NULL
-def	db_datadict_2	latin1	latin1_swedish_ci	NULL
+CATALOG_NAME	SCHEMA_NAME	DEFAULT_CHARACTER_SET_NAME	DEFAULT_COLLATION_NAME	SQL_PATH	SCHEMA_COMMENT
+def	db_datadict_1	latin1	latin1_swedish_ci	NULL	
+def	db_datadict_2	latin1	latin1_swedish_ci	NULL	
 SHOW DATABASES LIKE 'db_datadict_%';
 Database (db_datadict_%)
 db_datadict_1
@@ -105,7 +108,7 @@ db_datadict_2
 connect  testuser3, localhost, testuser3, , test;
 SELECT * FROM information_schema.schemata
 WHERE schema_name LIKE 'db_datadict_%' ORDER BY schema_name;
-CATALOG_NAME	SCHEMA_NAME	DEFAULT_CHARACTER_SET_NAME	DEFAULT_COLLATION_NAME	SQL_PATH
+CATALOG_NAME	SCHEMA_NAME	DEFAULT_CHARACTER_SET_NAME	DEFAULT_COLLATION_NAME	SQL_PATH	SCHEMA_COMMENT
 SHOW DATABASES LIKE 'db_datadict_%';
 Database (db_datadict_%)
 connection default;
@@ -122,11 +125,11 @@ DROP DATABASE db_datadict_2;
 #################################################################################
 DROP DATABASE IF EXISTS db_datadict;
 SELECT * FROM information_schema.schemata WHERE schema_name = 'db_datadict';
-CATALOG_NAME	SCHEMA_NAME	DEFAULT_CHARACTER_SET_NAME	DEFAULT_COLLATION_NAME	SQL_PATH
+CATALOG_NAME	SCHEMA_NAME	DEFAULT_CHARACTER_SET_NAME	DEFAULT_COLLATION_NAME	SQL_PATH	SCHEMA_COMMENT
 CREATE DATABASE db_datadict CHARACTER SET 'latin1' COLLATE 'latin1_swedish_ci';
 SELECT * FROM information_schema.schemata WHERE schema_name = 'db_datadict';
-CATALOG_NAME	SCHEMA_NAME	DEFAULT_CHARACTER_SET_NAME	DEFAULT_COLLATION_NAME	SQL_PATH
-def	db_datadict	latin1	latin1_swedish_ci	NULL
+CATALOG_NAME	SCHEMA_NAME	DEFAULT_CHARACTER_SET_NAME	DEFAULT_COLLATION_NAME	SQL_PATH	SCHEMA_COMMENT
+def	db_datadict	latin1	latin1_swedish_ci	NULL	
 SELECT schema_name, default_character_set_name
 FROM information_schema.schemata WHERE schema_name = 'db_datadict';
 schema_name	default_character_set_name
diff --git a/mysql-test/suite/funcs_1/r/is_schemata_is_mysql_test.result b/mysql-test/suite/funcs_1/r/is_schemata_is_mysql_test.result
index 0679142bd82..ccf0e513d88 100644
--- a/mysql-test/suite/funcs_1/r/is_schemata_is_mysql_test.result
+++ b/mysql-test/suite/funcs_1/r/is_schemata_is_mysql_test.result
@@ -9,10 +9,10 @@ GRANT SELECT ON db_datadict.* TO 'testuser1'@'localhost';
 SELECT * FROM information_schema.schemata
 WHERE schema_name IN ('information_schema','mysql','test')
 ORDER BY schema_name;
-CATALOG_NAME	SCHEMA_NAME	DEFAULT_CHARACTER_SET_NAME	DEFAULT_COLLATION_NAME	SQL_PATH
-def	information_schema	utf8	utf8_general_ci	NULL
-def	mysql	latin1	latin1_swedish_ci	NULL
-def	test	latin1	latin1_swedish_ci	NULL
+CATALOG_NAME	SCHEMA_NAME	DEFAULT_CHARACTER_SET_NAME	DEFAULT_COLLATION_NAME	SQL_PATH	SCHEMA_COMMENT
+def	information_schema	utf8	utf8_general_ci	NULL	
+def	mysql	latin1	latin1_swedish_ci	NULL	
+def	test	latin1	latin1_swedish_ci	NULL	
 SHOW DATABASES LIKE 'information_schema';
 Database (information_schema)
 information_schema
@@ -26,9 +26,9 @@ connect  testuser1, localhost, testuser1, , db_datadict;
 SELECT * FROM information_schema.schemata
 WHERE schema_name IN ('information_schema','mysql','test')
 ORDER BY schema_name;
-CATALOG_NAME	SCHEMA_NAME	DEFAULT_CHARACTER_SET_NAME	DEFAULT_COLLATION_NAME	SQL_PATH
-def	information_schema	utf8	utf8_general_ci	NULL
-def	test	latin1	latin1_swedish_ci	NULL
+CATALOG_NAME	SCHEMA_NAME	DEFAULT_CHARACTER_SET_NAME	DEFAULT_COLLATION_NAME	SQL_PATH	SCHEMA_COMMENT
+def	information_schema	utf8	utf8_general_ci	NULL	
+def	test	latin1	latin1_swedish_ci	NULL	
 SHOW DATABASES LIKE 'information_schema';
 Database (information_schema)
 information_schema