From de2dd0929ed36aed0488e78f426e782a97ed7109 Mon Sep 17 00:00:00 2001
From: Zsolt Parragi <zsolt.parragi@percona.com>
Date: Tue, 30 Apr 2019 12:27:36 -0700
Subject: [PATCH] FB8-120: Added db_metadata options to create database command
 (#972) (#972)

Summary:
JIRA ticket: https://jira.percona.com/browse/FB8-120

Reference commit: https://github.com/facebook/mysql-5.6/commit/2f08e3a
Reference commit: https://github.com/facebook/mysql-5.6/commit/a21e84f
Reference commit: https://github.com/facebook/mysql-5.6/commit/5983ba3181a
Reference commit: https://github.com/facebook/mysql-5.6/commit/414870abeee

Added new option db_metadata to the create database
`CREATE DATABASE [IF NOT EXISTS] db_name DB_METADATA [=] metadata`

The new option is stored in the db.opt file along with other database options like charset and read_only.
The options accepts any string value. If not specified, it writes empty string as the default value in the db.opt file.
To retrieve the option value for a particular database, the show command can be used as follows:
`SHOW CREATE DATABASE db_name`

Example Usage:

create database test2 charset utf8 read_only = true db_metadata '{\'shard_name\':\'myshard_for_test2\'}';
show create database test2;

Output:

+----------+--------------------------------------------------------------------------------------------------------------------------+
| Database | Create Database                                                                                                          |
+----------+--------------------------------------------------------------------------------------------------------------------------+
| test2    | CREATE DATABASE `test2` /*!40100 DEFAULT CHARACTER SET utf8 READ_ONLY DB_METADATA {'shard_name':'myshard_for_test2'} */  |
+----------+--------------------------------------------------------------------------------------------------------------------------+

Pull Request resolved: https://github.com/facebook/mysql-5.6/pull/972

Differential Revision: D14883632

Pulled By: yizhang82
---
 libs/mysql/binlog/event/binlog_event.h        |   3 +
 mysql-test/r/db_metadata.result               | 157 +++++++++++++++++
 .../r/information_schema_keywords.result      |   1 +
 mysql-test/t/db_metadata.test                 | 159 ++++++++++++++++++
 share/messages_to_clients.txt                 |  12 +-
 sql/dd/dd_schema.cc                           |   4 +-
 sql/dd/dd_schema.h                            |   2 +-
 sql/dd/impl/types/schema_impl.cc              |  25 ++-
 sql/dd/impl/types/schema_impl.h               |  23 +--
 sql/dd/types/schema.h                         |   3 +
 sql/dd/upgrade_57/schema.cc                   |   2 +-
 sql/handler.h                                 |   2 +
 sql/lex.h                                     |   1 +
 sql/sql_db.cc                                 |   6 +-
 sql/sql_show.cc                               |   8 +
 sql/sql_yacc.yy                               |  42 ++++-
 16 files changed, 425 insertions(+), 25 deletions(-)
 create mode 100644 mysql-test/r/db_metadata.result
 create mode 100644 mysql-test/t/db_metadata.test

diff --git a/libs/mysql/binlog/event/binlog_event.h b/libs/mysql/binlog/event/binlog_event.h
index 41e82db9cec6..183943440ab7 100644
--- a/libs/mysql/binlog/event/binlog_event.h
+++ b/libs/mysql/binlog/event/binlog_event.h
@@ -128,6 +128,9 @@
 */
 #define MAX_TIME_ZONE_NAME_LENGTH (NAME_LEN + 1)
 
+/* Max length for the db-metadata option */
+#define DB_METADATA_MAX_LENGTH 1024
+
 /**
   Max number of possible extra bytes in a replication event compared to a
   packet (i.e. a query) sent from client to master;
diff --git a/mysql-test/r/db_metadata.result b/mysql-test/r/db_metadata.result
new file mode 100644
index 000000000000..73888706f3f9
--- /dev/null
+++ b/mysql-test/r/db_metadata.result
@@ -0,0 +1,157 @@
+create database test2;
+show create database test2;
+Database	Create Database
+test2	CREATE DATABASE `test2` /*!40100 DEFAULT CHARACTER SET utf8mb4 COLLATE utf8mb4_0900_ai_ci */ /*!80016 DEFAULT ENCRYPTION='N' */
+create database test3 character set utf8;
+Warnings:
+Warning	3719	'utf8' is currently an alias for the character set UTF8MB3, but will be an alias for UTF8MB4 in a future release. Please consider using UTF8MB4 in order to be unambiguous.
+show create database test3;
+Database	Create Database
+test3	CREATE DATABASE `test3` /*!40100 DEFAULT CHARACTER SET utf8mb3 */ /*!80016 DEFAULT ENCRYPTION='N' */
+create database test4 read_only = true;
+show create database test4;
+Database	Create Database
+test4	CREATE DATABASE `test4` /*!40100 DEFAULT CHARACTER SET utf8mb4 COLLATE utf8mb4_0900_ai_ci */ /*!80016 DEFAULT ENCRYPTION='N' */
+create database test5 db_metadata = "{\"shard\":\"test5_shard\"}";
+show create database test5;
+Database	Create Database
+test5	CREATE DATABASE `test5` /*!40100 DEFAULT CHARACTER SET utf8mb4 COLLATE utf8mb4_0900_ai_ci DB_METADATA '{"shard":"test5_shard"}' */ /*!80016 DEFAULT ENCRYPTION='N' */
+drop database test5;
+CREATE DATABASE `test5` /*!40100 DEFAULT CHARACTER SET utf8mb4 COLLATE utf8mb4_0900_ai_ci DB_METADATA '{"shard":"test5_shard"}' */ /*!80016 DEFAULT ENCRYPTION='N' */;
+show create database test5;
+Database	Create Database
+test5	CREATE DATABASE `test5` /*!40100 DEFAULT CHARACTER SET utf8mb4 COLLATE utf8mb4_0900_ai_ci DB_METADATA '{"shard":"test5_shard"}' */ /*!80016 DEFAULT ENCRYPTION='N' */
+create database test6 character set utf8 db_metadata = "{\"shard\":\"test6_shard\"}";
+Warnings:
+Warning	3719	'utf8' is currently an alias for the character set UTF8MB3, but will be an alias for UTF8MB4 in a future release. Please consider using UTF8MB4 in order to be unambiguous.
+show create database test6;
+Database	Create Database
+test6	CREATE DATABASE `test6` /*!40100 DEFAULT CHARACTER SET utf8mb3 DB_METADATA '{"shard":"test6_shard"}' */ /*!80016 DEFAULT ENCRYPTION='N' */
+create database test7 read_only = true db_metadata = "{\"shard\":\"test7_shard\"}";
+show create database test7;
+Database	Create Database
+test7	CREATE DATABASE `test7` /*!40100 DEFAULT CHARACTER SET utf8mb4 COLLATE utf8mb4_0900_ai_ci DB_METADATA '{"shard":"test7_shard"}' */ /*!80016 DEFAULT ENCRYPTION='N' */
+create database test8 character set utf8 read_only = true;
+Warnings:
+Warning	3719	'utf8' is currently an alias for the character set UTF8MB3, but will be an alias for UTF8MB4 in a future release. Please consider using UTF8MB4 in order to be unambiguous.
+show create database test8;
+Database	Create Database
+test8	CREATE DATABASE `test8` /*!40100 DEFAULT CHARACTER SET utf8mb3 */ /*!80016 DEFAULT ENCRYPTION='N' */
+create database test9 character set utf8 read_only = true db_metadata = "{\"shard\":\"test9_shard\"}";
+Warnings:
+Warning	3719	'utf8' is currently an alias for the character set UTF8MB3, but will be an alias for UTF8MB4 in a future release. Please consider using UTF8MB4 in order to be unambiguous.
+show create database test9;
+Database	Create Database
+test9	CREATE DATABASE `test9` /*!40100 DEFAULT CHARACTER SET utf8mb3 DB_METADATA '{"shard":"test9_shard"}' */ /*!80016 DEFAULT ENCRYPTION='N' */
+alter database test3 character set ascii;
+show create database test3;
+Database	Create Database
+test3	CREATE DATABASE `test3` /*!40100 DEFAULT CHARACTER SET ascii */ /*!80016 DEFAULT ENCRYPTION='N' */
+alter database test4 read_only = true;
+show create database test4;
+Database	Create Database
+test4	CREATE DATABASE `test4` /*!40100 DEFAULT CHARACTER SET utf8mb4 COLLATE utf8mb4_0900_ai_ci READ_ONLY */ /*!80016 DEFAULT ENCRYPTION='N' */
+alter database test5 db_metadata = "{\"shard\":\"test5_shard_altered\"}";
+show create database test5;
+Database	Create Database
+test5	CREATE DATABASE `test5` /*!40100 DEFAULT CHARACTER SET utf8mb4 COLLATE utf8mb4_0900_ai_ci DB_METADATA '{"shard":"test5_shard_altered"}' */ /*!80016 DEFAULT ENCRYPTION='N' */
+alter database test5 character set ascii;
+show create database test5;
+Database	Create Database
+test5	CREATE DATABASE `test5` /*!40100 DEFAULT CHARACTER SET ascii DB_METADATA '{"shard":"test5_shard_altered"}' */ /*!80016 DEFAULT ENCRYPTION='N' */
+alter database test5 read_only = true;
+show create database test5;
+Database	Create Database
+test5	CREATE DATABASE `test5` /*!40100 DEFAULT CHARACTER SET ascii READ_ONLY DB_METADATA '{"shard":"test5_shard_altered"}' */ /*!80016 DEFAULT ENCRYPTION='N' */
+alter database test5 character set utf8 read_only = false;
+Warnings:
+Warning	3719	'utf8' is currently an alias for the character set UTF8MB3, but will be an alias for UTF8MB4 in a future release. Please consider using UTF8MB4 in order to be unambiguous.
+show create database test5;
+Database	Create Database
+test5	CREATE DATABASE `test5` /*!40100 DEFAULT CHARACTER SET utf8mb3 DB_METADATA '{"shard":"test5_shard_altered"}' */ /*!80016 DEFAULT ENCRYPTION='N' */
+alter database test5 db_metadata "";
+show create database test5;
+Database	Create Database
+test5	CREATE DATABASE `test5` /*!40100 DEFAULT CHARACTER SET utf8mb3 */ /*!80016 DEFAULT ENCRYPTION='N' */
+alter database test5 db_metadata "{\"shard\":\"Really long shard name. Really long shard name. Really long shard name. Really long shard name. Really long shard name. Really long shard name. Really long shard name. Really long shard name. Really long shard name. Really long shard name. Really long shard name. Really long shard name. Really long shard name. Really long shard name. Really long shard name. Really long shard name. Really long shard name. Really long shard name. Really long shard name. Really long shard name. Really long shard name. Really long shard name. Really long shard name. Really long shard name. Really long shard name. Really long shard name. Really long shard name. Really long shard name. Really long shard name. Really long shard name. Really long shard name. Really long shard name. Really long shard name. Really long shard name. Really long shard name. Really long shard name. Really long shard name. Really long shard name. Really long shard name. Really long shard name. Really long shard name. Really long shard name. Fin\"}";
+show create database test5;
+Database	Create Database
+test5	CREATE DATABASE `test5` /*!40100 DEFAULT CHARACTER SET utf8mb3 DB_METADATA '{"shard":"Really long shard name. Really long shard name. Really long shard name. Really long shard name. Really long shard name. Really long shard name. Really long shard name. Really long shard name. Really long shard name. Really long shard name. Really long shard name. Really long shard name. Really long shard name. Really long shard name. Really long shard name. Really long shard name. Really long shard name. Really long shard name. Really long shard name. Really long shard name. Really long shard name. Really long shard name. Really long shard name. Really long shard name. Really long shard name. Really long shard name. Really long shard name. Really long shard name. Really long shard name. Really long shard name. Really long shard name. Really long shard name. Really long shard name. Really long shard name. Really long shard name. Really long shard name. Really long shard name. Really long shard name. Really long shard name. Really long shard name. Really long shard name. Really long shard name. Fin"}' */ /*!80016 DEFAULT ENCRYPTION='N' */
+alter database test5 db_metadata "{\"shard\":\"Really long shard name. Really long shard name. Really long shard name. Really long shard name. Really long shard name. Really long shard name. Really long shard name. Really long shard name. Really long shard name. Really long shard name. Really long shard name. Really long shard name. Really long shard name. Really long shard name. Really long shard name. Really long shard name. Really long shard name. Really long shard name. Really long shard name. Really long shard name. Really long shard name. Really long shard name. Really long shard name. Really long shard name. Really long shard name. Really long shard name. Really long shard name. Really long shard name. Really long shard name. Really long shard name. Really long shard name. Really long shard name. Really long shard name. Really long shard name. Really long shard name. Really long shard name. Really long shard name. Really long shard name. Really long shard name. Really long shard name. Really long shard name. Really long shard name. Really long shard name. Fin\"}";;
+ERROR HY000: Metadata for the database is too long. Max length is 1024 bytes
+alter database test6 character set ascii db_metadata = "{\"shard\":\"test6_shard_altered\"}";
+show create database test6;
+Database	Create Database
+test6	CREATE DATABASE `test6` /*!40100 DEFAULT CHARACTER SET ascii DB_METADATA '{"shard":"test6_shard_altered"}' */ /*!80016 DEFAULT ENCRYPTION='N' */
+alter database test7 read_only = true db_metadata = "{\"shard\":\"test7_shard_altered\"}";
+show create database test7;
+Database	Create Database
+test7	CREATE DATABASE `test7` /*!40100 DEFAULT CHARACTER SET utf8mb4 COLLATE utf8mb4_0900_ai_ci READ_ONLY DB_METADATA '{"shard":"test7_shard_altered"}' */ /*!80016 DEFAULT ENCRYPTION='N' */
+alter database test8 character set ascii read_only = true;
+show create database test8;
+Database	Create Database
+test8	CREATE DATABASE `test8` /*!40100 DEFAULT CHARACTER SET ascii READ_ONLY */ /*!80016 DEFAULT ENCRYPTION='N' */
+alter database test9 character set ascii read_only = true db_metadata = "{\"shard\":\"test9_shard_altered\"}";
+show create database test9;
+Database	Create Database
+test9	CREATE DATABASE `test9` /*!40100 DEFAULT CHARACTER SET ascii READ_ONLY DB_METADATA '{"shard":"test9_shard_altered"}' */ /*!80016 DEFAULT ENCRYPTION='N' */
+show create database information_schema;
+Database	Create Database
+information_schema	CREATE DATABASE `information_schema` /*!40100 DEFAULT CHARACTER SET utf8mb3 */ /*!80016 DEFAULT ENCRYPTION='N' */
+show create database mysql;
+Database	Create Database
+mysql	CREATE DATABASE `mysql` /*!40100 DEFAULT CHARACTER SET utf8mb4 COLLATE utf8mb4_0900_ai_ci */ /*!80016 DEFAULT ENCRYPTION='N' */
+alter database information_schema db_metadata "{\"shard\":\"is_shard\"}";
+ERROR 42000: Access denied for user 'root'@'localhost' to database 'information_schema'
+alter database test9 db_metadata = "invalid_json";
+ERROR HY000: Invalid JSON for DB_METADATA attribute: invalid_json.
+show create database test9;
+Database	Create Database
+test9	CREATE DATABASE `test9` /*!40100 DEFAULT CHARACTER SET ascii READ_ONLY DB_METADATA '{"shard":"test9_shard_altered"}' */ /*!80016 DEFAULT ENCRYPTION='N' */
+create database test10;
+show create database test10;
+Database	Create Database
+test10	CREATE DATABASE `test10` /*!40100 DEFAULT CHARACTER SET utf8mb4 COLLATE utf8mb4_0900_ai_ci */ /*!80016 DEFAULT ENCRYPTION='N' */
+alter database test10 read_only = true;
+show create database test10;
+Database	Create Database
+test10	CREATE DATABASE `test10` /*!40100 DEFAULT CHARACTER SET utf8mb4 COLLATE utf8mb4_0900_ai_ci READ_ONLY */ /*!80016 DEFAULT ENCRYPTION='N' */
+alter database test10 db_metadata = "{\"shard\":\"test10_shard_altered\"}";
+show create database test10;
+Database	Create Database
+test10	CREATE DATABASE `test10` /*!40100 DEFAULT CHARACTER SET utf8mb4 COLLATE utf8mb4_0900_ai_ci READ_ONLY DB_METADATA '{"shard":"test10_shard_altered"}' */ /*!80016 DEFAULT ENCRYPTION='N' */
+alter database test10 read_only = false;
+show create database test10;
+Database	Create Database
+test10	CREATE DATABASE `test10` /*!40100 DEFAULT CHARACTER SET utf8mb4 COLLATE utf8mb4_0900_ai_ci DB_METADATA '{"shard":"test10_shard_altered"}' */ /*!80016 DEFAULT ENCRYPTION='N' */
+create database test11 db_metadata = "{\'shard\':\'test11_shard\'}";
+ERROR HY000: Invalid JSON for DB_METADATA attribute: {'shard':'test11_shard'}.
+create database test12 db_metadata = "{\"sha'rd\":\"test12\\\"_shard\"}";
+show create database test12;
+Database	Create Database
+test12	CREATE DATABASE `test12` /*!40100 DEFAULT CHARACTER SET utf8mb4 COLLATE utf8mb4_0900_ai_ci DB_METADATA '{"sha''rd":"test12\\"_shard"}' */ /*!80016 DEFAULT ENCRYPTION='N' */
+drop database test12;
+CREATE DATABASE `test12` /*!40100 DEFAULT CHARACTER SET utf8mb4 COLLATE utf8mb4_0900_ai_ci DB_METADATA '{"sha''rd":"test12\\"_shard"}' */ /*!80016 DEFAULT ENCRYPTION='N' */;
+show create database test12;
+Database	Create Database
+test12	CREATE DATABASE `test12` /*!40100 DEFAULT CHARACTER SET utf8mb4 COLLATE utf8mb4_0900_ai_ci DB_METADATA '{"sha''rd":"test12\\"_shard"}' */ /*!80016 DEFAULT ENCRYPTION='N' */
+create database test13 db_metadata = '{"sha\'\\"rd":"test13\'_sh\\"ard"}';
+show create database test13;
+Database	Create Database
+test13	CREATE DATABASE `test13` /*!40100 DEFAULT CHARACTER SET utf8mb4 COLLATE utf8mb4_0900_ai_ci DB_METADATA '{"sha''\\"rd":"test13''_sh\\"ard"}' */ /*!80016 DEFAULT ENCRYPTION='N' */
+drop database test13;
+CREATE DATABASE `test13` /*!40100 DEFAULT CHARACTER SET utf8mb4 COLLATE utf8mb4_0900_ai_ci DB_METADATA '{"sha''\\"rd":"test13''_sh\\"ard"}' */ /*!80016 DEFAULT ENCRYPTION='N' */;
+show create database test13;
+Database	Create Database
+test13	CREATE DATABASE `test13` /*!40100 DEFAULT CHARACTER SET utf8mb4 COLLATE utf8mb4_0900_ai_ci DB_METADATA '{"sha''\\"rd":"test13''_sh\\"ard"}' */ /*!80016 DEFAULT ENCRYPTION='N' */
+drop database test2;
+drop database test3;
+drop database test4;
+drop database test5;
+drop database test6;
+drop database test7;
+drop database test8;
+drop database test9;
+drop database test10;
+drop database test12;
+drop database test13;
diff --git a/mysql-test/r/information_schema_keywords.result b/mysql-test/r/information_schema_keywords.result
index b4f3f02faa20..292402637c61 100644
--- a/mysql-test/r/information_schema_keywords.result
+++ b/mysql-test/r/information_schema_keywords.result
@@ -122,6 +122,7 @@ DAY_HOUR	1
 DAY_MICROSECOND	1
 DAY_MINUTE	1
 DAY_SECOND	1
+DB_METADATA	0
 DEALLOCATE	0
 DEC	1
 DECIMAL	1
diff --git a/mysql-test/t/db_metadata.test b/mysql-test/t/db_metadata.test
new file mode 100644
index 000000000000..ae1850b4adea
--- /dev/null
+++ b/mysql-test/t/db_metadata.test
@@ -0,0 +1,159 @@
+# Test per-database database-metadata attribute
+
+let $MYSQLD_DATADIR= `select @@datadir`;
+
+# create database without any options
+create database test2;
+show create database test2;
+
+# create database with character set
+create database test3 character set utf8;
+show create database test3;
+
+# create database with read only
+create database test4 read_only = true;
+show create database test4;
+
+# create database with db metadata
+create database test5 db_metadata = "{\"shard\":\"test5_shard\"}";
+show create database test5;
+
+# verify show create is valid
+--let $db_create=query_get_value(show create database test5, 'Create Database', 1)
+drop database test5;
+eval $db_create;
+show create database test5;
+
+# create database with character set and db metadata
+create database test6 character set utf8 db_metadata = "{\"shard\":\"test6_shard\"}";
+show create database test6;
+
+# create database with read only and db metadata
+create database test7 read_only = true db_metadata = "{\"shard\":\"test7_shard\"}";
+show create database test7;
+
+# create database with character set and read only
+create database test8 character set utf8 read_only = true;
+show create database test8;
+
+# create database with character set, read only and db metadata
+create database test9 character set utf8 read_only = true db_metadata = "{\"shard\":\"test9_shard\"}";
+show create database test9;
+
+# alter database tests
+
+# alter database character set
+alter database test3 character set ascii;
+show create database test3;
+
+# alter database read only
+alter database test4 read_only = true;
+show create database test4;
+
+# alter database db metadata
+alter database test5 db_metadata = "{\"shard\":\"test5_shard_altered\"}";
+show create database test5;
+
+# alter database character set but keep db metadata intact
+alter database test5 character set ascii;
+show create database test5;
+
+# alter database read only but keep db metadata intact
+alter database test5 read_only = true;
+show create database test5;
+
+# alter database character set and read only but keep db metadata intact
+alter database test5 character set utf8 read_only = false;
+show create database test5;
+
+# alter database reset db metadata
+alter database test5 db_metadata "";
+show create database test5;
+
+# alter database set db metadata to max length string
+alter database test5 db_metadata "{\"shard\":\"Really long shard name. Really long shard name. Really long shard name. Really long shard name. Really long shard name. Really long shard name. Really long shard name. Really long shard name. Really long shard name. Really long shard name. Really long shard name. Really long shard name. Really long shard name. Really long shard name. Really long shard name. Really long shard name. Really long shard name. Really long shard name. Really long shard name. Really long shard name. Really long shard name. Really long shard name. Really long shard name. Really long shard name. Really long shard name. Really long shard name. Really long shard name. Really long shard name. Really long shard name. Really long shard name. Really long shard name. Really long shard name. Really long shard name. Really long shard name. Really long shard name. Really long shard name. Really long shard name. Really long shard name. Really long shard name. Really long shard name. Really long shard name. Really long shard name. Fin\"}";
+show create database test5;
+
+# alter database exceed db metadata max length
+--error ER_DB_METADATA_TOO_LONG
+--eval alter database test5 db_metadata \"{\\\"shard\\\":\\\"Really long shard name. Really long shard name. Really long shard name. Really long shard name. Really long shard name. Really long shard name. Really long shard name. Really long shard name. Really long shard name. Really long shard name. Really long shard name. Really long shard name. Really long shard name. Really long shard name. Really long shard name. Really long shard name. Really long shard name. Really long shard name. Really long shard name. Really long shard name. Really long shard name. Really long shard name. Really long shard name. Really long shard name. Really long shard name. Really long shard name. Really long shard name. Really long shard name. Really long shard name. Really long shard name. Really long shard name. Really long shard name. Really long shard name. Really long shard name. Really long shard name. Really long shard name. Really long shard name. Really long shard name. Really long shard name. Really long shard name. Really long shard name. Really long shard name. Really long shard name. Fin\\\"}\";
+
+# alter database character set and db metadata
+alter database test6 character set ascii db_metadata = "{\"shard\":\"test6_shard_altered\"}";
+show create database test6;
+
+# alter database read only and db metadata
+alter database test7 read_only = true db_metadata = "{\"shard\":\"test7_shard_altered\"}";
+show create database test7;
+
+# alter database character set and read only
+alter database test8 character set ascii read_only = true;
+show create database test8;
+
+# alter database character set, read only and db metadata
+alter database test9 character set ascii read_only = true db_metadata = "{\"shard\":\"test9_shard_altered\"}";
+show create database test9;
+
+# ensure information_schema and mysql tables are intact
+show create database information_schema;
+show create database mysql;
+
+--error ER_DBACCESS_DENIED_ERROR
+alter database information_schema db_metadata "{\"shard\":\"is_shard\"}";
+
+# alter database with invalid JSON string for db_metadata
+ --error ER_DB_METADATA_INVALID_JSON
+alter database test9 db_metadata = "invalid_json";
+show create database test9;
+
+
+
+# create database without any options
+create database test10;
+show create database test10;
+
+# alter database read only
+alter database test10 read_only = true;
+show create database test10;
+
+# alter database db metadata
+alter database test10 db_metadata = "{\"shard\":\"test10_shard_altered\"}";
+show create database test10;
+
+# alter database read only
+alter database test10 read_only = false;
+show create database test10;
+
+# create database with single quotation
+--error ER_DB_METADATA_INVALID_JSON
+create database test11 db_metadata = "{\'shard\':\'test11_shard\'}";
+
+# create database with double quote around metadata with single and double quotes in value
+create database test12 db_metadata = "{\"sha'rd\":\"test12\\\"_shard\"}";
+show create database test12;
+--let $db_create=query_get_value(show create database test12, 'Create Database', 1)
+drop database test12;
+eval $db_create;
+show create database test12;
+
+# create database with single quote around metadata with single and double quotes in value
+create database test13 db_metadata = '{"sha\'\\"rd":"test13\'_sh\\"ard"}';
+show create database test13;
+--let $db_create=query_get_value(show create database test13, 'Create Database', 1)
+drop database test13;
+eval $db_create;
+show create database test13;
+
+
+# cleanup
+drop database test2;
+drop database test3;
+drop database test4;
+drop database test5;
+drop database test6;
+drop database test7;
+drop database test8;
+drop database test9;
+drop database test10;
+drop database test12;
+drop database test13;
diff --git a/share/messages_to_clients.txt b/share/messages_to_clients.txt
index a6e6dfe97715..26db76acae1e 100644
--- a/share/messages_to_clients.txt
+++ b/share/messages_to_clients.txt
@@ -10536,14 +10536,14 @@ ER_NP_FAILED
 ER_CANT_SET_DEPENDENCY_REPLICATION_WITHOUT_IDEMPOTENT_RECOVERY
   eng "@@GLOBAL.MTS_DEPENDENCY_REPLICATION cannot be set when @@GLOBAL.SLAVE_USE_IDEMPOTENT_FOR_RECOVERY = NO"
 
-ER_PLACEHOLDER_50063
-  eng "Placeholder"
+ER_DB_METADATA_TOO_LONG
+  eng "Metadata for the database is too long. Max length is %d bytes"
 
-ER_PLACEHOLDER_50064
-  eng "Placeholder"
+ER_DB_METADATA_INVALID_JSON
+  eng "Invalid JSON for DB_METADATA attribute: %s."
 
-ER_PLACEHOLDER_50065
-  eng "Placeholder"
+ER_DB_METADATA_READ_ERROR
+  eng "Error reading db metadata option: '%-.64s'"
 
 ER_UPDATES_WITH_EXPLICIT_SNAPSHOT
   eng "Can't execute updates when an explicit snapshot is associated with the connection using CREATE|ATTACH EXPLICIT [ENGINE] SNAPSHOT"
diff --git a/sql/dd/dd_schema.cc b/sql/dd/dd_schema.cc
index 480a25f2a0a7..f888b5555c4e 100644
--- a/sql/dd/dd_schema.cc
+++ b/sql/dd/dd_schema.cc
@@ -59,7 +59,8 @@ bool schema_exists(THD *thd, const char *schema_name, bool *exists) {
 }
 
 bool create_schema(THD *thd, const char *schema_name,
-                   const CHARSET_INFO *charset_info, bool default_encryption) {
+                   const CHARSET_INFO *charset_info, bool default_encryption,
+                   const char *db_metadata) {
   // Create dd::Schema object.
   std::unique_ptr<dd::Schema> schema(dd::create_object<dd::Schema>());
 
@@ -68,6 +69,7 @@ bool create_schema(THD *thd, const char *schema_name,
   assert(charset_info);
   schema->set_default_collation_id(charset_info->number);
   schema->set_default_encryption(default_encryption);
+  schema->set_db_metadata(db_metadata != nullptr ? db_metadata : "");
 
   // Get statement start time.
   ulonglong ull_curtime = my_time_t_to_ull_datetime(thd->query_start_in_secs());
diff --git a/sql/dd/dd_schema.h b/sql/dd/dd_schema.h
index 930ce1250af7..a1b8c03775d9 100644
--- a/sql/dd/dd_schema.h
+++ b/sql/dd/dd_schema.h
@@ -47,7 +47,7 @@ bool schema_exists(THD *thd, const char *schema_name, bool *exists);
 /** Create a schema record into dd.schemata. */
 bool create_schema(THD *thd, const char *schema_name,
                    const CHARSET_INFO *charset_info,
-                   const bool default_encryption);
+                   const bool default_encryption, const char *db_metadata);
 
 /**
   Acquire MDL on schema name.
diff --git a/sql/dd/impl/types/schema_impl.cc b/sql/dd/impl/types/schema_impl.cc
index f8854ebe6ef5..109255801823 100644
--- a/sql/dd/impl/types/schema_impl.cc
+++ b/sql/dd/impl/types/schema_impl.cc
@@ -74,7 +74,7 @@ namespace dd {
 static constexpr auto fb_read_only_options_key = "read_only";
 static constexpr auto mysql_db_read_only_options_key = "mysql_db_read_only";
 static const std::set<String_type> default_valid_option_keys = {
-    mysql_db_read_only_options_key, fb_read_only_options_key};
+    "db_metadata", mysql_db_read_only_options_key, fb_read_only_options_key};
 
 ///////////////////////////////////////////////////////////////////////////
 // Schema_impl implementation.
@@ -112,6 +112,29 @@ void Schema_impl::set_read_only(bool state) {
   options().set(mysql_db_read_only_options_key, state);
 }
 
+static constexpr auto db_metadata_key = "db_metadata";
+
+bool Schema_impl::set_db_metadata(const String_type &metadata) {
+  if (metadata.empty()) {
+    if (options().exists(db_metadata_key)) {
+      options().remove(db_metadata_key);
+    }
+  } else {
+    options().set(db_metadata_key, metadata);
+  }
+  return true;
+}
+
+String_type Schema_impl::get_db_metadata() const noexcept {
+  if (options().exists(db_metadata_key)) {
+    bool ret;
+    String_type value;
+    ret = options().get(db_metadata_key, &value);
+    if (!ret) return value;
+  }
+  return "";
+}
+
 ///////////////////////////////////////////////////////////////////////////
 
 void Schema_impl::set_db_read_only(int state) {
diff --git a/sql/dd/impl/types/schema_impl.h b/sql/dd/impl/types/schema_impl.h
index 59ad8ae1e059..d741b240fbaa 100644
--- a/sql/dd/impl/types/schema_impl.h
+++ b/sql/dd/impl/types/schema_impl.h
@@ -153,6 +153,9 @@ class Schema_impl : public Entity_object_impl, public Schema {
   // options.
   /////////////////////////////////////////////////////////////////////////
 
+  virtual bool set_db_metadata(const String_type &metadata) override;
+  virtual String_type get_db_metadata() const noexcept override;
+
   const Properties &options() const override { return m_options; }
 
   Properties &options() override { return m_options; }
@@ -202,16 +205,16 @@ class Schema_impl : public Entity_object_impl, public Schema {
  public:
   void debug_print(String_type &outb) const override {
     char outbuf[1024];
-    sprintf(outbuf,
-            "SCHEMA OBJECT: id= {OID: %lld}, name= %s, "
-            "collation_id={OID: %lld},"
-            "m_created= %llu, m_last_altered= %llu,"
-            "m_default_encryption= %d, "
-            "se_private_data= %s, options= %s",
-            id(), name().c_str(), m_default_collation_id, m_created,
-            m_last_altered, static_cast<int>(m_default_encryption),
-            m_se_private_data.raw_string().c_str(),
-            m_options.raw_string().c_str());
+    snprintf(outbuf, sizeof(outbuf) / sizeof(char),
+             "SCHEMA OBJECT: id= {OID: %lld}, name= %s, "
+             "collation_id={OID: %lld},"
+             "m_created= %llu, m_last_altered= %llu,"
+             "m_default_encryption= %d, "
+             "se_private_data= %s, options= %s",
+             id(), name().c_str(), m_default_collation_id, m_created,
+             m_last_altered, static_cast<int>(m_default_encryption),
+             m_se_private_data.raw_string().c_str(),
+             m_options.raw_string().c_str());
     outb = String_type(outbuf);
   }
 
diff --git a/sql/dd/types/schema.h b/sql/dd/types/schema.h
index 3c697da390f9..243eb4c0ce19 100644
--- a/sql/dd/types/schema.h
+++ b/sql/dd/types/schema.h
@@ -139,6 +139,9 @@ class Schema : virtual public Entity_object {
   virtual bool set_se_private_data(const String_type &se_private_data_raw) = 0;
   virtual bool set_se_private_data(const Properties &se_private_data) = 0;
 
+  virtual bool set_db_metadata(const String_type &metadata) = 0;
+  virtual String_type get_db_metadata() const noexcept = 0;
+
  public:
   virtual Event *create_event(THD *thd) const = 0;
 
diff --git a/sql/dd/upgrade_57/schema.cc b/sql/dd/upgrade_57/schema.cc
index 5a6dd1ef74e4..5ae872a83ef4 100644
--- a/sql/dd/upgrade_57/schema.cc
+++ b/sql/dd/upgrade_57/schema.cc
@@ -178,7 +178,7 @@ bool migrate_schema_to_dd(THD *thd, const char *dbname) {
   // Disable autocommit option
   Disable_autocommit_guard autocommit_guard(thd);
 
-  if (dd::create_schema(thd, schema_name, schema_charset, false)) {
+  if (dd::create_schema(thd, schema_name, schema_charset, false, nullptr)) {
     trans_rollback_stmt(thd);
     // Full rollback in case we have THD::transaction_rollback_request.
     trans_rollback(thd);
diff --git a/sql/handler.h b/sql/handler.h
index a2d57d914b6b..0045615d7c74 100644
--- a/sql/handler.h
+++ b/sql/handler.h
@@ -74,6 +74,7 @@
 #include "sql/sql_const.h"       // SHOW_COMP_OPTION
 #include "sql/sql_list.h"        // SQL_I_List
 #include "sql/sql_plugin_ref.h"  // plugin_ref
+#include "sql_string.h"
 #include "string_with_len.h"     // STRING_WITH_LEN
 #include "thr_lock.h"            // thr_lock_type
 #include "typelib.h"
@@ -3215,6 +3216,7 @@ struct HA_CREATE_INFO {
   const CHARSET_INFO *default_table_charset{nullptr};
   bool schema_read_only{false};
   enum enum_db_read_only db_read_only { DB_READ_ONLY_NULL };
+  String db_metadata;
   LEX_STRING connect_string{nullptr, 0};
   const char *password{nullptr};
   const char *tablespace{nullptr};
diff --git a/sql/lex.h b/sql/lex.h
index 0cff848c5809..b734fd86add7 100644
--- a/sql/lex.h
+++ b/sql/lex.h
@@ -191,6 +191,7 @@ static const SYMBOL symbols[] = {
     {SYM("DAY_MICROSECOND", DAY_MICROSECOND_SYM)},
     {SYM("DAY_MINUTE", DAY_MINUTE_SYM)},
     {SYM("DAY_SECOND", DAY_SECOND_SYM)},
+    {SYM("DB_METADATA", DB_METADATA_SYM)},
     {SYM("DEALLOCATE", DEALLOCATE_SYM)},
     {SYM("DEC", DECIMAL_SYM)},
     {SYM("DECIMAL", DECIMAL_SYM)},
diff --git a/sql/sql_db.cc b/sql/sql_db.cc
index b77a8e37bf71..c0a84a909948 100644
--- a/sql/sql_db.cc
+++ b/sql/sql_db.cc
@@ -583,7 +583,7 @@ bool mysql_create_db(THD *thd, const char *db, HA_CREATE_INFO *create_info) {
     set_db_default_charset(thd, create_info);
 
     if (dd::create_schema(thd, db, create_info->default_table_charset,
-                          encrypt_schema)) {
+                          encrypt_schema, create_info->db_metadata.ptr())) {
       /*
         We could be here due an deadlock or some error reported
         by DD API framework. We remove the database directory
@@ -724,6 +724,10 @@ bool mysql_alter_db(THD *thd, const char *db, HA_CREATE_INFO *create_info) {
     }
   }
 
+  if (create_info->db_metadata.ptr() != nullptr) {
+    schema->set_db_metadata(create_info->db_metadata.ptr());
+  }
+
   // Set encryption type.
   if (create_info->used_fields & HA_CREATE_USED_DEFAULT_ENCRYPTION) {
     assert(create_info->encrypt_type.length > 0);
diff --git a/sql/sql_show.cc b/sql/sql_show.cc
index 1471e46ff42a..d80157d759a0 100644
--- a/sql/sql_show.cc
+++ b/sql/sql_show.cc
@@ -1391,6 +1391,8 @@ bool mysqld_show_create_db(THD *thd, char *dbname,
   }
 
   bool is_encrypted_schema = false;
+  std::string metadata;
+
   if (is_infoschema_db(dbname)) {
     create.default_table_charset = system_charset_info;
   } else {
@@ -1413,6 +1415,7 @@ bool mysqld_show_create_db(THD *thd, char *dbname,
     }
 
     schema_read_only = schema->read_only();
+    metadata = schema->get_db_metadata().c_str();
 
     create.db_read_only =
         static_cast<enum_db_read_only>(schema->get_db_read_only());
@@ -1455,6 +1458,11 @@ bool mysqld_show_create_db(THD *thd, char *dbname,
       buffer.append(STRING_WITH_LEN(" SUPER_READ_ONLY"));
     }
 
+    if (!metadata.empty()) {
+      buffer.append(STRING_WITH_LEN(" DB_METADATA "));
+      append_unescaped(&buffer, metadata.c_str(), metadata.size());
+    }
+
     buffer.append(STRING_WITH_LEN(" */"));
   }
   buffer.append(STRING_WITH_LEN(" /*!80016"));
diff --git a/sql/sql_yacc.yy b/sql/sql_yacc.yy
index f6c66867eb60..116f7cfaebe7 100644
--- a/sql/sql_yacc.yy
+++ b/sql/sql_yacc.yy
@@ -56,6 +56,10 @@ Note: YYTHD is passed as an argument to yyparse(), and subsequently to yylex().
 #include <string>
 #include <type_traits>
 #include <utility>
+#include <sstream>
+#define BOOST_BIND_GLOBAL_PLACEHOLDERS
+#include <boost/property_tree/ptree.hpp>
+#include <boost/property_tree/json_parser.hpp>
 
 #include "field_types.h"
 #include "ft_global.h"
@@ -562,7 +566,7 @@ void warn_on_deprecated_user_defined_collation(
   2. We should not introduce new shift/reduce conflicts any more.
 */
 
-%expect 65
+%expect 66
 
 /*
    MAINTAINER:
@@ -1477,6 +1481,7 @@ void warn_on_deprecated_user_defined_collation(
 %token<lexer.keyword> GTID_SYM 10001
 %token<lexer.keyword> GTID_EXECUTED 10002           /* MYSQL */
 %token<lexer.keyword> SUPER_READ_ONLY_SYM 10003
+%token<lexer.keyword> DB_METADATA_SYM 10004
 
 /*
   Resolve column attribute ambiguity -- force precedence of "UNIQUE KEY" against
@@ -6770,9 +6775,8 @@ create_database_option:
             Lex->create_info->encrypt_type= $1;
             Lex->create_info->used_fields |= HA_CREATE_USED_DEFAULT_ENCRYPTION;
           }
-        | db_read_only
-          {
-          }
+        | db_read_only {}
+        | db_metadata_str {}
         ;
 
 opt_if_not_exists:
@@ -7040,6 +7044,35 @@ boolean_val:
         | TRUE_SYM { $$ = 1; }
         ;
 
+db_metadata_str:
+          DB_METADATA_SYM opt_equal TEXT_STRING_sys
+          {
+            if ($3.length > DB_METADATA_MAX_LENGTH)
+            {
+              my_error(ER_DB_METADATA_TOO_LONG, MYF(0), DB_METADATA_MAX_LENGTH);
+              MYSQL_YYABORT;
+            }
+            /* Verify that a valid JSON is provided */
+            if ($3.length > 0)
+            {
+              boost::property_tree::ptree db_metadata_root;
+              std::istringstream is($3.str);
+              try
+              {
+                boost::property_tree::json_parser::read_json(is,
+                                                             db_metadata_root);
+              }
+              catch (const std::exception&)
+              {
+                my_error(ER_DB_METADATA_INVALID_JSON, MYF(0), $3.str);
+                MYSQL_YYABORT;
+              }
+            }
+            Lex->create_info->db_metadata= String($3.str, $3.length,
+              &my_charset_bin);
+          }
+        ;
+
 row_types:
           DEFAULT_SYM    { $$= ROW_TYPE_DEFAULT; }
         | FIXED_SYM      { $$= ROW_TYPE_FIXED; }
@@ -15586,6 +15619,7 @@ ident_keywords_ambiguous_2_labels:
         | COMMENT_SYM
         | COMMIT_SYM
         | CONTAINS_SYM
+        | DB_METADATA_SYM
         | DEALLOCATE_SYM
         | DO_SYM
         | END