MDEV-25325 built-in documentation for performance_schema tables

Improve documentation of performance_schema tables by appending COLUMN
comments to tables. Additionally improve test coverage and update corresponding
tests.

This is part of the patch covering newer columns and tables in 10.5.

mysql-test/suite/perfschema/r/dml_file_instances.result

@@ -87,3 +87,13 @@ DROP TABLE t_db_26152751;
 SELECT FILE_NAME FROM performance_schema.file_instances WHERE FILE_NAME LIKE "%t_db_26152751%";
 FILE_NAME
 DROP DATABASE db_26152751;
+#
+# MDEV-25325 column_comment for performance_shcema tables
+#
+select column_name, column_comment 
+from information_schema.columns 
+where table_schema='performance_schema' and table_name='file_instances';
+column_name	column_comment
+FILE_NAME	File name.
+EVENT_NAME	Instrument name associated with the file.
+OPEN_COUNT	Open handles on the file. A value of greater than zero means that the file is currently open.

mysql-test/suite/perfschema/r/dml_mems_by_account_by_event_name.result

@@ -24,3 +24,23 @@ UNLOCK TABLES;
 LOCK TABLES performance_schema.memory_summary_by_account_by_event_name WRITE;
 ERROR 42000: SELECT, LOCK TABLES command denied to user 'root'@'localhost' for table 'memory_summary_by_account_by_event_name'
 UNLOCK TABLES;
+#
+# MDEV-25325 column_comment for performance_shcema tables
+#
+select column_name, column_comment 
+from information_schema.columns 
+where table_schema='performance_schema' and table_name='memory_summary_by_account_by_event_name';
+column_name	column_comment
+USER	User portion of the account.
+HOST	Host portion of the account.
+EVENT_NAME	Event name.
+COUNT_ALLOC	Total number of allocations to memory.
+COUNT_FREE	Total number of attempts to free the allocated memory.
+SUM_NUMBER_OF_BYTES_ALLOC	Total number of bytes allocated.
+SUM_NUMBER_OF_BYTES_FREE	Total number of bytes freed
+LOW_COUNT_USED	Lowest number of allocated blocks (lowest value of CURRENT_COUNT_USED).
+CURRENT_COUNT_USED	Currently allocated blocks that have not been freed (COUNT_ALLOC minus COUNT_FREE).
+HIGH_COUNT_USED	Highest number of allocated blocks (highest value of CURRENT_COUNT_USED).
+LOW_NUMBER_OF_BYTES_USED	Lowest number of bytes used.
+CURRENT_NUMBER_OF_BYTES_USED	Current number of bytes used (total allocated minus total freed).
+HIGH_NUMBER_OF_BYTES_USED	Highest number of bytes used.

mysql-test/suite/perfschema/r/dml_mems_by_host_by_event_name.result

@@ -24,3 +24,22 @@ UNLOCK TABLES;
 LOCK TABLES performance_schema.memory_summary_by_host_by_event_name WRITE;
 ERROR 42000: SELECT, LOCK TABLES command denied to user 'root'@'localhost' for table 'memory_summary_by_host_by_event_name'
 UNLOCK TABLES;
+#
+# MDEV-25325 column_comment for performance_shcema tables
+#
+select column_name, column_comment 
+from information_schema.columns 
+where table_schema='performance_schema' and table_name='memory_summary_by_host_by_event_name';
+column_name	column_comment
+HOST	Host portion of the account.
+EVENT_NAME	Event name.
+COUNT_ALLOC	Total number of allocations to memory.
+COUNT_FREE	Total number of attempts to free the allocated memory.
+SUM_NUMBER_OF_BYTES_ALLOC	Total number of bytes allocated.
+SUM_NUMBER_OF_BYTES_FREE	Total number of bytes freed
+LOW_COUNT_USED	Lowest number of allocated blocks (lowest value of CURRENT_COUNT_USED).
+CURRENT_COUNT_USED	Currently allocated blocks that have not been freed (COUNT_ALLOC minus COUNT_FREE).
+HIGH_COUNT_USED	Highest number of allocated blocks (highest value of CURRENT_COUNT_USED).
+LOW_NUMBER_OF_BYTES_USED	Lowest number of bytes used.
+CURRENT_NUMBER_OF_BYTES_USED	Current number of bytes used (total allocated minus total freed).
+HIGH_NUMBER_OF_BYTES_USED	Highest number of bytes used.

mysql-test/suite/perfschema/r/dml_mems_by_user_by_event_name.result

@@ -24,3 +24,22 @@ UNLOCK TABLES;
 LOCK TABLES performance_schema.memory_summary_by_user_by_event_name WRITE;
 ERROR 42000: SELECT, LOCK TABLES command denied to user 'root'@'localhost' for table 'memory_summary_by_user_by_event_name'
 UNLOCK TABLES;
+#
+# MDEV-25325 column_comment for performance_shcema tables
+#
+select column_name, column_comment 
+from information_schema.columns 
+where table_schema='performance_schema' and table_name='memory_summary_by_user_by_event_name';
+column_name	column_comment
+USER	User portion of the account.
+EVENT_NAME	Event name.
+COUNT_ALLOC	Total number of allocations to memory.
+COUNT_FREE	Total number of attempts to free the allocated memory.
+SUM_NUMBER_OF_BYTES_ALLOC	Total number of bytes allocated.
+SUM_NUMBER_OF_BYTES_FREE	Total number of bytes freed
+LOW_COUNT_USED	Lowest number of allocated blocks (lowest value of CURRENT_COUNT_USED).
+CURRENT_COUNT_USED	Currently allocated blocks that have not been freed (COUNT_ALLOC minus COUNT_FREE).
+HIGH_COUNT_USED	Highest number of allocated blocks (highest value of CURRENT_COUNT_USED).
+LOW_NUMBER_OF_BYTES_USED	Lowest number of bytes used.
+CURRENT_NUMBER_OF_BYTES_USED	Current number of bytes used (total allocated minus total freed).
+HIGH_NUMBER_OF_BYTES_USED	Highest number of bytes used.

mysql-test/suite/perfschema/r/dml_mems_global_by_event_name.result

@@ -24,3 +24,21 @@ UNLOCK TABLES;
 LOCK TABLES performance_schema.memory_summary_global_by_event_name WRITE;
 ERROR 42000: SELECT, LOCK TABLES command denied to user 'root'@'localhost' for table 'memory_summary_global_by_event_name'
 UNLOCK TABLES;
+#
+# MDEV-25325 column_comment for performance_shcema tables
+#
+select column_name, column_comment 
+from information_schema.columns 
+where table_schema='performance_schema' and table_name='memory_summary_global_by_event_name';
+column_name	column_comment
+EVENT_NAME	Event name.
+COUNT_ALLOC	Total number of allocations to memory.
+COUNT_FREE	Total number of attempts to free the allocated memory.
+SUM_NUMBER_OF_BYTES_ALLOC	Total number of bytes allocated.
+SUM_NUMBER_OF_BYTES_FREE	Total number of bytes freed
+LOW_COUNT_USED	Lowest number of allocated blocks (lowest value of CURRENT_COUNT_USED).
+CURRENT_COUNT_USED	Currently allocated blocks that have not been freed (COUNT_ALLOC minus COUNT_FREE).
+HIGH_COUNT_USED	Highest number of allocated blocks (highest value of CURRENT_COUNT_USED).
+LOW_NUMBER_OF_BYTES_USED	Lowest number of bytes used.
+CURRENT_NUMBER_OF_BYTES_USED	Current number of bytes used (total allocated minus total freed).
+HIGH_NUMBER_OF_BYTES_USED	Highest number of bytes used.

mysql-test/suite/perfschema/r/dml_metadata_locks.result

@@ -19,3 +19,20 @@ UNLOCK TABLES;
 LOCK TABLES performance_schema.metadata_locks WRITE;
 ERROR 42000: SELECT, LOCK TABLES command denied to user 'root'@'localhost' for table 'metadata_locks'
 UNLOCK TABLES;
+#
+# MDEV-25325 column_comment for performance_shcema tables
+#
+select column_name, column_comment 
+from information_schema.columns 
+where table_schema='performance_schema' and table_name='metadata_locks';
+column_name	column_comment
+OBJECT_TYPE	Object type. One of BACKUP, COMMIT, EVENT, FUNCTION, GLOBAL, LOCKING SERVICE, PROCEDURE, SCHEMA, TABLE, TABLESPACE, TRIGGER (unused) or USER LEVEL LOCK.
+OBJECT_SCHEMA	Object schema.
+OBJECT_NAME	Object name.
+OBJECT_INSTANCE_BEGIN	Address in memory of the instrumented object.
+LOCK_TYPE	Lock type. One of BACKUP_FTWRL1, BACKUP_START, BACKUP_TRANS_DML, EXCLUSIVE, INTENTION_EXCLUSIVE, SHARED, SHARED_HIGH_PRIO, SHARED_NO_READ_WRITE, SHARED_NO_WRITE, SHARED_READ, SHARED_UPGRADABLE or SHARED_WRITE.
+LOCK_DURATION	Lock duration. One of EXPLICIT (locks released by explicit action, for example a global lock acquired with FLUSH TABLES WITH READ LOCK) , STATEMENT (locks implicitly released at statement end) or TRANSACTION (locks implicitly released at transaction end).
+LOCK_STATUS	Lock status. One of GRANTED, KILLED, PENDING, POST_RELEASE_NOTIFY, PRE_ACQUIRE_NOTIFY, TIMEOUT or VICTIM.
+SOURCE	Source file containing the instrumented code that produced the event, as well as the line number where the instrumentation occurred. This allows one to examine the source code involved.
+OWNER_THREAD_ID	Thread that requested the lock.
+OWNER_EVENT_ID	Event that requested the lock.

mysql-test/suite/perfschema/r/dml_replication_applier_status_by_worker.result

@@ -23,3 +23,19 @@ UNLOCK TABLES;
 LOCK TABLES performance_schema.replication_applier_status_by_worker WRITE;
 ERROR 42000: SELECT, LOCK TABLES command denied to user 'root'@'localhost' for table 'replication_applier_status_by_worker'
 UNLOCK TABLES;
+#
+# MDEV-25325 column_comment for performance_shcema tables
+#
+select column_name, column_comment 
+from information_schema.columns 
+where table_schema='performance_schema' and table_name='replication_applier_status_by_worker';
+column_name	column_comment
+CHANNEL_NAME	Name of replication channel through which the transaction is received.
+THREAD_ID	Thread_Id as displayed in the performance_schema.threads table for thread with name 'thread/sql/rpl_parallel_thread'. THREAD_ID will be NULL when worker threads are stopped due to error/force stop.
+SERVICE_STATE	Whether or not the thread is running.
+LAST_SEEN_TRANSACTION	Last GTID executed by worker
+LAST_ERROR_NUMBER	Last Error that occurred on a particular worker.
+LAST_ERROR_MESSAGE	Last error specific message.
+LAST_ERROR_TIMESTAMP	Time stamp of last error.
+WORKER_IDLE_TIME	Total idle time in seconds that the worker thread has spent waiting for work from SQL thread.
+LAST_TRANS_RETRY_COUNT	Total number of retries attempted by last transaction.