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.

mysql-test/suite/perfschema/t/dml_file_instances.test

@@ -103,3 +103,11 @@ DROP TABLE t_db_26152751;
 SELECT FILE_NAME FROM performance_schema.file_instances WHERE FILE_NAME LIKE "%t_db_26152751%";
 
 DROP DATABASE db_26152751;
+
+
+--echo #
+--echo # MDEV-25325 column_comment for performance_shcema tables
+--echo #
+select column_name, column_comment 
+from information_schema.columns 
+where table_schema='performance_schema' and table_name='file_instances';

mysql-test/suite/perfschema/t/dml_mems_by_account_by_event_name.test

@@ -40,3 +40,9 @@ UNLOCK TABLES;
 LOCK TABLES performance_schema.memory_summary_by_account_by_event_name WRITE;
 UNLOCK TABLES;
 
+--echo #
+--echo # MDEV-25325 column_comment for performance_shcema tables
+--echo #
+select column_name, column_comment 
+from information_schema.columns 
+where table_schema='performance_schema' and table_name='memory_summary_by_account_by_event_name';

mysql-test/suite/perfschema/t/dml_mems_by_host_by_event_name.test

@@ -40,3 +40,9 @@ UNLOCK TABLES;
 LOCK TABLES performance_schema.memory_summary_by_host_by_event_name WRITE;
 UNLOCK TABLES;
 
+--echo #
+--echo # MDEV-25325 column_comment for performance_shcema tables
+--echo #
+select column_name, column_comment 
+from information_schema.columns 
+where table_schema='performance_schema' and table_name='memory_summary_by_host_by_event_name';

mysql-test/suite/perfschema/t/dml_mems_by_user_by_event_name.test

@@ -40,3 +40,9 @@ UNLOCK TABLES;
 LOCK TABLES performance_schema.memory_summary_by_user_by_event_name WRITE;
 UNLOCK TABLES;
 
+--echo #
+--echo # MDEV-25325 column_comment for performance_shcema tables
+--echo #
+select column_name, column_comment 
+from information_schema.columns 
+where table_schema='performance_schema' and table_name='memory_summary_by_user_by_event_name';

mysql-test/suite/perfschema/t/dml_mems_global_by_event_name.test

@@ -40,3 +40,9 @@ UNLOCK TABLES;
 LOCK TABLES performance_schema.memory_summary_global_by_event_name WRITE;
 UNLOCK TABLES;
 
+--echo #
+--echo # MDEV-25325 column_comment for performance_shcema tables
+--echo #
+select column_name, column_comment 
+from information_schema.columns 
+where table_schema='performance_schema' and table_name='memory_summary_global_by_event_name';

mysql-test/suite/perfschema/t/dml_metadata_locks.test

@@ -33,3 +33,9 @@ UNLOCK TABLES;
 LOCK TABLES performance_schema.metadata_locks WRITE;
 UNLOCK TABLES;
 
+--echo #
+--echo # MDEV-25325 column_comment for performance_shcema tables
+--echo #
+select column_name, column_comment 
+from information_schema.columns 
+where table_schema='performance_schema' and table_name='metadata_locks';

mysql-test/suite/perfschema/t/dml_replication_applier_status_by_worker.test

@@ -41,3 +41,10 @@ UNLOCK TABLES;
 -- error ER_TABLEACCESS_DENIED_ERROR
 LOCK TABLES performance_schema.replication_applier_status_by_worker WRITE;
 UNLOCK TABLES;
+
+--echo #
+--echo # MDEV-25325 column_comment for performance_shcema tables
+--echo #
+select column_name, column_comment 
+from information_schema.columns 
+where table_schema='performance_schema' and table_name='replication_applier_status_by_worker';

storage/perfschema/table_md_locks.cc

@@ -49,16 +49,16 @@ table_metadata_locks::m_share=
   sizeof(PFS_simple_index),
   &m_table_lock,
   { C_STRING_WITH_LEN("CREATE TABLE metadata_locks("
-  "OBJECT_TYPE VARCHAR(64) not null,"
-  "OBJECT_SCHEMA VARCHAR(64),"
-  "OBJECT_NAME VARCHAR(64),"
-  "OBJECT_INSTANCE_BEGIN BIGINT unsigned not null,"
-  "LOCK_TYPE VARCHAR(32) not null,"
-  "LOCK_DURATION VARCHAR(32) not null,"
-  "LOCK_STATUS VARCHAR(32) not null,"
-  "SOURCE VARCHAR(64),"
-  "OWNER_THREAD_ID BIGINT unsigned,"
-  "OWNER_EVENT_ID BIGINT unsigned)")},
+  "OBJECT_TYPE VARCHAR(64) not null comment 'Object type. One of BACKUP, COMMIT, EVENT, FUNCTION, GLOBAL, LOCKING SERVICE, PROCEDURE, SCHEMA, TABLE, TABLESPACE, TRIGGER (unused) or USER LEVEL LOCK.',"
+  "OBJECT_SCHEMA VARCHAR(64) comment 'Object schema.',"
+  "OBJECT_NAME VARCHAR(64) comment 'Object name.',"
+  "OBJECT_INSTANCE_BEGIN BIGINT unsigned not null comment 'Address in memory of the instrumented object.',"
+  "LOCK_TYPE VARCHAR(32) not null comment '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 VARCHAR(32) not null comment '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 VARCHAR(32) not null comment 'Lock status. One of GRANTED, KILLED, PENDING, POST_RELEASE_NOTIFY, PRE_ACQUIRE_NOTIFY, TIMEOUT or VICTIM.',"
+  "SOURCE VARCHAR(64) comment '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 BIGINT unsigned comment 'Thread that requested the lock.',"
+  "OWNER_EVENT_ID BIGINT unsigned comment 'Event that requested the lock.')")},
   false  /* perpetual */
 };
 

storage/perfschema/table_mems_by_account_by_event_name.cc

@@ -51,19 +51,19 @@ table_mems_by_account_by_event_name::m_share=
   sizeof(pos_mems_by_account_by_event_name),
   &m_table_lock,
   { C_STRING_WITH_LEN("CREATE TABLE memory_summary_by_account_by_event_name("
-  "USER CHAR(32) collate utf8_bin default null,"
-  "HOST CHAR(60) collate utf8_bin default null,"
-  "EVENT_NAME VARCHAR(128) not null,"
-  "COUNT_ALLOC BIGINT unsigned not null,"
-  "COUNT_FREE BIGINT unsigned not null,"
-  "SUM_NUMBER_OF_BYTES_ALLOC BIGINT unsigned not null,"
-  "SUM_NUMBER_OF_BYTES_FREE BIGINT unsigned not null,"
-  "LOW_COUNT_USED BIGINT not null,"
-  "CURRENT_COUNT_USED BIGINT not null,"
-  "HIGH_COUNT_USED BIGINT not null,"
-  "LOW_NUMBER_OF_BYTES_USED BIGINT not null,"
-  "CURRENT_NUMBER_OF_BYTES_USED BIGINT not null,"
-  "HIGH_NUMBER_OF_BYTES_USED BIGINT not null)")},
+  "USER CHAR(32) collate utf8_bin default null comment 'User portion of the account.',"
+  "HOST CHAR(60) collate utf8_bin default null comment 'Host portion of the account.',"
+  "EVENT_NAME VARCHAR(128) not null comment 'Event name.',"
+  "COUNT_ALLOC BIGINT unsigned not null comment 'Total number of allocations to memory.',"
+  "COUNT_FREE BIGINT unsigned not null comment 'Total number of attempts to free the allocated memory.',"
+  "SUM_NUMBER_OF_BYTES_ALLOC BIGINT unsigned not null comment 'Total number of bytes allocated.',"
+  "SUM_NUMBER_OF_BYTES_FREE BIGINT unsigned not null comment 'Total number of bytes freed',"
+  "LOW_COUNT_USED BIGINT not null comment 'Lowest number of allocated blocks (lowest value of CURRENT_COUNT_USED).',"
+  "CURRENT_COUNT_USED BIGINT not null comment 'Currently allocated blocks that have not been freed (COUNT_ALLOC minus COUNT_FREE).',"
+  "HIGH_COUNT_USED BIGINT not null comment 'Highest number of allocated blocks (highest value of CURRENT_COUNT_USED).',"
+  "LOW_NUMBER_OF_BYTES_USED BIGINT not null comment 'Lowest number of bytes used.',"
+  "CURRENT_NUMBER_OF_BYTES_USED BIGINT not null comment 'Current number of bytes used (total allocated minus total freed).',"
+  "HIGH_NUMBER_OF_BYTES_USED BIGINT not null comment 'Highest number of bytes used.')")},
   false  /* perpetual */
 };
 

storage/perfschema/table_mems_by_host_by_event_name.cc

@@ -51,18 +51,18 @@ table_mems_by_host_by_event_name::m_share=
   sizeof(PFS_simple_index),
   &m_table_lock,
   { C_STRING_WITH_LEN("CREATE TABLE memory_summary_by_host_by_event_name("
-  "HOST CHAR(60) collate utf8_bin default null,"
-  "EVENT_NAME VARCHAR(128) not null,"
-  "COUNT_ALLOC BIGINT unsigned not null,"
-  "COUNT_FREE BIGINT unsigned not null,"
-  "SUM_NUMBER_OF_BYTES_ALLOC BIGINT unsigned not null,"
-  "SUM_NUMBER_OF_BYTES_FREE BIGINT unsigned not null,"
-  "LOW_COUNT_USED BIGINT not null,"
-  "CURRENT_COUNT_USED BIGINT not null,"
-  "HIGH_COUNT_USED BIGINT not null,"
-  "LOW_NUMBER_OF_BYTES_USED BIGINT not null,"
-  "CURRENT_NUMBER_OF_BYTES_USED BIGINT not null,"
-  "HIGH_NUMBER_OF_BYTES_USED BIGINT not null)")},
+  "HOST CHAR(60) collate utf8_bin default null comment 'Host portion of the account.',"
+  "EVENT_NAME VARCHAR(128) not null comment 'Event name.',"
+  "COUNT_ALLOC BIGINT unsigned not null comment 'Total number of allocations to memory.',"
+  "COUNT_FREE BIGINT unsigned not null comment 'Total number of attempts to free the allocated memory.',"
+  "SUM_NUMBER_OF_BYTES_ALLOC BIGINT unsigned not null comment 'Total number of bytes allocated.',"
+  "SUM_NUMBER_OF_BYTES_FREE BIGINT unsigned not null comment 'Total number of bytes freed',"
+  "LOW_COUNT_USED BIGINT not null comment 'Lowest number of allocated blocks (lowest value of CURRENT_COUNT_USED).',"
+  "CURRENT_COUNT_USED BIGINT not null comment 'Currently allocated blocks that have not been freed (COUNT_ALLOC minus COUNT_FREE).',"
+  "HIGH_COUNT_USED BIGINT not null comment 'Highest number of allocated blocks (highest value of CURRENT_COUNT_USED).',"
+  "LOW_NUMBER_OF_BYTES_USED BIGINT not null comment 'Lowest number of bytes used.',"
+  "CURRENT_NUMBER_OF_BYTES_USED BIGINT not null comment 'Current number of bytes used (total allocated minus total freed).',"
+  "HIGH_NUMBER_OF_BYTES_USED BIGINT not null comment 'Highest number of bytes used.')")},
   false  /* perpetual */
 };
 

storage/perfschema/table_mems_by_thread_by_event_name.cc

@@ -51,18 +51,18 @@ table_mems_by_thread_by_event_name::m_share=
   sizeof(PFS_simple_index),
   &m_table_lock,
   { C_STRING_WITH_LEN("CREATE TABLE memory_summary_by_thread_by_event_name("
-  "THREAD_ID BIGINT unsigned not null,"
-  "EVENT_NAME VARCHAR(128) not null,"
-  "COUNT_ALLOC BIGINT unsigned not null,"
-  "COUNT_FREE BIGINT unsigned not null,"
-  "SUM_NUMBER_OF_BYTES_ALLOC BIGINT unsigned not null,"
-  "SUM_NUMBER_OF_BYTES_FREE BIGINT unsigned not null,"
-  "LOW_COUNT_USED BIGINT not null,"
-  "CURRENT_COUNT_USED BIGINT not null,"
-  "HIGH_COUNT_USED BIGINT not null,"
-  "LOW_NUMBER_OF_BYTES_USED BIGINT not null,"
-  "CURRENT_NUMBER_OF_BYTES_USED BIGINT not null,"
-  "HIGH_NUMBER_OF_BYTES_USED BIGINT not null)")},
+  "THREAD_ID BIGINT unsigned not null comment 'Thread id.',"
+  "EVENT_NAME VARCHAR(128) not null comment 'Event name.',"
+  "COUNT_ALLOC BIGINT unsigned not null comment 'Total number of allocations to memory.',"
+  "COUNT_FREE BIGINT unsigned not null comment 'Total number of attempts to free the allocated memory.',"
+  "SUM_NUMBER_OF_BYTES_ALLOC BIGINT unsigned not null comment 'Total number of bytes allocated.',"
+  "SUM_NUMBER_OF_BYTES_FREE BIGINT unsigned not null comment 'Total number of bytes freed',"
+  "LOW_COUNT_USED BIGINT not null comment 'Lowest number of allocated blocks (lowest value of CURRENT_COUNT_USED).',"
+  "CURRENT_COUNT_USED BIGINT not null comment 'Currently allocated blocks that have not been freed (COUNT_ALLOC minus COUNT_FREE).',"
+  "HIGH_COUNT_USED BIGINT not null comment 'Highest number of allocated blocks (highest value of CURRENT_COUNT_USED).',"
+  "LOW_NUMBER_OF_BYTES_USED BIGINT not null comment 'Lowest number of bytes used.',"
+  "CURRENT_NUMBER_OF_BYTES_USED BIGINT not null comment 'Current number of bytes used (total allocated minus total freed).',"
+  "HIGH_NUMBER_OF_BYTES_USED BIGINT not null comment 'Highest number of bytes used.')")},
   false  /* perpetual */
 };
 

storage/perfschema/table_mems_by_user_by_event_name.cc

@@ -51,18 +51,18 @@ table_mems_by_user_by_event_name::m_share=
   sizeof(PFS_simple_index),
   &m_table_lock,
   { C_STRING_WITH_LEN("CREATE TABLE memory_summary_by_user_by_event_name("
-  "USER CHAR(32) collate utf8_bin default null,"
-  "EVENT_NAME VARCHAR(128) not null,"
-  "COUNT_ALLOC BIGINT unsigned not null,"
-  "COUNT_FREE BIGINT unsigned not null,"
-  "SUM_NUMBER_OF_BYTES_ALLOC BIGINT unsigned not null,"
-  "SUM_NUMBER_OF_BYTES_FREE BIGINT unsigned not null,"
-  "LOW_COUNT_USED BIGINT not null,"
-  "CURRENT_COUNT_USED BIGINT not null,"
-  "HIGH_COUNT_USED BIGINT not null,"
-  "LOW_NUMBER_OF_BYTES_USED BIGINT not null,"
-  "CURRENT_NUMBER_OF_BYTES_USED BIGINT not null,"
-  "HIGH_NUMBER_OF_BYTES_USED BIGINT not null)")},
+  "USER CHAR(32) collate utf8_bin default null comment 'User portion of the account.',"
+  "EVENT_NAME VARCHAR(128) not null comment 'Event name.',"
+  "COUNT_ALLOC BIGINT unsigned not null comment 'Total number of allocations to memory.',"
+  "COUNT_FREE BIGINT unsigned not null comment 'Total number of attempts to free the allocated memory.',"
+  "SUM_NUMBER_OF_BYTES_ALLOC BIGINT unsigned not null comment 'Total number of bytes allocated.',"
+  "SUM_NUMBER_OF_BYTES_FREE BIGINT unsigned not null comment 'Total number of bytes freed',"
+  "LOW_COUNT_USED BIGINT not null comment 'Lowest number of allocated blocks (lowest value of CURRENT_COUNT_USED).',"
+  "CURRENT_COUNT_USED BIGINT not null comment 'Currently allocated blocks that have not been freed (COUNT_ALLOC minus COUNT_FREE).',"
+  "HIGH_COUNT_USED BIGINT not null comment 'Highest number of allocated blocks (highest value of CURRENT_COUNT_USED).',"
+  "LOW_NUMBER_OF_BYTES_USED BIGINT not null comment 'Lowest number of bytes used.',"
+  "CURRENT_NUMBER_OF_BYTES_USED BIGINT not null comment 'Current number of bytes used (total allocated minus total freed).',"
+  "HIGH_NUMBER_OF_BYTES_USED BIGINT not null comment 'Highest number of bytes used.')")},
   false  /* perpetual */
 };
 

storage/perfschema/table_mems_global_by_event_name.cc

@@ -51,17 +51,17 @@ table_mems_global_by_event_name::m_share=
   sizeof(pos_t),
   &m_table_lock,
   { C_STRING_WITH_LEN("CREATE TABLE memory_summary_global_by_event_name("
-  "EVENT_NAME VARCHAR(128) not null,"
-  "COUNT_ALLOC BIGINT unsigned not null,"
-  "COUNT_FREE BIGINT unsigned not null,"
-  "SUM_NUMBER_OF_BYTES_ALLOC BIGINT unsigned not null,"
-  "SUM_NUMBER_OF_BYTES_FREE BIGINT unsigned not null,"
-  "LOW_COUNT_USED BIGINT not null,"
-  "CURRENT_COUNT_USED BIGINT not null,"
-  "HIGH_COUNT_USED BIGINT not null,"
-  "LOW_NUMBER_OF_BYTES_USED BIGINT not null,"
-  "CURRENT_NUMBER_OF_BYTES_USED BIGINT not null,"
-  "HIGH_NUMBER_OF_BYTES_USED BIGINT not null)")},
+  "EVENT_NAME VARCHAR(128) not null comment 'Event name.',"
+  "COUNT_ALLOC BIGINT unsigned not null comment 'Total number of allocations to memory.',"
+  "COUNT_FREE BIGINT unsigned not null comment 'Total number of attempts to free the allocated memory.',"
+  "SUM_NUMBER_OF_BYTES_ALLOC BIGINT unsigned not null comment 'Total number of bytes allocated.',"
+  "SUM_NUMBER_OF_BYTES_FREE BIGINT unsigned not null comment 'Total number of bytes freed',"
+  "LOW_COUNT_USED BIGINT not null comment 'Lowest number of allocated blocks (lowest value of CURRENT_COUNT_USED).',"
+  "CURRENT_COUNT_USED BIGINT not null comment 'Currently allocated blocks that have not been freed (COUNT_ALLOC minus COUNT_FREE).',"
+  "HIGH_COUNT_USED BIGINT not null comment 'Highest number of allocated blocks (highest value of CURRENT_COUNT_USED).',"
+  "LOW_NUMBER_OF_BYTES_USED BIGINT not null comment 'Lowest number of bytes used.',"
+  "CURRENT_NUMBER_OF_BYTES_USED BIGINT not null comment 'Current number of bytes used (total allocated minus total freed).',"
+  "HIGH_NUMBER_OF_BYTES_USED BIGINT not null comment 'Highest number of bytes used.')")},
   false  /* perpetual */
 };
 

storage/perfschema/table_replication_applier_status_by_worker.cc

@@ -54,14 +54,14 @@ table_replication_applier_status_by_worker::m_share=
   sizeof(pos_t), /* ref length */
   &m_table_lock,
   { C_STRING_WITH_LEN("CREATE TABLE replication_applier_status_by_worker("
-  "CHANNEL_NAME CHAR(64) collate utf8_general_ci not null,"
-  "WORKER_ID BIGINT UNSIGNED not null,"
-  "THREAD_ID BIGINT UNSIGNED,"
-  "SERVICE_STATE ENUM('ON','OFF') not null,"
-  "LAST_SEEN_TRANSACTION CHAR(57) not null,"
-  "LAST_ERROR_NUMBER INTEGER not null,"
-  "LAST_ERROR_MESSAGE VARCHAR(1024) not null,"
-  "LAST_ERROR_TIMESTAMP TIMESTAMP(0) not null)") },
+  "CHANNEL_NAME CHAR(64) collate utf8_general_ci not null comment 'Name of replication channel through which the transaction is received.',"
+  "WORKER_ID BIGINT UNSIGNED not null comment 'Worker identifier.,"
+  "THREAD_ID BIGINT UNSIGNED comment '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 ENUM('ON','OFF') not null comment 'Whether or not the thread is running.',"
+  "LAST_SEEN_TRANSACTION CHAR(57) not null comment 'Last GTID executed by worker',"
+  "LAST_ERROR_NUMBER INTEGER not null comment 'Last Error that occurred on a particular worker.',"
+  "LAST_ERROR_MESSAGE VARCHAR(1024) not null comment 'Last error specific message.',"
+  "LAST_ERROR_TIMESTAMP TIMESTAMP(0) not null comment 'Time stamp of last error.')") },
   false  /* perpetual */
 };