Performance_Schema Database

Performance_Schema Database

TDengine includes a built-in database named PERFORMANCE_SCHEMA to provide access to database performance statistics. This document introduces the tables of PERFORMANCE_SCHEMA and their structure.

PERF_APP

Provides information about clients (such as applications) that connect to the cluster. Similar to SHOW APPS.

#	Column	Data Type	Description
1	app_id	UBIGINT	Client ID
2	ip	BINARY(16)	Client IP address
3	pid	INT	Client process
4	name	BINARY(24)	Client name
5	start_time	TIMESTAMP	Time when client was started
6	insert_req	UBIGINT	Insert requests
7	insert_row	UBIGINT	Rows inserted
8	insert_time	UBIGINT	Time spent processing insert requests in microseconds
9	insert_bytes	UBIGINT	Size of data inserted in byted
10	fetch_bytes	UBIGINT	Size of query results in bytes
11	query_time	UBIGINT	Time spend processing query requests
12	slow_query	UBIGINT	Number of slow queries (greater than or equal to 3 seconds)
13	total_req	UBIGINT	Total requests
14	current_req	UBIGINT	Requests currently being processed
15	last_access	TIMESTAMP	Last update time

PERF_CONNECTIONS

Provides information about connections to the database. Similar to SHOW CONNECTIONS.

#	Column	Data Type	Description
1	conn_id	INT	Connection ID
2	user	BINARY(24)	User name
3	app	BINARY(24)	Client name
4	pid	UINT	Client process ID on client device that initiated the connection
5	end_point	BINARY(128)	Client endpoint
6	login_time	TIMESTAMP	Login time
7	last_access	TIMESTAMP	Last update time

PERF_QUERIES

Provides information about SQL queries currently running. Similar to SHOW QUERIES.

#	Column	Data Type	Description
1	kill_id	UBIGINT	ID used to stop the query
2	query_id	INT	Query ID
3	conn_id	UINT	Connection ID
4	app	BINARY(24)	Client name
5	pid	INT	Client process ID on client device
6	user	BINARY(24)	User name
7	end_point	BINARY(16)	Client endpoint
8	create_time	TIMESTAMP	Creation time
9	exec_usec	BIGINT	Elapsed time
10	stable_query	BOOL	Whether the query is on a supertable
11	sub_num	INT	Number of subqueries
12	sub_status	BINARY(1000)	Subquery status
13	sql	BINARY(1024)	SQL statement

PERF_CONSUMERS

#	Column	Data Type	Description
1	consumer_id	BIGINT	Consumer ID
2	consumer_group	BINARY(192)	Consumer group
3	client_id	BINARY(192)	Client ID (user-defined)
4	status	BINARY(20)	Consumer status
5	topics	BINARY(204)	Subscribed topic. Returns one row for each topic.
6	up_time	TIMESTAMP	Time of first connection to TDengine Server
7	subscribe_time	TIMESTAMP	Time of first subscription
8	rebalance_time	TIMESTAMP	Time of first rebalance triggering

PERF_TRANS

#	Column	Data Type	Description
1	id	INT	ID of the transaction currently running
2	create_time	TIMESTAMP	Creation time
3	stage	BINARY(12)	Transaction stage (redoAction, undoAction, or commit)
4	db1	BINARY(64)	First database having a conflict with the transaction
5	db2	BINARY(64)	Second database having a conflict with the transaction
6	failed_times	INT	Times the transaction has failed
7	last_exec_time	TIMESTAMP	Previous time the transaction was run
8	last_action_info	BINARY(511)	Reason for failure on previous run

PERF_SMAS

#	Column	Data Type	Description
1	sma_name	BINARY(192)	Time-range-wise SMA name
2	create_time	TIMESTAMP	Creation time
3	stable_name	BINARY(192)	Supertable name
4	vgroup_id	INT	Dedicated vgroup name