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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.

#ColumnData TypeDescription
1app_idUBIGINTClient ID
2ipBINARY(16)Client IP address
3pidINTClient process
4nameBINARY(24)Client name
5start_timeTIMESTAMPTime when client was started
6insert_reqUBIGINTInsert requests
7insert_rowUBIGINTRows inserted
8insert_timeUBIGINTTime spent processing insert requests in microseconds
9insert_bytesUBIGINTSize of data inserted in byted
10fetch_bytesUBIGINTSize of query results in bytes
11query_timeUBIGINTTime spend processing query requests
12slow_queryUBIGINTNumber of slow queries (greater than or equal to 3 seconds)
13total_reqUBIGINTTotal requests
14current_reqUBIGINTRequests currently being processed
15last_accessTIMESTAMPLast update time

PERF_CONNECTIONS

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

#ColumnData TypeDescription
1conn_idINTConnection ID
2userBINARY(24)User name
3appBINARY(24)Client name
4pidUINTClient process ID on client device that initiated the connection
5end_pointBINARY(128)Client endpoint
6login_timeTIMESTAMPLogin time
7last_accessTIMESTAMPLast update time

PERF_QUERIES

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

#ColumnData TypeDescription
1kill_idUBIGINTID used to stop the query
2query_idINTQuery ID
3conn_idUINTConnection ID
4appBINARY(24)Client name
5pidINTClient process ID on client device
6userBINARY(24)User name
7end_pointBINARY(16)Client endpoint
8create_timeTIMESTAMPCreation time
9exec_usecBIGINTElapsed time
10stable_queryBOOLWhether the query is on a supertable
11sub_numINTNumber of subqueries
12sub_statusBINARY(1000)Subquery status
13sqlBINARY(1024)SQL statement

PERF_CONSUMERS

#ColumnData TypeDescription
1consumer_idBIGINTConsumer ID
2consumer_groupBINARY(192)Consumer group
3client_idBINARY(192)Client ID (user-defined)
4statusBINARY(20)Consumer status. All possible status include: ready(consumer is in normal state), lost(the connection between consumer and mnode is broken), rebalance(the redistribution of vgroups that belongs to current consumer is now in progress), unknown(consumer is in invalid state)
5topicsBINARY(204)Subscribed topic. Returns one row for each topic.
6up_timeTIMESTAMPTime of first connection to TDengine Server
7subscribe_timeTIMESTAMPTime of first subscription
8rebalance_timeTIMESTAMPTime of first rebalance triggering

PERF_TRANS

#ColumnData TypeDescription
1idINTID of the transaction currently running
2create_timeTIMESTAMPCreation time
3stageBINARY(12)Transaction stage (redoAction, undoAction, or commit)
4db1BINARY(64)First database having a conflict with the transaction
5db2BINARY(64)Second database having a conflict with the transaction
6failed_timesINTTimes the transaction has failed
7last_exec_timeTIMESTAMPPrevious time the transaction was run
8last_action_infoBINARY(511)Reason for failure on previous run

PERF_SMAS

#ColumnData TypeDescription
1sma_nameBINARY(192)Time-range-wise SMA name
2create_timeTIMESTAMPCreation time
3stable_nameBINARY(192)Supertable name
4vgroup_idINTDedicated vgroup name