| sidebar_label |
title |
| Statistics |
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 |