PGXC_STAT_ACTIVITY

PGXC_STAT_ACTIVITY displays information about the query performed by the current user on all the CNs in the current cluster.

Table 1 PGXC_STAT_ACTIVITY columns

Name

Type

Description

coorname

text

Name of the CN in the current cluster

datid

oid

OID of the database that the user session connects to in the backend

datname

name

Name of the database that the user session connects to in the backend

pid

bigint

ID of the backend thread

lwtid

integer

Lightweight thread ID of the backend thread

usesysid

oid

OID of the user logging in to the backend

usename

name

Name of the user logging in to the backend

application_name

text

Name of the application connected to the backend

client_addr

inet

IP address of the client connected to the backend. If this column is null, it indicates either that the client is connected via a Unix socket on the server machine or that this is an internal process such as autovacuum.

client_hostname

text

Host name of the connected client, as reported by a reverse DNS lookup of client_addr. This column will only be non-null for IP connections, and only when log_hostname is enabled.

client_port

integer

TCP port number that the client uses for communication with this backend, or -1 if a Unix socket is used

backend_start

timestamp with time zone

Startup time of the backend process, that is, the time when the client connects to the server

xact_start

timestamp with time zone

Time when the current transaction was started, or NULL if no transaction is active. If the current query is the first of its transaction, this column is equal to the query_start column.

query_start

timestamp with time zone

Time when the currently active query was started, or time when the last query was started if state is not active

state_change

timestamp with time zone

Time for the last status change

waiting

boolean

The value is t if the backend is waiting for a lock or node. Otherwise, the value is f.

enqueue

text

Queuing status of a statement. Its value can be:

  • waiting in global queue: The statement is in the global concurrent queues.

  • waiting in respool queue: The statement is queuing in the resource pool. The scenarios are as follows:

    1. When dynamic load balancing is enabled, the number of simple jobs exceeds the upper limit (max_dop) of concurrent jobs on the fast lane.

    2. When dynamic load balancing is disabled, the number of simple jobs exceeds the upper limit (max_dop) of concurrent jobs on the fast lane or the number of complex jobs exceeds the upper limit of concurrent jobs on the slow lane.

  • waiting in ccn queue: The job is in the CCN queue, which may be global memory queuing, slow lane memory queuing, or concurrent queuing.

  • Empty or no waiting queue: The statement is running.

state

text

Overall state of the backend. Its value can be:

  • active: The backend is executing a query.

  • idle: The backend is waiting for a new client command.

  • idle in transaction: The backend is in a transaction, but there is no statement being executed in the transaction.

  • idle in transaction (aborted): The backend is in a transaction, but there are statements failed in the transaction.

  • fastpath function call: The backend is executing a fast-path function.

  • disabled: This state is reported if track_activities is disabled in this backend.

Note

Only system administrators can view the session status of their accounts. The state information of other accounts is empty.

resource_pool

name

Resource pool used by the user

stmt_type

text

Type of a user statement

query_id

bigint

ID of a query

query

text

Text of this backend's most recent query If the state is active, this column shows the executing query. In all other states, it shows the last query that was executed.

connection_info

text

A string in JSON format recording the driver type, driver version, driver deployment path, and process owner of the connected database (for details, see connection_info).

Example

Run the following command to view blocked query statements.

SELECT datname,usename,state,query FROM PGXC_STAT_ACTIVITY WHERE waiting = true;

Check the working status of the snapshot thread.

SELECT application_name,backend_start,state_change,state,query FROM PGXC_STAT_ACTIVITY WHERE application_name='WDRSnapshot';

View the running query statements.

SELECT datname,usename,state,pid FROM PGXC_STAT_ACTIVITY;
 datname  | usename | state  |       pid
----------+---------+--------+-----------------
 gaussdb | Ruby    | active | 140298793514752
 gaussdb | Ruby    | active | 140298718004992
 gaussdb | Ruby    | idle   | 140298650908416
 gaussdb | Ruby    | idle   | 140298625742592
 gaussdb | dbadmin | active | 140298575406848
(5 rows)

View the number of session connections that have been used by postgres. 1 indicates the number of session connections that have been used by postgres.

SELECT COUNT(*) FROM PGXC_STAT_ACTIVITY WHERE DATNAME='postgres';
 count
-------
     1
(1 row)