Help Center/ GaussDB/ Developer Guide(Distributed_V2.0-2.x)/ System Catalogs and System Views/ System Views/ PGXC_THREAD_WAIT_STATUS
Updated on 2025-08-19 GMT+08:00
View PDF

PGXC_THREAD_WAIT_STATUS

PGXC_THREAD_WAIT_STATUS displays all the call layer hierarchy relationship between threads of the SQL statements on all the nodes in a cluster, and the waiting status of the block for each thread, so that you can easily locate the causes of process response failures and similar phenomena.

The definitions of PGXC_THREAD_WAIT_STATUS and PG_THREAD_WAIT_STATUS are the same, because the essence of PGXC_THREAD_WAIT_STATUS is the query summary of PG_THREAD_WAIT_STATUS on each node in the cluster.

Table 1 PGXC_THREAD_WAIT_STATUS columns

Name

Type

Description

node_name

text

Current node name.

db_name

text

Database name.

thread_name

text

Thread name.

query_id

bigint

Query ID. It is equivalent to debug_query_id.

tid

bigint

Thread ID of the current thread.

sessionid

bigint

Session ID.

lwtid

integer

Lightweight thread ID of the current thread.

psessionid

bigint

Parent session ID.

tlevel

integer

Level of the streaming thread.

smpid

integer

Concurrent thread ID.

wait_status

text

Detailed information about the waiting status of the current thread.

wait_event

text

Event that the current thread is waiting for.

locktag

text

Information about the lock that the current thread is waiting for.

lockmode

text

Lock mode that the current thread is waiting to obtain.

block_sessionid

bigint

ID of the session that blocks the current thread from obtaining the lock.

global_sessionid

text

Global session ID.

Example:

If you run a statement on coordinator1 and no response is returned after a long period of time, establish another connection to coordinator1 to check the thread status on it.

 1
 2
 3
 4
 5
 6
 7
 8
 9
10
11
12
13
 
openGauss=# SELECT * FROM pg_thread_wait_status WHERE query_id > 0;
  node_name   | db_name  | thread_name  | query_id |       tid       | lwtid | ptid  | tlevel | smpid |     wait_status   |   wait_event   
--------------+----------+--------------+----------+-----------------+-------+-------+--------+-------+----------------------
 coordinator1 | postgres | gsql         | 20971544 | 140274089064208 | 22579 |       |      0 |     0 | wait node: datanode4 |
(1 rows)
openGauss=# SELECT * FROM pgxc_thread_wait_status WHERE query_id > 0;
  node_name   | db_name  | thread_name  |     query_id      |      tid       |   sessionid    | lwtid  | psessionid | tlevel | smpid | wait_status | wait_event
--------------+----------+--------------+-------------------+----------------+----------------+--------+------------+--------+-------+-------------+------------
 coordinator1 | postgres | gsql         | 77687093572155050 | 47212704827136 | 47212704827136 |  63191 |            |      0 |     0 | none        |
 coordinator2 | postgres | coordinator1 | 77687093572155050 | 47403117319936 | 47403117319936 | 159322 |            |      0 |     0 | none        |
 data_node1   | postgres | coordinator1 | 77687093572155050 | 47723869374208 | 47723869374208 | 159320 |            |      0 |     0 | none        |
 data_node2   | postgres | coordinator1 | 77687093572155050 | 47852867290880 | 47852867290880 | 159321 |            |      0 |     0 | none        |
(4 rows)
Parent topic: System Views