PGXC_THREAD_WAIT_STATUS

In PGXC_THREAD_WAIT_STATUS, you can see 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 view and PG_THREAD_WAIT_STATUS view are the same, because the essence of the PGXC_THREAD_WAIT_STATUS view is the query summary of the PG_THREAD_WAIT_STATUS view 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. For details, see Table 2.
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.

   
    
      
      
        gaussdb=# select * from pg_thread_wait_status where query_id > 0;
-[ RECORD 1 ]----+--------------------------------------
node_name        | cn_5001
db_name          | tpcc_row
thread_name      | PostgreSQL JDBC Driver
query_id         | 72620544050065400
tid              | 140650239031040
sessionid        | 11680
lwtid            | 26762
psessionid       |
tlevel           | 0
smpid            | 0
wait_status      | wait node: dn_6007_6008_6009, total 1
wait_event       | wait node
locktag          |
lockmode         |
block_sessionid  |
global_sessionid | 1120683504:11680#0
gaussdb=#  
select * from pgxc_thread_wait_status where query_id > 0;
-[ RECORD 1 ]----+--------------------------------------------------
node_name        | cn_5001
db_name          | tpcc_row
thread_name      | PostgreSQL JDBC Driver
query_id         | 72620544050081616
tid              | 140648290055936
sessionid        | 11680
lwtid            | 26839
psessionid       |
tlevel           | 0
smpid            | 0
wait_status      | wait node: dn_6004_6005_6006, total 2
wait_event       | wait node
locktag          |
lockmode         |
block_sessionid  |
global_sessionid | 1120683504:11680#0
(1 rows)

       

     

   
  