Other Functions

pgxc_pool_check()
Description: Checks whether the connection data buffered in the pool is consistent with pgxc_node.
Return type: Boolean
pgxc_pool_reload()
Description: Updates the connection information buffered in the pool.
Return type: Boolean
pgxc_lock_for_backup()
Description: Locks openGauss for taking backup that would be used for restoration on the new nodes.
Return type: Boolean
plan_seed()
Description: Obtains the seed value of the previous query statement (internal use).
Return type: int
pg_stat_get_env()
Description: Obtains the environment variable information about the current node.
Return type: record
pg_stat_get_thread()
Description: Provides information about the status of all threads under the current node.
Return type: record
pg_stat_get_sql_count()
Description: Provides the counts of the SELECT, UPDATE, INSERT, DELETE, and MERGE INTO statements executed on the current node.
Return type: record

copy_error_log_create()

Description: Creates the error table (public.pgxc_copy_error_log) required for creating the COPY FROM error tolerance mechanism.

Return type: Boolean

NOTE:
This function attempts to create the public.pgxc_copy_error_log table. For details about the table, see Table 1.
Create the B-tree index on the relname column and execute REVOKE ALL on public.pgxc_copy_error_log FROM public to manage permissions for the error table (the permissions are the same as those of the COPY statement).
public.pgxc_copy_error_log is a row-store table. Therefore, this function can be executed and COPY error tolerance is available only when row-store tables can be created in openGauss. Row-store tables cannot be created in openGauss if enable_hadoop_env is set to on. (By default, this parameter is set to off in openGauss.)
Same as the error table and the COPY statement, the function requires sysadmin or higher permissions.
If the public.pgxc_copy_error_log table or the copy_error_log_relname_idx index already exists before the function creates it, the function will report an error and roll back.

Table 1 Error table public.pgxc_copy_error_log

Column	Type	Description
relname	varchar	Table name in the form of Schema name.Table name
begintime	timestamp with time zone	Time when a data format error was reported
filename	character varying	Name of the source data file where a data format error occurs
rownum	bigint	Number of the row where a data format error occurs in a source data file
rawrecord	text	Raw record of a data format error in the source data file
detail	text	Error details

pg_stat_get_data_senders()
Description: Provides detailed information about the data-copy sending thread active at the moment.
Return type: record

generate_wdr_report(begin_snap_id Oid, end_snap_id Oid, int report_type, int report_scope, int node_name)

Description: Generates system diagnosis reports based on two snapshots.

Return type: record

Table 2 Parameter description

Parameter	Description	Value Range
begin_snap_id	Snapshot ID that starts the diagnosis report period.	-
end_snap_id	Snapshot ID that ends the diagnosis report period. By default, the value of end_snap_id is greater than that of begin_snap_id.	-
report_type	Specifies the type of the generated report.	summary detail all: Both summary and detail types are included.
report_scope	Specifies the scope for a report to be generated.	node: a node in openGauss
node_name	When report_scope is set to node, set this parameter to the name of the corresponding node.	-

create_wdr_snapshot(stat text, dbid Oid)

Description: Manually generates system diagnosis snapshots.

Return type: record

Table 3 Parameter description

Parameter	Description
stat	Specifies the name of the node for each snapshot. By default, the status information of all nodes is collected.
dbid	ID of the database whose status information is to be collected.

wdr_xdb_query(db_name_str text, query text)
Description: Provides the capability of executing cross-database queries at local. For example, when connecting to the Postgres database, access tables in the test database.
```
select col1 from wdr_xdb_query('dbname=test','select col1 from t1') as dd(col1 int);
```
Return type: record
pg_wlm_jump_queue(pid int)
Description: Moves a task to the top of the primary database node queue.
Return type: Boolean
- true: success
- false: failure
gs_wlm_switch_cgroup(pid int, cgroup text)
Description: Moves a job to other Cgroup to improve the job priority.
Return type: Boolean
- true: success
- false: failure
pv_session_memctx_detail(threadid tid, MemoryContextName text)
Description: Record information about the memory context MemoryContextName of the thread tid into the threadid_timestamp.log file in the /tmp/dumpmem directory. threadid can be obtained from sessid in the PV_SESSION_MEMORY_DETAIL table. When MemoryContextName is set to '', all memory context information is recorded.
Return type: Boolean
- true: success
- false: failure
pg_shared_memctx_detail(MemoryContextName text)
Description: Record information about the memory context MemoryContextName into the threadid_timestamp.log file in the /tmp/dumpmem directory.
Return type: Boolean
- true: success
- false: failure

NOTE:
pgxc_lock_for_backup locks openGauss before gs_dump or gs_dumpall is used to back up openGauss. After openGauss is locked, operations changing the system structure are not allowed. This function does not affect DML statements.