PGXC_WLM_SESSION_HISTORY

PGXC_WLM_SESSION_HISTORY displays load management information for completed jobs executed on all CNs. This view is used by Data Manager to query data from a database. Data in the database is cleared every 3 minutes. For details, see GS_WLM_SESSION_HISTORY.

The columns are similar to those in GS_WLM_SESSION_HISTORY. For details, see Table 1.

**Table 1** **GS_WLM_SESSION_HISTORY** columns
Name	Type	Description
datid	oid	OID of the database connected to the backend.
dbname	text	Name of the database connected to the backend.
schemaname	text	Schema name.
nodename	text	Name of the CN where the statement is run.
username	text	Username used for connecting 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 used by the client to communicate with the backend. If a Unix socket is used, it is –1.
query_band	text	Job type, which can be set through the GUC parameter query_band and is null string by default.
block_time	bigint	Blocking time before statement execution, including statement parsing and optimization time, in milliseconds.
start_time	timestamp with time zone	Start time of statement execution.
finish_time	timestamp with time zone	End time of statement execution.
duration	bigint	Execution time of a statement. The unit is ms.
estimate_total_time	bigint	Estimated execution time of a statement. The unit is ms.
status	text	End status of statement execution: finished for normal and aborted for abnormal. The statement status recorded here should be the database server execution status. When the server-side execution is successful and an error occurs when the result set is returned, the statement should be finished.
abort_info	text	Exception information displayed if the final statement execution status is aborted.
resource_pool	text	Resource pool used by the user.
control_group	text	Cgroup used by the statement.
estimate_memory	integer	Estimated memory used by the statement. The unit is MB.
min_peak_memory	integer	Minimum memory peak of a statement across all DNs. The unit is MB.
max_peak_memory	integer	Maximum memory peak of a statement across all DNs. The unit is MB.
average_peak_memory	integer	Average memory usage during statement execution. The unit is MB.
memory_skew_percent	integer	Memory usage skew of a statement among DNs.
spill_info	text	Statement spill information on all DNs. None: The statement has not been spilled to disks on any DNs. All: The statement has been spilled to disks on all DNs. [a:b]: The statement has been spilled to disks on a of b DNs.
min_spill_size	integer	Minimum spilled data among all DNs when a spill occurs. The default value is 0. The unit is MB.
max_spill_size	integer	Maximum spilled data among all DNs when a spill occurs. The default value is 0. The unit is MB.
average_spill_size	integer	Average spilled data among all DNs when a spill occurs. The default value is 0. The unit is MB.
spill_skew_percent	integer	DN spill skew when a spill occurs.
min_dn_time	bigint	Minimum execution time of a statement across all DNs. The unit is ms.
max_dn_time	bigint	Maximum execution time of a statement across all DNs. The unit is ms.
average_dn_time	bigint	Average execution time of a statement across all DNs. The unit is ms.
dntime_skew_percent	integer	Execution time skew of a statement among DNs.
min_cpu_time	bigint	Minimum CPU time of a statement across all DNs. The unit is ms.
max_cpu_time	bigint	Maximum CPU time of a statement across all DNs. The unit is ms.
total_cpu_time	bigint	Total CPU time of a statement across all DNs. The unit is ms.
cpu_skew_percent	integer	CPU time skew of a statement among DNs.
min_peak_iops	integer	Minimum I/O peak of a statement on all DNs (times/s in column-store tables and 10,000 times/s in row-store tables). This function is not enabled in clusters of version 8.1.3. Therefore, you are not advised to refer to this column to analyze memory problems.
max_peak_iops	integer	Maximum I/O peak of a statement on all DNs (times/s in column-store tables and 10,000 times/s in row-store tables). This function is not enabled in clusters of version 8.1.3. Therefore, you are not advised to refer to this column to analyze memory problems.
average_peak_iops	integer	Average I/O peak of a statement on all DNs (times/s in column-store tables and 10,000 times/s in row-store tables). This function is not enabled in clusters of version 8.1.3. Therefore, you are not advised to refer to this column to analyze memory problems.
iops_skew_percent	integer	I/O skew of a statement among DNs. This function is not enabled in clusters of version 8.1.3. You are not advised to refer to this column to analyze memory problems.
warning	text	Warning. The following warnings and warnings related to SQL self-diagnosis tuning are displayed: Spill file size large than 256MB Broadcast size large than 100MB Early spill Spill times is greater than 3 Spill on memory adaptive Hash table conflict
queryid	bigint	Internal query ID used for statement execution.
query	text	Executed statement.
query_plan	text	Execution plan of a statement.
node_group	text	Logical cluster of the user running the statement.
pid	bigint	PID of the backend thread for the statement.
lane	text	Fast/Slow lane where the statement is executed.
unique_sql_id	bigint	ID of the normalized unique SQL.