pg_stat_get_wlm_instance_info_with_cleanup
描述：返回当前实例负载信息，并且保存到系统表中。
参数：nan
返回值类型：instancename text, timestamp timestamp with time zone, used_cpu integer, free_memory integer, used_memory integer, io_await double precision, io_util double precision, disk_read double precision, disk_write double precision, process_read bigint, process_write bigint, logical_read bigint, logical_write bigint, read_counts bigint, write_counts bigint
pg_stat_get_wlm_realtime_session_info
描述：返回实时会话负载信息。
参数：nan
返回值类型：nodename text, threadid bigint, block_time bigint, duration bigint, estimate_total_time bigint, estimate_left_time bigint, schemaname text, query_band text, spill_info text, control_group text, estimate_memory integer, min_peak_memory integer, max_peak_memory integer, average_peak_memory integer, memory_skew_percent integer, min_spill_size integer, max_spill_size integer, average_spill_size integer, spill_skew_percent integer, min_dn_time bigint, max_dn_time bigint, average_dn_time bigint, dntime_skew_percent integer, min_cpu_time bigint, max_cpu_time bigint, total_cpu_time bigint, cpu_skew_percent integer, min_peak_iops integer, max_peak_iops integer, average_peak_iops integer, iops_skew_percent integer, warning text, query text, query_plan text, cpu_top1_node_name text, cpu_top2_node_name text, cpu_top3_node_name text, cpu_top4_node_name text, cpu_top5_node_name text, mem_top1_node_name text, mem_top2_node_name text, mem_top3_node_name text, mem_top4_node_name text, mem_top5_node_name text, cpu_top1_value bigint, cpu_top2_value bigint, cpu_top3_value bigint, cpu_top4_value bigint, cpu_top5_value bigint, mem_top1_value bigint, mem_top2_value bigint, mem_top3_value bigint, mem_top4_value bigint, mem_top5_value bigint, top_mem_dn text, top_cpu_dn text
pg_stat_get_wlm_session_iostat_info
描述：返回会话负载IO信息。
参数：nan
返回值类型：threadid bigint, maxcurr_iops integer, mincurr_iops integer, maxpeak_iops integer, minpeak_iops integer, iops_limits integer, io_priority integer, curr_io_limits integer
pg_stat_get_wlm_statistics
描述：返回会话负载统计数据。
参数：nan
返回值类型：statement text, block_time bigint, elapsed_time bigint, total_cpu_time bigint, qualification_time bigint, skew_percent integer, control_group text, status text, action text
