number of background workers that the planner will consider using is limited to at most max_paral- lel_workers_per_gather. The total number of background workers that can exist at any one time is limited performance. If this occurrence is frequent, consider increasing max_worker_processes and max_paral- lel_workers so that more workers can be run simultaneously or alternatively reducing max_par- allel_workers_per_gather Also, unlike a regular Append node, which can only have partial children when used within a paral- lel plan, a Parallel Append node can have both partial and non-partial child plans. Non-partial children

number of background workers that the planner will consider using is limited to at most max_paral- lel_workers_per_gather. The total number of background workers that can exist at any one time is limited performance. If this occurrence is frequent, consider increasing max_worker_processes and max_paral- lel_workers so that more workers can be run simultaneously or alternatively reducing max_par- allel_workers_per_gather Also, unlike a regular Append node, which can only have partial children when used within a paral- lel plan, a Parallel Append node can have both partial and non-partial child plans. Non-partial children

number of background workers that the planner will consider using is limited to at most max_paral- lel_workers_per_gather. The total number of background workers that can exist at any one time is limited performance. If this occurrence is frequent, consider increasing max_worker_processes and max_paral- lel_workers so that more workers can be run simultaneously or alternatively reducing max_par- allel_workers_per_gather Also, unlike a regular Append node, which can only have partial children when used within a paral- lel plan, a Parallel Append node can have both partial and non-partial child plans. Non-partial children

number of background workers that the planner will consider using is limited to at most max_paral- lel_workers_per_gather. The total number of background workers that can exist at any one time is limited performance. If this occurrence is frequent, consider increasing max_worker_processes and max_paral- lel_workers so that more workers can be run simultaneously or alternatively reducing max_par- allel_workers_per_gather Also, unlike a regular Append node, which can only have partial children when used within a paral- lel plan, a Parallel Append node can have both partial and non-partial child plans. Non-partial children

number of background workers that the planner will consider using is limited to at most max_paral- lel_workers_per_gather. The total number of background workers that can exist at any one time is limited performance. If this occurrence is frequent, consider increasing max_worker_processes and max_paral- lel_workers so that more workers can be run simultaneously or alternatively reducing max_par- allel_workers_per_gather Also, unlike a regular Append node, which can only have partial children when used within a paral- lel plan, a Parallel Append node can have both partial and non-partial child plans. Non-partial children

number of background workers that the planner will consider using is limited to at most max_paral- lel_workers_per_gather. The total number of background workers that can exist at any one time is limited performance. If this occurrence is frequent, consider increasing max_worker_processes and max_paral- lel_workers so that more workers can be run simultaneously or alternatively reducing max_par- allel_workers_per_gather Also, unlike a regular Append node, which can only have partial children when used within a paral- lel plan, a Parallel Append node can have both partial and non-partial child plans. Non-partial children

number of background workers that the planner will consider using is limited to at most max_paral- lel_workers_per_gather. The total number of background workers that can exist at any one time is limited performance. If this occurrence is frequent, consider increasing max_worker_processes and max_paral- lel_workers so that more workers can be run simultaneously or alternatively reducing max_par- allel_workers_per_gather Also, unlike a regular Append node, which can only have partial children when used within a paral- lel plan, a Parallel Append node can have both partial and non-partial child plans. Non-partial children

type no %p Process ID no %P Process ID of the parallel group leader, if this process is a paral- lel query worker no %t Time stamp without millisec- onds no %m Time stamp with milliseconds no %n parallel bitmap index scan. SharedTupleStore Waiting to access a shared tuple store during paral- lel query. ShmemIndex Waiting to find or allocate space in shared memo- ry. SInvalRead Waiting to retrieve pg_lsn Last write-ahead log location received, the initial value of this field being 0; NULL for paral- lel apply workers last_msg_send_time timestamp with time zone Send time of last message received from

type no %p Process ID no %P Process ID of the parallel group leader, if this process is a paral- lel query worker no %t Time stamp without millisec- onds no %m Time stamp with milliseconds no %n parallel bitmap index scan. SharedTupleStore Waiting to access a shared tuple store during paral- lel query. 879 Monitoring Database Activity LWLock Wait Event Description ShmemIndex Waiting to find pg_lsn Last write-ahead log location received, the initial value of this field being 0; NULL for paral- lel apply workers last_msg_send_time timestamp with time zone Send time of last message received from

of such a function in an SQL statement forces a serial execution plan. This is the default. PARAL- LEL RESTRICTED indicates that the function can be executed in parallel mode, but the execution is restricted optimized away.) proparallel char proparallel tells whether the function can be safely run in paral- lel mode. It is s for functions which are safe to run in parallel mode without restriction. It is r for be run in parallel mode, but their execution is restricted to the par- allel group leader; paral- lel worker processes can- not invoke these func- tions. It is u for functions which are unsafe in par-