/show/table,
/get/records, etc.) are processed simultaneously. When a write request
(/insert/records, /delete/records, etc.) is made, all subsequent read
and write requests are blocked until the current write request is finished.
If Job Manager is disabled, all inbound requests are broadcasted to all
worker nodes and can be executed in any order.
While enabled by default, Job Manager can be disabled by setting the
enable_job_manager configuration parameter to false in the
gpudb.conf file.
The Job Manager interface is available through
GAdmin, which allows jobs to be monitored and
cancelled, if needed.
Because read requests are processed simultaneously, read jobs can only be
cancelled while a preceding write request is being processed, which is also
referred to as a checkpoint.
Insert, update, and delete requests cannot be cancelled.
Otherwise, most user-facing non-admin jobs are cancellable.
job_user_data options parameter; e.g.,
(in Python):