Estimate the memory requirements for high-speed data load.
Up to 128 parallel workers to perform data load can be specified for this feature. The additional resources below are required depending on the number of parallel workers.
Dynamic shared memory created during data load
The feature creates shared memory and shared memory message queues during data load. These are used to send external data from the back end to the parallel workers, and for error notifications.
Note
If the value of shared_buffers in postgresql.conf is small, the system will often have to wait for write exclusive locks to the same data page (as described in "Database server memory" in "13.1.1 Deciding whether to Install"). Since input data cannot be loaded from the shared memory message queues during such waits, they will often be full. In these cases, it will not be possible to write to the shared memory message queues, resulting in degraded data load performance.
See
Refer to "High-Speed Data Load Memory Requirements" in the Installation and Setup Guide for Server for information on the formula for estimating memory requirements.
