Specifying the RAM disk for the stats_temp_directory
You can use the Aurora PostgreSQL parameter, rds.pg_stat_ramdisk_size
, to
specify the system memory allocated to a RAM disk for storing the PostgreSQL
stats_temp_directory
. The RAM disk parameter is only available in
Aurora PostgreSQL 14 and lower versions.
Under certain workloads, setting this parameter can improve performance and decrease
IO requirements. For more information about the stats_temp_directory
, see
Run-time Statisticsstats_temp_directory
.
To enable a RAM disk for your stats_temp_directory
, set the
rds.pg_stat_ramdisk_size
parameter to a non-zero value in the DB
cluster parameter group used by your DB cluster. This parameter denotes MB, so you must
use an integer value. Expressions, formulas, and functions aren't valid for the
rds.pg_stat_ramdisk_size
parameter. Be sure to restart the DB cluster
so that the change takes effect. For information about setting parameters, see Parameter groups for Amazon Aurora.
For more information about restarting the DB cluster, see Rebooting an Amazon Aurora DB cluster or Amazon Aurora DB instance.
As an example, the following Amazon CLI command sets the RAM disk parameter to 256 MB.
aws rds modify-db-cluster-parameter-group \ --db-cluster-parameter-group-name db-cl-pg-ramdisk-testing \ --parameters "ParameterName=rds.pg_stat_ramdisk_size, ParameterValue=256, ApplyMethod=pending-reboot"
After you restart the DB cluster, run the following command to see the status of the
stats_temp_directory
:
postgres=>
SHOW stats_temp_directory;
The command should return the following:
stats_temp_directory --------------------------- /rdsdbramdisk/pg_stat_tmp (1 row)