Tuning Database Parameters

actor_size: number of vCPUs and total memory per actor
actor: number of actors
dop: SMP degree of parallelism (DOP) Can be adjusted based on the volume of data being queried.

To ensure high performance of the database, you are advised to configure GUC parameters based on available resources and the actual workloads. This section describes some of the common parameters and the recommended configurations for them. For more details, see Viewing and Setting GUC Parameters.

Parameters Related to Database Memory

**Table 1** Parameters related to database memory
GUC Parameter	Description	Suggestion
fq_runtime	Sets the number of actors used for queries and their CPU/memory configurations.	This parameter can configure the following: actor_size: number of vCPUs and total memory per actor actor: number of actors dop: SMP degree of parallelism (DOP) Can be adjusted based on the volume of data being queried.
cstore_buffers	Specifies the size of the shared buffer used by column-store tables and column-store tables (ORC, Parquet, and CarbonData) of OBS and HDFS foreign tables.	Column-store tables use the shared buffer specified by cstore_buffers instead of that specified by shared_buffers. When column-store tables are mainly used, reduce the value of shared_buffers and increase that of cstore_buffers. Use cstore_buffers to specify the cache of ORC, Parquet, or CarbonData metadata and data for OBS or HDFS foreign tables. The metadata cache size should be 1/4 of cstore_buffers and not exceed 2 GB. The remaining cache is shared by column-store data and foreign table column-store data.