GS_STAT_DB_CU displays CU hits of each database in each node of a cluster. You can clear it using gs_stat_reset().

**Table 1** GS_STAT_DB_CU columns
Column	Type	Description
node_name1	Text	Node name
db_name	Text	Database name
mem_hit	Bigint	Number of memory hits
hdd_sync_read	Bigint	Number of disk synchronous reads
hdd_asyn_read	Bigint	Number of disk asynchronous reads