Memory Limit Of ERPnext frappe database

how to check Erpnext ,Frappe VERSION 15 database memory limit. If you can answer me that would be fine else please tell me the command or something to find the memory limit.

Please check the documentation.

There’s no such thing as memory limit for database in Frappe.

If your database is not using available RAM that’s likely because of bad or missing configuration value for bufferpool size.

It should be set to ~60% of available RAM and 60% of your RAM should be sufficient to fit your working set of database (think size of your db in last 1 year roughly). E.g. You have 150GB database but only 20GB of that was created in last year, then try to get ~34GB RAM and set bufferpool size to 20GB. Ofcourse this is just a thumb rule and you might need more or less depending on actual usage.