The recommended minimum tablespace for the Pega Platform database is 1 gigabyte. Most of the space in your Pega Platform database is used for work items, history, and attachments.
You might need to adjust the amount of tablespace based on your requirements. For more information about disk space planning, see the Pega Community article How to estimate disk space requirements for a PegaRULES Database (Oracle).
To provide good performance, the Pega Platform can use a single database account with multiple connections, in a pool. You can implement pooled connections by using a JNDI datasource and application server functions. Alternatively, you can limit the number of database connections to the Pega Platform database.