BW – Table space available

Hi Experts,

I am new to BW; I am in the process of analysing available free space at DB level.

How/Where can I find

• What is the Total and Available space in BW
• What is the total size of PSA Tables (So that I can analyse the impact of deleting PSA requests) and
• What is the total size of DSO Change Log Tables (So that I can analyse the impact of requests in change log table)

I already searched SDN, But its pretty confusing.

Thanks in advance.