rsdb/obj/buffersize is a SAP Parameter attribute which is used to control Size of export/import buffer [kB] information. This is available within R/3 SAP systems depending on the version and release level.
Below is the standard documentation available and a few details of the attributes values .
This parameter defines the size of the export/import buffer in KB. The
buffer is used to store data in shared memory and is addressed by the
ABAP commands EXPORT TO / IMPORT FROM SHARED BUFFER and DELETE FROM
SHARED BUFFER. The commands only have an effect locally; the buffers of
external application servers are not changed. If the buffer is full,
when new objects are exported to the buffer, old buffer objects are
replaced.
See SAP Parameter Documentation for full SAP documentation for this profile parameter.