Some resources do not change very often and considerable performance improvements can be
expected if the data can be read from the client cache instead of the backend system.
SAP Gateway supports the HTTP header field
if-modified-since. This field is a time
stamp and it can be read and compared with the last modification of the application
data. If the last modification is older than
if-modified-since then no application data
needs to be read, and instead only an HTTP 304 response is returned – ‘not modified’.
You can find details about last modified and cache control under: