"Tom Lane" <[EMAIL PROTECTED]> writes: > I don't see any good reason why overwriting a whole cache line oughtn't be > the same speed either way.
I can think of a couple theories, but I don't know if they're reasonable. The one the comes to mind is the inter-processor cache coherency protocol. When writing to a cache line the processor already owns maybe it can skip having to check for other processors owning that cache line? What happens if VACUUM comes across buffers that *are* already in the buffer cache. Does it throw those on the freelist too? That seems like it would be dangerous if they were in the buffer cache for a reason. -- Gregory Stark EnterpriseDB http://www.enterprisedb.com ---------------------------(end of broadcast)--------------------------- TIP 6: explain analyze is your friend
