Hi,
I'm learning how to use the "background worker processes" commited in
9.3. The usage basics are quite nicely illustrated in the worker_spi
extension (kudos to those who designed the feature / extension).
I'm not quite sure how to pass data between the regular backend and a
worker. Implementing the channel (socket/pipe/...) itself is not a big
deal, that's IPC 101, but deciding which data to copy (and how) is.
Say I need to forward a tuple to the worker process - e.g. from a
nodeAgg node, so that the worker can build the hash table. Is there
something (a rule of a thumb, method, ...) that would help me to
identify the pieces of data that need to be copied?
Or do I need to do the go through the objects and decide what to copy
and how on my own?
regards
Tomas
