I am unsure whether a remote request can access in its one SQL statement both a database that is non-remote (ie. at its own computer) as well as a database that is remote?
Or can only a distributed request do this?
This is why I am having a problem understanding Ass3 Ques 1.6 and 1.10
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My understanding is that a remote request is one that can be processed by a single data processor (see bottom of pg 485). I think that we can presume that the remote request can alternatively access data at a local DP.
The difference with the distributed request is that it can access several DPs with a single SQL statement (local and/or remote).
I am not fully understanding your explanation.
When you say "..can alternatively access data at a local DP" do you mean that either it can access a local DP or remote DP but not both in one statement?
Am I understanding you correctly?
Thanks
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What I mean is that a remote request is one that can be processed by only a single data processor i.e. a remote request can't access both a local and remote or two remote data processors at the same time because then it wouldn't be accessing a single DP. If the request were of this type it would have to be considered a distributed request because of the multiple DP access.