Posted: 21 Jan 2017 1:49 EST Last activity: 7 Feb 2017 1:01 EST
Why editable Data Pages do not have a node scope but only thread or requestor?
Editable data pages do not have a node scope but only thread or requestor. Why is that? My guess is because the node level data pages can be accessed by different requestors on the node, locking would be a potential issue. To avoid locking node level data pages are not editable. Any comments?
Yes, node level datapages , are always , read-only, and not editable. Because , a node level datapage , is the one that can be accessed by many requestors on the current node . If it is maintained as editable, we need to take care of locking issues,which is of high cost.
Hence mainly node level datapages are used for storing common, typically more static, reference data.
If it were possible, due to Node-Level Data-Pages being loaded from a fixed AccessGroup, writing to it from another would expose you to many new problems.
If you are willing to take the crowbar solution, you could try saving the data you need to exchange on the System-Page "pxProcess". It is the node Page.
As far as I know, you are already taking care of locking, at least on a low level. Data Pages are Thread-Save, meaning only one thread can access it at a time. This was probably implemented so the page cannot be (automatically) refreshed while something is reading from it, ex iterating over a list.