dynamic views cosnstency, do they use UNDO?

Hi

Since v$ views based on x$ are memry structures I guess there is no guarantee that they would give a consistent view correct? For example in some busy systems, for example a 2500 users CRM system running joins of v$ views is time consuming, for example if I try to join v$sesstat with v$session it takes really a while.

If let's say it takes 10 seconds does Oracle guarantee the values I am seeing are from 10 seconds ago? I am pretty sure undo is not used for memory structures or wrong?

I Cant seem to find a easy way to test this.

TIA Alex

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