Let x be a quantistic data accessor.
Thus, if you try read the number of rows of the table y or you do some sort of “SELECT * FROM y” (even with ordering clauses), you will get that exact value, but the data on the table will be modified after the reading process.
On the other hand, if you read a record of y, the total number of rows of y is going to change (through additions or removals).
This is the so called “Heisenberg DAO Uncertainty Principle“.
Stori M. and Di Bernardo D., on the Proceedings of the 4th IEEE coffee break, Uniteam Spa coffee room, July 2008.