I've heard about vector clocks and how to test if a message was sent before another message.

E.g. Message A was sent before message B if every element of the vector of message A is smaller or equal then the belonging element of the vector of message B.

Also, there needs to be at least one element in the vector of message A that is smaller (and not equal) than the belonging element of message B.

As I see, the second parts just tests if there are elements that differ.

Is there a possibility where all elements of the vector of message A are the same as the belonging element of the vector of message B or is the second check unnecessary?

I mean, each element can only be incremented by the belonging process only and there if e.g. process X sends a message to process Y and a message gets back, the element of process Y will be changed in process Y only and the element of process X will be changed in process X only. So, there would be an update from the own element and the foreign element in any case. This means, there could not possibly be a case where all elements of the vector of message A and all elements of the vector of message B are completely the same, right?

Could the performance of the vector clock be increased if the test for equality is removed?

I've heard about vector clocks and how to test if a message was sent before another message.

E.g. Message A was sent before message B if every element of the vector of message A is smaller or equal then the belonging element of the vector of message B.

Also, there needs to be at least one element in the vector of message A that is smaller (and not equal) than the belonging element of message B.

As I see, the second parts just tests if there are elements that differ.

Is there a possibility where all elements of the vector of message A are the same as the belonging element of the vector of message B or is the second check unnecessary?

I mean, each element can only be incremented by the belonging process only and there if e.g. process X sends a message to process Y and a message gets back, the element of process Y will be changed in process Y only and the element of process X will be changed in process X only. So, there would be an update from the own element and the foreign element in any case. This means, there could not possibly be a case where all elements of the vector of message A and all elements of the vector of message B are completely the same, right?

Could the performance of the vector clock be increased if the test for equality is removed?