Re: Surprising results from tests intended to show the difference in semantics between transaction_timestamp(), statement_timestamp(), and clock_timestamp() - Mailing list pgsql-general

Adrian Klaver wrote:

On 9/21/21 4:23 PM, Bryn Llewellyn wrote:

I'm surprised by the results that I describe below. Please help me interpret them.
Briefly, why does transaction_timestamp() report a later value than statement_timestamp() when they're both invoked in the very first statement after "start transaction". (They report identical values in an implicitly started txn.)

I'm not seeing it:

...

No matter how many times I run this the transaction_timestamp() is less then statement_timestamp().  This is as it should be, as transaction_timestamp() fires with the begin; and statement_timestamp() fires at select ... and then updates with the subsequent select .... and clock_timestamp() just keeps marching on through the whole process.