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pipelined functions

18c versus 19c

I had someone say to me at an event recently: “We’re are going to upgrade to 18c, because 19c is new and is probably less stable”.

Let me sum up that sentiment simply: It’s Wrong Smile

Now, don’t get me wrong. I am not claiming that every Oracle release is perfect, contains zero bugs, never has a regression, will mow your lawn, take your kids to school, clean your house and sort out all the climate change issues in the world.

SMON_SCN_TIME and ORA-8161? Digging deeper

In the recent versions of the Oracle database, we’ve had the ability to convert between a System Change Number (SCN) and the approximate time to which that SCN pertains. These functions are unsurprisingly called SCN_TO_TIMESTAMP and TIMESTAMP_TO_SCN. The only potential misnomer here is that even though the functions are called “timestamp” and return a datatype of timestamp, on most platforms you are going to notice that the granularity doesn’t run down into fractions of seconds


SQL> select scn_to_timestamp(14816563713652) from dual;

SCN_TO_TIMESTAMP(14816563713652)
---------------------------------------------------------
08-JUN-19 02.30.59.000000000 AM

This all looks great until you start poking around too far into the past, and you end up in territory like this: