No kidding? So, when I install DDL and get a successful "Package body created" message, no one can start using it until all processes using the old version finish? From: Ric Van Dyke [mailto:ric.van.dyke@xxxxxxxxxx] Sent: Wednesday, February 26, 2014 3:27 PM To: McPeak, Matt; ORACLE-L Subject: RE: DBA_HIST_ACTIVE_SESS_HISTORY library cache pin waits Sure makes perfect sense to me. S1 was already running so will continue to completion with the version of P as it was when it started. S2 has to wait for S1 to finish so it can in effect recompile P. +--+--+--+--+--+--+--+--+--+--+--+--+--+--+ Ric Van Dyke Education Director Hotsos Ltd. Hotsos Symposium March 2-6 2014 Make your plans to be there now! From: oracle-l-bounce@xxxxxxxxxxxxx<mailto:oracle-l-bounce@xxxxxxxxxxxxx> [mailto:oracle-l-bounce@xxxxxxxxxxxxx] On Behalf Of McPeak, Matt Sent: Wednesday, February 26, 2014 3:09 PM To: ORACLE-L Subject: RE: DBA_HIST_ACTIVE_SESS_HISTORY library cache pin waits More information... There was a package (call it "P") re-installed at 4:29pm. There was a long-running (4hr) process ( call it "S1" ) running at that time that uses that package. Should that have prevented us from installing a new version of the package? It doesn't seem to have. Then, other processes (call it "S2") - started after 4:29pm and that refer to "P" -- all seemed to start waiting indefinitely for the long-running process "S1". Does that make sense? Thanks, Matt From: oracle-l-bounce@xxxxxxxxxxxxx<mailto:oracle-l-bounce@xxxxxxxxxxxxx> [mailto:oracle-l-bounce@xxxxxxxxxxxxx] On Behalf Of McPeak, Matt Sent: Wednesday, February 26, 2014 2:40 PM To: ORACLE-L Subject: DBA_HIST_ACTIVE_SESS_HISTORY library cache pin waits Hi, I have been asked what a process on Monday (2/24) timed out. Going to DBA_HIST_ACTIVE_SESS_HISTORY, I can see that the process in question spent all its time waiting for a library cache pin. I can see a lot written on how to get more information about current library cache pin waits. But does anyone know how to find out more about a library cache pin wait showing up only in ASH? Thanks in advance! Matt