Aurora Postgres 9.6.3 So, no chance to recompile (AFAIK). Is there a design anti-pattern at the schema or data access level that we should look for and correct?
And as for the recompile, are you thinking 'NUM_SUBTRANS_BUFFERS'? Thanks On Thu, Aug 16, 2018 at 2:36 PM Alvaro Herrera <alvhe...@2ndquadrant.com> wrote: > On 2018-Aug-16, Fred Habash wrote: > > > One of our database API's is run concurrently by near 40 sessions. We see > > all of them waiting back and forth on this wait state. > > What version are you running? > > > Why is it called Subtrans Control Lock? > > It controls access to the pg_subtrans structure, which is used to record > parent/child transaction relationships (as you say, savepoints and > EXCEPTIONs in plpgsql are the most common uses, but not the only ones). > Normally lookup of these is optimized away, but once you cross a > threshold it cannot any longer. > > > What are the common user session scenarios causing this wait? > > - I have read some describe the use of SQL savepoints or PL/pgSQL > > exception handling. > > What are known resolution measures? > > Are you in a position to recompile Postgres? > > -- > Álvaro Herrera https://www.2ndQuadrant.com/ > PostgreSQL Development, 24x7 Support, Remote DBA, Training & Services > -- ---------------------------------------- Thank you
