Re: [PERFORM] Concurrency issue under very heay loads

"ramasubramanian" <ramasubramanian.g@xxxxxxxxxxxxxxxxxx> · Thu, 16 Jul 2009 10:49:17 +0530

Hi,
Are you using automatic sequence increment in 
table?

  ----- Original Message ----- 
  From: 
  Raji Sridar (raji) 

  To: pgsql-general@xxxxxxxxxxxxxx ; 
  pgsql-performance@xxxxxxxxxxxxxx 

  Sent: Thursday, July 16, 2009 10:29 
  AM
  Subject: [PERFORM] Concurrency issue 
  under very heay loads

  Hi,

  We use a typical counter within a transaction to 
  generate order sequence number and update the next sequence number. This is a 
  simple next counter - nothing fancy about it.  When multiple clients are 
  concurrently accessing this table and updating it, under extermely heavy loads 
  in the system (stress testing), we find that the same order number is being 
  generated for multiple clients. Could this be a bug? Is there a workaround? 
  Please let me know.

  Thanks
  Raji