Those who have been with the community from long ago might remember discussion about implementing a undo log. The big advantage of this is that it allows UPDATE to _replace_ rows and limits the amount of cleanup required for UPDATEs.
I am hoping that with HOT we will no longer have any need to even consider undo. -- Bruce Momjian <[EMAIL PROTECTED]> http://momjian.us EnterpriseDB http://postgres.enterprisedb.com + If your life is a hard drive, Christ can be your backup. + ---------------------------(end of broadcast)--------------------------- TIP 9: In versions below 8.0, the planner will ignore your desire to choose an index scan if your joining column's datatypes do not match
