Alvaro Herrera wrote: > > Also, we will need a phantom xid for every xid1/xid2 pair. You can't > > just create one phantom xid per subtransaction because you must be able > > to control independently commit/rollback rows based on the status of the > > insert transaction. > > Oh, sure. This could get huge pretty fast. > > We still need to think on the effects this could have on crash recovery > though -- we'd have to write the phantom Xids to Xlog somehow > (indicating which ones are committed and which are aborted). And we > still don't know what effect it would have on CPU cost for every > visibility check.
As I understand, this overhead would only be needed for subtransactions. I also don't think there will be a lot of them because it is only for creation/expire in the same main transaction, and it is only needed for unique creation/expire combinations, which should be pretty small. -- Bruce Momjian | http://candle.pha.pa.us [EMAIL PROTECTED] | (610) 359-1001 + If your life is a hard drive, | 13 Roberts Road + Christ can be your backup. | Newtown Square, Pennsylvania 19073 ---------------------------(end of broadcast)--------------------------- TIP 1: subscribe and unsubscribe commands go to [EMAIL PROTECTED]
