From ae04bf50277ae25ca741cf3322d231c7dfb4c997 Mon Sep 17 00:00:00 2001 From: Alvaro Herrera <alvherre@alvh.no-ip.org> Date: Fri, 28 Nov 2014 18:06:18 -0300 Subject: [PATCH] Update transaction README for persistent multixacts Multixacts are now maintained during recovery, but the README didn't get the memo. Backpatch to 9.3, where the divergence was introduced. --- src/backend/access/transam/README | 5 +---- 1 file changed, 1 insertion(+), 4 deletions(-) diff --git a/src/backend/access/transam/README b/src/backend/access/transam/README index ba6ae05d653..b619de5ad3a 100644 --- a/src/backend/access/transam/README +++ b/src/backend/access/transam/README @@ -840,10 +840,7 @@ parent transaction to complete. Not all transactional behaviour is emulated, for example we do not insert a transaction entry into the lock table, nor do we maintain the transaction -stack in memory. Clog entries are made normally. Multixact is not maintained -because its purpose is to record tuple level locks that an application has -requested to prevent other tuple locks. Since tuple locks cannot be obtained at -all, there is never any conflict and so there is no reason to update multixact. +stack in memory. Clog and multixact entries are made normally. Subtrans is maintained during recovery but the details of the transaction tree are ignored and all subtransactions reference the top-level TransactionId directly. Since commit is atomic this provides correct lock wait behaviour -- GitLab