5 Commits (f3ed72ca0765bdd726a31b7fa20219e96baf312c)

Author	SHA1	Message	Date
Bruce Momjian	50e6eb731d	Update copyright for 2025 ... Backpatch-through: 13	12 months ago
Noah Misch	65c310b310	Optimize pg_visibility with read streams. ... We've measured 5% performance improvement, and this arranges to benefit automatically from future optimizations to the read_stream subsystem. The area lacked test coverage, so close that gap. Nazir Bilal Yavuz Discussion: https://postgr.es/m/CAN55FZ1_Ru3XpMgTwsU67FTH2fs_FrRROmb7x6zs+F44QBEiww@mail.gmail.com Discussion: https://postgr.es/m/CAEudQAozv3wTY5TV2t29JcwPydbmKbiWQkZD42S2OgzdixPMDQ@mail.gmail.com	1 year ago
Alexander Korotkov	e3ec9dc1bf	Add missing wait_for_catchup() to pg_visibility tap test ... e2ed7e3227 introduced check of pg_visibility on standby. This commit adds missing wait_for_catchup() to synchronize standby before querying it.	1 year ago
Alexander Korotkov	e2ed7e3227	Fix GetStrictOldestNonRemovableTransactionId() on standby ... e85662df44 implemented GetStrictOldestNonRemovableTransactionId() function for computation of xid horizon that avoid reporting of false errors. However, GetStrictOldestNonRemovableTransactionId() uses GetRunningTransactionData() even on standby leading to an assertion failure. Given that we decided to ignore KnownAssignedXids and standby can't have own running xids, we switch to use TransamVariables->nextXid as a xid horizon. Also, revise the comment regarding ignoring KnownAssignedXids with more detailed reasoning provided by Heikki. Reported-by: Heikki Linnakangas Discussion: https://postgr.es/m/42218c4f-2c8d-40a3-8743-4d34dd0e4cce%40iki.fi Reviewed-by: Heikki Linnakangas	1 year ago
Alexander Korotkov	e85662df44	Fix false reports in pg_visibility ... Currently, pg_visibility computes its xid horizon using the GetOldestNonRemovableTransactionId(). The problem is that this horizon can sometimes go backward. That can lead to reporting false errors. In order to fix that, this commit implements a new function GetStrictOldestNonRemovableTransactionId(). This function computes the xid horizon, which would be guaranteed to be newer or equal to any xid horizon computed before. We have to do the following to achieve this. 1. Ignore processes xmin's, because they consider connection to other databases that were ignored before. 2. Ignore KnownAssignedXids, because they are not database-aware. At the same time, the primary could compute its horizons database-aware. 3. Ignore walsender xmin, because it could go backward if some replication connections don't use replication slots. As a result, we're using only currently running xids to compute the horizon. Surely these would significantly sacrifice accuracy. But we have to do so to avoid reporting false errors. Inspired by earlier patch by Daniel Shelepanov and the following discussion with Robert Haas and Tom Lane. Discussion: https://postgr.es/m/1649062270.289865713%40f403.i.mail.ru Reviewed-by: Alexander Lakhin, Dmitry Koval	2 years ago