From 1463f22d42fddc620ca29c6fa9eb7dce0e56a2fe Mon Sep 17 00:00:00 2001 From: Bruce Momjian Date: Wed, 22 Jun 2022 14:33:26 -0400 Subject: [PATCH] doc: clarify wording about phantom reads Reported-by: akhilhello@gmail.com Discussion: https://postgr.es/m/165222922369.669.10475917322916060899@wrigleys.postgresql.org Backpatch-through: 10 --- doc/src/sgml/high-availability.sgml | 2 +- doc/src/sgml/mvcc.sgml | 7 ++++--- 2 files changed, 5 insertions(+), 4 deletions(-) diff --git a/doc/src/sgml/high-availability.sgml b/doc/src/sgml/high-availability.sgml index a265409f025..eaa6f4b53cc 100644 --- a/doc/src/sgml/high-availability.sgml +++ b/doc/src/sgml/high-availability.sgml @@ -2194,7 +2194,7 @@ HINT: You can then restart the server after making the necessary configuration Currently, temporary table creation is not allowed during read-only transactions, so in some cases existing scripts will not run correctly. This restriction might be relaxed in a later release. This is - both an SQL Standard compliance issue and a technical issue. + both an SQL standard compliance issue and a technical issue. diff --git a/doc/src/sgml/mvcc.sgml b/doc/src/sgml/mvcc.sgml index 6c94f6a9429..3d3cbb339ce 100644 --- a/doc/src/sgml/mvcc.sgml +++ b/doc/src/sgml/mvcc.sgml @@ -277,9 +277,10 @@ The table also shows that PostgreSQL's Repeatable Read implementation - does not allow phantom reads. Stricter behavior is permitted by the - SQL standard: the four isolation levels only define which phenomena - must not happen, not which phenomena must happen. + does not allow phantom reads. This is acceptable under the SQL + standard because the standard specifies which anomalies must + not occur at certain isolation levels; higher + guarantees are acceptable. The behavior of the available isolation levels is detailed in the following subsections.