On Mon, Feb 3, 2020 at 05:04:00PM +0000, PG Doc comments form wrote:
> The following documentation comment has been logged on the website:
>
> Page: https://www.postgresql.org/docs/9.4/explicit-locking.html
> Description:
>
> Hi
>
> The "13.3.1. Table-level Locks" subsection mentions the following: "Once
> acquired, a lock is normally held till end of transaction." (maybe we should
> also squeeze a "...till the end of a transaction" in there) According to a
Sorry for the delay in replying. Yes, this wording needs improvement,
which I have done in the attached patch.
> helpful stranger on IRC, this behavior is also true for row-level locks.
>
> Since this sentence also applies to the row-level locks described in the
> following subsection 13.3.2 I think it would be more fitting to move the
> paragraph containing this sentence to the introduction of the topic in
> section "13.3. Explicit Locking". This would then read something like:
Uh, we can't move that paragraph up because Page-Level Locks and
Advisory Locks aren't always released on transaction end or rollback.
What I did do was to mention that row-level locks are released in a
similar way to table-level locks.
Patch attached.
--
Bruce Momjian <[email protected]> https://momjian.us
EnterpriseDB https://enterprisedb.com
+ As you are, so once was I. As I am, so you will be. +
+ Ancient Roman grave inscription +
diff --git a/doc/src/sgml/mvcc.sgml b/doc/src/sgml/mvcc.sgml
index f8c9655111..95465d581b 100644
--- a/doc/src/sgml/mvcc.sgml
+++ b/doc/src/sgml/mvcc.sgml
@@ -1039,9 +1039,9 @@ ERROR: could not serialize access due to read/write dependencies among transact
</tip>
<para>
- Once acquired, a lock is normally held till end of transaction. But if a
+ Once acquired, a lock is normally held until the end of the transaction. But if a
lock is acquired after establishing a savepoint, the lock is released
- immediately if the savepoint is rolled back to. This is consistent with
+ immediately if the savepoint is rolled back. This is consistent with
the principle that <command>ROLLBACK</command> cancels all effects of the
commands since the savepoint. The same holds for locks acquired within a
<application>PL/pgSQL</application> exception block: an error escape from the block
@@ -1178,7 +1178,10 @@ ERROR: could not serialize access due to read/write dependencies among transact
conflicting locks on the same row, even in different subtransactions;
but other than that, two transactions can never hold conflicting locks
on the same row. Row-level locks do not affect data querying; they
- block only <emphasis>writers and lockers</emphasis> to the same row.
+ block only <emphasis>writers and lockers</emphasis> to the same
+ row. Row-level locks are released at transaction end or during
+ savepoint rollback, just like table-level locks.
+
</para>
<variablelist>
