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authorPeter Eisentraut2018-07-30 20:01:04 +0000
committerPeter Eisentraut2018-07-30 20:09:48 +0000
commit70de0abdb7c6dce24dd5c0e276708ca7c534f99f (patch)
treeb94a6705b6d727a211b425c10ef81f5c27440e67
parentc0a552921b0f5f22ac982b5ad24f1df4fd8ca1b1 (diff)
doc: Improve CREATE COLLATION locking documentation
Move out of the concurrency control chapter, where mostly only user table locks are discussed, and move to CREATE COLLATION reference page. Author: Amit Langote <[email protected]> Author: Kyotaro HORIGUCHI <[email protected]>
-rw-r--r--doc/src/sgml/mvcc.sgml3
-rw-r--r--doc/src/sgml/ref/create_collation.sgml7
2 files changed, 8 insertions, 2 deletions
diff --git a/doc/src/sgml/mvcc.sgml b/doc/src/sgml/mvcc.sgml
index 24613e3c75..73934e5cf3 100644
--- a/doc/src/sgml/mvcc.sgml
+++ b/doc/src/sgml/mvcc.sgml
@@ -970,8 +970,7 @@ ERROR: could not serialize access due to read/write dependencies among transact
</para>
<para>
- Acquired by <command>CREATE COLLATION</command>,
- <command>CREATE TRIGGER</command>, and many forms of
+ Acquired by <command>CREATE TRIGGER</command> and many forms of
<command>ALTER TABLE</command> (see <xref linkend="sql-altertable"/>).
</para>
</listitem>
diff --git a/doc/src/sgml/ref/create_collation.sgml b/doc/src/sgml/ref/create_collation.sgml
index 5bc9af5499..038797fce1 100644
--- a/doc/src/sgml/ref/create_collation.sgml
+++ b/doc/src/sgml/ref/create_collation.sgml
@@ -163,6 +163,13 @@ CREATE COLLATION [ IF NOT EXISTS ] <replaceable>name</replaceable> FROM <replace
<title>Notes</title>
<para>
+ <command>CREATE COLLATION</command> takes a <literal>SHARE ROW
+ EXCLUSIVE</literal> lock, which is self-conflicting, on the
+ <structname>pg_collation</structname> system catalog, so only one
+ <command>CREATE COLLATION</command> command can run at a time.
+ </para>
+
+ <para>
Use <command>DROP COLLATION</command> to remove user-defined collations.
</para>