database/postgres
1
0
Fork 0
mirror of https://github.com/postgres/postgres.git synced 2026-10-23 13:29:09 +03:00
Code Activity

contrib/isn: Make weak mode a GUC setting, and fix related functions.

Browse Source 
isn's weak mode used to be a simple static variable, settable only
via the isn_weak(boolean) function.  This wasn't optimal, as this
means it doesn't respect transactions nor respond to RESET ALL.

This patch makes isn.weak a GUC parameter instead, so that
it acts like any other user-settable parameter.

The isn_weak() functions are retained for backwards compatibility.
But we must fix their volatility markings: they were marked IMMUTABLE
which is surely incorrect, and PARALLEL RESTRICTED which isn't right
for GUC-related functions either.  Mark isn_weak(boolean) as
VOLATILE and PARALLEL UNSAFE, matching set_config().  Mark isn_weak()
as STABLE and PARALLEL SAFE, matching current_setting().

Reported-by: Viktor Holmberg <v@viktorh.net>
Diagnosed-by: Daniel Gustafsson <daniel@yesql.se>
Author: Viktor Holmberg <v@viktorh.net>
Reviewed-by: Tom Lane <tgl@sss.pgh.pa.us>
Discussion: https://postgr.es/m/790bc1f9-74dc-4b50-94d2-8147315b1556@Spark
This commit is contained in:
Tom Lane
2025-03-16 13:45:48 -04:00
parent 682c5be25c
commit 4489044239
9 changed files with 147 additions and 45 deletions
Download Patch File Download Diff File Expand all files Collapse all files

91
doc/src/sgml/isn.sgml
View File

@@ -230,7 +230,7 @@
<para>
The <filename>isn</filename> module provides the standard comparison operators,
plus B-tree and hash indexing support for all these data types. In
addition there are several specialized functions; shown in <xref linkend="isn-functions"/>.
addition, there are several specialized functions, shown in <xref linkend="isn-functions"/>.
In this table,
<type>isn</type> means any one of the module's data types.
</para>
@@ -250,27 +250,6 @@
</thead>
<tbody>
<row>
<entry role="func_table_entry"><para role="func_signature">
<indexterm><primary>isn_weak</primary></indexterm>
<function>isn_weak</function> ( <type>boolean</type> )
<returnvalue>boolean</returnvalue>
</para>
<para>
Sets the weak input mode, and returns new setting.
</para></entry>
</row>
<row>
<entry role="func_table_entry"><para role="func_signature">
<function>isn_weak</function> ()
<returnvalue>boolean</returnvalue>
</para>
<para>
Returns the current status of the weak mode.
</para></entry>
</row>
<row>
<entry role="func_table_entry"><para role="func_signature">
<indexterm><primary>make_valid</primary></indexterm>
@@ -278,7 +257,7 @@
<returnvalue>isn</returnvalue>
</para>
<para>
Validates an invalid number (clears the invalid flag).
Clears the invalid-check-digit flag of the value.
</para></entry>
</row>
@@ -289,18 +268,62 @@
<returnvalue>boolean</returnvalue>
</para>
<para>
Checks for the presence of the invalid flag.
Checks for the presence of the invalid-check-digit flag.
</para></entry>
</row>
<row>
<entry role="func_table_entry"><para role="func_signature">
<indexterm><primary>isn_weak</primary></indexterm>
<function>isn_weak</function> ( <type>boolean</type> )
<returnvalue>boolean</returnvalue>
</para>
<para>
Sets the weak input mode, and returns the new setting.
This function is retained for backward compatibility.
The recommended way to set weak mode is via
the <varname>isn.weak</varname> configuration parameter.
</para></entry>
</row>
<row>
<entry role="func_table_entry"><para role="func_signature">
<function>isn_weak</function> ()
<returnvalue>boolean</returnvalue>
</para>
<para>
Returns the current status of the weak mode.
This function is retained for backward compatibility.
The recommended way to check weak mode is via
the <varname>isn.weak</varname> configuration parameter.
</para></entry>
</row>
</tbody>
</tgroup>
</table>
</sect2>
<para>
<firstterm>Weak</firstterm> mode is used to be able to insert invalid data
into a table. Invalid means the check digit is wrong, not that there are
missing numbers.
</para>
<sect2 id="isn-configuration-parameters">
<title>Configuration Parameters</title>
<variablelist>
<varlistentry id="isn-configuration-parameters-weak">
<term>
<varname>isn.weak</varname> (<type>boolean</type>)
<indexterm>
<primary><varname>isn.weak</varname> configuration parameter</primary>
</indexterm>
</term>
<listitem>
<para>
<varname>isn.weak</varname> enables the weak input mode, which allows
ISN input values to be accepted even when their check digit is wrong.
The default is <literal>false</literal>, which rejects invalid check
digits.
</para>
</listitem>
</varlistentry>
</variablelist>
<para>
Why would you want to use the weak mode? Well, it could be that
@@ -325,9 +348,9 @@
</para>
<para>
You can also force the insertion of invalid numbers even when not in the
weak mode, by appending the <literal>!</literal> character at the end of the
number.
You can also force the insertion of marked-as-invalid numbers even when not
in the weak mode, by appending the <literal>!</literal> character at the
end of the number.
</para>
<para>
@@ -366,11 +389,11 @@ SELECT issn('3251231?');
SELECT ismn('979047213542?');
--Using the weak mode:
SELECT isn_weak(true);
SET isn.weak TO true;
INSERT INTO test VALUES('978-0-11-000533-4');
INSERT INTO test VALUES('9780141219307');
INSERT INTO test VALUES('2-205-00876-X');
SELECT isn_weak(false);
SET isn.weak TO false;
SELECT id FROM test WHERE NOT is_valid(id);
UPDATE test SET id = make_valid(id) WHERE id = '2-205-00876-X!';