doc: Fix section of functions age(xid) and mxid_age(xid)

In 17~, age(xid) and mxid_age(xid) were listed as deprecated.  Based on
the discussion that led to 48b5aa3143, this is not intentional as this
could break many existing monitoring queries.  Note that vacuumdb also
uses both of them.

In 16, both functions were listed under "Control Data Functions", which
is incorrect, so let's move them to the list of functions related to
transaction IDs and snapshots.

Author: Bertrand Drouvot
Discussion: https://postgr.es/m/Zzr2zZFyeFKXWe8a@ip-10-97-1-34.eu-west-3.compute.internal
Discussion: https://postgr.es/m/20231114013224.4z6oxa6p6va33rxr@awork3.anarazel.de
Backpatch-through: 16
This commit is contained in:
Michael Paquier 2024-11-20 14:21:07 +09:00
parent c1ebef3c10
commit 6fc3c587b8

View File

@ -27009,6 +27009,34 @@ SELECT currval(pg_get_serial_sequence('sometable', 'id'));
</thead>
<tbody>
<row>
<entry role="func_table_entry"><para role="func_signature">
<indexterm>
<primary>age</primary>
</indexterm>
<function>age</function> ( <type>xid</type> )
<returnvalue>integer</returnvalue>
</para>
<para>
Returns the number of transactions between the supplied
transaction id and the current transaction counter.
</para></entry>
</row>
<row>
<entry role="func_table_entry"><para role="func_signature">
<indexterm>
<primary>mxid_age</primary>
</indexterm>
<function>mxid_age</function> ( <type>xid</type> )
<returnvalue>integer</returnvalue>
</para>
<para>
Returns the number of multixacts IDs between the supplied
multixact ID and the current multixacts counter.
</para></entry>
</row>
<row>
<entry role="func_table_entry"><para role="func_signature">
<indexterm>
@ -27153,7 +27181,8 @@ SELECT currval(pg_get_serial_sequence('sometable', 'id'));
<para>
The internal transaction ID type <type>xid</type> is 32 bits wide and
wraps around every 4 billion transactions. However,
the functions shown in <xref linkend="functions-pg-snapshot"/> use a
the functions shown in <xref linkend="functions-pg-snapshot"/>, except
<function>age</function> and <function>mxid_age</function>, use a
64-bit type <type>xid8</type> that does not wrap around during the life
of an installation and can be converted to <type>xid</type> by casting if
required; see <xref linkend="transaction-id"/> for details.
@ -27235,33 +27264,6 @@ SELECT currval(pg_get_serial_sequence('sometable', 'id'));
</thead>
<tbody>
<row>
<entry role="func_table_entry"><para role="func_signature">
<indexterm>
<primary>age</primary>
</indexterm>
<function>age</function> ( <type>xid</type> )
<returnvalue>integer</returnvalue>
</para>
<para>
Returns the number of transactions between the supplied
transaction id and the current transaction counter.
</para></entry>
</row>
<row>
<entry role="func_table_entry"><para role="func_signature">
<indexterm>
<primary>mxid_age</primary>
</indexterm>
<function>mxid_age</function> ( <type>xid</type> )
<returnvalue>integer</returnvalue>
</para>
<para>
Returns the number of multixacts IDs between the supplied
multixact ID and the current multixacts counter.
</para></entry>
</row>
<row>
<entry role="func_table_entry"><para role="func_signature">