Daniel Gustafsson <dan...@yesql.se> writes:
>> On 30 Jan 2022, at 16:52, Tom Lane <t...@sss.pgh.pa.us> wrote:
>> I could get behind documenting the more modern
>> one first, though.
> +1
Proposed patch attached.
>> I wonder if it's time to remove the references to PG 8.1?
> I think it's time to remove references to 8.0 and 8.1 to de-clutter the page,
> 8.3 or 8.4 seems like a better lower limit to keep.
It's hard to explain why lo_creat is there at all without mentioning
8.1, so I ended up with the below, which basically says that lo_creat
is only useful for talking to pre-8.1 servers. Comments?
regards, tom lane
diff --git a/doc/src/sgml/lobj.sgml b/doc/src/sgml/lobj.sgml
index 57bb57083a..b767ba1d05 100644
--- a/doc/src/sgml/lobj.sgml
+++ b/doc/src/sgml/lobj.sgml
@@ -138,57 +138,59 @@
<title>Creating a Large Object</title>
<para>
- <indexterm><primary>lo_creat</primary></indexterm>
+ <indexterm><primary>lo_create</primary></indexterm>
The function
<synopsis>
-Oid lo_creat(PGconn *conn, int mode);
+Oid lo_create(PGconn *conn, Oid lobjId);
</synopsis>
- creates a new large object.
+ creates a new large object. The OID to be assigned can be
+ specified by <replaceable class="parameter">lobjId</replaceable>;
+ if so, failure occurs if that OID is already in use for some large
+ object. If <replaceable class="parameter">lobjId</replaceable>
+ is <symbol>InvalidOid</symbol> (zero) then <function>lo_create</function>
+ assigns an unused OID.
The return value is the OID that was assigned to the new large object,
or <symbol>InvalidOid</symbol> (zero) on failure.
-
- <replaceable class="parameter">mode</replaceable> is unused and
- ignored as of <productname>PostgreSQL</productname> 8.1; however, for
- backward compatibility with earlier releases it is best to
- set it to <symbol>INV_READ</symbol>, <symbol>INV_WRITE</symbol>,
- or <symbol>INV_READ</symbol> <literal>|</literal> <symbol>INV_WRITE</symbol>.
- (These symbolic constants are defined
- in the header file <filename>libpq/libpq-fs.h</filename>.)
</para>
<para>
An example:
<programlisting>
-inv_oid = lo_creat(conn, INV_READ|INV_WRITE);
+inv_oid = lo_create(conn, desired_oid);
</programlisting>
</para>
<para>
- <indexterm><primary>lo_create</primary></indexterm>
- The function
+ <indexterm><primary>lo_creat</primary></indexterm>
+ The older function
<synopsis>
-Oid lo_create(PGconn *conn, Oid lobjId);
+Oid lo_creat(PGconn *conn, int mode);
</synopsis>
- also creates a new large object. The OID to be assigned can be
- specified by <replaceable class="parameter">lobjId</replaceable>;
- if so, failure occurs if that OID is already in use for some large
- object. If <replaceable class="parameter">lobjId</replaceable>
- is <symbol>InvalidOid</symbol> (zero) then <function>lo_create</function> assigns an unused
- OID (this is the same behavior as <function>lo_creat</function>).
+ also creates a new large object, always assigning an unused OID.
The return value is the OID that was assigned to the new large object,
or <symbol>InvalidOid</symbol> (zero) on failure.
</para>
<para>
- <function>lo_create</function> is new as of <productname>PostgreSQL</productname>
- 8.1; if this function is run against an older server version, it will
- fail and return <symbol>InvalidOid</symbol>.
+ In <productname>PostgreSQL</productname> releases 8.1 and later,
+ the <replaceable class="parameter">mode</replaceable> is ignored,
+ so that <function>lo_creat</function> is exactly equivalent to
+ <function>lo_create</function> with a zero second argument.
+ However, there is little reason to use <function>lo_creat</function>
+ unless you need to work with servers older than 8.1.
+ To work with such an old server, you must
+ use <function>lo_creat</function> not <function>lo_create</function>,
+ and you must set <replaceable class="parameter">mode</replaceable> to
+ one of <symbol>INV_READ</symbol>, <symbol>INV_WRITE</symbol>,
+ or <symbol>INV_READ</symbol> <literal>|</literal> <symbol>INV_WRITE</symbol>.
+ (These symbolic constants are defined
+ in the header file <filename>libpq/libpq-fs.h</filename>.)
</para>
<para>
An example:
<programlisting>
-inv_oid = lo_create(conn, desired_oid);
+inv_oid = lo_creat(conn, INV_READ|INV_WRITE);
</programlisting>
</para>
</sect2>
