From 61307dccc5f2f352d7dfed5c13abf3f0e26ec85d Mon Sep 17 00:00:00 2001
From: Robert Haas <rhaas@postgresql.org>
Date: Tue, 21 Jun 2011 22:52:52 -0400
Subject: [PATCH] Add smallserial pseudotype.

This is just like serial and bigserial, except it generates an int2
column rather than int4 or int8.

Mike Pultz, reviewed by Brar Piening and Josh Kupershmidt
---
 doc/src/sgml/datatype.sgml         | 29 ++++++++++++++++++++++++++---
 doc/src/sgml/ecpg.sgml             |  5 +++++
 doc/src/sgml/func.sgml             |  2 +-
 src/backend/parser/parse_utilcmd.c |  9 ++++++++-
 4 files changed, 40 insertions(+), 5 deletions(-)

diff --git a/doc/src/sgml/datatype.sgml b/doc/src/sgml/datatype.sgml
index ab8eb2d30b..0b4f978d98 100644
--- a/doc/src/sgml/datatype.sgml
+++ b/doc/src/sgml/datatype.sgml
@@ -198,6 +198,12 @@
        <entry>signed two-byte integer</entry>
       </row>
 
+      <row>
+       <entry><type>smallserial</type></entry>
+       <entry><type>serial2</type></entry>
+       <entry>autoincrementing two-byte integer</entry>
+      </row>
+
       <row>
        <entry><type>serial</type></entry>
        <entry><type>serial4</type></entry>
@@ -368,6 +374,13 @@
         <entry>15 decimal digits precision</entry>
        </row>
 
+       <row>
+        <entry><type>smallserial</type></entry>
+        <entry>2 bytes</entry>
+        <entry>small autoincrementing integer</entry>
+        <entry>1 to 32767</entry>
+       </row>
+
        <row>
         <entry><type>serial</></entry>
         <entry>4 bytes</entry>
@@ -742,6 +755,10 @@ NUMERIC
    <sect2 id="datatype-serial">
     <title>Serial Types</title>
 
+    <indexterm zone="datatype-serial">
+     <primary>smallserial</primary>
+    </indexterm>
+
     <indexterm zone="datatype-serial">
      <primary>serial</primary>
     </indexterm>
@@ -750,6 +767,10 @@ NUMERIC
      <primary>bigserial</primary>
     </indexterm>
 
+    <indexterm zone="datatype-serial">
+     <primary>serial2</primary>
+    </indexterm>
+
     <indexterm zone="datatype-serial">
      <primary>serial4</primary>
     </indexterm>
@@ -769,8 +790,8 @@ NUMERIC
     </indexterm>
 
     <para>
-     The data types <type>serial</type> and <type>bigserial</type>
-     are not true types, but merely
+     The data types <type>smallserial</type>, <type>serial</type> and 
+     <type>bigserial</type> are not true types, but merely
      a notational convenience for creating unique identifier columns
      (similar to the <literal>AUTO_INCREMENT</literal> property
      supported by some other databases). In the current
@@ -828,7 +849,9 @@ ALTER SEQUENCE <replaceable class="parameter">tablename</replaceable>_<replaceab
      the same way, except that they create a <type>bigint</type>
      column.  <type>bigserial</type> should be used if you anticipate
      the use of more than 2<superscript>31</> identifiers over the
-     lifetime of the table.
+     lifetime of the table. The type names <type>smallserial</type> and
+     <type>serial2</type> also work the same way, execpt that they
+     create a <type>smallint</type> column.
     </para>
 
     <para>
diff --git a/doc/src/sgml/ecpg.sgml b/doc/src/sgml/ecpg.sgml
index def250c156..847012293b 100644
--- a/doc/src/sgml/ecpg.sgml
+++ b/doc/src/sgml/ecpg.sgml
@@ -844,6 +844,11 @@ do
        <entry><type>double</type></entry>
       </row>
 
+      <row>
+       <entry><type>smallserial</type></entry>
+       <entry><type>short</type></entry>
+      </row>
+
       <row>
        <entry><type>serial</type></entry>
        <entry><type>int</type></entry>
diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 8f223d6891..628fbef001 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -13366,7 +13366,7 @@ SELECT pg_type_is_visible('myschema.widget'::regtype);
       <row>
        <entry><literal><function>pg_get_serial_sequence(<parameter>table_name</parameter>, <parameter>column_name</parameter>)</function></literal></entry>
        <entry><type>text</type></entry>
-       <entry>get name of the sequence that a <type>serial</type> or <type>bigserial</type> column
+       <entry>get name of the sequence that a <type>serial</type>, <type>smallserial</type> or <type>bigserial</type> column
        uses</entry>
       </row>
       <row>
diff --git a/src/backend/parser/parse_utilcmd.c b/src/backend/parser/parse_utilcmd.c
index 622efe592d..8744654f34 100644
--- a/src/backend/parser/parse_utilcmd.c
+++ b/src/backend/parser/parse_utilcmd.c
@@ -307,7 +307,14 @@ transformColumnDefinition(CreateStmtContext *cxt, ColumnDef *column)
 	{
 		char	   *typname = strVal(linitial(column->typeName->names));
 
-		if (strcmp(typname, "serial") == 0 ||
+		if (strcmp(typname, "smallserial") == 0 ||
+			strcmp(typname, "serial2") == 0)
+		{
+			is_serial = true;
+			column->typeName->names = NIL;
+			column->typeName->typeOid = INT2OID;
+		}
+		else if (strcmp(typname, "serial") == 0 ||
 			strcmp(typname, "serial4") == 0)
 		{
 			is_serial = true;