Create a GUC parameter temp_tablespaces that allows selection of the

tablespace(s) in which to store temp tables and temporary files.  This is a
list to allow spreading the load across multiple tablespaces (a random list
element is chosen each time a temp object is to be created).  Temp files are
not stored in per-database pgsql_tmp/ directories anymore, but per-tablespace
directories.

Jaime Casanova and Albert Cervera, with review by Bernd Helmle and Tom Lane.

doc/src/sgml/config.sgml

@@ -1,4 +1,4 @@
-<!-- $PostgreSQL: pgsql/doc/src/sgml/config.sgml,v 1.124 2007/05/17 23:36:04 neilc Exp $ -->
+<!-- $PostgreSQL: pgsql/doc/src/sgml/config.sgml,v 1.125 2007/06/03 17:05:29 tgl Exp $ -->
 
 <chapter Id="runtime-config">
   <title>Server Configuration</title>
@@ -281,7 +281,7 @@ SET ENABLE_SEQSCAN TO OFF;
       If you wish, you can specify the configuration file names and locations
       individually using the parameters <varname>config_file</>,
       <varname>hba_file</> and/or <varname>ident_file</>.
-      <varname>config_file</> can only be specified on the 
+      <varname>config_file</> can only be specified on the
       <command>postgres</command> command line, but the others can be
       set within the main configuration file.  If all three parameters plus
       <varname>data_directory</> are explicitly set, then it is not necessary
@@ -311,7 +311,7 @@ SET ENABLE_SEQSCAN TO OFF;
       <listitem>
        <para>
          Specifies the TCP/IP address(es) on which the server is
-         to listen for connections from client applications.  
+         to listen for connections from client applications.
          The value takes the form of a comma-separated list of host names
          and/or numeric IP addresses.  The special entry <literal>*</>
          corresponds to all available IP interfaces.
@@ -362,7 +362,7 @@ SET ENABLE_SEQSCAN TO OFF;
        </para>
       </listitem>
      </varlistentry>
-     
+
      <varlistentry id="guc-superuser-reserved-connections"
      xreflabel="superuser_reserved_connections">
       <term><varname>superuser_reserved_connections</varname>
@@ -461,7 +461,7 @@ SET ENABLE_SEQSCAN TO OFF;
        </para>
       </listitem>
      </varlistentry>
-     
+
      <varlistentry id="guc-bonjour-name" xreflabel="bonjour_name">
       <term><varname>bonjour_name</varname> (<type>string</type>)</term>
       <indexterm>
@@ -478,7 +478,7 @@ SET ENABLE_SEQSCAN TO OFF;
        </para>
       </listitem>
      </varlistentry>
-     
+
      <varlistentry id="guc-tcp-keepalives-idle" xreflabel="tcp_keepalives_idle">
       <term><varname>tcp_keepalives_idle</varname> (<type>integer</type>)</term>
       <indexterm>
@@ -494,7 +494,7 @@ SET ENABLE_SEQSCAN TO OFF;
        </para>
       </listitem>
      </varlistentry>
-     
+
      <varlistentry id="guc-tcp-keepalives-interval" xreflabel="tcp_keepalives_interval">
       <term><varname>tcp_keepalives_interval</varname> (<type>integer</type>)</term>
       <indexterm>
@@ -510,7 +510,7 @@ SET ENABLE_SEQSCAN TO OFF;
        </para>
       </listitem>
      </varlistentry>
-     
+
      <varlistentry id="guc-tcp-keepalives-count" xreflabel="tcp_keepalives_count">
       <term><varname>tcp_keepalives_count</varname> (<type>integer</type>)</term>
       <indexterm>
@@ -519,19 +519,19 @@ SET ENABLE_SEQSCAN TO OFF;
       <listitem>
        <para>
         On systems that support the <symbol>TCP_KEEPCNT</symbol> socket option, specifies how
-        many keepalives can be lost before the connection is considered dead. 
+        many keepalives can be lost before the connection is considered dead.
         A value of zero uses the system default. If <symbol>TCP_KEEPCNT</symbol> is not
         supported, this parameter must be zero. This parameter is ignored
         for connections made via a Unix-domain socket.
        </para>
       </listitem>
      </varlistentry>
-     
+
      </variablelist>
      </sect2>
      <sect2 id="runtime-config-connection-security">
      <title>Security and Authentication</title>
-     
+
      <variablelist>
      <varlistentry id="guc-authentication-timeout" xreflabel="authentication_timeout">
       <term><varname>authentication_timeout</varname> (<type>integer</type>)</term>
@@ -826,7 +826,7 @@ SET ENABLE_SEQSCAN TO OFF;
        </para>
       </listitem>
      </varlistentry>
-     
+
      <varlistentry id="guc-maintenance-work-mem" xreflabel="maintenance_work_mem">
       <term><varname>maintenance_work_mem</varname> (<type>integer</type>)</term>
       <indexterm>
@@ -896,7 +896,7 @@ SET ENABLE_SEQSCAN TO OFF;
       is not in the map cannot be re-used; instead <productname>PostgreSQL</>
       will request more disk space from the operating system when it needs
       to store new data.
-      The last few lines displayed by a database-wide <command>VACUUM VERBOSE</> 
+      The last few lines displayed by a database-wide <command>VACUUM VERBOSE</>
       command can help in determining if the current settings are adequate.
       A <literal>NOTICE</> message is also printed during such an operation
       if the current settings are too low.
@@ -944,7 +944,7 @@ SET ENABLE_SEQSCAN TO OFF;
        </para>
       </listitem>
      </varlistentry>
-     
+
      </variablelist>
      </sect2>
      <sect2 id="runtime-config-resource-kernel">
@@ -3475,7 +3475,14 @@ SELECT * FROM parent WHERE key = 2400;
         to specify using the default tablespace of the current database.
         If the value does not match the name of any existing tablespace,
         <productname>PostgreSQL</> will automatically use the default
-        tablespace of the current database.
+        tablespace of the current database.  If a nondefault tablespace
+        is specified, the user must have <literal>CREATE</> privilege
+        for it, or creation attempts will fail.
+       </para>
+
+       <para>
+        This variable is not used for temporary tables; for them,
+        <xref linkend="guc-temp-tablespaces"> is consulted instead.
        </para>
 
        <para>
@@ -3485,6 +3492,42 @@ SELECT * FROM parent WHERE key = 2400;
       </listitem>
      </varlistentry>
 
+     <varlistentry id="guc-temp-tablespaces" xreflabel="temp_tablespaces">
+      <term><varname>temp_tablespaces</varname> (<type>string</type>)</term>
+      <indexterm>
+       <primary><varname>temp_tablespaces</> configuration parameter</primary>
+      </indexterm>
+      <indexterm><primary>tablespace</><secondary>temporary</></>
+      <listitem>
+       <para>
+        This variable specifies tablespace(s) in which to create temporary
+        objects (temp tables and indexes on temp tables) when a
+        <command>CREATE</> command does not explicitly specify a tablespace.
+        Temporary files for purposes such as sorting large data sets
+        are also created in these tablespace(s).
+       </para>
+
+       <para>
+        The value is a list of names of tablespaces.  When there is more than
+        one name in the list, <productname>PostgreSQL</> chooses a random
+        member of the list each time a temporary object is to be created.
+       </para>
+
+       <para>
+        If any element of the list is an empty string or does not match the
+        name of any existing tablespace, <productname>PostgreSQL</> will
+        automatically use the default tablespace of the current database
+        instead.  If a nondefault tablespace
+        is specified, the user must have <literal>CREATE</> privilege
+        for it, or creation attempts will fail.
+       </para>
+
+       <para>
+        See also <xref linkend="guc-default-tablespace">.
+       </para>
+      </listitem>
+     </varlistentry>
+
      <varlistentry id="guc-check-function-bodies" xreflabel="check_function_bodies">
       <term><varname>check_function_bodies</varname> (<type>boolean</type>)</term>
       <indexterm>
@@ -3605,7 +3648,7 @@ SELECT * FROM parent WHERE key = 2400;
        </para>
       </listitem>
      </varlistentry>
-     
+
      <varlistentry id="guc-xmlbinary" xreflabel="xmlbinary">
       <term><varname>xmlbinary</varname> (<type>string</type>)</term>
       <indexterm>
@@ -3632,7 +3675,7 @@ SELECT * FROM parent WHERE key = 2400;
        </para>
       </listitem>
      </varlistentry>
-     
+
      <varlistentry id="guc-xmloption" xreflabel="xmloption">
       <term><varname>xmloption</varname> (<type>string</type>)</term>
       <indexterm>
@@ -3664,7 +3707,7 @@ SET XML OPTION { DOCUMENT | CONTENT };
        </para>
       </listitem>
      </varlistentry>
-     
+
      </variablelist>
     </sect2>
      <sect2 id="runtime-config-client-format">
@@ -3945,7 +3988,7 @@ dynamic_library_path = 'C:\tools\postgresql;H:\my_project\lib;$libdir'
        </para>
       </listitem>
      </varlistentry>
-     
+
      <varlistentry id="guc-local-preload-libraries" xreflabel="local_preload_libraries">
       <term><varname>local_preload_libraries</varname> (<type>string</type>)</term>
       <indexterm>
@@ -3994,7 +4037,7 @@ dynamic_library_path = 'C:\tools\postgresql;H:\my_project\lib;$libdir'
        <para>
         Every  PostgreSQL-supported library has a <quote>magic
         block</> that is checked to guarantee compatibility.  
-        For this reason, non-PostgreSQL libraries cannot be 
+        For this reason, non-PostgreSQL libraries cannot be
         loaded in this way.
        </para>
       </listitem>

doc/src/sgml/manage-ag.sgml

@@ -1,4 +1,4 @@
-<!-- $PostgreSQL: pgsql/doc/src/sgml/manage-ag.sgml,v 2.53 2007/02/01 00:28:17 momjian Exp $ -->
+<!-- $PostgreSQL: pgsql/doc/src/sgml/manage-ag.sgml,v 2.54 2007/06/03 17:05:52 tgl Exp $ -->
 
 <chapter id="managing-databases">
  <title>Managing Databases</title>
@@ -423,13 +423,23 @@ CREATE TABLE foo(i int);
     do not have an explicit one.
    </para>
 
+   <para>
+    There is also a <xref linkend="guc-temp-tablespaces"> parameter, which
+    determines the placement of temporary tables and indexes, as well as
+    temporary files that are used for purposes such as sorting large data
+    sets.  This can be a list of tablespace names, rather than only one,
+    so that the load associated with temporary objects can be spread over
+    multiple tablespaces.  A random member of the list is picked each time
+    a temporary object is to be created.
+   </para>
+
    <para>
     The tablespace associated with a database is used to store the system
-    catalogs of that database, as well as any temporary files created by
+    catalogs of that database.  Furthermore, it is the default tablespace
-    server processes using that database.  Furthermore, it is the default
+    used for tables, indexes, and temporary files created within the database,
-    tablespace selected for tables and indexes created within the database,
+    if no <literal>TABLESPACE</> clause is given and no other selection is
-    if no <literal>TABLESPACE</> clause is given (either explicitly or via
+    specified by <varname>default_tablespace</> or
-    <varname>default_tablespace</>) when the objects are created.
+    <varname>temp_tablespaces</> (as appropriate).
     If a database is created without specifying a tablespace for it,
     it uses the same tablespace as the template database it is copied from.
    </para>
@@ -468,7 +478,7 @@ SELECT spcname FROM pg_tablespace;
    </para>
 
    <para>
-    <productname>PostgreSQL</> makes extensive use of symbolic links
+    <productname>PostgreSQL</> makes use of symbolic links
     to simplify the implementation of tablespaces. This
     means that tablespaces can be used <emphasis>only</> on systems
     that support symbolic links.

doc/src/sgml/ref/create_index.sgml

@@ -1,5 +1,5 @@
 <!--
-$PostgreSQL: pgsql/doc/src/sgml/ref/create_index.sgml,v 1.62 2007/04/06 22:33:41 tgl Exp $
+$PostgreSQL: pgsql/doc/src/sgml/ref/create_index.sgml,v 1.63 2007/06/03 17:05:53 tgl Exp $
 PostgreSQL documentation
 -->
 
@@ -240,9 +240,9 @@ CREATE [ UNIQUE ] INDEX [ CONCURRENTLY ] <replaceable class="parameter">name</re
       <listitem>
        <para>
         The tablespace in which to create the index.  If not specified,
-        <xref linkend="guc-default-tablespace"> is used, or the database's
+        <xref linkend="guc-default-tablespace"> is consulted, or
-        default tablespace if <varname>default_tablespace</> is an empty
+        <xref linkend="guc-temp-tablespaces"> for indexes on temporary
-        string.
+        tables.
        </para>
       </listitem>
      </varlistentry>

doc/src/sgml/ref/create_table.sgml

@@ -1,5 +1,5 @@
 <!--
-$PostgreSQL: pgsql/doc/src/sgml/ref/create_table.sgml,v 1.107 2007/02/01 00:28:18 momjian Exp $
+$PostgreSQL: pgsql/doc/src/sgml/ref/create_table.sgml,v 1.108 2007/06/03 17:06:03 tgl Exp $
 PostgreSQL documentation
 -->
 
@@ -645,9 +645,8 @@ and <replaceable class="PARAMETER">table_constraint</replaceable> is:
       The <replaceable class="PARAMETER">tablespace</replaceable> is the name
       of the tablespace in which the new table is to be created.
       If not specified,
-      <xref linkend="guc-default-tablespace"> is used, or the database's
+      <xref linkend="guc-default-tablespace"> is consulted, or
-      default tablespace if <varname>default_tablespace</> is an empty
+      <xref linkend="guc-temp-tablespaces"> if the table is temporary.
-      string.
      </para>
     </listitem>
    </varlistentry>
@@ -660,9 +659,8 @@ and <replaceable class="PARAMETER">table_constraint</replaceable> is:
       associated with a <literal>UNIQUE</literal> or <literal>PRIMARY
       KEY</literal> constraint will be created.
       If not specified,
-      <xref linkend="guc-default-tablespace"> is used, or the database's
+      <xref linkend="guc-default-tablespace"> is consulted, or
-      default tablespace if <varname>default_tablespace</> is an empty
+      <xref linkend="guc-temp-tablespaces"> if the table is temporary.
-      string.
      </para>
     </listitem>
    </varlistentry>

doc/src/sgml/ref/create_table_as.sgml

@@ -1,5 +1,5 @@
 <!--
-$PostgreSQL: pgsql/doc/src/sgml/ref/create_table_as.sgml,v 1.36 2006/09/18 19:54:01 tgl Exp $
+$PostgreSQL: pgsql/doc/src/sgml/ref/create_table_as.sgml,v 1.37 2007/06/03 17:06:12 tgl Exp $
 PostgreSQL documentation
 -->
 
@@ -184,9 +184,8 @@ CREATE [ [ GLOBAL | LOCAL ] { TEMPORARY | TEMP } ] TABLE <replaceable>table_name
       The <replaceable class="PARAMETER">tablespace</replaceable> is the name
       of the tablespace in which the new table is to be created.
       If not specified,
-      <xref linkend="guc-default-tablespace"> is used, or the database's
+      <xref linkend="guc-default-tablespace"> is consulted, or
-      default tablespace if <varname>default_tablespace</> is an empty
+      <xref linkend="guc-temp-tablespaces"> if the table is temporary.
-      string.
      </para>
     </listitem>
    </varlistentry>

doc/src/sgml/ref/drop_tablespace.sgml

@@ -1,5 +1,5 @@
 <!--
-$PostgreSQL: pgsql/doc/src/sgml/ref/drop_tablespace.sgml,v 1.6 2007/01/31 23:26:03 momjian Exp $
+$PostgreSQL: pgsql/doc/src/sgml/ref/drop_tablespace.sgml,v 1.7 2007/06/03 17:06:13 tgl Exp $
 PostgreSQL documentation
 -->
 
@@ -36,7 +36,10 @@ DROP TABLESPACE [ IF EXISTS ] <replaceable class="PARAMETER">tablespacename</rep
    The tablespace must be empty of all database objects before it can be
    dropped. It is possible that objects in other databases might still reside
    in the tablespace even if no objects in the current database are using
-   the tablespace.
+   the tablespace.  Also, if the tablespace is listed in the <xref
+   linkend="guc-temp-tablespaces"> setting of any active session, the
+   <command>DROP</> might fail due to temporary files residing in the
+   tablespace.
   </para>
  </refsect1>
 

doc/src/sgml/ref/grant.sgml

@@ -1,5 +1,5 @@
 <!--
-$PostgreSQL: pgsql/doc/src/sgml/ref/grant.sgml,v 1.65 2007/04/07 03:48:25 momjian Exp $
+$PostgreSQL: pgsql/doc/src/sgml/ref/grant.sgml,v 1.66 2007/06/03 17:06:13 tgl Exp $
 PostgreSQL documentation
 -->
 
@@ -211,10 +211,10 @@ GRANT <replaceable class="PARAMETER">role</replaceable> [, ...] TO <replaceable
        have this privilege for the containing schema.
       </para>
       <para>
-       For tablespaces, allows tables and indexes to be created within the
+       For tablespaces, allows tables, indexes, and temporary files to be
-       tablespace, and allows databases to be created that have the tablespace
+       created within the tablespace, and allows databases to be created that
-       as their default tablespace.  (Note that revoking this privilege
+       have the tablespace as their default tablespace.  (Note that revoking
-       will not alter the placement of existing objects.)
+       this privilege will not alter the placement of existing objects.)
       </para>
      </listitem>
     </varlistentry>

doc/src/sgml/storage.sgml

@@ -1,4 +1,4 @@
-<!-- $PostgreSQL: pgsql/doc/src/sgml/storage.sgml,v 1.17 2007/04/06 04:21:41 tgl Exp $ -->
+<!-- $PostgreSQL: pgsql/doc/src/sgml/storage.sgml,v 1.18 2007/06/03 17:05:53 tgl Exp $ -->
 
 <chapter id="storage">
 
@@ -170,6 +170,17 @@ tablespace is not accessed through <filename>pg_tblspc</>, but corresponds to
 <varname>PGDATA</><filename>/global</>.
 </para>
 
+<para>
+Temporary files (for operations such as sorting more data than can fit in
+memory) are created within <varname>PGDATA</><filename>/base/pgsql_tmp</>,
+or within a <filename>pgsql_tmp</> subdirectory of a tablespace directory
+if a tablespace other than <literal>pg_default</> is specified for them.
+The name of a temporary file has the form
+<filename>pgsql_tmp<replaceable>PPP</>.<replaceable>NNN</></filename>,
+where <replaceable>PPP</> is the PID of the owning backend and
+<replaceable>NNN</> distinguishes different files of that backend.
+</para>
+
 </sect1>
 
 <sect1 id="storage-toast">

src/backend/commands/indexcmds.c

@@ -8,7 +8,7 @@
  *
  *
  * IDENTIFICATION
- *	  $PostgreSQL: pgsql/src/backend/commands/indexcmds.c,v 1.158 2007/05/02 21:08:45 tgl Exp $
+ *	  $PostgreSQL: pgsql/src/backend/commands/indexcmds.c,v 1.159 2007/06/03 17:06:16 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -194,7 +194,7 @@ DefineIndex(RangeVar *heapRelation,
 	}
 
 	/*
-	 * Select tablespace to use.  If not specified, use default_tablespace
+	 * Select tablespace to use.  If not specified, use default tablespace
 	 * (which may in turn default to database's default).
 	 */
 	if (tableSpaceName)
@@ -208,7 +208,7 @@ DefineIndex(RangeVar *heapRelation,
 	}
 	else
 	{
-		tablespaceId = GetDefaultTablespace();
+		tablespaceId = GetDefaultTablespace(rel->rd_istemp);
 		/* note InvalidOid is OK in this case */
 	}
 

src/backend/commands/tablecmds.c

@@ -8,7 +8,7 @@
  *
  *
  * IDENTIFICATION
- *	  $PostgreSQL: pgsql/src/backend/commands/tablecmds.c,v 1.225 2007/05/18 23:19:41 alvherre Exp $
+ *	  $PostgreSQL: pgsql/src/backend/commands/tablecmds.c,v 1.226 2007/06/03 17:06:25 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -319,7 +319,7 @@ DefineRelation(CreateStmt *stmt, char relkind)
 	}
 
 	/*
-	 * Select tablespace to use.  If not specified, use default_tablespace
+	 * Select tablespace to use.  If not specified, use default tablespace
 	 * (which may in turn default to database's default).
 	 */
 	if (stmt->tablespacename)
@@ -333,17 +333,10 @@ DefineRelation(CreateStmt *stmt, char relkind)
 	}
 	else
 	{
-		tablespaceId = GetDefaultTablespace();
+		tablespaceId = GetDefaultTablespace(stmt->relation->istemp);
 		/* note InvalidOid is OK in this case */
 	}
 
-	/*
-	 * Parse and validate reloptions, if any.
-	 */
-	reloptions = transformRelOptions((Datum) 0, stmt->options, true, false);
-
-	(void) heap_reloptions(relkind, reloptions, true);
-
 	/* Check permissions except when using database's default */
 	if (OidIsValid(tablespaceId))
 	{
@@ -356,6 +349,13 @@ DefineRelation(CreateStmt *stmt, char relkind)
 						   get_tablespace_name(tablespaceId));
 	}
 
+	/*
+	 * Parse and validate reloptions, if any.
+	 */
+	reloptions = transformRelOptions((Datum) 0, stmt->options, true, false);
+
+	(void) heap_reloptions(relkind, reloptions, true);
+
 	/*
 	 * Look up inheritance ancestors and generate relation schema, including
 	 * inherited attributes.

src/backend/commands/tablespace.c

@@ -37,7 +37,7 @@
  *
  *
  * IDENTIFICATION
- *	  $PostgreSQL: pgsql/src/backend/commands/tablespace.c,v 1.46 2007/05/31 15:13:02 petere Exp $
+ *	  $PostgreSQL: pgsql/src/backend/commands/tablespace.c,v 1.47 2007/06/03 17:06:59 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -65,12 +65,14 @@
 #include "utils/lsyscache.h"
 
 
-/* GUC variable */
+/* GUC variables */
 char	   *default_tablespace = NULL;
+char	   *temp_tablespaces = NULL;
 
 
 static bool remove_tablespace_directories(Oid tablespaceoid, bool redo);
 static void set_short_version(const char *path);
+static Oid	getTempTablespace(void);
 
 
 /*
@@ -903,16 +905,26 @@ assign_default_tablespace(const char *newval, bool doit, GucSource source)
 /*
  * GetDefaultTablespace -- get the OID of the current default tablespace
  *
- * May return InvalidOid to indicate "use the database's default tablespace"
+ * Regular objects and temporary objects have different default tablespaces,
+ * hence the forTemp parameter must be specified.
+ *
+ * May return InvalidOid to indicate "use the database's default tablespace".
+ *
+ * Note that caller is expected to check appropriate permissions for any
+ * result other than InvalidOid.
  *
  * This exists to hide (and possibly optimize the use of) the
  * default_tablespace GUC variable.
  */
 Oid
-GetDefaultTablespace(void)
+GetDefaultTablespace(bool forTemp)
 {
 	Oid			result;
 
+	/* The temp-table case is handled by getTempTablespace() */
+	if (forTemp)
+		return getTempTablespace();
+
 	/* Fast path for default_tablespace == "" */
 	if (default_tablespace == NULL || default_tablespace[0] == '\0')
 		return InvalidOid;
@@ -936,6 +948,179 @@ GetDefaultTablespace(void)
 }
 
 
+/*
+ * Routines for handling the GUC variable 'temp_tablespaces'.
+ */
+
+/* assign_hook: validate new temp_tablespaces, do extra actions as needed */
+const char *
+assign_temp_tablespaces(const char *newval, bool doit, GucSource source)
+{
+	char	   *rawname;
+	List	   *namelist;
+	ListCell   *l;
+
+	/* Need a modifiable copy of string */
+	rawname = pstrdup(newval);
+
+	/* Parse string into list of identifiers */
+	if (!SplitIdentifierString(rawname, ',', &namelist))
+	{
+		/* syntax error in name list */
+		pfree(rawname);
+		list_free(namelist);
+		return NULL;
+	}
+
+	/*
+	 * If we aren't inside a transaction, we cannot do database access so
+	 * cannot verify the individual names.	Must accept the list on faith.
+	 */
+	if (source >= PGC_S_INTERACTIVE && IsTransactionState())
+	{
+		foreach(l, namelist)
+		{
+			char	   *curname = (char *) lfirst(l);
+
+			/* Allow an empty string (signifying database default) */
+			if (curname[0] == '\0')
+				continue;
+
+			/* Else verify that name is a valid tablespace name */
+			if (get_tablespace_oid(curname) == InvalidOid)
+				ereport(ERROR,
+						(errcode(ERRCODE_UNDEFINED_OBJECT),
+						 errmsg("tablespace \"%s\" does not exist",
+								curname)));
+		}
+	}
+
+	pfree(rawname);
+	list_free(namelist);
+
+	return newval;
+}
+
+/*
+ * GetTempTablespace -- get the OID of the next temp tablespace to use
+ *
+ * May return InvalidOid to indicate "use the database's default tablespace".
+ *
+ * This is different from GetDefaultTablespace(true) in just two ways:
+ * 1. We check privileges here instead of leaving it to the caller.
+ * 2. It's safe to call this outside a transaction (we just return InvalidOid).
+ * The transaction state check is used so that this can be called from
+ * low-level places that might conceivably run outside a transaction.
+ */
+Oid
+GetTempTablespace(void)
+{
+	Oid			result;
+
+	/* Can't do catalog access unless within a transaction */
+	if (!IsTransactionState())
+		return InvalidOid;
+
+	/* OK, select a temp tablespace */
+	result = getTempTablespace();
+
+	/* Check permissions except when using database's default */
+	if (OidIsValid(result))
+	{
+		AclResult	aclresult;
+
+		aclresult = pg_tablespace_aclcheck(result, GetUserId(),
+										   ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, ACL_KIND_TABLESPACE,
+						   get_tablespace_name(result));
+	}
+
+	return result;
+}
+
+/*
+ * getTempTablespace -- get the OID of the next temp tablespace to use
+ *
+ * This has exactly the API defined for GetDefaultTablespace(true),
+ * in particular that caller is responsible for permissions checks.
+ *
+ * This exists to hide (and possibly optimize the use of) the
+ * temp_tablespaces GUC variable.
+ */
+static Oid
+getTempTablespace(void)
+{
+	Oid			result;
+	char	   *rawname;
+	List	   *namelist;
+	int			nnames;
+	char	   *curname;
+
+	if (temp_tablespaces == NULL)
+		return InvalidOid;
+
+	/*
+	 * We re-parse the string on each call; this is a bit expensive, but
+	 * we don't expect this function will be called many times per query,
+	 * so it's probably not worth being tenser.
+	 */
+
+	/* Need a modifiable copy of string */
+	rawname = pstrdup(temp_tablespaces);
+
+	/* Parse string into list of identifiers */
+	if (!SplitIdentifierString(rawname, ',', &namelist))
+	{
+		/* syntax error in name list */
+		pfree(rawname);
+		list_free(namelist);
+		return InvalidOid;
+	}
+	nnames = list_length(namelist);
+
+	/* Fast path for temp_tablespaces == "" */
+	if (nnames == 0)
+	{
+		pfree(rawname);
+		list_free(namelist);
+		return InvalidOid;
+	}
+
+	/* Select a random element */
+	if (nnames == 1)			/* no need for a random() call */
+		curname = (char *) linitial(namelist);
+	else
+		curname = (char *) list_nth(namelist, random() % nnames);
+
+	/*
+	 * Empty string means "database's default", else look up the tablespace.
+	 *
+	 * It is tempting to cache this lookup for more speed, but then we would
+	 * fail to detect the case where the tablespace was dropped since the GUC
+	 * variable was set.  Note also that we don't complain if the value fails
+	 * to refer to an existing tablespace; we just silently return InvalidOid,
+	 * causing the new object to be created in the database's tablespace.
+	 */
+	if (curname[0] == '\0')
+		result = InvalidOid;
+	else
+		result = get_tablespace_oid(curname);
+
+	/*
+	 * Allow explicit specification of database's default tablespace in
+	 * temp_tablespaces without triggering permissions checks.
+	 */
+	if (result == MyDatabaseTableSpace)
+		result = InvalidOid;
+
+	pfree(rawname);
+	list_free(namelist);
+
+	return result;
+}
+
+
 /*
  * get_tablespace_oid - given a tablespace name, look up the OID
  *
@@ -950,7 +1135,11 @@ get_tablespace_oid(const char *tablespacename)
 	HeapTuple	tuple;
 	ScanKeyData entry[1];
 
-	/* Search pg_tablespace */
+	/*
+	 * Search pg_tablespace.  We use a heapscan here even though there is an
+	 * index on name, on the theory that pg_tablespace will usually have just
+	 * a few entries and so an indexed lookup is a waste of effort.
+	 */
 	rel = heap_open(TableSpaceRelationId, AccessShareLock);
 
 	ScanKeyInit(&entry[0],
@@ -960,6 +1149,7 @@ get_tablespace_oid(const char *tablespacename)
 	scandesc = heap_beginscan(rel, SnapshotNow, 1, entry);
 	tuple = heap_getnext(scandesc, ForwardScanDirection);
 
+	/* We assume that there can be at most one matching tuple */
 	if (HeapTupleIsValid(tuple))
 		result = HeapTupleGetOid(tuple);
 	else
@@ -985,7 +1175,11 @@ get_tablespace_name(Oid spc_oid)
 	HeapTuple	tuple;
 	ScanKeyData entry[1];
 
-	/* Search pg_tablespace */
+	/*
+	 * Search pg_tablespace.  We use a heapscan here even though there is an
+	 * index on oid, on the theory that pg_tablespace will usually have just
+	 * a few entries and so an indexed lookup is a waste of effort.
+	 */
 	rel = heap_open(TableSpaceRelationId, AccessShareLock);
 
 	ScanKeyInit(&entry[0],

src/backend/executor/execMain.c

@@ -26,7 +26,7 @@
  *
  *
  * IDENTIFICATION
- *	  $PostgreSQL: pgsql/src/backend/executor/execMain.c,v 1.293 2007/04/27 22:05:47 tgl Exp $
+ *	  $PostgreSQL: pgsql/src/backend/executor/execMain.c,v 1.294 2007/06/03 17:07:00 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -2430,7 +2430,7 @@ OpenIntoRel(QueryDesc *queryDesc)
 					   get_namespace_name(namespaceId));
 
 	/*
-	 * Select tablespace to use.  If not specified, use default_tablespace
+	 * Select tablespace to use.  If not specified, use default tablespace
 	 * (which may in turn default to database's default).
 	 */
 	if (into->tableSpaceName)
@@ -2444,7 +2444,7 @@ OpenIntoRel(QueryDesc *queryDesc)
 	}
 	else
 	{
-		tablespaceId = GetDefaultTablespace();
+		tablespaceId = GetDefaultTablespace(into->rel->istemp);
 		/* note InvalidOid is OK in this case */
 	}
 

src/backend/executor/nodeHash.c

@@ -8,7 +8,7 @@
  *
  *
  * IDENTIFICATION
- *	  $PostgreSQL: pgsql/src/backend/executor/nodeHash.c,v 1.112 2007/06/01 17:38:44 tgl Exp $
+ *	  $PostgreSQL: pgsql/src/backend/executor/nodeHash.c,v 1.113 2007/06/03 17:07:14 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -24,6 +24,7 @@
 #include <math.h>
 #include <limits.h>
 
+#include "commands/tablespace.h"
 #include "executor/execdebug.h"
 #include "executor/hashjoin.h"
 #include "executor/instrument.h"
@@ -266,6 +267,7 @@ ExecHashTableCreate(Hash *node, List *hashOperators)
 	hashtable->totalTuples = 0;
 	hashtable->innerBatchFile = NULL;
 	hashtable->outerBatchFile = NULL;
+	hashtable->hashTblSpc = InvalidOid;
 	hashtable->spaceUsed = 0;
 	hashtable->spaceAllowed = work_mem * 1024L;
 
@@ -325,6 +327,8 @@ ExecHashTableCreate(Hash *node, List *hashOperators)
 		hashtable->outerBatchFile = (BufFile **)
 			palloc0(nbatch * sizeof(BufFile *));
 		/* The files will not be opened until needed... */
+		/* ... but we want to choose the tablespace only once */
+		hashtable->hashTblSpc = GetTempTablespace();
 	}
 
 	/*
@@ -506,6 +510,8 @@ ExecHashIncreaseNumBatches(HashJoinTable hashtable)
 			palloc0(nbatch * sizeof(BufFile *));
 		hashtable->outerBatchFile = (BufFile **)
 			palloc0(nbatch * sizeof(BufFile *));
+		/* time to choose the tablespace, too */
+		hashtable->hashTblSpc = GetTempTablespace();
 	}
 	else
 	{
@@ -558,7 +564,8 @@ ExecHashIncreaseNumBatches(HashJoinTable hashtable)
 			{
 				/* dump it out */
 				Assert(batchno > curbatch);
-				ExecHashJoinSaveTuple(HJTUPLE_MINTUPLE(tuple),
+				ExecHashJoinSaveTuple(hashtable,
+									  HJTUPLE_MINTUPLE(tuple),
 									  tuple->hashvalue,
 									  &hashtable->innerBatchFile[batchno]);
 				/* and remove from hash table */
@@ -650,7 +657,8 @@ ExecHashTableInsert(HashJoinTable hashtable,
 		 * put the tuple into a temp file for later batches
 		 */
 		Assert(batchno > hashtable->curbatch);
-		ExecHashJoinSaveTuple(tuple,
+		ExecHashJoinSaveTuple(hashtable,
+							  tuple,
 							  hashvalue,
 							  &hashtable->innerBatchFile[batchno]);
 	}

src/backend/executor/nodeHashjoin.c

@@ -8,7 +8,7 @@
  *
  *
  * IDENTIFICATION
- *	  $PostgreSQL: pgsql/src/backend/executor/nodeHashjoin.c,v 1.89 2007/02/02 00:07:03 tgl Exp $
+ *	  $PostgreSQL: pgsql/src/backend/executor/nodeHashjoin.c,v 1.90 2007/06/03 17:07:26 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -223,7 +223,8 @@ ExecHashJoin(HashJoinState *node)
 				 * in the corresponding outer-batch file.
 				 */
 				Assert(batchno > hashtable->curbatch);
-				ExecHashJoinSaveTuple(ExecFetchSlotMinimalTuple(outerTupleSlot),
+				ExecHashJoinSaveTuple(hashtable,
+									  ExecFetchSlotMinimalTuple(outerTupleSlot),
 									  hashvalue,
 									  &hashtable->outerBatchFile[batchno]);
 				node->hj_NeedNewOuter = true;
@@ -754,7 +755,8 @@ start_over:
  * will get messed up.
  */
 void
-ExecHashJoinSaveTuple(MinimalTuple tuple, uint32 hashvalue,
+ExecHashJoinSaveTuple(HashJoinTable hashtable,
+					  MinimalTuple tuple, uint32 hashvalue,
 					  BufFile **fileptr)
 {
 	BufFile    *file = *fileptr;
@@ -763,7 +765,7 @@ ExecHashJoinSaveTuple(MinimalTuple tuple, uint32 hashvalue,
 	if (file == NULL)
 	{
 		/* First write to this batch file, so open it. */
-		file = BufFileCreateTemp(false);
+		file = BufFileCreateTemp(false, hashtable->hashTblSpc);
 		*fileptr = file;
 	}
 

src/backend/storage/file/buffile.c

@@ -7,7 +7,7 @@
  * Portions Copyright (c) 1994, Regents of the University of California
  *
  * IDENTIFICATION
- *	  $PostgreSQL: pgsql/src/backend/storage/file/buffile.c,v 1.26 2007/06/01 23:43:11 tgl Exp $
+ *	  $PostgreSQL: pgsql/src/backend/storage/file/buffile.c,v 1.27 2007/06/03 17:07:30 tgl Exp $
  *
  * NOTES:
  *
@@ -60,6 +60,7 @@ struct BufFile
 	 * offsets[i] is the current seek position of files[i].  We use this to
 	 * avoid making redundant FileSeek calls.
 	 */
+	Oid			tblspcOid;		/* tablespace to use (InvalidOid = default) */
 
 	bool		isTemp;			/* can only add files if this is TRUE */
 	bool		isInterXact;	/* keep open over transactions? */
@@ -85,7 +86,7 @@ static int	BufFileFlush(BufFile *file);
 
 /*
  * Create a BufFile given the first underlying physical file.
- * NOTE: caller must set isTemp true if appropriate.
+ * NOTE: caller must set tblspcOid, isTemp, isInterXact if appropriate.
  */
 static BufFile *
 makeBufFile(File firstfile)
@@ -97,7 +98,9 @@ makeBufFile(File firstfile)
 	file->files[0] = firstfile;
 	file->offsets = (long *) palloc(sizeof(long));
 	file->offsets[0] = 0L;
+	file->tblspcOid = InvalidOid;
 	file->isTemp = false;
+	file->isInterXact = false;
 	file->dirty = false;
 	file->curFile = 0;
 	file->curOffset = 0L;
@@ -116,7 +119,7 @@ extendBufFile(BufFile *file)
 	File		pfile;
 
 	Assert(file->isTemp);
-	pfile = OpenTemporaryFile(file->isInterXact);
+	pfile = OpenTemporaryFile(file->isInterXact, file->tblspcOid);
 	Assert(pfile >= 0);
 
 	file->files = (File *) repalloc(file->files,
@@ -133,19 +136,24 @@ extendBufFile(BufFile *file)
  * multiple temporary files if more than MAX_PHYSICAL_FILESIZE bytes are
  * written to it).
  *
+ * If interXact is true, the temp file will not be automatically deleted
+ * at end of transaction.  If tblspcOid is not InvalidOid, the temp file
+ * is created in the specified tablespace instead of the default one.
+ *
  * Note: if interXact is true, the caller had better be calling us in a
  * memory context that will survive across transaction boundaries.
  */
 BufFile *
-BufFileCreateTemp(bool interXact)
+BufFileCreateTemp(bool interXact, Oid tblspcOid)
 {
 	BufFile    *file;
 	File		pfile;
 
-	pfile = OpenTemporaryFile(interXact);
+	pfile = OpenTemporaryFile(interXact, tblspcOid);
 	Assert(pfile >= 0);
 
 	file = makeBufFile(pfile);
+	file->tblspcOid = tblspcOid;
 	file->isTemp = true;
 	file->isInterXact = interXact;
 

src/backend/storage/file/fd.c

@@ -7,7 +7,7 @@
  * Portions Copyright (c) 1994, Regents of the University of California
  *
  * IDENTIFICATION
- *	  $PostgreSQL: pgsql/src/backend/storage/file/fd.c,v 1.137 2007/03/06 02:06:14 momjian Exp $
+ *	  $PostgreSQL: pgsql/src/backend/storage/file/fd.c,v 1.138 2007/06/03 17:07:31 tgl Exp $
  *
  * NOTES:
  *
@@ -48,6 +48,7 @@
 
 #include "miscadmin.h"
 #include "access/xact.h"
+#include "catalog/pg_tablespace.h"
 #include "storage/fd.h"
 #include "storage/ipc.h"
 #include "utils/guc.h"
@@ -225,7 +226,7 @@ static File AllocateVfd(void);
 static void FreeVfd(File file);
 
 static int	FileAccess(File file);
-static char *make_database_relative(const char *filename);
+static File OpenTemporaryFileInTablespace(Oid tblspcOid, bool rejectError);
 static void AtProcExit_Files(int code, Datum arg);
 static void CleanupTempFiles(bool isProcExit);
 static void RemovePgTempFilesInDir(const char *tmpdirname);
@@ -721,23 +722,6 @@ FreeVfd(File file)
 	VfdCache[0].nextFree = file;
 }
 
-/*
- * make_database_relative()
- *		Prepend DatabasePath to the given file name.
- *
- * Result is a palloc'd string.
- */
-static char *
-make_database_relative(const char *filename)
-{
-	char	   *buf;
-
-	Assert(!is_absolute_path(filename));
-	buf = (char *) palloc(strlen(DatabasePath) + strlen(filename) + 2);
-	sprintf(buf, "%s/%s", DatabasePath, filename);
-	return buf;
-}
-
 /* returns 0 on success, -1 on re-open failure (with errno set) */
 static int
 FileAccess(File file)
@@ -844,24 +828,6 @@ PathNameOpenFile(FileName fileName, int fileFlags, int fileMode)
 	return file;
 }
 
-/*
- * open a file in the database directory ($PGDATA/base/DIROID/)
- *
- * The passed name MUST be a relative path.  Effectively, this
- * prepends DatabasePath to it and then acts like PathNameOpenFile.
- */
-File
-FileNameOpenFile(FileName fileName, int fileFlags, int fileMode)
-{
-	File		fd;
-	char	   *fname;
-
-	fname = make_database_relative(fileName);
-	fd = PathNameOpenFile(fname, fileFlags, fileMode);
-	pfree(fname);
-	return fd;
-}
-
 /*
  * Open a temporary file that will disappear when we close it.
  *
@@ -874,62 +840,110 @@ FileNameOpenFile(FileName fileName, int fileFlags, int fileMode)
  * that created them, so this should be false -- but if you need
  * "somewhat" temporary storage, this might be useful. In either case,
  * the file is removed when the File is explicitly closed.
+ *
+ * tblspcOid: the Oid of the tablespace where the temp file should be created.
+ * If InvalidOid, or if the tablespace can't be found, we silently fall back
+ * to the database's default tablespace.
  */
 File
-OpenTemporaryFile(bool interXact)
+OpenTemporaryFile(bool interXact, Oid tblspcOid)
 {
+	File		file = 0;
+
+	/*
+	 * If caller specified a tablespace, try to create there.
+	 */
+	if (OidIsValid(tblspcOid))
+		file = OpenTemporaryFileInTablespace(tblspcOid, false);
+
+	/*
+	 * If not, or if tablespace is bad, create in database's default
+	 * tablespace.  MyDatabaseTableSpace should normally be set before we get
+	 * here, but just in case it isn't, fall back to pg_default tablespace.
+	 */
+	if (file <= 0)
+		file = OpenTemporaryFileInTablespace(MyDatabaseTableSpace ?
+											 MyDatabaseTableSpace :
+											 DEFAULTTABLESPACE_OID,
+											 true);
+
+	/* Mark it for deletion at close */
+	VfdCache[file].fdstate |= FD_TEMPORARY;
+
+	/* Mark it for deletion at EOXact */
+	if (!interXact)
+	{
+		VfdCache[file].fdstate |= FD_XACT_TEMPORARY;
+		VfdCache[file].create_subid = GetCurrentSubTransactionId();
+	}
+
+	return file;
+}
+
+/*
+ * Open a temporary file in a specific tablespace.
+ * Subroutine for OpenTemporaryFile, which see for details.
+ */
+static File
+OpenTemporaryFileInTablespace(Oid tblspcOid, bool rejectError)
+{
+	char		tempdirpath[MAXPGPATH];
 	char		tempfilepath[MAXPGPATH];
 	File		file;
 
+	/*
+	 * Identify the tempfile directory for this tablespace.
+	 *
+	 * If someone tries to specify pg_global, use pg_default instead.
+	 */
+	if (tblspcOid == DEFAULTTABLESPACE_OID ||
+		tblspcOid == GLOBALTABLESPACE_OID)
+	{
+		/* The default tablespace is {datadir}/base */
+		snprintf(tempdirpath, sizeof(tempdirpath), "base/%s",
+				 PG_TEMP_FILES_DIR);
+	}
+	else
+	{
+		/* All other tablespaces are accessed via symlinks */
+		snprintf(tempdirpath, sizeof(tempdirpath), "pg_tblspc/%u/%s",
+				 tblspcOid, PG_TEMP_FILES_DIR);
+	}
+
 	/*
 	 * Generate a tempfile name that should be unique within the current
 	 * database instance.
 	 */
-	snprintf(tempfilepath, sizeof(tempfilepath),
+	snprintf(tempfilepath, sizeof(tempfilepath), "%s/%s%d.%ld",
-			 "%s/%s%d.%ld", PG_TEMP_FILES_DIR, PG_TEMP_FILE_PREFIX,
+			 tempdirpath, PG_TEMP_FILE_PREFIX, MyProcPid, tempFileCounter++);
-			 MyProcPid, tempFileCounter++);
 
 	/*
 	 * Open the file.  Note: we don't use O_EXCL, in case there is an orphaned
 	 * temp file that can be reused.
 	 */
-	file = FileNameOpenFile(tempfilepath,
+	file = PathNameOpenFile(tempfilepath,
 							O_RDWR | O_CREAT | O_TRUNC | PG_BINARY,
 							0600);
 	if (file <= 0)
 	{
-		char	   *dirpath;
-
 		/*
-		 * We might need to create the pg_tempfiles subdirectory, if no one
+		 * We might need to create the tablespace's tempfile directory,
-		 * has yet done so.
+		 * if no one has yet done so.
 		 *
 		 * Don't check for error from mkdir; it could fail if someone else
 		 * just did the same thing.  If it doesn't work then we'll bomb out on
 		 * the second create attempt, instead.
 		 */
-		dirpath = make_database_relative(PG_TEMP_FILES_DIR);
+		mkdir(tempdirpath, S_IRWXU);
-		mkdir(dirpath, S_IRWXU);
-		pfree(dirpath);
 
-		file = FileNameOpenFile(tempfilepath,
+		file = PathNameOpenFile(tempfilepath,
 								O_RDWR | O_CREAT | O_TRUNC | PG_BINARY,
 								0600);
-		if (file <= 0)
+		if (file <= 0 && rejectError)
 			elog(ERROR, "could not create temporary file \"%s\": %m",
 				 tempfilepath);
 	}
 
-	/* Mark it for deletion at close */
-	VfdCache[file].fdstate |= FD_TEMPORARY;
-
-	/* Mark it for deletion at EOXact */
-	if (!interXact)
-	{
-		VfdCache[file].fdstate |= FD_XACT_TEMPORARY;
-		VfdCache[file].create_subid = GetCurrentSubTransactionId();
-	}
-
 	return file;
 }
 
@@ -1643,27 +1657,32 @@ void
 RemovePgTempFiles(void)
 {
 	char		temp_path[MAXPGPATH];
-	DIR		   *db_dir;
+	DIR		   *spc_dir;
-	struct dirent *db_de;
+	struct dirent *spc_de;
+
+	/*
+	 * First process temp files in pg_default ($PGDATA/base)
+	 */
+	snprintf(temp_path, sizeof(temp_path), "base/%s", PG_TEMP_FILES_DIR);
+	RemovePgTempFilesInDir(temp_path);
 
 	/*
-	 * Cycle through pgsql_tmp directories for all databases and remove old
+	 * Cycle through temp directories for all non-default tablespaces.
-	 * temp files.
 	 */
-	db_dir = AllocateDir("base");
+	spc_dir = AllocateDir("pg_tblspc");
 
-	while ((db_de = ReadDir(db_dir, "base")) != NULL)
+	while ((spc_de = ReadDir(spc_dir, "pg_tblspc")) != NULL)
 	{
-		if (strcmp(db_de->d_name, ".") == 0 ||
+		if (strcmp(spc_de->d_name, ".") == 0 ||
-			strcmp(db_de->d_name, "..") == 0)
+			strcmp(spc_de->d_name, "..") == 0)
 			continue;
 
-		snprintf(temp_path, sizeof(temp_path), "base/%s/%s",
+		snprintf(temp_path, sizeof(temp_path), "pg_tblspc/%s/%s",
-				 db_de->d_name, PG_TEMP_FILES_DIR);
+				 spc_de->d_name, PG_TEMP_FILES_DIR);
 		RemovePgTempFilesInDir(temp_path);
 	}
 
-	FreeDir(db_dir);
+	FreeDir(spc_dir);
 
 	/*
 	 * In EXEC_BACKEND case there is a pgsql_tmp directory at the top level of

src/backend/utils/misc/guc.c

@@ -10,7 +10,7 @@
  * Written by Peter Eisentraut <peter_e@gmx.net>.
  *
  * IDENTIFICATION
- *	  $PostgreSQL: pgsql/src/backend/utils/misc/guc.c,v 1.392 2007/06/02 23:36:35 petere Exp $
+ *	  $PostgreSQL: pgsql/src/backend/utils/misc/guc.c,v 1.393 2007/06/03 17:07:34 tgl Exp $
  *
  *--------------------------------------------------------------------
  */
@@ -103,6 +103,7 @@ extern bool Log_disconnections;
 extern int	CommitDelay;
 extern int	CommitSiblings;
 extern char *default_tablespace;
+extern char *temp_tablespaces;
 extern bool fullPageWrites;
 
 #ifdef TRACE_SORT
@@ -1967,6 +1968,16 @@ static struct config_string ConfigureNamesString[] =
 		"", assign_default_tablespace, NULL
 	},
 
+	{
+		{"temp_tablespaces", PGC_USERSET, CLIENT_CONN_STATEMENT,
+			gettext_noop("Sets the tablespace(s) to use for temporary tables and sort files."),
+			NULL,
+			GUC_LIST_INPUT | GUC_LIST_QUOTE
+		},
+		&temp_tablespaces,
+		"", assign_temp_tablespaces, NULL
+	},
+
 	{
 		{"default_transaction_isolation", PGC_USERSET, CLIENT_CONN_STATEMENT,
 			gettext_noop("Sets the transaction isolation level of each new transaction."),

src/backend/utils/misc/postgresql.conf.sample

@@ -408,6 +408,8 @@
 #search_path = '"$user",public'		# schema names
 #default_tablespace = ''		# a tablespace name, '' uses
 					# the default
+#temp_tablespaces = ''			# a list of tablespace names,
+					# '' uses only default tablespace
 #check_function_bodies = on
 #default_transaction_isolation = 'read committed'
 #default_transaction_read_only = off

src/backend/utils/sort/logtape.c

@@ -70,13 +70,14 @@
  * Portions Copyright (c) 1994, Regents of the University of California
  *
  * IDENTIFICATION
- *	  $PostgreSQL: pgsql/src/backend/utils/sort/logtape.c,v 1.23 2007/01/05 22:19:47 momjian Exp $
+ *	  $PostgreSQL: pgsql/src/backend/utils/sort/logtape.c,v 1.24 2007/06/03 17:08:23 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
 
 #include "postgres.h"
 
+#include "commands/tablespace.h"
 #include "storage/buffile.h"
 #include "utils/logtape.h"
 
@@ -528,7 +529,7 @@ LogicalTapeSetCreate(int ntapes)
 	Assert(ntapes > 0);
 	lts = (LogicalTapeSet *) palloc(sizeof(LogicalTapeSet) +
 									(ntapes - 1) *sizeof(LogicalTape));
-	lts->pfile = BufFileCreateTemp(false);
+	lts->pfile = BufFileCreateTemp(false, GetTempTablespace());
 	lts->nFileBlocks = 0L;
 	lts->forgetFreeSpace = false;
 	lts->blocksSorted = true;	/* a zero-length array is sorted ... */

src/backend/utils/sort/tuplestore.c

@@ -38,7 +38,7 @@
  * Portions Copyright (c) 1994, Regents of the University of California
  *
  * IDENTIFICATION
- *	  $PostgreSQL: pgsql/src/backend/utils/sort/tuplestore.c,v 1.31 2007/05/21 17:57:34 tgl Exp $
+ *	  $PostgreSQL: pgsql/src/backend/utils/sort/tuplestore.c,v 1.32 2007/06/03 17:08:26 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -46,6 +46,7 @@
 #include "postgres.h"
 
 #include "access/heapam.h"
+#include "commands/tablespace.h"
 #include "executor/executor.h"
 #include "storage/buffile.h"
 #include "utils/memutils.h"
@@ -424,8 +425,14 @@ tuplestore_puttuple_common(Tuplestorestate *state, void *tuple)
 
 			/*
 			 * Nope; time to switch to tape-based operation.
+			 *
+			 * If the temp table is slated to outlive the current transaction,
+			 * force it into my database's default tablespace, so that it will
+			 * not pose a threat to possible tablespace drop attempts.
 			 */
-			state->myfile = BufFileCreateTemp(state->interXact);
+			state->myfile = BufFileCreateTemp(state->interXact,
+											  state->interXact ? InvalidOid :
+											  GetTempTablespace());
 			state->status = TSS_WRITEFILE;
 			dumptuples(state);
 			break;

src/include/commands/tablespace.h

@@ -7,7 +7,7 @@
  * Portions Copyright (c) 1996-2007, PostgreSQL Global Development Group
  * Portions Copyright (c) 1994, Regents of the University of California
  *
- * $PostgreSQL: pgsql/src/include/commands/tablespace.h,v 1.16 2007/03/06 02:06:15 momjian Exp $
+ * $PostgreSQL: pgsql/src/include/commands/tablespace.h,v 1.17 2007/06/03 17:08:29 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -40,7 +40,8 @@ extern void AlterTableSpaceOwner(const char *name, Oid newOwnerId);
 
 extern void TablespaceCreateDbspace(Oid spcNode, Oid dbNode, bool isRedo);
 
-extern Oid	GetDefaultTablespace(void);
+extern Oid	GetDefaultTablespace(bool forTemp);
+extern Oid	GetTempTablespace(void);
 
 extern Oid	get_tablespace_oid(const char *tablespacename);
 extern char *get_tablespace_name(Oid spc_oid);

src/include/executor/hashjoin.h

@@ -7,7 +7,7 @@
  * Portions Copyright (c) 1996-2007, PostgreSQL Global Development Group
  * Portions Copyright (c) 1994, Regents of the University of California
  *
- * $PostgreSQL: pgsql/src/include/executor/hashjoin.h,v 1.45 2007/06/01 17:38:44 tgl Exp $
+ * $PostgreSQL: pgsql/src/include/executor/hashjoin.h,v 1.46 2007/06/03 17:08:32 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -102,6 +102,8 @@ typedef struct HashJoinTableData
 	BufFile   **innerBatchFile; /* buffered virtual temp file per batch */
 	BufFile   **outerBatchFile; /* buffered virtual temp file per batch */
 
+	Oid			hashTblSpc;		/* tablespace to put temp files in */
+
 	/*
 	 * Info about the datatype-specific hash functions for the datatypes being
 	 * hashed. These are arrays of the same length as the number of hash join

src/include/executor/nodeHashjoin.h

@@ -7,7 +7,7 @@
  * Portions Copyright (c) 1996-2007, PostgreSQL Global Development Group
  * Portions Copyright (c) 1994, Regents of the University of California
  *
- * $PostgreSQL: pgsql/src/include/executor/nodeHashjoin.h,v 1.34 2007/01/05 22:19:54 momjian Exp $
+ * $PostgreSQL: pgsql/src/include/executor/nodeHashjoin.h,v 1.35 2007/06/03 17:08:32 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -23,7 +23,8 @@ extern TupleTableSlot *ExecHashJoin(HashJoinState *node);
 extern void ExecEndHashJoin(HashJoinState *node);
 extern void ExecReScanHashJoin(HashJoinState *node, ExprContext *exprCtxt);
 
-extern void ExecHashJoinSaveTuple(MinimalTuple tuple, uint32 hashvalue,
+extern void ExecHashJoinSaveTuple(HashJoinTable hashtable,
-					  BufFile **fileptr);
+								  MinimalTuple tuple, uint32 hashvalue,
+								  BufFile **fileptr);
 
 #endif   /* NODEHASHJOIN_H */

src/include/storage/buffile.h

@@ -18,7 +18,7 @@
  * Portions Copyright (c) 1996-2007, PostgreSQL Global Development Group
  * Portions Copyright (c) 1994, Regents of the University of California
  *
- * $PostgreSQL: pgsql/src/include/storage/buffile.h,v 1.20 2007/01/05 22:19:57 momjian Exp $
+ * $PostgreSQL: pgsql/src/include/storage/buffile.h,v 1.21 2007/06/03 17:08:32 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -34,7 +34,7 @@ typedef struct BufFile BufFile;
  * prototypes for functions in buffile.c
  */
 
-extern BufFile *BufFileCreateTemp(bool interXact);
+extern BufFile *BufFileCreateTemp(bool interXact, Oid tblspcOid);
 extern void BufFileClose(BufFile *file);
 extern size_t BufFileRead(BufFile *file, void *ptr, size_t size);
 extern size_t BufFileWrite(BufFile *file, void *ptr, size_t size);

src/include/storage/fd.h

@@ -7,7 +7,7 @@
  * Portions Copyright (c) 1996-2007, PostgreSQL Global Development Group
  * Portions Copyright (c) 1994, Regents of the University of California
  *
- * $PostgreSQL: pgsql/src/include/storage/fd.h,v 1.57 2007/01/05 22:19:57 momjian Exp $
+ * $PostgreSQL: pgsql/src/include/storage/fd.h,v 1.58 2007/06/03 17:08:33 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -59,9 +59,8 @@ extern int	max_files_per_process;
  */
 
 /* Operations on virtual Files --- equivalent to Unix kernel file ops */
-extern File FileNameOpenFile(FileName fileName, int fileFlags, int fileMode);
 extern File PathNameOpenFile(FileName fileName, int fileFlags, int fileMode);
-extern File OpenTemporaryFile(bool interXact);
+extern File OpenTemporaryFile(bool interXact, Oid tblspcOid);
 extern void FileClose(File file);
 extern void FileUnlink(File file);
 extern int	FileRead(File file, char *buffer, int amount);

src/include/utils/guc.h

@@ -7,7 +7,7 @@
  * Copyright (c) 2000-2007, PostgreSQL Global Development Group
  * Written by Peter Eisentraut <peter_e@gmx.net>.
  *
- * $PostgreSQL: pgsql/src/include/utils/guc.h,v 1.81 2007/04/12 06:53:48 neilc Exp $
+ * $PostgreSQL: pgsql/src/include/utils/guc.h,v 1.82 2007/06/03 17:08:34 tgl Exp $
  *--------------------------------------------------------------------
  */
 #ifndef GUC_H
@@ -225,6 +225,8 @@ extern void read_nondefault_variables(void);
 /* in commands/tablespace.c */
 extern const char *assign_default_tablespace(const char *newval,
 						  bool doit, GucSource source);
+extern const char *assign_temp_tablespaces(const char *newval,
+						  bool doit, GucSource source);
 
 /* in utils/adt/regexp.c */
 extern const char *assign_regex_flavor(const char *value,