Extend COPY to support COPY (SELECT ...) TO ...

Bernd Helmle

doc/src/sgml/ref/copy.sgml

@@ -1,5 +1,5 @@
 <!--
-$PostgreSQL: pgsql/doc/src/sgml/ref/copy.sgml,v 1.74 2006/04/22 03:03:11 momjian Exp $
+$PostgreSQL: pgsql/doc/src/sgml/ref/copy.sgml,v 1.75 2006/08/30 23:34:20 tgl Exp $
 PostgreSQL documentation
 -->
 
@@ -33,7 +33,7 @@ COPY <replaceable class="parameter">tablename</replaceable> [ ( <replaceable cla
                 [ ESCAPE [ AS ] '<replaceable class="parameter">escape</replaceable>' ]
                 [ FORCE NOT NULL <replaceable class="parameter">column</replaceable> [, ...] ]
 
-COPY <replaceable class="parameter">tablename</replaceable> [ ( <replaceable class="parameter">column</replaceable> [, ...] ) ]
+COPY { <replaceable class="parameter">tablename</replaceable> [ ( <replaceable class="parameter">column</replaceable> [, ...] ) ] | ( <replaceable class="parameter">query</replaceable> ) }
     TO { '<replaceable class="parameter">filename</replaceable>' | STDOUT }
     [ [ WITH ] 
           [ BINARY ]
@@ -57,7 +57,8 @@ COPY <replaceable class="parameter">tablename</replaceable> [ ( <replaceable cla
    files. <command>COPY TO</command> copies the contents of a table
    <emphasis>to</> a file, while <command>COPY FROM</command> copies
    data <emphasis>from</> a file to a table (appending the data to
-   whatever is in the table already).
+   whatever is in the table already).  <command>COPY TO</command>
+   can also copy the results of a <command>SELECT</> query.
   </para>
 
   <para>
@@ -97,7 +98,17 @@ COPY <replaceable class="parameter">tablename</replaceable> [ ( <replaceable cla
      <listitem>
      <para>
       An optional list of columns to be copied.  If no column list is
-      specified, all columns will be used.
+      specified, all columns of the table will be copied.
+     </para>
+    </listitem>
+   </varlistentry>
+
+   <varlistentry>
+    <term><replaceable class="parameter">query</replaceable></term>
+    <listitem>
+     <para>
+      A <command>SELECT</> query whose results are to be copied.
+      Note that parentheses are required around the query.
      </para>
     </listitem>
    </varlistentry>
@@ -148,7 +159,8 @@ COPY <replaceable class="parameter">tablename</replaceable> [ ( <replaceable cla
      <para>
       Specifies copying the OID for each row.  (An error is raised if
       <literal>OIDS</literal> is specified for a table that does not
-      have OIDs.)
+      have OIDs, or in the case of copying a <replaceable
+      class="parameter">query</replaceable>.)
      </para>
     </listitem>
    </varlistentry>
@@ -265,7 +277,7 @@ COPY <replaceable class="parameter">tablename</replaceable> [ ( <replaceable cla
 COPY <replaceable class="parameter">count</replaceable>
 </screen>
    The <replaceable class="parameter">count</replaceable> is the number
-   of rows inserted into or copied from the table.
+   of rows copied.
   </para>
  </refsect1>
 
@@ -274,7 +286,8 @@ COPY <replaceable class="parameter">count</replaceable>
 
    <para>
     <command>COPY</command> can only be used with plain tables, not
-    with views.
+    with views.  However, you can write <literal>COPY (SELECT * FROM
+    <replaceable class="parameter">viewname</replaceable>) TO ...</literal>.
    </para>
 
    <para>
@@ -320,8 +333,8 @@ COPY <replaceable class="parameter">count</replaceable>
     server in the case of <command>COPY TO</command>, but for
     <command>COPY FROM</command> you do have the option of reading from
     a file specified by a relative path. The path will be interpreted
-    relative to the working directory of the server process (somewhere below
+    relative to the working directory of the server process (normally
-    the data directory), not the client's working directory.
+    the cluster's data directory), not the client's working directory.
    </para>
 
    <para>
@@ -737,14 +750,9 @@ COPY country FROM '/usr1/proj/bray/sql/country_data';
   </para>
 
   <para>
-   To copy into a file just the countries whose names start with 'A'
+   To copy into a file just the countries whose names start with 'A':
-   using a temporary table which is automatically deleted:
 <programlisting>
-BEGIN;
+COPY (SELECT * FROM country WHERE country_name LIKE 'A%') TO '/usr1/proj/bray/sql/a_list_countries.copy';
-CREATE TEMP TABLE a_list_countries AS
-    SELECT * FROM country WHERE country_name LIKE 'A%';
-COPY a_list_countries TO '/usr1/proj/bray/sql/a_list_countries.copy';
-ROLLBACK;
 </programlisting>
   </para>
 

doc/src/sgml/ref/psql-ref.sgml

@@ -1,5 +1,5 @@
 <!--
-$PostgreSQL: pgsql/doc/src/sgml/ref/psql-ref.sgml,v 1.167 2006/08/29 22:25:04 tgl Exp $
+$PostgreSQL: pgsql/doc/src/sgml/ref/psql-ref.sgml,v 1.168 2006/08/30 23:34:21 tgl Exp $
 PostgreSQL documentation
 -->
 
@@ -739,8 +739,7 @@ testdb=&gt;
       </varlistentry>
 
       <varlistentry>
-        <term><literal>\copy <replaceable class="parameter">table</replaceable>
+        <term><literal>\copy { <replaceable class="parameter">table</replaceable> [ ( <replaceable class="parameter">column_list</replaceable> ) ] | ( <replaceable class="parameter">query</replaceable> ) }
-        [ ( <replaceable class="parameter">column_list</replaceable> ) ]
         { <literal>from</literal> | <literal>to</literal> }
         { <replaceable class="parameter">filename</replaceable> | stdin | stdout | pstdin | pstdout }
         [ with ]
@@ -779,9 +778,7 @@ testdb=&gt;
         </para>
 
         <para>
-        <literal>\copy <replaceable
+        <literal>\copy ... from stdin | to stdout</literal>
-        class="parameter">table</replaceable> from <replaceable
-        class="parameter">stdin | stdout</replaceable></literal>
         reads/writes based on the command input and output respectively.
         All rows are read from the same source that issued the command,
         continuing until <literal>\.</literal> is read or the stream

src/backend/commands/copy.c

@@ -8,7 +8,7 @@
  *
  *
  * IDENTIFICATION
- *	  $PostgreSQL: pgsql/src/backend/commands/copy.c,v 1.268 2006/07/14 14:52:18 momjian Exp $
+ *	  $PostgreSQL: pgsql/src/backend/commands/copy.c,v 1.269 2006/08/30 23:34:21 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -31,6 +31,7 @@
 #include "libpq/pqformat.h"
 #include "mb/pg_wchar.h"
 #include "miscadmin.h"
+#include "optimizer/planner.h"
 #include "parser/parse_relation.h"
 #include "rewrite/rewriteHandler.h"
 #include "storage/fd.h"
@@ -99,18 +100,21 @@ typedef struct CopyStateData
 
 	/* parameters from the COPY command */
 	Relation	rel;			/* relation to copy to or from */
+	QueryDesc  *queryDesc;		/* executable query to copy from */
 	List	   *attnumlist;		/* integer list of attnums to copy */
+	char	   *filename;		/* filename, or NULL for STDIN/STDOUT */
 	bool		binary;			/* binary format? */
 	bool		oids;			/* include OIDs? */
 	bool		csv_mode;		/* Comma Separated Value format? */
 	bool		header_line;	/* CSV header line? */
 	char	   *null_print;		/* NULL marker string (server encoding!) */
 	int			null_print_len; /* length of same */
+	char	   *null_print_client; /* same converted to client encoding */
 	char	   *delim;			/* column delimiter (must be 1 byte) */
 	char	   *quote;			/* CSV quote char (must be 1 byte) */
 	char	   *escape;			/* CSV escape char (must be 1 byte) */
-	List	   *force_quote_atts;		/* integer list of attnums to FQ */
+	bool	   *force_quote_flags;		/* per-column CSV FQ flags */
-	List	   *force_notnull_atts;		/* integer list of attnums to FNN */
+	bool	   *force_notnull_flags;	/* per-column CSV FNN flags */
 
 	/* these are just for error messages, see copy_in_error_callback */
 	const char *cur_relname;	/* table name for error messages */
@@ -118,6 +122,12 @@ typedef struct CopyStateData
 	const char *cur_attname;	/* current att for error messages */
 	const char *cur_attval;		/* current att value for error messages */
 
+	/*
+	 * Working state for COPY TO
+	 */
+	FmgrInfo   *out_functions;		/* lookup info for output functions */
+	MemoryContext rowcontext;		/* per-row evaluation context */
+
 	/*
 	 * These variables are used to reduce overhead in textual COPY FROM.
 	 *
@@ -153,6 +163,13 @@ typedef struct CopyStateData
 
 typedef CopyStateData *CopyState;
 
+/* DestReceiver for COPY (SELECT) TO */
+typedef struct
+{
+	DestReceiver pub;			/* publicly-known function pointers */
+	CopyState	cstate;			/* CopyStateData for the command */
+} DR_copy;
+
 
 /*
  * These macros centralize code used to process line_buf and raw_buf buffers.
@@ -225,6 +242,8 @@ static const char BinarySignature[11] = "PGCOPY\n\377\r\n\0";
 /* non-export function prototypes */
 static void DoCopyTo(CopyState cstate);
 static void CopyTo(CopyState cstate);
+static void CopyOneRowTo(CopyState cstate, Oid tupleOid,
+						 Datum *values, bool *nulls);
 static void CopyFrom(CopyState cstate);
 static bool CopyReadLine(CopyState cstate);
 static bool CopyReadLineText(CopyState cstate);
@@ -239,7 +258,8 @@ static Datum CopyReadBinaryAttribute(CopyState cstate,
 static void CopyAttributeOutText(CopyState cstate, char *string);
 static void CopyAttributeOutCSV(CopyState cstate, char *string,
 					bool use_quote, bool single_attr);
-static List *CopyGetAttnums(Relation rel, List *attnamelist);
+static List *CopyGetAttnums(TupleDesc tupDesc, Relation rel,
+							List *attnamelist);
 static char *limit_printout_length(const char *str);
 
 /* Low-level communications functions */
@@ -668,7 +688,8 @@ CopyLoadRawBuf(CopyState cstate)
  *	 DoCopy executes the SQL COPY statement.
  *
  * Either unload or reload contents of table <relation>, depending on <from>.
- * (<from> = TRUE means we are inserting into the table.)
+ * (<from> = TRUE means we are inserting into the table.)  In the "TO" case
+ * we also support copying the output of an arbitrary SELECT query.
  *
  * If <pipe> is false, transfer is between the table and the file named
  * <filename>.	Otherwise, transfer is between the table and our regular
@@ -697,8 +718,6 @@ uint64
 DoCopy(const CopyStmt *stmt)
 {
 	CopyState	cstate;
-	RangeVar   *relation = stmt->relation;
-	char	   *filename = stmt->filename;
 	bool		is_from = stmt->is_from;
 	bool		pipe = (stmt->filename == NULL);
 	List	   *attnamelist = stmt->attlist;
@@ -707,6 +726,8 @@ DoCopy(const CopyStmt *stmt)
 	AclMode		required_access = (is_from ? ACL_INSERT : ACL_SELECT);
 	AclResult	aclresult;
 	ListCell   *option;
+	TupleDesc	tupDesc;
+	int			num_phys_attrs;
 	uint64		processed;
 
 	/* Allocate workspace and zero all fields */
@@ -920,10 +941,31 @@ DoCopy(const CopyStmt *stmt)
 				(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
 				 errmsg("CSV quote character must not appear in the NULL specification")));
 
+	/* Disallow file COPY except to superusers. */
+	if (!pipe && !superuser())
+		ereport(ERROR,
+				(errcode(ERRCODE_INSUFFICIENT_PRIVILEGE),
+				 errmsg("must be superuser to COPY to or from a file"),
+				 errhint("Anyone can COPY to stdout or from stdin. "
+						 "psql's \\copy command also works for anyone.")));
+
+	if (stmt->relation)
+	{
+		Assert(!stmt->query);
+		cstate->queryDesc = NULL;
+
 		/* Open and lock the relation, using the appropriate lock type. */
-	cstate->rel = heap_openrv(relation,
+		cstate->rel = heap_openrv(stmt->relation,
 								  (is_from ? RowExclusiveLock : AccessShareLock));
 
+		/* Check relation permissions. */
+		aclresult = pg_class_aclcheck(RelationGetRelid(cstate->rel),
+									  GetUserId(),
+									  required_access);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, ACL_KIND_CLASS,
+						   RelationGetRelationName(cstate->rel));
+
 		/* check read-only transaction */
 		if (XactReadOnly && is_from &&
 			!isTempNamespace(RelationGetNamespace(cstate->rel)))
@@ -931,19 +973,6 @@ DoCopy(const CopyStmt *stmt)
 					(errcode(ERRCODE_READ_ONLY_SQL_TRANSACTION),
 					 errmsg("transaction is read-only")));
 
-	/* Check permissions. */
-	aclresult = pg_class_aclcheck(RelationGetRelid(cstate->rel), GetUserId(),
-								  required_access);
-	if (aclresult != ACLCHECK_OK)
-		aclcheck_error(aclresult, ACL_KIND_CLASS,
-					   RelationGetRelationName(cstate->rel));
-	if (!pipe && !superuser())
-		ereport(ERROR,
-				(errcode(ERRCODE_INSUFFICIENT_PRIVILEGE),
-				 errmsg("must be superuser to COPY to or from a file"),
-				 errhint("Anyone can COPY to stdout or from stdin. "
-						 "psql's \\copy command also works for anyone.")));
-
 		/* Don't allow COPY w/ OIDs to or from a table without them */
 		if (cstate->oids && !cstate->rel->rd_rel->relhasoids)
 			ereport(ERROR,
@@ -951,19 +980,106 @@ DoCopy(const CopyStmt *stmt)
 					 errmsg("table \"%s\" does not have OIDs",
 							RelationGetRelationName(cstate->rel))));
 
-	/* Generate or convert list of attributes to process */
+		tupDesc = RelationGetDescr(cstate->rel);
-	cstate->attnumlist = CopyGetAttnums(cstate->rel, attnamelist);
+	}
+	else
+	{
+		Query	   *query = stmt->query;
+		List	   *rewritten;
+		Plan	   *plan;
+		DestReceiver *dest;
 
-	/* Convert FORCE QUOTE name list to column numbers, check validity */
+		Assert(query);
+		Assert(!is_from);
+		cstate->rel = NULL;
+
+		/* Don't allow COPY w/ OIDs from a select */
+		if (cstate->oids)
+			ereport(ERROR,
+					(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
+					 errmsg("COPY (SELECT) WITH OIDS is not supported")));
+
+		if (query->into)
+			ereport(ERROR,
+					(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
+					 errmsg("COPY (SELECT INTO) is not supported")));
+
+		/*
+		 * The query has already been through parse analysis, but not
+		 * rewriting or planning.  Do that now.
+		 *
+		 * Because the planner is not cool about not scribbling on its input,
+		 * we make a preliminary copy of the source querytree.  This prevents
+		 * problems in the case that the COPY is in a portal or plpgsql
+		 * function and is executed repeatedly.  (See also the same hack in
+		 * EXPLAIN, DECLARE CURSOR and PREPARE.)  XXX the planner really
+		 * shouldn't modify its input ... FIXME someday.
+		 */
+		query = copyObject(query);
+		Assert(query->commandType == CMD_SELECT);
+
+		/*
+		 * Must acquire locks in case we didn't come fresh from the parser.
+		 * XXX this also scribbles on query, another reason for copyObject
+		 */
+		AcquireRewriteLocks(query);
+
+		/* Rewrite through rule system */
+		rewritten = QueryRewrite(query);
+
+		/* We don't expect more or less than one result query */
+		if (list_length(rewritten) != 1)
+			elog(ERROR, "unexpected rewrite result");
+
+		query = (Query *) linitial(rewritten);
+		Assert(query->commandType == CMD_SELECT);
+
+		/* plan the query */
+		plan = planner(query, false, 0, NULL);
+
+		/*
+		 * Update snapshot command ID to ensure this query sees results of any
+		 * previously executed queries.  (It's a bit cheesy to modify
+		 * ActiveSnapshot without making a copy, but for the limited ways in
+		 * which COPY can be invoked, I think it's OK, because the active
+		 * snapshot shouldn't be shared with anything else anyway.)
+		 */
+		ActiveSnapshot->curcid = GetCurrentCommandId();
+
+		/* Create dest receiver for COPY OUT */
+		dest = CreateDestReceiver(DestCopyOut, NULL);
+		((DR_copy *) dest)->cstate = cstate;
+
+		/* Create a QueryDesc requesting no output */
+		cstate->queryDesc = CreateQueryDesc(query, plan,
+											ActiveSnapshot, InvalidSnapshot,
+											dest, NULL, false);
+
+		/*
+		 * Call ExecutorStart to prepare the plan for execution.
+		 *
+		 * ExecutorStart computes a result tupdesc for us
+		 */
+		ExecutorStart(cstate->queryDesc, 0);
+
+		tupDesc = cstate->queryDesc->tupDesc;
+	}
+
+	/* Generate or convert list of attributes to process */
+	cstate->attnumlist = CopyGetAttnums(tupDesc, cstate->rel, attnamelist);
+
+	num_phys_attrs = tupDesc->natts;
+
+	/* Convert FORCE QUOTE name list to per-column flags, check validity */
+	cstate->force_quote_flags = (bool *) palloc0(num_phys_attrs * sizeof(bool));
 	if (force_quote)
 	{
-		TupleDesc	tupDesc = RelationGetDescr(cstate->rel);
+		List	   *attnums;
-		Form_pg_attribute *attr = tupDesc->attrs;
 		ListCell   *cur;
 
-		cstate->force_quote_atts = CopyGetAttnums(cstate->rel, force_quote);
+		attnums = CopyGetAttnums(tupDesc, cstate->rel, force_quote);
 
-		foreach(cur, cstate->force_quote_atts)
+		foreach(cur, attnums)
 		{
 			int			attnum = lfirst_int(cur);
 
@@ -971,21 +1087,21 @@ DoCopy(const CopyStmt *stmt)
 				ereport(ERROR,
 						(errcode(ERRCODE_INVALID_COLUMN_REFERENCE),
 				   errmsg("FORCE QUOTE column \"%s\" not referenced by COPY",
-						  NameStr(attr[attnum - 1]->attname))));
+						  NameStr(tupDesc->attrs[attnum - 1]->attname))));
+			cstate->force_quote_flags[attnum - 1] = true;
 		}
 	}
 
-	/* Convert FORCE NOT NULL name list to column numbers, check validity */
+	/* Convert FORCE NOT NULL name list to per-column flags, check validity */
+	cstate->force_notnull_flags = (bool *) palloc0(num_phys_attrs * sizeof(bool));
 	if (force_notnull)
 	{
-		TupleDesc	tupDesc = RelationGetDescr(cstate->rel);
+		List	   *attnums;
-		Form_pg_attribute *attr = tupDesc->attrs;
 		ListCell   *cur;
 
-		cstate->force_notnull_atts = CopyGetAttnums(cstate->rel,
+		attnums = CopyGetAttnums(tupDesc, cstate->rel, force_notnull);
-													force_notnull);
 
-		foreach(cur, cstate->force_notnull_atts)
+		foreach(cur, attnums)
 		{
 			int			attnum = lfirst_int(cur);
 
@@ -993,7 +1109,8 @@ DoCopy(const CopyStmt *stmt)
 				ereport(ERROR,
 						(errcode(ERRCODE_INVALID_COLUMN_REFERENCE),
 				errmsg("FORCE NOT NULL column \"%s\" not referenced by COPY",
-					   NameStr(attr[attnum - 1]->attname))));
+					   NameStr(tupDesc->attrs[attnum - 1]->attname))));
+			cstate->force_notnull_flags[attnum - 1] = true;
 		}
 	}
 
@@ -1018,67 +1135,59 @@ DoCopy(const CopyStmt *stmt)
 	cstate->encoding_embeds_ascii = PG_ENCODING_IS_CLIENT_ONLY(cstate->client_encoding);
 
 	cstate->copy_dest = COPY_FILE;		/* default */
+	cstate->filename = stmt->filename;
 
-	if (is_from)
+	if (is_from)				/* copy from file to database */
-	{							/* copy from file to database */
-		if (cstate->rel->rd_rel->relkind != RELKIND_RELATION)
-		{
-			if (cstate->rel->rd_rel->relkind == RELKIND_VIEW)
-				ereport(ERROR,
-						(errcode(ERRCODE_WRONG_OBJECT_TYPE),
-						 errmsg("cannot copy to view \"%s\"",
-								RelationGetRelationName(cstate->rel))));
-			else if (cstate->rel->rd_rel->relkind == RELKIND_SEQUENCE)
-				ereport(ERROR,
-						(errcode(ERRCODE_WRONG_OBJECT_TYPE),
-						 errmsg("cannot copy to sequence \"%s\"",
-								RelationGetRelationName(cstate->rel))));
-			else
-				ereport(ERROR,
-						(errcode(ERRCODE_WRONG_OBJECT_TYPE),
-						 errmsg("cannot copy to non-table relation \"%s\"",
-								RelationGetRelationName(cstate->rel))));
-		}
-		if (pipe)
-		{
-			if (whereToSendOutput == DestRemote)
-				ReceiveCopyBegin(cstate);
-			else
-				cstate->copy_file = stdin;
-		}
-		else
-		{
-			struct stat st;
-
-			cstate->copy_file = AllocateFile(filename, PG_BINARY_R);
-
-			if (cstate->copy_file == NULL)
-				ereport(ERROR,
-						(errcode_for_file_access(),
-						 errmsg("could not open file \"%s\" for reading: %m",
-								filename)));
-
-			fstat(fileno(cstate->copy_file), &st);
-			if (S_ISDIR(st.st_mode))
-			{
-				FreeFile(cstate->copy_file);
-				ereport(ERROR,
-						(errcode(ERRCODE_WRONG_OBJECT_TYPE),
-						 errmsg("\"%s\" is a directory", filename)));
-			}
-		}
-
 		CopyFrom(cstate);
-	}
+	else						/* copy from database to file */
+		DoCopyTo(cstate);
+
+	/*
+	 * Close the relation or query.  If reading, we can release the
+	 * AccessShareLock we got; if writing, we should hold the lock until end
+	 * of transaction to ensure that updates will be committed before lock is
+	 * released.
+	 */
+	if (cstate->rel)
+		heap_close(cstate->rel, (is_from ? NoLock : AccessShareLock));
 	else
-	{							/* copy from database to file */
+	{
+		/* Close down the query and free resources. */
+		ExecutorEnd(cstate->queryDesc);
+		FreeQueryDesc(cstate->queryDesc);
+	}
+
+	/* Clean up storage (probably not really necessary) */
+	processed = cstate->processed;
+
+	pfree(cstate->attribute_buf.data);
+	pfree(cstate->line_buf.data);
+	pfree(cstate->raw_buf);
+	pfree(cstate);
+
+	return processed;
+}
+
+
+/*
+ * This intermediate routine exists mainly to localize the effects of setjmp
+ * so we don't need to plaster a lot of variables with "volatile".
+ */
+static void
+DoCopyTo(CopyState cstate)
+{
+	bool		pipe = (cstate->filename == NULL);
+
+	if (cstate->rel)
+	{
 		if (cstate->rel->rd_rel->relkind != RELKIND_RELATION)
 		{
 			if (cstate->rel->rd_rel->relkind == RELKIND_VIEW)
 				ereport(ERROR,
 						(errcode(ERRCODE_WRONG_OBJECT_TYPE),
 						 errmsg("cannot copy from view \"%s\"",
-								RelationGetRelationName(cstate->rel))));
+								RelationGetRelationName(cstate->rel)),
+						 errhint("Try the COPY (SELECT ...) TO variant.")));
 			else if (cstate->rel->rd_rel->relkind == RELKIND_SEQUENCE)
 				ereport(ERROR,
 						(errcode(ERRCODE_WRONG_OBJECT_TYPE),
@@ -1090,6 +1199,8 @@ DoCopy(const CopyStmt *stmt)
 						 errmsg("cannot copy from non-table relation \"%s\"",
 								RelationGetRelationName(cstate->rel))));
 		}
+	}
+
 	if (pipe)
 	{
 		if (whereToSendOutput == DestRemote)
@@ -1106,20 +1217,20 @@ DoCopy(const CopyStmt *stmt)
 		 * Prevent write to relative path ... too easy to shoot oneself in
 		 * the foot by overwriting a database file ...
 		 */
-			if (!is_absolute_path(filename))
+		if (!is_absolute_path(cstate->filename))
 			ereport(ERROR,
 					(errcode(ERRCODE_INVALID_NAME),
 					 errmsg("relative path not allowed for COPY to file")));
 
 		oumask = umask((mode_t) 022);
-			cstate->copy_file = AllocateFile(filename, PG_BINARY_W);
+		cstate->copy_file = AllocateFile(cstate->filename, PG_BINARY_W);
 		umask(oumask);
 
 		if (cstate->copy_file == NULL)
 			ereport(ERROR,
 					(errcode_for_file_access(),
 					 errmsg("could not open file \"%s\" for writing: %m",
-								filename)));
+							cstate->filename)));
 
 		fstat(fileno(cstate->copy_file), &st);
 		if (S_ISDIR(st.st_mode))
@@ -1127,49 +1238,10 @@ DoCopy(const CopyStmt *stmt)
 			FreeFile(cstate->copy_file);
 			ereport(ERROR,
 					(errcode(ERRCODE_WRONG_OBJECT_TYPE),
-						 errmsg("\"%s\" is a directory", filename)));
+					 errmsg("\"%s\" is a directory", cstate->filename)));
 		}
 	}
 
-		DoCopyTo(cstate);
-	}
-
-	if (!pipe)
-	{
-		/* we assume only the write case could fail here */
-		if (FreeFile(cstate->copy_file))
-			ereport(ERROR,
-					(errcode_for_file_access(),
-					 errmsg("could not write to file \"%s\": %m",
-							filename)));
-	}
-
-	/*
-	 * Close the relation.	If reading, we can release the AccessShareLock we
-	 * got; if writing, we should hold the lock until end of transaction to
-	 * ensure that updates will be committed before lock is released.
-	 */
-	heap_close(cstate->rel, (is_from ? NoLock : AccessShareLock));
-
-	/* Clean up storage (probably not really necessary) */
-	processed = cstate->processed;
-
-	pfree(cstate->attribute_buf.data);
-	pfree(cstate->line_buf.data);
-	pfree(cstate->raw_buf);
-	pfree(cstate);
-
-	return processed;
-}
-
-
-/*
- * This intermediate routine just exists to localize the effects of setjmp
- * so we don't need to plaster a lot of variables with "volatile".
- */
-static void
-DoCopyTo(CopyState cstate)
-{
 	PG_TRY();
 	{
 		if (cstate->fe_copy)
@@ -1191,40 +1263,41 @@ DoCopyTo(CopyState cstate)
 		PG_RE_THROW();
 	}
 	PG_END_TRY();
+
+	if (!pipe)
+	{
+		if (FreeFile(cstate->copy_file))
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not write to file \"%s\": %m",
+							cstate->filename)));
+	}
 }
 
 /*
- * Copy from relation TO file.
+ * Copy from relation or query TO file.
  */
 static void
 CopyTo(CopyState cstate)
 {
-	HeapTuple	tuple;
 	TupleDesc	tupDesc;
-	HeapScanDesc scandesc;
 	int			num_phys_attrs;
-	int			attr_count;
 	Form_pg_attribute *attr;
-	FmgrInfo   *out_functions;
-	bool	   *force_quote;
-	char	   *string;
-	char	   *null_print_client;
 	ListCell   *cur;
-	MemoryContext oldcontext;
-	MemoryContext mycontext;
 
-	tupDesc = cstate->rel->rd_att;
+	if (cstate->rel)
+		tupDesc = RelationGetDescr(cstate->rel);
+	else
+		tupDesc = cstate->queryDesc->tupDesc;
 	attr = tupDesc->attrs;
 	num_phys_attrs = tupDesc->natts;
-	attr_count = list_length(cstate->attnumlist);
+	cstate->null_print_client = cstate->null_print;		/* default */
-	null_print_client = cstate->null_print;		/* default */
 
 	/* We use fe_msgbuf as a per-row buffer regardless of copy_dest */
 	cstate->fe_msgbuf = makeStringInfo();
 
 	/* Get info about the columns we need to process. */
-	out_functions = (FmgrInfo *) palloc(num_phys_attrs * sizeof(FmgrInfo));
+	cstate->out_functions = (FmgrInfo *) palloc(num_phys_attrs * sizeof(FmgrInfo));
-	force_quote = (bool *) palloc(num_phys_attrs * sizeof(bool));
 	foreach(cur, cstate->attnumlist)
 	{
 		int			attnum = lfirst_int(cur);
@@ -1239,12 +1312,7 @@ CopyTo(CopyState cstate)
 			getTypeOutputInfo(attr[attnum - 1]->atttypid,
 							  &out_func_oid,
 							  &isvarlena);
-		fmgr_info(out_func_oid, &out_functions[attnum - 1]);
+		fmgr_info(out_func_oid, &cstate->out_functions[attnum - 1]);
-
-		if (list_member_int(cstate->force_quote_atts, attnum))
-			force_quote[attnum - 1] = true;
-		else
-			force_quote[attnum - 1] = false;
 	}
 
 	/*
@@ -1253,7 +1321,7 @@ CopyTo(CopyState cstate)
 	 * datatype output routines, and should be faster than retail pfree's
 	 * anyway.	(We don't need a whole econtext as CopyFrom does.)
 	 */
-	mycontext = AllocSetContextCreate(CurrentMemoryContext,
+	cstate->rowcontext = AllocSetContextCreate(CurrentMemoryContext,
 											   "COPY TO",
 											   ALLOCSET_DEFAULT_MINSIZE,
 											   ALLOCSET_DEFAULT_INITSIZE,
@@ -1282,7 +1350,7 @@ CopyTo(CopyState cstate)
 		 * encoding, because it will be sent directly with CopySendString.
 		 */
 		if (cstate->need_transcoding)
-			null_print_client = pg_server_to_client(cstate->null_print,
+			cstate->null_print_client = pg_server_to_client(cstate->null_print,
 													cstate->null_print_len);
 
 		/* if a header has been requested send the line */
@@ -1309,29 +1377,73 @@ CopyTo(CopyState cstate)
 		}
 	}
 
+	if (cstate->rel)
+	{
+		Datum	   *values;
+		bool	   *nulls;
+		HeapScanDesc scandesc;
+		HeapTuple	tuple;
+
+		values = (Datum *) palloc(num_phys_attrs * sizeof(Datum));
+		nulls = (bool *) palloc(num_phys_attrs * sizeof(bool));
+
 		scandesc = heap_beginscan(cstate->rel, ActiveSnapshot, 0, NULL);
 
 		while ((tuple = heap_getnext(scandesc, ForwardScanDirection)) != NULL)
 		{
-		bool		need_delim = false;
-
 			CHECK_FOR_INTERRUPTS();
 
-		MemoryContextReset(mycontext);
+			/* Deconstruct the tuple ... faster than repeated heap_getattr */
-		oldcontext = MemoryContextSwitchTo(mycontext);
+			heap_deform_tuple(tuple, tupDesc, values, nulls);
+
+			/* Format and send the data */
+			CopyOneRowTo(cstate, HeapTupleGetOid(tuple), values, nulls);
+		}
+
+		heap_endscan(scandesc);
+	}
+	else
+	{
+		/* run the plan --- the dest receiver will send tuples */
+		ExecutorRun(cstate->queryDesc, ForwardScanDirection, 0L);
+	}
+
+	if (cstate->binary)
+	{
+		/* Generate trailer for a binary copy */
+		CopySendInt16(cstate, -1);
+		/* Need to flush out the trailer */
+		CopySendEndOfRow(cstate);
+	}
+
+	MemoryContextDelete(cstate->rowcontext);
+}
+
+/*
+ * Emit one row during CopyTo().
+ */
+static void
+CopyOneRowTo(CopyState cstate, Oid tupleOid, Datum *values, bool *nulls)
+{
+	bool		need_delim = false;
+	FmgrInfo   *out_functions = cstate->out_functions;
+	MemoryContext oldcontext;
+	ListCell   *cur;
+	char	   *string;
+
+	MemoryContextReset(cstate->rowcontext);
+	oldcontext = MemoryContextSwitchTo(cstate->rowcontext);
 
 	if (cstate->binary)
 	{
 		/* Binary per-tuple header */
-			CopySendInt16(cstate, attr_count);
+		CopySendInt16(cstate, list_length(cstate->attnumlist));
-			/* Send OID if wanted --- note attr_count doesn't include it */
+		/* Send OID if wanted --- note attnumlist doesn't include it */
 		if (cstate->oids)
 		{
-				Oid			oid = HeapTupleGetOid(tuple);
-
 			/* Hack --- assume Oid is same size as int32 */
 			CopySendInt32(cstate, sizeof(int32));
-				CopySendInt32(cstate, oid);
+			CopySendInt32(cstate, tupleOid);
 		}
 	}
 	else
@@ -1341,7 +1453,7 @@ CopyTo(CopyState cstate)
 		if (cstate->oids)
 		{
 			string = DatumGetCString(DirectFunctionCall1(oidout,
-								  ObjectIdGetDatum(HeapTupleGetOid(tuple))));
+												ObjectIdGetDatum(tupleOid)));
 			CopySendString(cstate, string);
 			need_delim = true;
 		}
@@ -1350,10 +1462,8 @@ CopyTo(CopyState cstate)
 	foreach(cur, cstate->attnumlist)
 	{
 		int			attnum = lfirst_int(cur);
-			Datum		value;
+		Datum		value = values[attnum - 1];
-			bool		isnull;
+		bool		isnull = nulls[attnum - 1];
-
-			value = heap_getattr(tuple, attnum, tupDesc, &isnull);
 
 		if (!cstate->binary)
 		{
@@ -1365,7 +1475,7 @@ CopyTo(CopyState cstate)
 		if (isnull)
 		{
 			if (!cstate->binary)
-					CopySendString(cstate, null_print_client);
+				CopySendString(cstate, cstate->null_print_client);
 			else
 				CopySendInt32(cstate, -1);
 		}
@@ -1377,7 +1487,7 @@ CopyTo(CopyState cstate)
 											value);
 				if (cstate->csv_mode)
 					CopyAttributeOutCSV(cstate, string,
-											force_quote[attnum - 1],
+										cstate->force_quote_flags[attnum - 1],
 										list_length(cstate->attnumlist) == 1);
 				else
 					CopyAttributeOutText(cstate, string);
@@ -1400,22 +1510,6 @@ CopyTo(CopyState cstate)
 	MemoryContextSwitchTo(oldcontext);
 		
 	cstate->processed++;
-	}
-
-	heap_endscan(scandesc);
-
-	if (cstate->binary)
-	{
-		/* Generate trailer for a binary copy */
-		CopySendInt16(cstate, -1);
-		/* Need to flush out the trailer */
-		CopySendEndOfRow(cstate);
-	}
-
-	MemoryContextDelete(mycontext);
-
-	pfree(out_functions);
-	pfree(force_quote);
 }
 
 
@@ -1528,6 +1622,7 @@ limit_printout_length(const char *str)
 static void
 CopyFrom(CopyState cstate)
 {
+	bool		pipe = (cstate->filename == NULL);
 	HeapTuple	tuple;
 	TupleDesc	tupDesc;
 	Form_pg_attribute *attr;
@@ -1538,7 +1633,6 @@ CopyFrom(CopyState cstate)
 	FmgrInfo	oid_in_function;
 	Oid		   *typioparams;
 	Oid			oid_typioparam;
-	bool	   *force_notnull;
 	int			attnum;
 	int			i;
 	Oid			in_func_oid;
@@ -1558,6 +1652,56 @@ CopyFrom(CopyState cstate)
 	MemoryContext oldcontext = CurrentMemoryContext;
 	ErrorContextCallback errcontext;
 
+	Assert(cstate->rel);
+
+	if (cstate->rel->rd_rel->relkind != RELKIND_RELATION)
+	{
+		if (cstate->rel->rd_rel->relkind == RELKIND_VIEW)
+			ereport(ERROR,
+					(errcode(ERRCODE_WRONG_OBJECT_TYPE),
+					 errmsg("cannot copy to view \"%s\"",
+							RelationGetRelationName(cstate->rel))));
+		else if (cstate->rel->rd_rel->relkind == RELKIND_SEQUENCE)
+			ereport(ERROR,
+					(errcode(ERRCODE_WRONG_OBJECT_TYPE),
+					 errmsg("cannot copy to sequence \"%s\"",
+							RelationGetRelationName(cstate->rel))));
+		else
+			ereport(ERROR,
+					(errcode(ERRCODE_WRONG_OBJECT_TYPE),
+					 errmsg("cannot copy to non-table relation \"%s\"",
+							RelationGetRelationName(cstate->rel))));
+	}
+
+	if (pipe)
+	{
+		if (whereToSendOutput == DestRemote)
+			ReceiveCopyBegin(cstate);
+		else
+			cstate->copy_file = stdin;
+	}
+	else
+	{
+		struct stat st;
+
+		cstate->copy_file = AllocateFile(cstate->filename, PG_BINARY_R);
+
+		if (cstate->copy_file == NULL)
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not open file \"%s\" for reading: %m",
+							cstate->filename)));
+
+		fstat(fileno(cstate->copy_file), &st);
+		if (S_ISDIR(st.st_mode))
+		{
+			FreeFile(cstate->copy_file);
+			ereport(ERROR,
+					(errcode(ERRCODE_WRONG_OBJECT_TYPE),
+					 errmsg("\"%s\" is a directory", cstate->filename)));
+		}
+	}
+
 	tupDesc = RelationGetDescr(cstate->rel);
 	attr = tupDesc->attrs;
 	num_phys_attrs = tupDesc->natts;
@@ -1599,7 +1743,6 @@ CopyFrom(CopyState cstate)
 	typioparams = (Oid *) palloc(num_phys_attrs * sizeof(Oid));
 	defmap = (int *) palloc(num_phys_attrs * sizeof(int));
 	defexprs = (ExprState **) palloc(num_phys_attrs * sizeof(ExprState *));
-	force_notnull = (bool *) palloc(num_phys_attrs * sizeof(bool));
 
 	for (attnum = 1; attnum <= num_phys_attrs; attnum++)
 	{
@@ -1616,11 +1759,6 @@ CopyFrom(CopyState cstate)
 							 &in_func_oid, &typioparams[attnum - 1]);
 		fmgr_info(in_func_oid, &in_functions[attnum - 1]);
 
-		if (list_member_int(cstate->force_notnull_atts, attnum))
-			force_notnull[attnum - 1] = true;
-		else
-			force_notnull[attnum - 1] = false;
-
 		/* Get default info if needed */
 		if (!list_member_int(cstate->attnumlist, attnum))
 		{
@@ -1810,7 +1948,8 @@ CopyFrom(CopyState cstate)
 									NameStr(attr[m]->attname))));
 				string = field_strings[fieldno++];
 
-				if (cstate->csv_mode && string == NULL && force_notnull[m])
+				if (cstate->csv_mode && string == NULL &&
+					cstate->force_notnull_flags[m])
 				{
 					/* Go ahead and read the NULL string */
 					string = cstate->null_print;
@@ -1972,13 +2111,21 @@ CopyFrom(CopyState cstate)
 	pfree(typioparams);
 	pfree(defmap);
 	pfree(defexprs);
-	pfree(force_notnull);
 
 	ExecDropSingleTupleTableSlot(slot);
 
 	ExecCloseIndices(resultRelInfo);
 
 	FreeExecutorState(estate);
+
+	if (!pipe)
+	{
+		if (FreeFile(cstate->copy_file))
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not read from file \"%s\": %m",
+							cstate->filename)));
+	}
 }
 
 
@@ -3055,16 +3202,17 @@ CopyAttributeOutCSV(CopyState cstate, char *string,
  * The input attnamelist is either the user-specified column list,
  * or NIL if there was none (in which case we want all the non-dropped
  * columns).
+ *
+ * rel can be NULL ... it's only used for error reports.
  */
 static List *
-CopyGetAttnums(Relation rel, List *attnamelist)
+CopyGetAttnums(TupleDesc tupDesc, Relation rel, List *attnamelist)
 {
 	List	   *attnums = NIL;
 
 	if (attnamelist == NIL)
 	{
 		/* Generate default column list */
-		TupleDesc	tupDesc = RelationGetDescr(rel);
 		Form_pg_attribute *attr = tupDesc->attrs;
 		int			attr_count = tupDesc->natts;
 		int			i;
@@ -3085,15 +3233,33 @@ CopyGetAttnums(Relation rel, List *attnamelist)
 		{
 			char	   *name = strVal(lfirst(l));
 			int			attnum;
+			int			i;
 
 			/* Lookup column name */
-			/* Note we disallow system columns here */
+			attnum = InvalidAttrNumber;
-			attnum = attnameAttNum(rel, name, false);
+			for (i = 0; i < tupDesc->natts; i++)
+			{
+				if (tupDesc->attrs[i]->attisdropped)
+					continue;
+				if (namestrcmp(&(tupDesc->attrs[i]->attname), name) == 0)
+				{
+					attnum = tupDesc->attrs[i]->attnum;
+					break;
+				}
+			}
 			if (attnum == InvalidAttrNumber)
+			{
+				if (rel != NULL)
 					ereport(ERROR,
 						(errcode(ERRCODE_UNDEFINED_COLUMN),
 						 errmsg("column \"%s\" of relation \"%s\" does not exist",
 						 		name, RelationGetRelationName(rel))));
+				else
+					ereport(ERROR,
+						(errcode(ERRCODE_UNDEFINED_COLUMN),
+						 errmsg("column \"%s\" does not exist",
+								name)));
+			}
 			/* Check for duplicates */
 			if (list_member_int(attnums, attnum))
 				ereport(ERROR,
@@ -3106,3 +3272,66 @@ CopyGetAttnums(Relation rel, List *attnamelist)
 
 	return attnums;
 }
+
+
+/*
+ * copy_dest_startup --- executor startup
+ */
+static void
+copy_dest_startup(DestReceiver *self, int operation, TupleDesc typeinfo)
+{
+	/* no-op */
+}
+
+/*
+ * copy_dest_receive --- receive one tuple
+ */
+static void
+copy_dest_receive(TupleTableSlot *slot, DestReceiver *self)
+{
+	DR_copy	   *myState = (DR_copy *) self;
+	CopyState	cstate = myState->cstate;
+
+	/* Make sure the tuple is fully deconstructed */
+	slot_getallattrs(slot);
+
+	/* And send the data */
+	CopyOneRowTo(cstate, InvalidOid, slot->tts_values, slot->tts_isnull);
+}
+
+/*
+ * copy_dest_shutdown --- executor end
+ */
+static void
+copy_dest_shutdown(DestReceiver *self)
+{
+	/* no-op */
+}
+
+/*
+ * copy_dest_destroy --- release DestReceiver object
+ */
+static void
+copy_dest_destroy(DestReceiver *self)
+{
+	pfree(self);
+}
+
+/*
+ * CreateCopyDestReceiver -- create a suitable DestReceiver object
+ */
+DestReceiver *
+CreateCopyDestReceiver(void)
+{
+	DR_copy *self = (DR_copy *) palloc(sizeof(DR_copy));
+
+	self->pub.receiveSlot = copy_dest_receive;
+	self->pub.rStartup = copy_dest_startup;
+	self->pub.rShutdown = copy_dest_shutdown;
+	self->pub.rDestroy = copy_dest_destroy;
+	self->pub.mydest = DestCopyOut;
+
+	self->cstate = NULL;		/* will be set later */
+
+	return (DestReceiver *) self;
+}

src/backend/nodes/copyfuncs.c

@@ -15,7 +15,7 @@
  * Portions Copyright (c) 1994, Regents of the University of California
  *
  * IDENTIFICATION
- *	  $PostgreSQL: pgsql/src/backend/nodes/copyfuncs.c,v 1.349 2006/08/25 04:06:49 tgl Exp $
+ *	  $PostgreSQL: pgsql/src/backend/nodes/copyfuncs.c,v 1.350 2006/08/30 23:34:21 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -1934,6 +1934,7 @@ _copyCopyStmt(CopyStmt *from)
 	CopyStmt   *newnode = makeNode(CopyStmt);
 
 	COPY_NODE_FIELD(relation);
+	COPY_NODE_FIELD(query);
 	COPY_NODE_FIELD(attlist);
 	COPY_SCALAR_FIELD(is_from);
 	COPY_STRING_FIELD(filename);

src/backend/nodes/equalfuncs.c

@@ -18,7 +18,7 @@
  * Portions Copyright (c) 1994, Regents of the University of California
  *
  * IDENTIFICATION
- *	  $PostgreSQL: pgsql/src/backend/nodes/equalfuncs.c,v 1.283 2006/08/25 04:06:49 tgl Exp $
+ *	  $PostgreSQL: pgsql/src/backend/nodes/equalfuncs.c,v 1.284 2006/08/30 23:34:21 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -863,6 +863,7 @@ static bool
 _equalCopyStmt(CopyStmt *a, CopyStmt *b)
 {
 	COMPARE_NODE_FIELD(relation);
+	COMPARE_NODE_FIELD(query);
 	COMPARE_NODE_FIELD(attlist);
 	COMPARE_SCALAR_FIELD(is_from);
 	COMPARE_STRING_FIELD(filename);

src/backend/parser/analyze.c

@@ -6,7 +6,7 @@
  * Portions Copyright (c) 1996-2006, PostgreSQL Global Development Group
  * Portions Copyright (c) 1994, Regents of the University of California
  *
- *	$PostgreSQL: pgsql/src/backend/parser/analyze.c,v 1.348 2006/08/25 04:06:51 tgl Exp $
+ *	$PostgreSQL: pgsql/src/backend/parser/analyze.c,v 1.349 2006/08/30 23:34:21 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -341,6 +341,19 @@ transformStmt(ParseState *pstate, Node *parseTree,
 			}
 			break;
 
+		case T_CopyStmt:
+			{
+				CopyStmt *n = (CopyStmt *) parseTree;
+
+				result = makeNode(Query);
+				result->commandType = CMD_UTILITY;
+				if (n->query)
+					n->query = transformStmt(pstate, (Node *) n->query,
+											 extras_before, extras_after);
+				result->utilityStmt = (Node *) parseTree;
+			}
+			break;
+
 		case T_AlterTableStmt:
 			result = transformAlterTableStmt(pstate,
 											 (AlterTableStmt *) parseTree,

src/backend/parser/gram.y

@@ -11,7 +11,7 @@
  *
  *
  * IDENTIFICATION
- *	  $PostgreSQL: pgsql/src/backend/parser/gram.y,v 2.558 2006/08/25 04:06:51 tgl Exp $
+ *	  $PostgreSQL: pgsql/src/backend/parser/gram.y,v 2.559 2006/08/30 23:34:21 tgl Exp $
  *
  * HISTORY
  *	  AUTHOR			DATE			MAJOR EVENT
@@ -1614,11 +1614,15 @@ ClosePortalStmt:
 /*****************************************************************************
  *
  *		QUERY :
- *				COPY <relname> ['(' columnList ')'] FROM/TO [WITH options]
+ *				COPY relname ['(' columnList ')'] FROM/TO file [WITH options]
  *
  *				BINARY, OIDS, and DELIMITERS kept in old locations
  *				for backward compatibility.  2002-06-18
  *
+ *				COPY ( SELECT ... ) TO file [WITH options]
+ *				This form doesn't have the backwards-compatible option
+ *				syntax.
+ *
  *****************************************************************************/
 
 CopyStmt:	COPY opt_binary qualified_name opt_column_list opt_oids
@@ -1626,6 +1630,7 @@ CopyStmt:	COPY opt_binary qualified_name opt_column_list opt_oids
 				{
 					CopyStmt *n = makeNode(CopyStmt);
 					n->relation = $3;
+					n->query = NULL;
 					n->attlist = $4;
 					n->is_from = $6;
 					n->filename = $7;
@@ -1642,6 +1647,18 @@ CopyStmt:	COPY opt_binary qualified_name opt_column_list opt_oids
 						n->options = list_concat(n->options, $10);
 					$$ = (Node *)n;
 				}
+			| COPY select_with_parens TO copy_file_name opt_with
+			  copy_opt_list
+				{
+					CopyStmt *n = makeNode(CopyStmt);
+					n->relation = NULL;
+					n->query = (Query *) $2;
+					n->attlist = NIL;
+					n->is_from = false;
+					n->filename = $4;
+					n->options = $6;
+					$$ = (Node *)n;
+				}
 		;
 
 copy_from:
@@ -1652,7 +1669,7 @@ copy_from:
 /*
  * copy_file_name NULL indicates stdio is used. Whether stdin or stdout is
  * used depends on the direction. (It really doesn't make sense to copy from
- * stdout. We silently correct the "typo".		 - AY 9/94
+ * stdout. We silently correct the "typo".)		 - AY 9/94
  */
 copy_file_name:
 			Sconst									{ $$ = $1; }

src/backend/tcop/dest.c

@@ -8,7 +8,7 @@
  * Portions Copyright (c) 1994, Regents of the University of California
  *
  * IDENTIFICATION
- *	  $PostgreSQL: pgsql/src/backend/tcop/dest.c,v 1.69 2006/08/12 02:52:05 tgl Exp $
+ *	  $PostgreSQL: pgsql/src/backend/tcop/dest.c,v 1.70 2006/08/30 23:34:21 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -30,6 +30,7 @@
 
 #include "access/printtup.h"
 #include "access/xact.h"
+#include "commands/copy.h"
 #include "executor/executor.h"
 #include "executor/tstoreReceiver.h"
 #include "libpq/libpq.h"
@@ -128,6 +129,9 @@ CreateDestReceiver(CommandDest dest, Portal portal)
 
 		case DestIntoRel:
 			return CreateIntoRelDestReceiver();
+
+		case DestCopyOut:
+			return CreateCopyDestReceiver();
 	}
 
 	/* should never get here */
@@ -153,6 +157,7 @@ EndCommand(const char *commandTag, CommandDest dest)
 		case DestSPI:
 		case DestTuplestore:
 		case DestIntoRel:
+		case DestCopyOut:
 			break;
 	}
 }
@@ -192,6 +197,7 @@ NullCommand(CommandDest dest)
 		case DestSPI:
 		case DestTuplestore:
 		case DestIntoRel:
+		case DestCopyOut:
 			break;
 	}
 }
@@ -233,6 +239,7 @@ ReadyForQuery(CommandDest dest)
 		case DestSPI:
 		case DestTuplestore:
 		case DestIntoRel:
+		case DestCopyOut:
 			break;
 	}
 }

src/bin/psql/copy.c

@@ -3,7 +3,7 @@
  *
  * Copyright (c) 2000-2006, PostgreSQL Global Development Group
  *
- * $PostgreSQL: pgsql/src/bin/psql/copy.c,v 1.67 2006/08/29 15:19:50 tgl Exp $
+ * $PostgreSQL: pgsql/src/bin/psql/copy.c,v 1.68 2006/08/30 23:34:22 tgl Exp $
  */
 #include "postgres_fe.h"
 #include "copy.h"
@@ -39,6 +39,9 @@
  *	\copy tablename [(columnlist)] from|to filename
  *	  [ with ] [ binary ] [ oids ] [ delimiter [as] char ] [ null [as] string ]
  *
+ *	\copy ( select stmt ) to filename
+ *	  [ with ] [ binary ] [ delimiter [as] char ] [ null [as] string ]
+ *
  * The pre-7.3 syntax was:
  *	\copy [ binary ] tablename [(columnlist)] [with oids] from|to filename
  *		[ [using] delimiters char ] [ with null as string ]
@@ -142,6 +145,26 @@ parse_slash_copy(const char *args)
 
 	result->table = pg_strdup(token);
 
+	/* Handle COPY (SELECT) case */
+	if (token[0] == '(')
+	{
+		int	parens = 1;
+
+		while (parens > 0)
+		{
+			token = strtokx(NULL, whitespace, ".,()", "\"'",
+							nonstd_backslash, true, false, pset.encoding);
+			if (!token)
+				goto error;
+			if (token[0] == '(')
+				parens++;
+			else if (token[0] == ')')
+				parens--;
+			xstrcat(&result->table, " ");
+			xstrcat(&result->table, token);
+		}
+	}
+
 	token = strtokx(NULL, whitespace, ".,()", "\"",
 					0, false, false, pset.encoding);
 	if (!token)

src/include/commands/copy.h

@@ -7,7 +7,7 @@
  * Portions Copyright (c) 1996-2006, PostgreSQL Global Development Group
  * Portions Copyright (c) 1994, Regents of the University of California
  *
- * $PostgreSQL: pgsql/src/include/commands/copy.h,v 1.27 2006/03/05 15:58:55 momjian Exp $
+ * $PostgreSQL: pgsql/src/include/commands/copy.h,v 1.28 2006/08/30 23:34:22 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -15,8 +15,11 @@
 #define COPY_H
 
 #include "nodes/parsenodes.h"
+#include "tcop/dest.h"
 
 
 extern uint64 DoCopy(const CopyStmt *stmt);
 
+extern DestReceiver *CreateCopyDestReceiver(void);
+
 #endif   /* COPY_H */

src/include/nodes/parsenodes.h

@@ -7,7 +7,7 @@
  * Portions Copyright (c) 1996-2006, PostgreSQL Global Development Group
  * Portions Copyright (c) 1994, Regents of the University of California
  *
- * $PostgreSQL: pgsql/src/include/nodes/parsenodes.h,v 1.325 2006/08/25 04:06:56 tgl Exp $
+ * $PostgreSQL: pgsql/src/include/nodes/parsenodes.h,v 1.326 2006/08/30 23:34:22 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -1012,16 +1012,22 @@ typedef struct GrantRoleStmt
 
 /* ----------------------
  *		Copy Statement
+ *
+ * We support "COPY relation FROM file", "COPY relation TO file", and
+ * "COPY (query) TO file".  In any given CopyStmt, exactly one of "relation"
+ * and "query" must be non-NULL.  Note: "query" is a SelectStmt before
+ * parse analysis, and a Query afterwards.
  * ----------------------
  */
 typedef struct CopyStmt
 {
 	NodeTag		type;
 	RangeVar   *relation;		/* the relation to copy */
+	Query	   *query;			/* the query to copy */
 	List	   *attlist;		/* List of column names (as Strings), or NIL
 								 * for all columns */
 	bool		is_from;		/* TO or FROM */
-	char	   *filename;		/* if NULL, use stdin/stdout */
+	char	   *filename;		/* filename, or NULL for STDIN/STDOUT */
 	List	   *options;		/* List of DefElem nodes */
 } CopyStmt;
 

src/include/tcop/dest.h

@@ -54,7 +54,7 @@
  * Portions Copyright (c) 1996-2006, PostgreSQL Global Development Group
  * Portions Copyright (c) 1994, Regents of the University of California
  *
- * $PostgreSQL: pgsql/src/include/tcop/dest.h,v 1.51 2006/08/12 02:52:06 tgl Exp $
+ * $PostgreSQL: pgsql/src/include/tcop/dest.h,v 1.52 2006/08/30 23:34:22 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -85,7 +85,8 @@ typedef enum
 	DestRemoteExecute,			/* sent to frontend, in Execute command */
 	DestSPI,					/* results sent to SPI manager */
 	DestTuplestore,				/* results sent to Tuplestore */
-	DestIntoRel					/* results sent to relation (SELECT INTO) */
+	DestIntoRel,				/* results sent to relation (SELECT INTO) */
+	DestCopyOut					/* results sent to COPY TO code */
 } CommandDest;
 
 /* ----------------

src/test/regress/expected/copyselect.out

@@ -0,0 +1,126 @@
+--
+-- Test cases for COPY (select) TO
+--
+create table test1 (id serial, t text);
+NOTICE:  CREATE TABLE will create implicit sequence "test1_id_seq" for serial column "test1.id"
+insert into test1 (t) values ('a');
+insert into test1 (t) values ('b');
+insert into test1 (t) values ('c');
+insert into test1 (t) values ('d');
+insert into test1 (t) values ('e');
+create table test2 (id serial, t text);
+NOTICE:  CREATE TABLE will create implicit sequence "test2_id_seq" for serial column "test2.id"
+insert into test2 (t) values ('A');
+insert into test2 (t) values ('B');
+insert into test2 (t) values ('C');
+insert into test2 (t) values ('D');
+insert into test2 (t) values ('E');
+create view v_test1
+as select 'v_'||t from test1;
+--
+-- Test COPY table TO
+--
+copy test1 to stdout;
+1	a
+2	b
+3	c
+4	d
+5	e
+--
+-- This should fail
+--
+copy v_test1 to stdout;
+ERROR:  cannot copy from view "v_test1"
+HINT:  Try the COPY (SELECT ...) TO variant.
+--
+-- Test COPY (select) TO
+--
+copy (select t from test1 where id=1) to stdout;
+a
+--
+-- Test COPY (select for update) TO
+--
+copy (select t from test1 where id=3 for update) to stdout;
+c
+--
+-- This should fail
+--
+copy (select t into temp test3 from test1 where id=3) to stdout;
+ERROR:  COPY (SELECT INTO) is not supported
+--
+-- This should fail
+--
+copy (select * from test1) from stdin;
+ERROR:  syntax error at or near "from"
+LINE 1: copy (select * from test1) from stdin;
+                                   ^
+--
+-- This should fail
+--
+copy (select * from test1) (t,id) to stdout;
+ERROR:  syntax error at or near "("
+LINE 1: copy (select * from test1) (t,id) to stdout;
+                                   ^
+--
+-- Test JOIN
+--
+copy (select * from test1 join test2 using (id)) to stdout;
+1	a	A
+2	b	B
+3	c	C
+4	d	D
+5	e	E
+--
+-- Test UNION SELECT
+--
+copy (select t from test1 where id = 1 UNION select * from v_test1) to stdout;
+a
+v_a
+v_b
+v_c
+v_d
+v_e
+--
+-- Test subselect
+--
+copy (select * from (select t from test1 where id = 1 UNION select * from v_test1) t1) to stdout;
+a
+v_a
+v_b
+v_c
+v_d
+v_e
+--
+-- Test headers, CSV and quotes
+--
+copy (select t from test1 where id = 1) to stdout csv header force quote t;
+t
+"a"
+--
+-- Test psql builtins, plain table
+--
+\copy test1 to stdout
+1	a
+2	b
+3	c
+4	d
+5	e
+--
+-- This should fail
+--
+\copy v_test1 to stdout
+ERROR:  cannot copy from view "v_test1"
+HINT:  Try the COPY (SELECT ...) TO variant.
+\copy: ERROR:  cannot copy from view "v_test1"
+HINT:  Try the COPY (SELECT ...) TO variant.
+-- 
+-- Test \copy (select ...)
+--
+\copy (select "id",'id','id""'||t,(id + 1)*id,t,"test1"."t" from test1 where id=3) to stdout
+3	id	id""c	12	c	c
+--
+-- Drop everything
+--
+drop table test2;
+drop view v_test1;
+drop table test1;

src/test/regress/parallel_schedule

@@ -1,6 +1,6 @@
 # ----------
 # The first group of parallel test
-# $PostgreSQL: pgsql/src/test/regress/parallel_schedule,v 1.34 2006/08/12 02:52:06 tgl Exp $
+# $PostgreSQL: pgsql/src/test/regress/parallel_schedule,v 1.35 2006/08/30 23:34:22 tgl Exp $
 # ----------
 test: boolean char name varchar text int2 int4 int8 oid float4 float8 bit numeric
 
@@ -34,7 +34,7 @@ test: create_function_2
 # execute two copy tests parallel, to check that copy itself
 # is concurrent safe.
 # ----------
-test: copy
+test: copy copyselect
 
 # ----------
 # The third group of parallel test

src/test/regress/serial_schedule

@@ -1,4 +1,4 @@
-# $PostgreSQL: pgsql/src/test/regress/serial_schedule,v 1.32 2006/08/12 02:52:06 tgl Exp $
+# $PostgreSQL: pgsql/src/test/regress/serial_schedule,v 1.33 2006/08/30 23:34:22 tgl Exp $
 # This should probably be in an order similar to parallel_schedule.
 test: boolean
 test: char
@@ -43,6 +43,7 @@ test: create_type
 test: create_table
 test: create_function_2
 test: copy
+test: copyselect
 test: constraints
 test: triggers
 test: create_misc

src/test/regress/sql/copyselect.sql

@@ -0,0 +1,82 @@
+--
+-- Test cases for COPY (select) TO
+--
+create table test1 (id serial, t text);
+insert into test1 (t) values ('a');
+insert into test1 (t) values ('b');
+insert into test1 (t) values ('c');
+insert into test1 (t) values ('d');
+insert into test1 (t) values ('e');
+
+create table test2 (id serial, t text);
+insert into test2 (t) values ('A');
+insert into test2 (t) values ('B');
+insert into test2 (t) values ('C');
+insert into test2 (t) values ('D');
+insert into test2 (t) values ('E');
+
+create view v_test1
+as select 'v_'||t from test1;
+
+--
+-- Test COPY table TO
+--
+copy test1 to stdout;
+--
+-- This should fail
+--
+copy v_test1 to stdout;
+--
+-- Test COPY (select) TO
+--
+copy (select t from test1 where id=1) to stdout;
+--
+-- Test COPY (select for update) TO
+--
+copy (select t from test1 where id=3 for update) to stdout;
+--
+-- This should fail
+--
+copy (select t into temp test3 from test1 where id=3) to stdout;
+--
+-- This should fail
+--
+copy (select * from test1) from stdin;
+--
+-- This should fail
+--
+copy (select * from test1) (t,id) to stdout;
+--
+-- Test JOIN
+--
+copy (select * from test1 join test2 using (id)) to stdout;
+--
+-- Test UNION SELECT
+--
+copy (select t from test1 where id = 1 UNION select * from v_test1) to stdout;
+--
+-- Test subselect
+--
+copy (select * from (select t from test1 where id = 1 UNION select * from v_test1) t1) to stdout;
+--
+-- Test headers, CSV and quotes
+--
+copy (select t from test1 where id = 1) to stdout csv header force quote t;
+--
+-- Test psql builtins, plain table
+--
+\copy test1 to stdout
+--
+-- This should fail
+--
+\copy v_test1 to stdout
+-- 
+-- Test \copy (select ...)
+--
+\copy (select "id",'id','id""'||t,(id + 1)*id,t,"test1"."t" from test1 where id=3) to stdout
+--
+-- Drop everything
+--
+drop table test2;
+drop view v_test1;
+drop table test1;