Remove option to change parser of an existing text search configuration.

This prevents needing to do complex and poorly-defined updates of the
mapping table if the new parser has different token types than the old.
Per discussion.

doc/src/sgml/ref/alter_tsconfig.sgml

@@ -1,5 +1,5 @@
 <!--
-$PostgreSQL: pgsql/doc/src/sgml/ref/alter_tsconfig.sgml,v 1.1 2007/08/21 21:08:47 tgl Exp $
+$PostgreSQL: pgsql/doc/src/sgml/ref/alter_tsconfig.sgml,v 1.2 2007/08/22 05:13:50 tgl Exp $
 PostgreSQL documentation
 -->
 
@@ -20,9 +20,6 @@ PostgreSQL documentation
 
  <refsynopsisdiv>
 <synopsis>
-ALTER TEXT SEARCH CONFIGURATION <replaceable>name</replaceable> (
-    PARSER = <replaceable class="parameter">parser_name</replaceable>
-)
 ALTER TEXT SEARCH CONFIGURATION <replaceable>name</replaceable>
     ADD MAPPING FOR <replaceable class="parameter">token_type</replaceable> [, ... ] WITH <replaceable class="parameter">dictionary_name</replaceable> [, ... ]
 ALTER TEXT SEARCH CONFIGURATION <replaceable>name</replaceable>
@@ -43,8 +40,8 @@ ALTER TEXT SEARCH CONFIGURATION <replaceable>name</replaceable> OWNER TO <replac
 
   <para>
    <command>ALTER TEXT SEARCH CONFIGURATION</command> changes the definition of
-   a text search configuration.  You can change which parser it uses, modify
+   a text search configuration.  You can modify
-   its mapping from token types to dictionaries,
+   its mappings from token types to dictionaries,
    or change the configuration's name or owner.
   </para>
 
@@ -68,15 +65,6 @@ ALTER TEXT SEARCH CONFIGURATION <replaceable>name</replaceable> OWNER TO <replac
     </listitem>
    </varlistentry>
 
-   <varlistentry>
-    <term><replaceable class="parameter">parser_name</replaceable></term>
-    <listitem>
-     <para>
-      The name of a new text search parser to use for this configuration.
-     </para>
-    </listitem>
-   </varlistentry>
-
    <varlistentry>
     <term><replaceable class="parameter">token_type</replaceable></term>
     <listitem>
@@ -154,19 +142,7 @@ ALTER TEXT SEARCH CONFIGURATION <replaceable>name</replaceable> OWNER TO <replac
   </para>
 
  </refsect1>
-  
- <refsect1>
-  <title>Notes</title>
 
-  <para>
-   While changing the text search parser used by a configuration is allowed,
-   this will only work nicely if old and new parsers use the same set of
-   token types.  It is advisable to drop the mappings for any incompatible
-   token types before changing parsers.
-  </para>
-
- </refsect1>
-  
  <refsect1>
   <title>Examples</title>
 

doc/src/sgml/ref/create_tsconfig.sgml

@@ -1,5 +1,5 @@
 <!--
-$PostgreSQL: pgsql/doc/src/sgml/ref/create_tsconfig.sgml,v 1.1 2007/08/21 21:08:47 tgl Exp $
+$PostgreSQL: pgsql/doc/src/sgml/ref/create_tsconfig.sgml,v 1.2 2007/08/22 05:13:50 tgl Exp $
 PostgreSQL documentation
 -->
 
@@ -98,10 +98,9 @@ CREATE TEXT SEARCH CONFIGURATION <replaceable class="parameter">name</replaceabl
   <title>Notes</title>
 
   <para>
-   It is allowed to specify both <literal>PARSER</> and <literal>COPY</>,
+   The <literal>PARSER</> and <literal>COPY</> options are mutually
-   resulting in the specified parser being used with whatever mappings
+   exclusive, because when an existing configuration is copied, its
-   are in the source configuration.  This is generally inadvisable,
+   parser selection is copied too.
-   unless you know that both parsers involved use the same token type set.
   </para>
 
  </refsect1>

src/backend/commands/tsearchcmds.c

@@ -9,7 +9,7 @@
  *
  *
  * IDENTIFICATION
- *	  $PostgreSQL: pgsql/src/backend/commands/tsearchcmds.c,v 1.3 2007/08/22 01:39:44 tgl Exp $
+ *	  $PostgreSQL: pgsql/src/backend/commands/tsearchcmds.c,v 1.4 2007/08/22 05:13:50 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -46,12 +46,10 @@
 #include "utils/syscache.h"
 
 
-static HeapTuple UpdateTSConfiguration(AlterTSConfigurationStmt *stmt,
-									   HeapTuple tup);
 static void MakeConfigurationMapping(AlterTSConfigurationStmt *stmt,
-									 HeapTuple tup);
+									 HeapTuple tup, Relation relMap);
 static void DropConfigurationMapping(AlterTSConfigurationStmt *stmt,
-									 HeapTuple tup);
+									 HeapTuple tup, Relation relMap);
 
 
 /* --------------------- TS Parser commands ------------------------ */
@@ -1265,7 +1263,6 @@ DefineTSConfiguration(List *names, List *parameters)
 	Oid			namespaceoid;
 	char	   *cfgname;
 	NameData	cname;
-	List	   *sourceName = NIL;
 	Oid			sourceOid = InvalidOid;
 	Oid			prsOid = InvalidOid;
 	Oid			cfgOid;
@@ -1290,7 +1287,7 @@ DefineTSConfiguration(List *names, List *parameters)
 		if (pg_strcasecmp(defel->defname, "parser") == 0)
 			prsOid = TSParserGetPrsid(defGetQualifiedName(defel), false);
 		else if (pg_strcasecmp(defel->defname, "copy") == 0)
-			sourceName = defGetQualifiedName(defel);
+			sourceOid = TSConfigGetCfgid(defGetQualifiedName(defel), false);
 		else
 			ereport(ERROR,
 					(errcode(ERRCODE_SYNTAX_ERROR),
@@ -1298,15 +1295,18 @@ DefineTSConfiguration(List *names, List *parameters)
 							defel->defname)));
 	}
 
+	if (OidIsValid(sourceOid) && OidIsValid(prsOid))
+		ereport(ERROR,
+				(errcode(ERRCODE_SYNTAX_ERROR),
+				 errmsg("cannot specify both PARSER and COPY options")));
+
 	/*
 	 * Look up source config if given.
 	 */
-	if (sourceName)
+	if (OidIsValid(sourceOid))
 	{
 		Form_pg_ts_config cfg;
 
-		sourceOid = TSConfigGetCfgid(sourceName, false);
-
 		tup = SearchSysCache(TSCONFIGOID,
 							 ObjectIdGetDatum(sourceOid),
 							 0, 0, 0);
@@ -1316,9 +1316,8 @@ DefineTSConfiguration(List *names, List *parameters)
 
 		cfg = (Form_pg_ts_config) GETSTRUCT(tup);
 
-		/* Use source's parser if no other was specified */
+		/* use source's parser */
-		if (!OidIsValid(prsOid))
+		prsOid = cfg->cfgparser;
-			prsOid = cfg->cfgparser;
 
 		ReleaseSysCache(tup);
 	}
@@ -1626,8 +1625,7 @@ void
 AlterTSConfiguration(AlterTSConfigurationStmt *stmt)
 {
 	HeapTuple	tup;
-	HeapTuple	newtup;
+	Relation	relMap;
-	Relation	mapRel;
 
 	/* Find the configuration */
 	tup = GetTSConfigTuple(stmt->cfgname);
@@ -1642,84 +1640,22 @@ AlterTSConfiguration(AlterTSConfigurationStmt *stmt)
 		aclcheck_error(ACLCHECK_NOT_OWNER, ACL_KIND_TSCONFIGURATION,
 					   NameListToString(stmt->cfgname));
 
-	/* Update fields of config tuple? */
+	relMap = heap_open(TSConfigMapRelationId, RowExclusiveLock);
-	if (stmt->options)
-		newtup = UpdateTSConfiguration(stmt, tup);
-	else
-		newtup = tup;
 
-	/* Add or drop mappings? */
+	/* Add or drop mappings */
 	if (stmt->dicts)
-		MakeConfigurationMapping(stmt, newtup);
+		MakeConfigurationMapping(stmt, tup, relMap);
 	else if (stmt->tokentype)
-		DropConfigurationMapping(stmt, newtup);
+		DropConfigurationMapping(stmt, tup, relMap);
-
-	/*
-	 * Even if we aren't changing mappings, there could already be some,
-	 * so makeConfigurationDependencies always has to look.
-	 */
-	mapRel = heap_open(TSConfigMapRelationId, AccessShareLock);
 
 	/* Update dependencies */
-	makeConfigurationDependencies(newtup, true, mapRel);
+	makeConfigurationDependencies(tup, true, relMap);
 
-	heap_close(mapRel, AccessShareLock);
+	heap_close(relMap, RowExclusiveLock);
 
 	ReleaseSysCache(tup);
 }
 
-/*
- * ALTER TEXT SEARCH CONFIGURATION - update fields of pg_ts_config tuple
- */
-static HeapTuple
-UpdateTSConfiguration(AlterTSConfigurationStmt *stmt, HeapTuple tup)
-{
-	Relation	cfgRel;
-	ListCell   *pl;
-	Datum		repl_val[Natts_pg_ts_config];
-	char		repl_null[Natts_pg_ts_config];
-	char		repl_repl[Natts_pg_ts_config];
-	HeapTuple	newtup;
-
-	memset(repl_val, 0, sizeof(repl_val));
-	memset(repl_null, ' ', sizeof(repl_null));
-	memset(repl_repl, ' ', sizeof(repl_repl));
-
-	cfgRel = heap_open(TSConfigRelationId, RowExclusiveLock);
-
-	foreach(pl, stmt->options)
-	{
-		DefElem    *defel = (DefElem *) lfirst(pl);
-
-		if (pg_strcasecmp(defel->defname, "parser") == 0)
-		{
-			Oid			newPrs;
-
-			newPrs = TSParserGetPrsid(defGetQualifiedName(defel), false);
-			repl_val[Anum_pg_ts_config_cfgparser - 1] = ObjectIdGetDatum(newPrs);
-			repl_repl[Anum_pg_ts_config_cfgparser - 1] = 'r';
-		}
-		else
-			ereport(ERROR,
-					(errcode(ERRCODE_SYNTAX_ERROR),
-					 errmsg("text search configuration parameter \"%s\" not recognized",
-							defel->defname)));
-	}
-
-	newtup = heap_modifytuple(tup, RelationGetDescr(cfgRel),
-							  repl_val, repl_null, repl_repl);
-
-	simple_heap_update(cfgRel, &newtup->t_self, newtup);
-
-	CatalogUpdateIndexes(cfgRel, newtup);
-
-	heap_close(cfgRel, RowExclusiveLock);
-
-	return newtup;
-}
-
-/*------------------- TS Configuration mapping stuff ----------------*/
-
 /*
  * Translate a list of token type names to an array of token type numbers
  */
@@ -1780,10 +1716,10 @@ getTokenTypes(Oid prsId, List *tokennames)
  * ALTER TEXT SEARCH CONFIGURATION ADD/ALTER MAPPING
  */
 static void
-MakeConfigurationMapping(AlterTSConfigurationStmt *stmt, HeapTuple tup)
+MakeConfigurationMapping(AlterTSConfigurationStmt *stmt,
+						 HeapTuple tup, Relation relMap)
 {
 	Oid			cfgId = HeapTupleGetOid(tup);
-	Relation	relMap;
 	ScanKeyData skey[2];
 	SysScanDesc scan;
 	HeapTuple	maptup;
@@ -1801,8 +1737,6 @@ MakeConfigurationMapping(AlterTSConfigurationStmt *stmt, HeapTuple tup)
 	tokens = getTokenTypes(prsId, stmt->tokentype);
 	ntoken = list_length(stmt->tokentype);
 
-	relMap = heap_open(TSConfigMapRelationId, RowExclusiveLock);
-
 	if (stmt->override)
 	{
 		/*
@@ -1938,18 +1872,16 @@ MakeConfigurationMapping(AlterTSConfigurationStmt *stmt, HeapTuple tup)
 			}
 		}
 	}
-
-	heap_close(relMap, RowExclusiveLock);
 }
 
 /*
  * ALTER TEXT SEARCH CONFIGURATION DROP MAPPING
  */
 static void
-DropConfigurationMapping(AlterTSConfigurationStmt *stmt, HeapTuple tup)
+DropConfigurationMapping(AlterTSConfigurationStmt *stmt,
+						 HeapTuple tup, Relation relMap)
 {
 	Oid			cfgId = HeapTupleGetOid(tup);
-	Relation	relMap;
 	ScanKeyData skey[2];
 	SysScanDesc scan;
 	HeapTuple	maptup;
@@ -1964,8 +1896,6 @@ DropConfigurationMapping(AlterTSConfigurationStmt *stmt, HeapTuple tup)
 	tokens = getTokenTypes(prsId, stmt->tokentype);
 	ntoken = list_length(stmt->tokentype);
 
-	relMap = heap_open(TSConfigMapRelationId, RowExclusiveLock);
-
 	i = 0;
 	foreach(c, stmt->tokentype)
 	{
@@ -2011,8 +1941,6 @@ DropConfigurationMapping(AlterTSConfigurationStmt *stmt, HeapTuple tup)
 
 		i++;
 	}
-
-	heap_close(relMap, RowExclusiveLock);
 }
 
 

src/backend/parser/gram.y

@@ -11,7 +11,7 @@
  *
  *
  * IDENTIFICATION
- *	  $PostgreSQL: pgsql/src/backend/parser/gram.y,v 2.599 2007/08/21 15:13:42 tgl Exp $
+ *	  $PostgreSQL: pgsql/src/backend/parser/gram.y,v 2.600 2007/08/22 05:13:50 tgl Exp $
  *
  * HISTORY
  *	  AUTHOR			DATE			MAJOR EVENT
@@ -5523,14 +5523,7 @@ AlterTSDictionaryStmt:
 		;
 
 AlterTSConfigurationStmt:
-			ALTER TEXT_P SEARCH CONFIGURATION any_name definition
+			ALTER TEXT_P SEARCH CONFIGURATION any_name ADD_P MAPPING FOR name_list WITH any_name_list
-				{
-					AlterTSConfigurationStmt *n = makeNode(AlterTSConfigurationStmt);
-					n->cfgname = $5;
-					n->options = $6;
-					$$ = (Node *)n;
-				}
-			| ALTER TEXT_P SEARCH CONFIGURATION any_name ADD_P MAPPING FOR name_list WITH any_name_list
 				{
 					AlterTSConfigurationStmt *n = makeNode(AlterTSConfigurationStmt);
 					n->cfgname = $5;

src/include/nodes/parsenodes.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/nodes/parsenodes.h,v 1.351 2007/08/21 01:11:28 tgl Exp $
+ * $PostgreSQL: pgsql/src/include/nodes/parsenodes.h,v 1.352 2007/08/22 05:13:50 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -2054,10 +2054,8 @@ typedef struct AlterTSConfigurationStmt
 {
 	NodeTag		type;
 	List	   *cfgname;		/* qualified name (list of Value strings) */
-	List	   *options;		/* List of DefElem nodes */
 
 	/*
-	 * These fields are used for ADD/ALTER/DROP MAPPING variants.
 	 * dicts will be non-NIL if ADD/ALTER MAPPING was specified.
 	 * If dicts is NIL, but tokentype isn't, DROP MAPPING was specified.
 	 */