New findoidjoins examines oid columns to find join relationships.

contrib/README

@@ -18,6 +18,11 @@ earthdistance -
 	Operator for computing earth distance for two points
 	by Hal Snyder <hal@vailsys.com>
 
+findoidjoins -
+	Finds the joins used by oid columns by examining the actual
+	values in the oid columns and row oids.
+	by Bruce Momjian <root@candle.pha.pa.us>
+
 fulltextindex -
 	Full text indexing using triggers
 	by Maarten Boekhold <maartenb@dutepp0.et.tudelft.nl>

contrib/findoidjoins/Makefile

+#
+# Makefile, requires pgsql/contrib/pginterface
+#
+#
+PGINTERFACE = pginterface.o halt.o # these have to be in your library search path
+TARGET = findoidjoins
+CFLAGS = -g -Wall -I. -I../../src/interfaces/libpq  -I/usr/local/pgsql/include
+LDFLAGS = -L/usr/local/pgsql/lib -lpq
+
+all : $(TARGET)
+
+findoidjoins:	$(PGINTERFACE) findoidjoins.c
+	gcc -o $@ $(CFLAGS) $@.c $(PGINTERFACE) $(LDFLAGS)
+
+clean:
+	rm -f *.o $(TARGET) log core
+
+install:
+	install -s -o bin -g bin $(TARGET) /usr/local/pgsql/bin
+

contrib/findoidjoins/README

+
+
+   			      findoidjoins
+
+This program scans the a database, and prints oid fields, and the tables
+they join to.  PostgreSQL version 6.3.2 crashes with aggregates on
+views, so I have removed the view pg_user from the list of relations to
+examine.
+
+Run on am empty database, it returns the system join relationships:
+
+---------------------------------------------------------------------------
+
+Join pg_aggregate.aggfinaltype => pg_proc.oid
+Join pg_aggregate.aggfinaltype => pg_type.oid
+Join pg_aggregate.aggowner => pg_proc.oid
+Join pg_aggregate.aggbasetype => pg_proc.oid
+Join pg_aggregate.aggbasetype => pg_type.oid
+Join pg_aggregate.aggtranstype1 => pg_proc.oid
+Join pg_aggregate.aggtranstype1 => pg_type.oid
+Join pg_aggregate.aggtranstype2 => pg_type.oid
+Join pg_am.amowner => pg_proc.oid
+Join pg_amop.amopid => pg_am.oid
+Join pg_amop.amopopr => pg_operator.oid
+Join pg_amop.amopclaid => pg_opclass.oid
+Join pg_amproc.amproc => pg_operator.oid
+Join pg_amproc.amproc => pg_proc.oid
+Join pg_amproc.amopclaid => pg_opclass.oid
+Join pg_amproc.amopclaid => pg_operator.oid
+Join pg_amproc.amopclaid => pg_proc.oid
+Join pg_amproc.amid => pg_am.oid
+Join pg_attribute.attrelid => pg_class.oid
+Join pg_attribute.atttypid => pg_type.oid
+Join pg_class.relam => pg_am.oid
+Join pg_class.reltype => pg_type.oid
+Join pg_class.relowner => pg_proc.oid
+Join pg_description.objoid => pg_proc.oid
+Join pg_description.objoid => pg_type.oid
+Join pg_index.indexrelid => pg_class.oid
+Join pg_index.indrelid => pg_class.oid
+Join pg_index.indproc => pg_proc.oid
+Join pg_opclass.opcdeftype => pg_type.oid
+Join pg_operator.oprcom => pg_operator.oid
+Join pg_operator.oprrsortop => pg_operator.oid
+Join pg_operator.oprlsortop => pg_operator.oid
+Join pg_operator.oprnegate => pg_operator.oid
+Join pg_operator.oprresult => pg_type.oid
+Join pg_operator.oprright => pg_type.oid
+Join pg_operator.oprleft => pg_type.oid
+Join pg_operator.oprowner => pg_proc.oid
+Join pg_parg.partype => pg_type.oid
+Join pg_parg.parproid => pg_operator.oid
+Join pg_parg.parproid => pg_proc.oid
+Join pg_proc.prolang => pg_language.oid
+Join pg_proc.prorettype => pg_type.oid
+Join pg_proc.proowner => pg_proc.oid
+Join pg_rewrite.ev_class => pg_class.oid
+Join pg_statistic.starelid => pg_class.oid
+Join pg_type.typrelid => pg_class.oid
+Join pg_type.typowner => pg_proc.oid
+Join pg_type.typelem => pg_operator.oid
+Join pg_type.typelem => pg_proc.oid
+Join pg_type.typelem => pg_type.oid
+
+
+---------------------------------------------------------------------------
+
+Bruce Momjian (root@candle.pha.pa.us)

contrib/findoidjoins/findoidjoins.c

+/*
+ * findoidjoins.c, required pgsql/contrib/pginterface
+ *
+ */
+
+#include <stdio.h>
+#include "halt.h"
+#include <libpq-fe.h>
+#include "pginterface.h"
+
+PGresult *attres, *relres;
+
+int
+main(int argc, char **argv)
+{
+	char		query[4000];
+	char		relname[256];
+	char		relname2[256];
+	char		attname[256];
+	int			count;
+
+	if (argc != 2)
+		halt("Usage:  %s database\n", argv[0]);
+
+	connectdb(argv[1], NULL, NULL, NULL, NULL);
+	on_error_continue();
+	on_error_stop();
+
+	doquery("BEGIN WORK");
+	doquery("\
+		DECLARE c_attributes BINARY CURSOR FOR \
+		SELECT relname, a.attname \
+		FROM pg_class c, pg_attribute a, pg_type t \
+		WHERE a.attnum > 0 AND \
+			  relkind = 'r' AND \
+			  typname = 'oid' AND \
+			  a.attrelid = c.oid AND \
+			  a.atttypid = t.oid \
+		ORDER BY 1; \
+		");
+	doquery("FETCH ALL IN c_attributes");
+	attres = get_result();
+
+	doquery("\
+		DECLARE c_relations BINARY CURSOR FOR \
+		SELECT relname \
+		FROM pg_class c \
+		WHERE relkind = 'r' AND \
+			  relname != 'pg_user' \
+		ORDER BY 1; \
+		");
+	doquery("FETCH ALL IN c_relations");
+	relres = get_result();
+	
+	set_result(attres);
+	while (fetch(relname, attname) != END_OF_TUPLES)
+	{
+		set_result(relres);
+		reset_fetch();
+		while (fetch(relname2) != END_OF_TUPLES)
+		{
+			unset_result(relres);
+			sprintf(query,"\
+				DECLARE c_matches BINARY CURSOR FOR \
+				SELECT	count(*)
+				FROM	%s t1, %s t2 \
+				WHERE	t1.%s = t2.oid", relname, relname2, attname);
+
+			doquery(query);
+			doquery("FETCH ALL IN c_matches");
+			fetch(&count);
+			if (count != 0)
+				printf("Join %s.%s => %s.oid\n", relname, attname, relname2);
+			doquery("CLOSE c_matches");
+			set_result(relres);
+		}
+		set_result(attres);
+	}
+
+	set_result(relres);
+	doquery("CLOSE c_relations");
+	PQclear(relres);
+
+	set_result(attres);
+	doquery("CLOSE c_attributes");
+	PQclear(attres);
+	unset_result(attres);
+	
+	doquery("COMMIT WORK");
+
+	disconnectdb();
+	return 0;
+}

contrib/pginterface/README

@@ -22,6 +22,11 @@ useful if you are running the query engine on a system with a different
 architecture than the database server.  If you pass a NULL pointer, the
 column is skipped, and you can use libpq to handle it as you wish.
 
+There are two functions, get_result() and set_result, that allow you to
+handle multiple result sets at the same time.
+
+There is a reset_fetch() that starts the fetch back at the beginning.
+
 There is a demo program called pginsert that demonstrates how the
 library can be used.
 

contrib/pginterface/pginterface.c

@@ -22,6 +22,9 @@ static PGresult *res = NULL;
 
 static int	on_error_state = ON_ERROR_STOP;
 
+static in_result_block = false;
+static was_get_unset_result = false;
+
 /* LOCAL VARIABLES */
 static int	tuple;
 
@@ -64,9 +67,10 @@ disconnectdb()
 PGresult   *
 doquery(char *query)
 {
-	if (res != NULL)
+	if (res != NULL && in_result_block == false && was_get_unset_result == false)
 		PQclear(res);
 
+	was_get_unset_result = false;
 	res = PQexec(conn, query);
 
 	if (on_error_state == ON_ERROR_STOP &&
@@ -187,3 +191,69 @@ on_error_continue()
 {
 	on_error_state = ON_ERROR_CONTINUE;
 }
+
+
+/*
+**
+**		get_result
+**
+*/
+PGresult   *get_result()
+{
+	was_get_unset_result = true;
+	/* we have to store the fetch location somewhere */
+	memcpy(&res->cmdStatus[CMDSTATUS_LEN-sizeof(tuple)],&tuple, sizeof(tuple));
+	return res;
+}
+	
+/*
+**
+**		set_result
+**
+*/
+void        set_result(PGresult *newres)
+{
+	if (newres == NULL)
+		halt("set_result called with null result pointer\n");
+
+	if (res != NULL && was_get_unset_result == false)
+		if (in_result_block == false)
+			PQclear(res);
+		else
+			memcpy(&res->cmdStatus[CMDSTATUS_LEN-sizeof(tuple)], &tuple, sizeof(tuple));
+		
+	in_result_block = true;
+	was_get_unset_result = false;
+	memcpy(&tuple, &newres->cmdStatus[CMDSTATUS_LEN-sizeof(tuple)], sizeof(tuple));
+	res = newres;
+}
+
+
+/*
+**
+**		unset_result
+**
+*/
+void       unset_result(PGresult *oldres)
+{
+	if (oldres == NULL)
+		halt("unset_result called with null result pointer\n");
+
+	if (in_result_block == false)
+		halt("Unset of result without being set.\n");
+
+	was_get_unset_result = true;
+	memcpy(&oldres->cmdStatus[CMDSTATUS_LEN-sizeof(tuple)], &tuple, sizeof(tuple));
+	in_result_block = false;
+}
+
+/*
+**
+**		reset_fetch
+**
+*/
+void        reset_fetch()
+{
+	tuple = 0;
+}
+

contrib/pginterface/pginterface.h

@@ -10,5 +10,9 @@ int			fetch(void *param,...);
 int			fetchwithnulls(void *param,...);
 void		on_error_continue();
 void		on_error_stop();
+PGresult   *get_result();
+void        set_result(PGresult *newres);
+void        unset_result(PGresult *oldres);
+void        reset_fetch();
 
 #define END_OF_TUPLES	(-1)