Support Docs & Contrib

contrib/array/array_iterator.c

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+/*
+ * array_iterator.c --
+ *
+ * This file defines a new group of operators which take an
+ * array and a scalar value, iterate a scalar operator over the
+ * elements of the array and the value and compute a result as
+ * the logical OR or AND of the results.
+ * For example array_int4eq returns true if some of the elements
+ * of an array of int4 is equal to the given value:
+ *
+ *	array_int4eq({1,2,3}, 1)  -->  true
+ *	array_int4eq({1,2,3}, 4)  -->  false
+ *
+ * If we have defined T array types and O scalar operators
+ * we can define T x O array operators, each of them has a name
+ * like "array_<basetype><operation>" and takes an array of type T
+ * iterating the operator O over all the elements. Note however
+ * that some of the possible combination are invalid, for example
+ * the array_int4_like because there is no like operator for int4.
+ * It is now possible to write queries which look inside the arrays:
+ *
+ *      create table t(id int4[], txt text[]);
+ *	select * from t where t.id *= 123;
+ *	select * from t where t.txt *~ '[a-z]';
+ *	select * from t where t.txt[1:3] **~ '[a-z]';
+ *
+ * Copyright (c) 1996, Massimo Dal Zotto <dz@cs.unitn.it>
+ */
+
+#include <ctype.h>
+#include <stdio.h>
+#include <sys/types.h>
+#include <string.h>
+
+#include "postgres.h"
+#include "pg_type.h"
+#include "miscadmin.h"
+#include "syscache.h"
+#include "access/xact.h"
+#include "utils/builtins.h"
+#include "utils/elog.h"
+
+static int32
+array_iterator(Oid elemtype, Oid proc, int and, ArrayType *array, Datum value)
+{
+    HeapTuple typ_tuple;
+    TypeTupleForm typ_struct;
+    bool typbyval;
+    int typlen;
+    func_ptr proc_fn;
+    int pronargs;
+    int nitems, i, result;
+    int ndim, *dim;
+    char *p;
+
+    /* Sanity checks */
+    if ((array == (ArrayType *) NULL)
+	|| (ARR_IS_LO(array) == true)) {
+	/* elog(NOTICE, "array_iterator: array is null"); */
+        return (0);
+    }
+    ndim = ARR_NDIM(array);
+    dim = ARR_DIMS(array);
+    nitems = getNitems(ndim, dim);
+    if (nitems == 0) {
+	/* elog(NOTICE, "array_iterator: nitems = 0"); */
+        return (0);
+    }
+
+    /* Lookup element type information */
+    typ_tuple = SearchSysCacheTuple(TYPOID, ObjectIdGetDatum(elemtype),0,0,0);
+    if (!HeapTupleIsValid(typ_tuple)) {
+        elog(WARN,"array_iterator: cache lookup failed for type %d", elemtype);
+        return 0;
+    }
+    typ_struct = (TypeTupleForm) GETSTRUCT(typ_tuple);
+    typlen   = typ_struct->typlen;
+    typbyval = typ_struct->typbyval;
+
+    /* Lookup the function entry point */
+    proc_fn == (func_ptr) NULL;
+    fmgr_info(proc, &proc_fn, &pronargs);
+    if ((proc_fn == NULL) || (pronargs != 2)) {
+	elog(WARN, "array_iterator: fmgr_info lookup failed for oid %d", proc);
+        return (0);
+    }
+
+    /* Scan the array and apply the operator to each element */
+    result = 0;
+    p = ARR_DATA_PTR(array);
+    for (i = 0; i < nitems; i++) {
+        if (typbyval) {
+            switch(typlen) {
+	      case 1:
+		result = (int) (*proc_fn)(*p, value);
+		break;
+	    case 2:
+		result = (int) (*proc_fn)(* (int16 *) p, value);
+		break;
+	    case 3:
+	    case 4:
+		result = (int) (*proc_fn)(* (int32 *) p, value);
+		break;
+            }
+            p += typlen;
+        } else {
+	    result = (int) (*proc_fn)(p, value);
+            if (typlen > 0) {
+		p += typlen;
+	    } else {
+                p += INTALIGN(* (int32 *) p);
+	    }
+        }
+	if (result) {
+	    if (!and) {
+		return (1);
+	    }
+	} else {
+	    if (and) {
+		return (0);
+	    }
+	}
+    }
+
+    if (and && result) {
+	return (1);
+    } else {
+	return (0);
+    }
+}
+
+/*
+ * Iterators for type _text
+ */
+
+int32
+array_texteq(ArrayType *array, char* value)
+{
+    return array_iterator((Oid) 25,	/* text */
+			  (Oid) 67,	/* texteq */
+			  0,		/* logical or */
+			  array, (Datum)value);
+}
+
+int32
+array_all_texteq(ArrayType *array, char* value)
+{
+    return array_iterator((Oid) 25,	/* text */
+			  (Oid) 67,	/* texteq */
+			  1,		/* logical and */
+			  array, (Datum)value);
+}
+
+int32
+array_textregexeq(ArrayType *array, char* value)
+{
+    return array_iterator((Oid) 25,	/* text */
+			  (Oid) 81,	/* textregexeq */
+			  0,		/* logical or */
+			  array, (Datum)value);
+}
+
+int32
+array_all_textregexeq(ArrayType *array, char* value)
+{
+    return array_iterator((Oid) 25,	/* text */
+			  (Oid) 81,	/* textregexeq */
+			  1,		/* logical and */
+			  array, (Datum)value);
+}
+
+/*
+ * Iterators for type _char16. Note that the regexp operators
+ * take the second argument of type text.
+ */
+
+int32
+array_char16eq(ArrayType *array, char* value)
+{
+    return array_iterator((Oid) 20,	/* char16 */
+			  (Oid) 490,	/* char16eq */
+			  0,		/* logical or */
+			  array, (Datum)value);
+}
+
+int32
+array_all_char16eq(ArrayType *array, char* value)
+{
+    return array_iterator((Oid) 20,	/* char16 */
+			  (Oid) 490,	/* char16eq */
+			  1,		/* logical and */
+			  array, (Datum)value);
+}
+
+int32
+array_char16regexeq(ArrayType *array, char* value)
+{
+    return array_iterator((Oid) 20,	/* char16 */
+			  (Oid) 700,	/* char16regexeq */
+			  0,		/* logical or */
+			  array, (Datum)value);
+}
+
+int32
+array_all_char16regexeq(ArrayType *array, char* value)
+{
+    return array_iterator((Oid) 20,	/* char16 */
+			  (Oid) 700,	/* char16regexeq */
+			  1,		/* logical and */
+			  array, (Datum)value);
+}
+
+/*
+ * Iterators for type _int4
+ */
+
+int32
+array_int4eq(ArrayType *array, int4 value)
+{
+    return array_iterator((Oid) 23,	/* int4 */
+			  (Oid) 65,	/* int4eq */
+			  0,		/* logical or */
+			  array, (Datum)value);
+}
+
+int32
+array_all_int4eq(ArrayType *array, int4 value)
+{
+    return array_iterator((Oid) 23,	/* int4 */
+			  (Oid) 65,	/* int4eq */
+			  1,		/* logical and */
+			  array, (Datum)value);
+}
+
+int32
+array_int4gt(ArrayType *array, int4 value)
+{
+    return array_iterator((Oid) 23,	/* int4 */
+			  (Oid) 147,	/* int4gt */
+			  0,		/* logical or */
+			  array, (Datum)value);
+}
+
+int32
+array_all_int4gt(ArrayType *array, int4 value)
+{
+    return array_iterator((Oid) 23,	/* int4 */
+			  (Oid) 147,	/* int4gt */
+			  1,		/* logical and */
+			  array, (Datum)value);
+}

contrib/array/array_iterator.doc

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+From: Massimo Dal Zotto <dz@cs.unitn.it>
+Date: Mon, 6 May 1996 01:03:37 +0200 (MET DST)
+Subject: [PG95]: new operators for arrays
+
+- -----BEGIN PGP SIGNED MESSAGE-----
+
+Hi,
+
+I have written an extension to Postgres95 which allows to use qualification
+clauses based on the values of single elements of arrays.
+For example I can now select rows having some or all element of an array
+attribute equal to a given value or matching a regular expression:
+
+select * from t where t.foo *= 'bar';
+select * from t where t.foo **~ '^ba[rz]';
+
+The scheme is quite general, each operator which operates on a base type can
+be iterated over the elements of an array. It seem to work well but defining
+each new operators requires writing a different C function. Furthermore in
+each function there are two hardcoded OIDs which reference a base type and
+a procedure. Not very portable. Can anyone suggest a better and more portable
+way to do it ?  Do you think this could be a useful feature for next release ?
+Here is my code, it can be compiled and loaded as a dynamic module without
+need to recompile the backend. I have defined only the few operators I needed,
+the list can be extended. Feddback is welcome.
+

contrib/array/array_iterator.sql

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+/*
+ * SQL code
+
+- - -- load the new functions
+- - --
+load '/home/dz/lib/postgres/array_iterator.so';
+
+- - -- define the array operators *=, **=, *~ and **~ for type _text
+- - --
+create function array_texteq(_text, text)
+  returns bool
+  as '/home/dz/lib/postgres/array_iterator.so' 
+  language 'c';
+
+create function array_all_texteq(_text, text)
+  returns bool
+  as '/home/dz/lib/postgres/array_iterator.so' 
+  language 'c';
+
+create function array_textregexeq(_text, text)
+  returns bool
+  as '/home/dz/lib/postgres/array_iterator.so' 
+  language 'c';
+
+create function array_all_textregexeq(_text, text)
+  returns bool
+  as '/home/dz/lib/postgres/array_iterator.so' 
+  language 'c';
+
+create operator *= (
+  leftarg=_text, 
+  rightarg=text, 
+  procedure=array_texteq);
+
+create operator **= (
+  leftarg=_text,
+  rightarg=text,
+  procedure=array_all_texteq);
+
+create operator *~ (
+  leftarg=_text,
+  rightarg=text,
+  procedure=array_textregexeq);
+
+create operator **~ (
+  leftarg=_text,
+  rightarg=text,
+  procedure=array_all_textregexeq);
+
+- - -- define the array operators *=, **=, *~ and **~ for type _char16
+- - --
+create function array_char16eq(_char16, char16)
+  returns bool
+  as '/home/dz/lib/postgres/array_iterator.so' 
+  language 'c';
+
+create function array_all_char16eq(_char16, char16)
+  returns bool
+  as '/home/dz/lib/postgres/array_iterator.so' 
+  language 'c';
+
+create function array_char16regexeq(_char16, text)
+  returns bool
+  as '/home/dz/lib/postgres/array_iterator.so' 
+  language 'c';
+
+create function array_all_char16regexeq(_char16, text)
+  returns bool
+  as '/home/dz/lib/postgres/array_iterator.so' 
+  language 'c';
+
+create operator *= (
+  leftarg=_char16,
+  rightarg=char16,
+  procedure=array_char16eq);
+
+create operator **= (
+  leftarg=_char16,
+  rightarg=char16,
+  procedure=array_all_char16eq);
+
+create operator *~ (
+  leftarg=_char16,
+  rightarg=text,
+  procedure=array_char16regexeq);
+
+create operator **~ (
+  leftarg=_char16,
+  rightarg=text,
+  procedure=array_all_char16regexeq);
+
+- - -- define the array operators *=, **=, *> and **> for type _int4
+- - --
+create function array_int4eq(_int4, int4)
+  returns bool
+  as '/home/dz/lib/postgres/array_iterator.so' 
+  language 'c';
+
+create function array_all_int4eq(_int4, int4)
+  returns bool
+  as '/home/dz/lib/postgres/array_iterator.so' 
+  language 'c';
+
+create function array_int4gt(_int4, int4)
+  returns bool
+  as '/home/dz/lib/postgres/array_iterator.so' 
+  language 'c';
+
+create function array_all_int4gt(_int4, int4)
+  returns bool
+  as '/home/dz/lib/postgres/array_iterator.so' 
+  language 'c';
+
+create operator *= (
+  leftarg=_int4,
+  rightarg=int4,
+  procedure=array_int4eq);
+
+create operator **= (
+  leftarg=_int4,
+  rightarg=int4,
+  procedure=array_all_int4eq);
+
+create operator *> (
+  leftarg=_int4,
+  rightarg=int4,
+  procedure=array_int4gt);
+
+create operator **> (
+  leftarg=_int4,
+  rightarg=int4,
+  procedure=array_all_int4gt);
+
+*/
+
+/* end of file */
+

contrib/datetime/datetime_functions.c

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+/*
+ * datetime_functions.c --
+ *
+ * This file defines new functions for the time and date data types.
+ *
+ * Copyright (c) 1996, Massimo Dal Zotto <dz@cs.unitn.it>
+ */
+
+#include <time.h>
+
+#include "postgres.h"
+#include "pg_type.h"
+#include "utils/palloc.h"
+
+typedef struct DateADT {
+    char	day;
+    char	month;
+    short	year;
+} DateADT;
+
+typedef struct TimeADT {
+    short	hr;
+    short	min;
+    float	sec;
+} TimeADT;
+
+TimeADT *
+time_difference(TimeADT *time1, TimeADT *time2)
+{
+    TimeADT *time = (TimeADT*)palloc(sizeof(TimeADT));
+
+    time->sec = time1->sec - time2->sec;
+    time->min = time1->min - time2->min;
+    time->hr  = time1->hr  - time2->hr;
+
+    if (time->sec < 0) {
+	time->sec += 60.0;
+	time->min--;
+    } else if (time->sec >= 60.0) {
+	time->sec -= 60.0;
+	time->min++;
+    }
+
+    if (time->min < 0) {
+	time->min += 60;
+	time->hr--;
+    } else if (time->min >= 60) {
+	time->min -= 60;
+	time->hr++;
+    }
+
+    if (time->hr < 0) {
+	time->hr += 24;
+    } else if (time->hr >= 24) {
+	time->hr -= 24;
+    }
+
+    return (time);
+}
+
+TimeADT *
+currentTime()
+{
+    time_t current_time;
+    struct tm *tm;
+    TimeADT *result = (TimeADT*)palloc(sizeof(TimeADT));
+
+    current_time = time(NULL);
+    tm = localtime(&current_time);
+    result->sec = tm->tm_sec;
+    result->min = tm->tm_min;
+    result->hr  = tm->tm_hour;
+
+    return (result);
+}
+
+int4
+currentDate()
+{
+    time_t current_time;
+    struct tm *tm;
+    int4 result;
+    DateADT *date = (DateADT*)&result;
+
+    current_time = time(NULL);
+    tm = localtime(&current_time);
+    date->day   = tm->tm_mday;
+    date->month = tm->tm_mon+1;
+    date->year  = tm->tm_year+1900;
+
+    return (result);
+}
+
+int4
+hours(TimeADT *time)
+{
+    return (time->hr);
+}
+
+int4
+minutes(TimeADT *time)
+{
+    return (time->min);
+}
+
+int4
+seconds(TimeADT *time)
+{
+    int seconds = (int)time->sec;
+    return (seconds);
+}
+
+int4
+day(int4 val)
+{
+    DateADT *date = (DateADT*)&val;
+    return (date->day);
+}
+
+int4
+month(int4 val)
+{
+    DateADT *date = (DateADT*)&val;
+    return (date->month);
+}
+
+int4
+year(int4 val)
+{
+    DateADT *date = (DateADT*)&val;
+    return (date->year);
+}
+
+int4
+asMinutes(TimeADT *time)
+{
+    int seconds = (int)time->sec;
+    return (time->min + 60*time->hr);
+}
+
+int4
+asSeconds(TimeADT *time)
+{
+    int seconds = (int)time->sec;
+    return (seconds + 60*time->min + 3600*time->hr);
+}
+

contrib/datetime/datetime_functions.doc

@@ -0,0 +1,25 @@
+From: Massimo Dal Zotto <dz@cs.unitn.it>
+Date: Tue, 14 May 1996 14:31:18 +0200 (MET DST)
+Subject: [PG95]: new postgres functions
+
+- -----BEGIN PGP SIGNED MESSAGE-----
+
+Some time ago I read in the mailing list requests of people looking
+for more time and date functions.  I have now written some of them:
+
+  time_difference(time1, time2) ,also defined as operator '-'
+  hour(time)
+  minutes(time)
+  seconds(time)
+  asMinutes(time)
+  asSeconds(time)
+  currentTime()
+  currentDate()
+
+The file can be compiled as shared library and loaded as dynamic module
+without need to recompile the backend.  This can also be taken as an example
+of the extensibility of postgres (user-defined functions, operators, etc).
+I would be nice to see more of these user contributed modules posted to this
+list and hopefully accessible from the Postgres home page.
+
+

contrib/datetime/datetime_functions.sql

@@ -0,0 +1,69 @@
+
+-- SQL code to load and define 'datetime' functions
+
+-- load the new functions
+
+load '/home/dz/lib/postgres/datetime_functions.so';
+
+-- define the new functions in postgres
+
+create function time_difference(time,time)
+  returns time
+  as '/home/dz/lib/postgres/datetime_functions.so' 
+  language 'c';
+
+create function currentDate()
+  returns date
+  as '/home/dz/lib/postgres/datetime_functions.so' 
+  language 'c';
+
+create function currentTime()
+  returns time
+  as '/home/dz/lib/postgres/datetime_functions.so' 
+  language 'c';
+
+create function hours(time)
+  returns int4
+  as '/home/dz/lib/postgres/datetime_functions.so' 
+  language 'c';
+
+create function minutes(time)
+  returns int4
+  as '/home/dz/lib/postgres/datetime_functions.so' 
+  language 'c';
+
+create function seconds(time)
+  returns int4
+  as '/home/dz/lib/postgres/datetime_functions.so' 
+  language 'c';
+
+create function day(date)
+  returns int4
+  as '/home/dz/lib/postgres/datetime_functions.so'
+  language 'c';
+
+create function month(date)
+  returns int4
+  as '/home/dz/lib/postgres/datetime_functions.so'
+  language 'c';
+
+create function year(date)
+  returns int4
+  as '/home/dz/lib/postgres/datetime_functions.so'
+  language 'c';
+
+create function asMinutes(time)
+  returns int4
+  as '/home/dz/lib/postgres/datetime_functions.so' 
+  language 'c';
+
+create function asSeconds(time)
+  returns int4
+  as '/home/dz/lib/postgres/datetime_functions.so' 
+  language 'c';
+
+create operator - (
+  leftarg=time, 
+  rightarg=time, 
+  procedure=time_difference);
+

contrib/pginterface/Makefile

@@ -0,0 +1,19 @@
+#
+# Makefile
+#
+#
+TARGET = pginsert
+CFLAGS = -g -Wall -I/u/postgres95/include
+LIBS = -L/u/postgres95/lib -lpq
+
+$(TARGET) : pginsert.o pginterface.o halt.o
+	$(CC) -o $(TARGET) $(XFLAGS) $(CFLAGS) \
+		 pginsert.o pginterface.o halt.o $(LIBS)
+
+clean:
+	rm -f *.o $(TARGET) log core
+
+install:
+	make clean
+	make CFLAGS=-O
+	install -s -o bin -g bin $(TARGET) /usr/local/bin

contrib/pginterface/README

@@ -0,0 +1,42 @@
+
+
+   			      Pginterface 1.0
+
+Attached is a copy of the Postgres support routines I wrote to allow me
+to more cleanly interface to the libpg library, more like a 4gl SQL
+interface.
+
+It has several features that may be useful for others:
+
+I have simplified the C code that calls libpq by wrapping all the
+functionality of libpq in calls to connectdb(), doquery(), fetch(), and
+disconnectdb().  Each call returns a structure or value, so if you need
+to do more work with the result, you can.  Also, I have a global
+variable that allows you to disable the error checking I have added to
+the doquery() routine.
+
+I have added a function called fetch(), which allows you to pass
+pointers as parameters, and on return the variables are filled with the
+data from the binary cursor you opened.  These binary cursors are not
+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.
+
+I have used sigprocmask() to block the reception of certain signals
+while the program is executing SQL queries.  This prevents a user
+pressing Control-C from stopping all the back ends.  It blocks SIGHUP,
+SIGINT, and SIGTERM, but does not block SIGQUIT or obviously kill -9. 
+If your platform does not support sigprocmask(), you can remove those
+function calls.  ( Am I correct that abnormal termination can cause
+shared memory resynchronization?)
+
+There is a demo program called pginsert that demonstrates how the
+library can be used.
+
+You can create a library of pginterface.c and halt.c, and just include
+pginterface.h in your source code.
+
+I am willing to maintain this if people find problems or want additional
+functionality. 
+
+Bruce Momjian (root@candle.pha.pa.us)

contrib/pginterface/halt.c

@@ -0,0 +1,58 @@
+/*
+**
+**	halt.c
+**
+**	This is used to print out error messages and exit
+*/
+
+#include <varargs.h>
+#include <signal.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <errno.h>
+
+
+/*-------------------------------------------------------------------------
+**
+**	halt - print error message, and call clean up routine or exit
+**
+**------------------------------------------------------------------------*/
+
+/*VARARGS*/
+void halt(va_alist)
+va_dcl
+{
+	va_list arg_ptr;
+	char	*format, *pstr;
+	void (*sig_func)();
+
+	va_start(arg_ptr);
+	format = va_arg(arg_ptr,char *);
+	if (strncmp(format,"PERROR", 6) != 0)
+		vfprintf(stderr,format,arg_ptr);
+	else
+	{
+		for (pstr=format+6; *pstr == ' ' || *pstr == ':'; pstr++)
+			;
+		vfprintf(stderr,pstr,arg_ptr);
+		perror("");
+	}			
+	va_end(arg_ptr);
+	fflush(stderr);
+
+		/* call one clean up function if defined */
+	if ( (sig_func = signal(SIGTERM, SIG_DFL)) != SIG_DFL &&
+	      sig_func != SIG_IGN)
+		(*sig_func)(0);
+	else if ( (sig_func = signal(SIGHUP, SIG_DFL)) != SIG_DFL &&
+	      		sig_func != SIG_IGN)
+		(*sig_func)(0);
+	else if ( (sig_func = signal(SIGINT, SIG_DFL)) != SIG_DFL &&
+	      		sig_func != SIG_IGN)
+		(*sig_func)(0);
+	else if ( (sig_func = signal(SIGQUIT, SIG_DFL)) != SIG_DFL &&
+	      		sig_func != SIG_IGN)
+		(*sig_func)(0);
+	exit(1);
+}

contrib/pginterface/halt.h

@@ -0,0 +1,7 @@
+/*
+** halt.h
+**
+*/
+
+void halt();
+

contrib/pginterface/pginsert.c

@@ -0,0 +1,98 @@
+/*
+ * insert.c
+ *
+*/
+
+#include <stdio.h>
+#include <signal.h>
+#include <time.h>
+#include "halt.h"
+#include <libpq-fe.h>
+#include "pginterface.h"
+
+int main(int argc, char **argv)
+{
+	char query[4000];
+	int row =1;
+	int	aint;
+	float afloat;
+	double adouble;
+	char achar[11], achar16[17], abpchar[11], avarchar[51], atext[51];
+	time_t aabstime;
+	
+	if (argc != 2)
+		halt("Usage:  %s database\n",argv[0]);
+
+	connectdb(argv[1],NULL,NULL,NULL,NULL);
+
+	on_error_continue();
+	doquery("DROP TABLE testfetch");
+	on_error_stop();
+
+	doquery("\
+		CREATE TABLE testfetch( \
+			aint 	int4, \
+			afloat 	float4, \
+			adouble float8, \
+			achar	char, \
+			achar16	char16, \
+			abpchar char(10), \
+			avarchar varchar(50), \
+			atext	text, \
+			aabstime abstime) \
+		");
+
+	while(1)
+	{
+		sprintf(query,"INSERT INTO testfetch VALUES ( \
+			%d, \
+			2322.12, \
+			'923121.0323'::float8, \
+			'A', \
+			'Betty', \
+			'Charley', \
+			'Doug', \
+			'Ernie', \
+			'now' )", row);
+		doquery(query);
+		
+		doquery("BEGIN WORK");
+  		doquery("DECLARE c_testfetch BINARY CURSOR FOR \
+					SELECT * FROM testfetch");
+
+		doquery("FETCH ALL IN c_testfetch");
+
+		while (fetch(
+			&aint, 	
+			&afloat, 	
+			&adouble, 
+			achar,	
+			achar16,	
+			abpchar, 
+			avarchar, 
+			atext,
+			&aabstime) != END_OF_TUPLES)
+				printf("int %d\nfloat %f\ndouble %f\nchar %s\nchar16 %s\n\
+bpchar %s\nvarchar %s\ntext %s\nabstime %s",
+				aint, 	
+				afloat, 	
+				adouble, 
+				achar,	
+				achar16,	
+				abpchar, 
+				avarchar,
+				atext,
+				ctime(&aabstime));
+
+		
+		doquery("CLOSE c_testfetch");
+		doquery("COMMIT WORK");
+		printf("--- %-d rows inserted so far\n",row);
+		
+		row++;
+	}
+
+	disconnectdb();
+	return 0;
+}
+

contrib/pginterface/pginterface.c

@@ -0,0 +1,177 @@
+/*
+ * pginterface.c
+ *
+*/
+
+#include <stdio.h>
+#include <signal.h>
+#include <string.h>
+#include <stdarg.h>
+
+#include "halt.h"
+#include <libpq-fe.h>
+#include "pginterface.h"
+
+static void sig_disconnect();
+static void set_signals();
+
+#define NUL '\0'
+
+/* GLOBAL VARIABLES */
+static PGconn* conn;
+static PGresult* res = NULL;
+
+#define ON_ERROR_STOP	0
+#define ON_ERROR_CONTINUE	1
+
+static int	on_error_state = ON_ERROR_STOP;
+
+/* LOCAL VARIABLES */
+static sigset_t block_sigs, unblock_sigs;
+static int tuple;
+
+/*
+**
+**	connectdb - returns PGconn structure
+**
+*/
+PGconn *connectdb(	char *dbName,
+					char *pghost,
+					char *pgport,
+					char *pgoptions,
+					char *pgtty)
+{
+	/* make a connection to the database */
+	conn = PQsetdb(pghost, pgport, pgoptions, pgtty, dbName);
+	if (PQstatus(conn) == CONNECTION_BAD)
+		halt("Connection to database '%s' failed.\n%s\n", dbName,
+			PQerrorMessage(conn));
+	set_signals();
+	return conn;
+}
+
+/*
+**
+**	disconnectdb
+**
+*/
+void disconnectdb()
+{
+	PQfinish(conn);
+}
+
+/*
+**
+**	doquery	- returns PGresult structure
+**
+*/
+PGresult *doquery(char *query)
+{
+	if (res != NULL)
+		PQclear(res);
+
+	sigprocmask(SIG_SETMASK,&block_sigs,NULL);
+	res = PQexec(conn, query);
+	sigprocmask(SIG_SETMASK,&unblock_sigs,NULL);
+
+	if (on_error_state == ON_ERROR_STOP &&
+		(res == NULL ||
+		 PQresultStatus(res) ==	PGRES_BAD_RESPONSE ||
+		 PQresultStatus(res) ==	PGRES_NONFATAL_ERROR ||
+		 PQresultStatus(res) ==	PGRES_FATAL_ERROR))
+	{
+		if (res != NULL)
+				fprintf(stderr,"query error:  %s\n",PQcmdStatus(res));
+		else	fprintf(stderr,"connection error:  %s\n",PQerrorMessage(conn));
+		PQfinish(conn);
+		halt("failed request:  %s\n", query);
+	}
+	tuple = 0;
+	return res;
+}
+
+/*
+**
+**	fetch - returns tuple number (starts at 0), or the value END_OF_TUPLES
+**			NULL pointers are skipped
+**
+*/
+int fetch(void *param, ...)
+{
+	va_list ap;
+	int arg, num_args;
+
+	num_args = PQnfields(res);
+
+	if (tuple >= PQntuples(res))
+		return END_OF_TUPLES;
+	va_start(ap, param);
+	for (arg = 0; arg < num_args; arg++)
+	{
+		if (param != NULL)
+		{
+			if (PQfsize(res, arg) == -1)
+			{
+				memcpy(param,PQgetvalue(res,tuple,arg),PQgetlength(res,tuple,arg));
+				((char *)param)[PQgetlength(res,tuple,arg)] = NUL;
+			}
+			else
+				memcpy(param,PQgetvalue(res,tuple,arg),PQfsize(res,arg));
+		}
+		param = va_arg(ap, char *);
+	}
+	va_end(ap);
+	return tuple++;
+}
+
+/*
+**
+**	on_error_stop
+**
+*/
+void on_error_stop()
+{
+	on_error_state = ON_ERROR_STOP;
+}
+	
+/*
+**
+**	on_error_continue
+**
+*/
+void on_error_continue()
+{
+	on_error_state = ON_ERROR_CONTINUE;
+}
+	
+/*
+**
+**	sig_disconnect
+**
+*/
+static void sig_disconnect()
+{
+	fprintf(stderr,"exiting...\n");
+	PQfinish(conn);
+	exit(1);
+}
+
+/*
+**
+**	set_signals
+**
+*/
+static void set_signals()
+{
+	sigemptyset(&block_sigs);
+	sigemptyset(&unblock_sigs);
+	sigaddset(&block_sigs,SIGTERM);
+	sigaddset(&block_sigs,SIGHUP);
+	sigaddset(&block_sigs,SIGINT);
+/*	sigaddset(&block_sigs,SIGQUIT); no block */
+	sigprocmask(SIG_SETMASK,&unblock_sigs,NULL);
+	signal(SIGTERM,sig_disconnect);
+	signal(SIGHUP,sig_disconnect);
+	signal(SIGINT,sig_disconnect);
+	signal(SIGQUIT,sig_disconnect);
+}

contrib/pginterface/pginterface.h

@@ -0,0 +1,13 @@
+/*
+ * pglib.h
+ *
+*/
+
+PGresult *doquery(char *query);
+PGconn 	*connectdb();
+void	disconnectdb();
+int		fetch(void *param, ...);
+void	on_error_continue();
+void	on_error_stop();
+
+#define END_OF_TUPLES	(-1)

contrib/soundex/soundex.c

@@ -0,0 +1,83 @@
+/*****************************************************************************/
+/* soundex.c */
+/*****************************************************************************/
+
+#include <string.h>
+#include <stdio.h>
+#include "postgres.h"	  /* for char16, etc. */
+#include "utils/palloc.h" /* for palloc */
+#include "libpq-fe.h" /* for TUPLE */
+#include <stdio.h>
+#include <ctype.h>
+
+/* prototype for soundex function */
+char *soundex(char *instr, char *outstr);
+
+text *text_soundex(text *t)
+{
+                /* ABCDEFGHIJKLMNOPQRSTUVWXYZ */
+    char *table = "01230120022455012623010202";
+    int count = 0;
+    text *new_t;
+
+    char outstr[6+1]; /* max length of soundex is 6 */
+    char *instr;
+
+    /* make a null-terminated string */
+    instr=palloc(VARSIZE(t)+1);
+    memcpy(instr,VARDATA(t),VARSIZE(t)-VARHDRSZ);
+    instr[VARSIZE(t)-VARHDRSZ] = (char)0;
+
+    /* load soundex into outstr */
+    soundex(instr, outstr);
+
+    /* Now the outstr contains the soundex of instr */
+    /* copy outstr to new_t */
+    new_t = (text *) palloc(strlen(outstr)+VARHDRSZ);
+    memset(new_t, 0, strlen(outstr)+1);
+    VARSIZE(new_t) = strlen(outstr)+VARHDRSZ;
+    memcpy((void *) VARDATA(new_t),
+           (void *) outstr,
+           strlen(outstr));
+
+    /* free instr */
+    pfree(instr);
+
+    return(new_t);
+}
+
+char *soundex(char *instr, char *outstr)
+{                   /* ABCDEFGHIJKLMNOPQRSTUVWXYZ */
+    char *table = "01230120022455012623010202";
+    int count = 0;
+
+    while(!isalpha(instr[0]) && instr[0])
+        ++instr;
+
+    if(!instr[0]) {   /* Hey!  Where'd the string go? */
+        outstr[0]=(char)0;
+        return outstr;
+    }
+
+    if(toupper(instr[0]) == 'P' && toupper(instr[1]) == 'H') {
+        instr[0] = 'F';
+        instr[1] = 'A';
+    }
+
+    *outstr++ = (char)toupper(*instr++);
+
+    while(*instr && count < 5) {
+        if(isalpha(*instr) && *instr != *(instr-1)) {
+            *outstr = table[toupper(instr[0]) - 'A'];
+            if(*outstr != '0') {
+                ++outstr;
+                ++count;
+            }
+        }
+        ++instr;
+    }
+
+    *outstr = '\0';
+    return(outstr);
+}
+

contrib/soundex/soundex.sql

@@ -0,0 +1,57 @@
+--------------- soundex.sql:
+
+CREATE FUNCTION text_soundex(text) RETURNS text
+   AS '/usr/local/postgres/postgres95/src/funcs/soundex.so' LANGUAGE 'c';
+
+SELECT text_soundex('hello world!');
+
+CREATE TABLE s (nm text)\g
+
+insert into s values ('john')\g
+insert into s values ('joan')\g
+insert into s values ('wobbly')\g
+
+select * from s
+where text_soundex(nm) = text_soundex('john')\g
+
+select nm from s a, s b
+where text_soundex(a.nm) = text_soundex(b.nm)
+and a.oid <> b.oid\g
+
+CREATE FUNCTION text_sx_eq(text, text) RETURNS bool AS
+'select text_soundex($1) = text_soundex($2)'
+LANGUAGE 'sql'\g
+
+CREATE FUNCTION text_sx_lt(text,text) RETURNS bool AS
+'select text_soundex($1) < text_soundex($2)'
+LANGUAGE 'sql'\g
+
+CREATE FUNCTION text_sx_gt(text,text) RETURNS bool AS
+'select text_soundex($1) > text_soundex($2)'
+LANGUAGE 'sql';
+
+CREATE FUNCTION text_sx_le(text,text) RETURNS bool AS
+'select text_soundex($1) <= text_soundex($2)'
+LANGUAGE 'sql';
+
+CREATE FUNCTION text_sx_ge(text,text) RETURNS bool AS
+'select text_soundex($1) >= text_soundex($2)'
+LANGUAGE 'sql';
+
+CREATE FUNCTION text_sx_ne(text,text) RETURNS bool AS
+'select text_soundex($1) <> text_soundex($2)'
+LANGUAGE 'sql';
+
+DROP OPERATOR #= (text,text)\g
+
+CREATE OPERATOR #= (leftarg=text, rightarg=text, procedure=text_sx_eq,
+commutator=text_sx_eq)\g
+
+SELECT *
+FROM s
+WHERE text_sx_eq(nm,'john')\g
+
+SELECT *
+from s
+where s.nm #= 'john';
+

contrib/string/string_io.c

@@ -0,0 +1,361 @@
+/*
+ * string_io.c --
+ *
+ * This file defines new input/output conversion routines for strings.
+ *
+ * Copyright (c) 1996, Massimo Dal Zotto <dz@cs.unitn.it>
+ */
+
+#include <ctype.h>
+#include <string.h>
+
+#include "postgres.h"
+#include "utils/elog.h"
+#include "utils/palloc.h"
+#include "utils/builtins.h"
+
+/* define this if you want to see iso-8859 characters */
+#define ISO8859
+
+#define MIN(x, y)	((x) < (y) ? (x) : (y))
+#define	VALUE(char) 	((char) - '0')
+#define	DIGIT(val)	((val) + '0')
+#define ISOCTAL(c) 	(((c) >= '0') && ((c) <= '7'))
+#ifndef ISO8859
+#define NOTPRINTABLE(c)	(!isprint(c))
+#else
+#define NOTPRINTABLE(c)	(!isprint(c) && ((c) < 0xa0))
+#endif
+
+/*
+ * string_output() --
+ *
+ * This function takes a pointer to a string data and an optional
+ * data size and returns a printable representation of the data
+ * translating all escape sequences to C-like \nnn or \c escapes.
+ * The function is used by output methods of various string types.
+ *
+ * Arguments:
+ *	data -		input data (can be NULL)
+ *	size -		optional size of data. A negative value indicates
+ *			that data is a null terminated string.
+ *
+ * Returns:
+ *	a pointer to a new string containing the printable
+ *	representation of data.
+ */
+
+char *
+string_output(char *data, int size)
+{
+    register unsigned char c, *p, *r, *result;
+    register int l, len;
+
+    if (data == NULL) {
+	result = (char *) palloc(2);
+	result[0] = '-';
+	result[1] = '\0';
+	return (result);
+    }
+
+    if (size < 0) {
+	size = strlen(data);
+    }
+
+    /* adjust string length for escapes */
+    len = size;
+    for (p=data,l=size; l>0; p++,l--) {
+	switch (*p) {
+	  case '\\':
+	  case '"' :
+	  case '{':
+	  case '}':
+	  case '\b':
+	  case '\f':
+	  case '\n':
+	  case '\r':
+	  case '\t':
+	  case '\v':
+	    len++;
+	    break;
+	  default:
+	    if (NOTPRINTABLE(c)) {
+		len += 3;
+	    }
+	}
+    }
+    len++;
+
+    result = (char *) palloc(len);
+
+    for (p=data,r=result,l=size; (l > 0) && (c = *p); p++,l--) {
+	switch (c) {
+	  case '\\':
+	  case '"' :
+	  case '{':
+	  case '}':
+	    *r++ = '\\';
+	    *r++ = c;
+	    break;
+	  case '\b':
+	    *r++ = '\\';
+	    *r++ = 'b';
+	    break;
+	  case '\f':
+	    *r++ = '\\';
+	    *r++ = 'f';
+	    break;
+	  case '\n':
+	    *r++ = '\\';
+	    *r++ = 'n';
+	    break;
+	  case '\r':
+	    *r++ = '\\';
+	    *r++ = 'r';
+	    break;
+	  case '\t':
+	    *r++ = '\\';
+	    *r++ = 't';
+	    break;
+	  case '\v':
+	    *r++ = '\\';
+	    *r++ = 'v';
+	    break;
+	  default:
+	    if (NOTPRINTABLE(c)) {
+		*r = '\\';
+		r += 3;
+		*r-- = DIGIT(c & 07);
+		c >>= 3;
+		*r-- = DIGIT(c & 07);
+		c >>= 3;
+		*r   = DIGIT(c & 03);
+		r += 3;
+	    } else {
+		*r++ = c;
+	    }
+	}
+    }
+    *r = '\0';
+
+    return((char *) result);
+}
+
+/*
+ * string_input() --
+ *
+ * This function accepts a C string in input and copies it into a new 
+ * object allocated with palloc() translating all escape sequences.
+ * An optional header can be allocatd before the string, for example
+ * to hold the length of a varlena object.
+ * This function is not necessary for input from sql commands because
+ * the parser already does escape translation, all data input routines
+ * receive strings in internal form.
+ *
+ * Arguments:
+ *	str -		input string possibly with escapes
+ *	size -		the required size of new data. A value of 0
+ *			indicates a variable size string, while a
+ *			negative value indicates a variable size string
+ *			of size not greater than this absolute value.
+ *	hdrsize -	size of an optional header to be allocated before
+ *			the data. It must then be filled by the caller.
+ *	rtn_size -	an optional pointer to an int variable where the
+ *			size of the new string is stored back.
+ *
+ * Returns:
+ *	a pointer to the new string or the header.
+ */
+
+char *
+string_input(char *str, int size, int hdrsize, int *rtn_size)
+{
+    register unsigned char *p, *r;
+    unsigned char *result;
+    int len;
+
+    if ((str == NULL) || (hdrsize < 0)) {
+	return (char *) NULL;
+    }
+
+    /* Compute result size */
+    len = strlen(str);
+    for (p=str; *p; ) {
+	if (*p++ == '\\') {
+	    if (ISOCTAL(*p)) {
+		if (ISOCTAL(*(p+1))) {
+		    p++;
+		    len--;
+		}
+		if (ISOCTAL(*(p+1))) {
+		    p++;
+		    len--;
+		}
+	    }
+	    if (*p) p++;
+	    len--;
+	}
+    }
+
+    /* result has variable length */
+    if (size == 0) {
+	size = len+1;
+    } else
+
+    /* result has variable length with maximum size */
+    if (size < 0) {
+	size = MIN(len, - size)+1;
+    }
+
+    result = (char *) palloc(hdrsize+size);
+    memset(result, 0, hdrsize+size);
+    if (rtn_size) {
+	*rtn_size = size;
+    }
+
+    r = result + hdrsize;
+    for (p=str; *p; ) {
+	register unsigned char c;
+	if ((c = *p++) == '\\') {
+	    switch (c = *p++) {
+	      case '\0':
+		p--;
+		break;
+	      case '0':
+	      case '1':
+	      case '2':
+	      case '3':
+	      case '4':
+	      case '5':
+	      case '6':
+	      case '7':
+		c = VALUE(c);
+		if (isdigit(*p)) {
+		    c = (c<<3) + VALUE(*p++);
+		}
+		if (isdigit(*p)) {
+		    c = (c<<3) + VALUE(*p++);
+		}
+		*r++ = c;
+		break;
+	      case 'b':
+		*r++ = '\b';
+		break;
+	      case 'f':
+		*r++ = '\f';
+		break;
+	      case 'n':
+		*r++ = '\n';
+		break;
+	      case 'r':
+		*r++ = '\r';
+		break;
+	      case 't':
+		*r++ = '\t';
+		break;
+	      case 'v':
+		*r++ = '\v';
+		break;
+	      default:
+		*r++ = c;
+	    }
+	} else {
+	    *r++ = c;
+	}
+    }
+
+    return((char *) result);
+}
+
+char *
+c_charout(int32 c)
+{
+    char str[2];
+
+    str[0] = (char) c;
+    str[1] = '\0';
+
+    return (string_output(str, 1));
+}
+
+char *
+c_char2out(uint16 s)
+{
+    return (string_output((char *) &s, 2));
+}
+
+char *
+c_char4out(uint32 s)
+{
+    return (string_output((char *) &s, 4));
+}
+
+char *
+c_char8out(char *s)
+{
+    return (string_output(s, 8));
+}
+
+char *
+c_char16out(char *s)
+{
+    return (string_output(s, 16));
+}
+
+/*
+ * This can be used for text, bytea, SET and unknown data types
+ */
+
+char *
+c_textout(struct varlena *vlena)
+{
+    int len = 0;
+    char *s = NULL;
+
+    if (vlena) {
+	len = VARSIZE(vlena) - VARHDRSZ;
+	s = VARDATA(vlena);
+    }
+    return (string_output(s, len));
+}
+
+/*
+ * This can be used for varchar and bpchar strings
+ */
+
+char *
+c_varcharout(char *s)
+{
+    int len;
+
+    if (s) {
+	len = *(int32*)s - 4;
+	s += 4;
+    }
+    return (string_output(s, len));
+}
+
+#ifdef 0
+struct varlena *
+c_textin(char *str)
+{
+    struct varlena *result;
+    int len;
+
+    if (str == NULL) {
+	return ((struct varlena *) NULL);
+    }
+
+    result = (struct varlena *) string_input(str, 0, VARHDRSZ, &len);
+    VARSIZE(result) = len;
+
+    return (result);
+}
+
+char *
+c_char16in(char *str)
+{
+    return (string_input(str, 16, 0, NULL));
+}
+#endif
+

contrib/string/string_io.sql

@@ -0,0 +1,111 @@
+
+- - -- load the new functions
+- - --
+load '/home/dz/lib/postgres/string_output.so';
+
+- - -- create function c_textin(opaque)
+- - --   returns text
+- - --   as '/home/dz/lib/postgres/string_output.so' 
+- - --   language 'c';
+
+create function c_charout(opaque)
+  returns int4
+  as '/home/dz/lib/postgres/string_output.so' 
+  language 'c';
+
+create function c_char2out(opaque)
+  returns int4
+  as '/home/dz/lib/postgres/string_output.so' 
+  language 'c';
+
+create function c_char4out(opaque)
+  returns int4
+  as '/home/dz/lib/postgres/string_output.so' 
+  language 'c';
+
+create function c_char8out(opaque)
+  returns int4
+  as '/home/dz/lib/postgres/string_output.so' 
+  language 'c';
+
+create function c_char16out(opaque)
+  returns int4
+  as '/home/dz/lib/postgres/string_output.so' 
+  language 'c';
+
+create function c_textout(opaque)
+  returns int4
+  as '/home/dz/lib/postgres/string_output.so' 
+  language 'c';
+
+create function c_varcharout(opaque)
+  returns int4
+  as '/home/dz/lib/postgres/string_output.so' 
+  language 'c';
+
+- - -- define a function which sets the new output routines for char types
+- - --
+- - --   select c_mode();
+- - --
+create function c_mode()
+  returns text
+  as 'update pg_type set typoutput=''c_charout''    where typname=''char''\;
+      update pg_type set typoutput=''c_char2out''   where typname=''char2''\;
+      update pg_type set typoutput=''c_char4out''   where typname=''char4''\;
+      update pg_type set typoutput=''c_char8out''   where typname=''char8''\;
+      update pg_type set typoutput=''c_char16out''  where typname=''char16''\;
+      update pg_type set typoutput=''c_textout''    where typname=''text''\;
+      update pg_type set typoutput=''c_textout''    where typname=''bytea''\;
+      update pg_type set typoutput=''c_textout''    where typname=''unknown''\;
+      update pg_type set typoutput=''c_textout''    where typname=''SET''\;
+      update pg_type set typoutput=''c_varcharout'' where typname=''varchar''\;
+      update pg_type set typoutput=''c_varcharout'' where typname=''bpchar''\;
+      select ''c_mode''::text'
+  language 'sql';
+
+- - -- define a function which restores the original routines for char types
+- - --
+- - --   select pg_mode();
+- - --
+create function pg_mode()
+  returns text
+  as 'update pg_type set typoutput=''charout''    where typname=''char''\;
+      update pg_type set typoutput=''char2out''   where typname=''char2''\;
+      update pg_type set typoutput=''char4out''   where typname=''char4''\;
+      update pg_type set typoutput=''char8out''   where typname=''char8''\;
+      update pg_type set typoutput=''char16out''  where typname=''char16''\;
+      update pg_type set typoutput=''textout''    where typname=''text''\;
+      update pg_type set typoutput=''textout''    where typname=''bytea''\;
+      update pg_type set typoutput=''textout''    where typname=''unknown''\;
+      update pg_type set typoutput=''textout''    where typname=''SET''\;
+      update pg_type set typoutput=''varcharout'' where typname=''varchar''\;
+      update pg_type set typoutput=''varcharout'' where typname=''bpchar''\;
+      select ''pg_mode''::text'
+  language 'sql';
+
+- - -- or do the changes manually
+- - --
+- - -- update pg_type set typoutput='charout'    where typname='char';
+- - -- update pg_type set typoutput='char2out'   where typname='char2';
+- - -- update pg_type set typoutput='char4out'   where typname='char4';
+- - -- update pg_type set typoutput='char8out'   where typname='char8';
+- - -- update pg_type set typoutput='char16out'  where typname='char16';
+- - -- update pg_type set typoutput='textout'    where typname='text';
+- - -- update pg_type set typoutput='textout'    where typname='bytea';
+- - -- update pg_type set typoutput='textout'    where typname='unknown';
+- - -- update pg_type set typoutput='textout'    where typname='SET';
+- - -- update pg_type set typoutput='varcharout' where typname='varchar';
+- - -- update pg_type set typoutput='varcharout' where typname='bpchar';
+- - --
+- - -- update pg_type set typoutput='c_charout'    where typname='char';
+- - -- update pg_type set typoutput='c_char2out'   where typname='char2';
+- - -- update pg_type set typoutput='c_char4out'   where typname='char4';
+- - -- update pg_type set typoutput='c_char8out'   where typname='char8';
+- - -- update pg_type set typoutput='c_char16out'  where typname='char16';
+- - -- update pg_type set typoutput='c_textout'    where typname='text';
+- - -- update pg_type set typoutput='c_textout'    where typname='bytea';
+- - -- update pg_type set typoutput='c_textout'    where typname='unknown';
+- - -- update pg_type set typoutput='c_textout'    where typname='SET';
+- - -- update pg_type set typoutput='c_varcharout' where typname='varchar';
+- - -- update pg_type set typoutput='c_varcharout' where typname='bpchar';
+

contrib/zap_ltv/README

@@ -0,0 +1,180 @@
+From ccshag@cclabs.missouri.edu  Wed Jul 10 04:27:16 1996
+Received: from realtime.cc.missouri.edu (realtime.cc.missouri.edu [128.206.212.69]) by ki.net (8.7.5/8.7.5) with ESMTP id EAA12722 for <scrappy@ki.net>; Wed, 10 Jul 1996 04:27:13 -0400 (EDT)
+Received: from localhost (ccshag@localhost) by realtime.cc.missouri.edu (8.7.1/8.7.1) with SMTP id DAA00915; Wed, 10 Jul 1996 03:26:42 -0500 (CDT)
+X-Authentication-Warning: realtime.cc.missouri.edu: ccshag owned process doing -bs
+Date: Wed, 10 Jul 1996 03:26:41 -0500 (CDT)
+From: "Paul 'Shag' Walmsley" <ccshag@cclabs.missouri.edu>
+Sender: ccshag@cclabs.missouri.edu
+To: postgres95-hackers@oozoo.vnet.net
+cc: pixel@tiger.coe.missouri.edu, michael.siebenborn@ae3.Hypo.DE,
+        scrappy@ki.net
+Subject: Workaround for database corruption problems [long]
+Message-ID: <Pine.SGI.3.93.960710023021.673B-100000@realtime.cc.missouri.edu>
+X-Disclaimer: The opinions of this writer do not necessarily represent those of the University of Missouri-Columbia.
+MIME-Version: 1.0
+Content-Type: TEXT/PLAIN; charset=US-ASCII
+Status: RO
+X-Status: 
+
+
+I've been poking through the guts of POSTGRES95 in pursuit of the
+previously-mentioned "database corruption" problem, and I think that I
+have some preliminary answers and a workaround for people to play around
+with. 
+
+Specifically, the problem that I'm referring to is manifested by
+pg_log, pg_time, or pg_variable either growing to huge sizes (usually
+128MB) or showing evidence of internal corruption.  Symptoms that appear
+to the user include receiving messages like the following in psql or
+monitor:
+	"WARN:cannot open segment 1 of relation pg_time"
+	"WARN:cannot write block 16384 of pg_log"
+.. which are followed up in a 'postmaster -d 3' debug log by a
+	"NOTICE:AbortTransaction and not in in-progress state"
+
+It's been my experience that this problem is difficult to reproduce on
+demand; I've tried several different ways and haven't succeeded.  (If
+anyone knows how to reliably reproduce this, please E-mail me.)  I was,
+however, able to obtain a database in a corrupted state from one of the
+fellows on campus here running POSTGRES95; and following is something of a
+post-mortem. 
+
+---------- 
+The problem with the database is that after any query, POSTGRES95 attempts
+to generate a huge pg_log file and fails (running out of disk space) with
+a "WARN:cannot write block 16384 of pg_log" message.  The contents of the
+database and its internal structure were reasonably intact - I discovered
+that I was able to execute a single SQL query per-backend, and could
+therefore back the contents of the database up with a COPY command.  (I
+wasn't able to use pg_dump; it failed on its BEGIN TRANSACTION step.) 
+Inspection of data/pg_log, data/pg_variable, and data/pg_time revealed the
+following;
+
+realtime /usr/postgres95 > od -x data/pg_log.old | head
+0000000 0060 2000 2000 2000 f680 0000 ed00 0000
+0000020 e300 0000 dc00 0000 ce00 0000 bc00 0000
+0000040 b140 0000 a740 0000 9dc0 0000 9180 0000
+0000060 8580 0000 7c80 0000 6fc0 0000 6480 0000
+0000100 58c0 0000 4fc0 0000 4640 0000 3a80 0000
+0000120 30c0 0000 23c0 0000 1900 0000 0c40 0000
+0000140 0000 0000 0000 0000 0000 0000 0000 0000
+*
+0000200 8800 0000 0000 0000 0800 0000 0000 0000
+0000220 0800 0000 0000 0000 0800 0000 0000 0000
+
+
+Now, already something is obviously wrong: pg_log shouldn't have any
+values other than 0, 1, 2, 4, 8, a, c, or e for each nybble (see the XID_
+... definitions in src/backend/access/transam.h:35; two of these can be
+stored per nybble.)   
+
+
+realtime /usr/postgres95 > od -x data/pg_variable.old | head
+0000000 0058 2000 2000 2740 f240 0000 e400 0000
+0000020 d780 0000 cac0 0000 b840 0000 a900 0000
+0000040 9f80 0000 9280 0000 8580 0000 78c0 0000
+0000060 6c80 0000 6200 0000 5800 0000 4f80 0000
+0000100 44c0 0000 39c0 0000 2d80 0000 2600 0000
+0000120 1c00 0000 0e00 0000 0000 0000 0000 0000
+0000140 0000 0000 0000 0000 0000 0000 0000 0000
+*
+0000700 0000 01bc 0000 009c 0014 ffff ffff 0000
+0000720 0004 5f0b 0000 0000 0000 0ba3 0000 0c23
+
+
+This is obviously broken too; the only bytes that should be non-zero in
+pg_variable are the first 16 (see src/backend/access/transam.h:99).
+
+
+realtime /usr/postgres95 > od -x data/pg_time.old | head -10
+0000000 0000 0000 0000 0000 0000 0000 0000 0000
+*
+0004000 31c6 09ae 0000 0000 31c6 09b3 31a9 79a6
+0004020 31a9 79a6 31a9 79a8 31a9 79a9 31a9 79a9
+0004040 31a9 79a9 31a9 79aa 31a9 79aa 31a9 79aa
+0004060 31a9 79aa 31a9 79aa 31a9 79ab 31a9 79ab
+0004100 31a9 79ab 31a9 79ac 31a9 79ac 31a9 79ac
+0004120 31a9 79ac 31a9 79ad 31a9 79ad 31a9 79ae
+0004140 31a9 79ae 31a9 79af 31a9 79af 31a9 79af
+0004160 31a9 79b0 31a9 79b0 31a9 79b4 31a9 79b4
+realtime /usr/postgres95 > od -x data/pg_time.old +32b | head -10
+0032000 6665 6520 666f 7220 31c5 cb61 696e 6720
+0032020 6465 7665 6c6f 7065 7273 2062 7579 2061
+0032040 206c 6f77 2d69 6e63 6f6d 6520 6170 6172
+0032060 746d 656e 7420 636f 6d70 6c65 7869 6e20
+0032100 7468 6520 7472 6561 7375 7265 7227 7320
+0032120 7761 7264 2066 726f 6d20 7468 6520 6665
+0032140 6465 7261 6c20 676f 7665 726e 6d65 6e74
+0032160 2066 6f72 2024 313b 2064 6576 656c 6f70
+0032200 6572 7361 6c73 6f20 31c5 cb7c 31be 91a2
+0032220 31be 91a2 31be 91a2 31be 91a2 31be 91a3
+
+The first part of pg_time looked okay -- filled with 4-byte time values
+with the occasional "00 00 00 00" here and there -- but inspection into 
+pg_time's guts revealed some preposterous numbers.
+
+For your comparing pleasure, I include copies of what these files
+_should_ look like -- more or less -- from a newly initdb'd database
+directory:
+
+realtime /usr/postgres95 > od -x data-new-initdb/pg_log
+0000000 0000 0000 0000 0000 0000 0000 0000 0000
+*
+0000200 8aaa aaaa aaaa aaa8 0000 0000 0000 0000
+0000220 0000 0000 0000 0000 0000 0000 0000 0000
+*
+0020000
+realtime /usr/postgres95 > od -x data-new-initdb/pg_variable
+0000000 0000 0000 0000 0222 0000 021e 0000 5120
+0000020 0000 0000 0000 0000 0000 0000 0000 0000
+*
+0020000
+realtime /usr/postgres95 > od -x data-new-initdb/pg_time
+0000000 0000 0000 0000 0000 0000 0000 0000 0000
+*
+0004000 31e3 4fb3 0000 0000 31e3 4fb4 31e3 4fb4
+0004020 31e3 4fb4 31e3 4fb5 31e3 4fb5 31e3 4fb5
+0004040 31e3 4fb6 31e3 4fb6 31e3 4fb6 31e3 4fb6
+0004060 31e3 4fb7 31e3 4fb7 31e3 4fb7 31e3 4fb7
+0004100 31e3 4fb8 31e3 4fb8 31e3 4fb8 31e3 4fb9
+0004120 31e3 4fb9 31e3 4fb9 31e3 4fb9 31e3 4fba
+0004140 31e3 4fba 31e3 4fba 31e3 4fbb 31e3 4fbb
+0004160 31e3 4fbb 31e3 4fbb 31e3 4fbb 0000 0000
+0004200 0000 0000 0000 0000 0000 0000 0000 0000
+*
+0020000
+
+
+What's more, if I view pg_log, pg_variable, and pg_time with a text
+editor, I discover that the corrupted areas contain fragments of tuples
+from the database!  
+----------
+
+
+Since I have been unable to reproduce this problem on demand (and
+therefore have a complete picture of all of the queries executed on the
+database), I've only been able to speculate on the original cause of the
+problem.  One explanation would be some kind of buffer manager bug; or
+perhaps the backend is running low on file descriptors and bollixing
+existing ones?  I intend to continue tracking this down as I have the
+time, but in the interim, I've created a quick Perl script that is
+designed to restore some sense of rationality to the
+pg_{log,time,variable} files.  It's a horribly barbaric way to do this --
+at the very least, it almost certainly breaks time travel, and will
+almost certainly result in duplicate oid problems -- but it restored my
+pathological database here to a sufficiently working state such that I
+could run pg_dump on it and do various other queries with it.  The script
+is included at the bottom of this message.
+
+Anyway, fellow posthackers, assuming that no one raises any red flags
+about this, I'll post it on postgres95@oozoo.vnet.net as a temporary
+stop-gap workaround to allow people to recover their databases when this
+sort of problem occurs. 
+
+I wish I had more time to do this kind of thing.
+
+
+- Paul "Shag" Walmsley <ccshag@cclabs.missouri.edu>
+  "Knowing is not enough." -- Hal Hartley, "Surviving Desire"
+
+

contrib/zap_ltv/zap_ltv.pl

@@ -0,0 +1,93 @@
+#!/bin/perl
+#
+# zap_ltv - attempt to restore a POSTGRES95 database afflicted with 
+#           pg_log, pg_time, or pg_variable corruption to
+#           minimal functionality
+#
+# Paul Walmsley <ccshag@cclabs.missouri.edu>
+#
+# Legalese:
+#
+# In no event shall Paul Walmsley be liable to any party for direct,
+# indirect, special, incidental, or consequential damages, including
+# lost profits, arising from the use of this software, even if Paul Walmsley
+# has been advised of the possibility of such damage.  Paul Walmsley
+# specifically disclaims any warranties, including, but not limited to,
+# the implied warranties of merchantability and fitness for a particular
+# purpose.  The software provided hereunder is on an "as is" basis, 
+# and Paul Walmsley has no obligations to provide maintenance, support,
+# updates, enhancements, or modifications.
+#
+# Thanks, Berkeley ;-)
+ 
+print "This program should only be run if POSTGRES95 is not currently\n";
+print "running on this system.  It should also not be run unless you \n";
+print "are having seemingly unrecoverable problems with your POSTGRES95\n";
+print "database related to pg_log, pg_time, or pg_variable corruption.\n\n";
+print "This program replaces the existing pg_log, pg_time, and pg_variable\n";
+print "files with \"clean\" copies of those files.  This will almost \n";
+print "certainly result in duplicate IDs when any INSERTs are attempted,\n";
+print "and probably has other side-effects as well.  Back up your databases\n"
+print "and re-initdb from scratch after using this!\n\n";
+print "This program will attempt to make a backup of your pg_time,\n";
+print "pg_log, and pg_variable files (to pg_time.backup, pg_log.backup,\n";
+print "and pg_variable.backup, respectively).\n\n";
+print "This program bears no guarantees nor any warranties whatsoever.\n";
+print "View the source for details.\n\n";
+print "Press ENTER to zap your pg_log, pg_time, and pg_variable files:";
+
+$trash=<STDIN>;
+
+$pg_log_data=pack('xxxx@8192',0);
+$pg_time_data=pack('xxxx@8192',0);
+# next_tid, last_tid, and oid are pulled from a fresh initdb 
+$pg_variable_data=pack('xxxxxxCCxxCCxxCC@8192',2,34,2,30,81,32);
+
+if (length($pg_log_data)!=8192) { 
+	die "pg_log_data must be exactly 8192 bytes long";
+}
+if (length($pg_time_data)!=8192) { 
+        die "pg_time_data must be exactly 8192 bytes long";
+}
+if (length($pg_variable_data)!=8192) { 
+        die "pg_variable_data must be exactly 8192 bytes long";
+}
+
+
+if (! -f 'pg_database') {
+	die "This program must be run from your POSTGRES95 data directory.";
+}
+
+system('cp pg_log pg_log.backup');
+open(PG_LOG,'>pg_log');
+binmode(PG_LOG);
+$written=syswrite(PG_LOG,$pg_log_data,8192);
+close(PG_LOG);
+
+if ($written!=8192) {
+	die "pg_log write failed: $!";
+}
+
+$written=0;
+system('cp pg_time pg_time.backup');
+open(PG_TIME,'>pg_time');
+binmode(PG_TIME);
+$written=syswrite(PG_TIME,$pg_time_data,8192);
+close(PG_TIME);
+
+if ($written!=8192) {
+        die "pg_time write failed: $!";
+}
+
+$written=0;
+system('cp pg_variable pg_variable.backup');
+open(PG_VARIABLE,'>pg_variable');
+binmode(PG_VARIABLE);
+$written=syswrite(PG_VARIABLE,$pg_variable_data,8192);
+close(PG_VARIABLE);
+
+if ($written!=8192) {
+        die "pg_variable write failed: $!";
+}
+
+print "Done.\n";