I've written on like that a while ago:

http://webmail.postgresql.org/~petere/dbsize.html

The tarball can be rolled into contrib -- now that I think of it I don't
know why I never did that.

Never imagined this would have anything to do with that TODO item,
though.
I figured oid2name accomplished that.

Peter Eisentraut   peter_e@gmx.net

diff --git a/contrib/Makefile b/contrib/Makefile
index f31f604ed333578599be803d7d0eb3a41cabcfb0..fc265216e11935681a37ba3ea41cec3864197b78 100644 (file)
--- a/contrib/Makefile
+++ b/contrib/Makefile
@@ -1,4 +1,4 @@
-# $Header: /cvsroot/pgsql/contrib/Makefile,v 1.30 2001/10/12 23:19:09 tgl Exp $
+# $Header: /cvsroot/pgsql/contrib/Makefile,v 1.31 2002/02/22 23:05:34 momjian Exp $
 
 subdir = contrib
 top_builddir = ..
@@ -11,6 +11,7 @@ WANTED_DIRS = \
        cube        \
        dbase       \
        dblink      \
+       dbsize      \
        earthdistance   \
        findoidjoins    \
        fulltextindex   \

diff --git a/contrib/README b/contrib/README
index c5ff55c2f10b5d173357428abff74eca653bc5d1..ec9c04d3c3dff799a99a89c2da5748bae75202f0 100644 (file)
--- a/contrib/README
+++ b/contrib/README
@@ -48,7 +48,11 @@ dbase -
 
 dblink -
    Allows remote query execution
-   by  Joe Conway, joe.conway@mail.com
+   by  Joe Conway <joe.conway@mail.com>
+
+dbsize -
+   Reports database and table disk space
+   by Peter Eisentraut <peter_e@gmx.net>
 
 earthdistance -
    Operator for computing earth distance for two points

diff --git a/contrib/dbsize/Makefile b/contrib/dbsize/Makefile
new file mode 100644 (file)
index 0000000..ad72a12
--- /dev/null
+++ b/contrib/dbsize/Makefile
@@ -0,0 +1,9 @@
+subdir = contrib/dbsize
+top_builddir = ../..
+include $(top_builddir)/src/Makefile.global
+
+MODULES = dbsize
+DATA_built = dbsize.sql
+DOCS = README.dbsize
+
+include $(top_srcdir)/contrib/contrib-global.mk

diff --git a/contrib/dbsize/README.dbsize b/contrib/dbsize/README.dbsize
new file mode 100644 (file)
index 0000000..879341c
--- /dev/null
+++ b/contrib/dbsize/README.dbsize
@@ -0,0 +1,11 @@
+This module contains two functions that report the size of a given
+database or relation.  E.g.,
+
+SELECT database_size('template1');
+SELECT relation_size('pg_class');
+
+These functions report the actual file system space.  Thus, users can
+avoid digging through the details of the database directories.
+
+Copy this directory to contrib/dbsize in your PostgreSQL source tree.
+Then just run make; make install.

diff --git a/contrib/dbsize/dbsize.c b/contrib/dbsize/dbsize.c
new file mode 100644 (file)
index 0000000..597b307
--- /dev/null
+++ b/contrib/dbsize/dbsize.c
@@ -0,0 +1,169 @@
+#include "postgres.h"
+#include "fmgr.h"
+
+#include "access/heapam.h"
+#include "catalog/catalog.h"
+#include "catalog/catname.h"
+#include "catalog/pg_database.h"
+#include "utils/fmgroids.h"
+
+#include <stdlib.h>
+#include <sys/types.h>
+#include <dirent.h>
+#include <sys/stat.h>
+#include <unistd.h>
+#include <errno.h>
+
+
+static char *
+psnprintf(size_t len, const char *fmt,...)
+{
+   va_list     ap;
+   char       *buf;
+
+   buf = palloc(len);
+
+   va_start(ap, fmt);
+   vsnprintf(buf, len, fmt, ap);
+   va_end(ap);
+
+   return buf;
+}
+
+
+
+/*
+ * SQL function: database_size(name) returns bigint
+ */
+
+PG_FUNCTION_INFO_V1(database_size);
+
+Datum
+database_size(PG_FUNCTION_ARGS)
+{
+   Name        dbname = PG_GETARG_NAME(0);
+
+   HeapTuple   tuple;
+   Relation    relation;
+   ScanKeyData scanKey;
+   HeapScanDesc scan;
+   Oid         dbid;
+   char       *dbpath;
+   DIR        *dirdesc;
+   struct dirent *direntry;
+   int64       totalsize;
+
+   relation = heap_openr(DatabaseRelationName, AccessShareLock);
+   ScanKeyEntryInitialize(&scanKey, 0, Anum_pg_database_datname,
+                          F_NAMEEQ, NameGetDatum(dbname));
+   scan = heap_beginscan(relation, 0, SnapshotNow, 1, &scanKey);
+   tuple = heap_getnext(scan, 0);
+
+   if (!HeapTupleIsValid(tuple))
+       elog(ERROR, "database %s does not exist", NameStr(*dbname));
+
+   dbid = tuple->t_data->t_oid;
+   if (dbid == InvalidOid)
+       elog(ERROR, "invalid database id");
+
+   heap_endscan(scan);
+   heap_close(relation, NoLock);
+
+   dbpath = GetDatabasePath(dbid);
+
+   dirdesc = opendir(dbpath);
+   if (!dirdesc)
+       elog(ERROR, "could not open directory %s: %s", dbpath, strerror(errno));
+
+   totalsize = 0;
+   for (;;)
+   {
+       char       *fullname;
+       struct stat statbuf;
+
+       errno = 0;
+       direntry = readdir(dirdesc);
+       if (!direntry)
+       {
+           if (errno)
+               elog(ERROR, "error reading directory: %s", strerror(errno));
+           else
+               break;
+       }
+
+       fullname = psnprintf(strlen(dbpath) + 1 + strlen(direntry->d_name) + 1,
+                            "%s/%s", dbpath, direntry->d_name);
+       if (stat(fullname, &statbuf) == -1)
+           elog(ERROR, "could not stat %s: %s", fullname, strerror(errno));
+       totalsize += statbuf.st_size;
+       pfree(fullname);
+   }
+
+   closedir(dirdesc);
+
+   PG_RETURN_INT64(totalsize);
+}
+
+
+
+/*
+ * SQL function: relation_size(name) returns bigint
+ */
+
+PG_FUNCTION_INFO_V1(relation_size);
+
+Datum
+relation_size(PG_FUNCTION_ARGS)
+{
+   Name        relname = PG_GETARG_NAME(0);
+
+   HeapTuple   tuple;
+   Relation    relation;
+   ScanKeyData scanKey;
+   HeapScanDesc scan;
+   Oid         relnode;
+   int64       totalsize;
+   unsigned int segcount;
+
+   relation = heap_openr(RelationRelationName, AccessShareLock);
+   ScanKeyEntryInitialize(&scanKey, 0, Anum_pg_class_relname,
+                          F_NAMEEQ, NameGetDatum(relname));
+   scan = heap_beginscan(relation, 0, SnapshotNow, 1, &scanKey);
+   tuple = heap_getnext(scan, 0);
+
+   if (!HeapTupleIsValid(tuple))
+       elog(ERROR, "relation %s does not exist", NameStr(*relname));
+
+   relnode = ((Form_pg_class) GETSTRUCT(tuple))->relfilenode;
+   if (relnode == InvalidOid)
+       elog(ERROR, "invalid relation node id");
+
+   heap_endscan(scan);
+   heap_close(relation, NoLock);
+
+   totalsize = 0;
+   segcount = 0;
+   for (;;)
+   {
+       char       *fullname;
+       struct stat statbuf;
+
+       if (segcount == 0)
+           fullname = psnprintf(25, "%u", (unsigned) relnode);
+       else
+           fullname = psnprintf(50, "%u.%u", (unsigned) relnode, segcount);
+
+       if (stat(fullname, &statbuf) == -1)
+       {
+           if (errno == ENOENT)
+               break;
+           else
+               elog(ERROR, "could not stat %s: %s", fullname, strerror(errno));
+       }
+       totalsize += statbuf.st_size;
+       pfree(fullname);
+       segcount++;
+   }
+
+   PG_RETURN_INT64(totalsize);
+}

diff --git a/contrib/dbsize/dbsize.sql.in b/contrib/dbsize/dbsize.sql.in
new file mode 100644 (file)
index 0000000..d4d4d32
--- /dev/null
+++ b/contrib/dbsize/dbsize.sql.in
@@ -0,0 +1,7 @@
+CREATE FUNCTION database_size (name) RETURNS bigint
+    AS '@MODULE_FILENAME@', 'database_size'
+    LANGUAGE C WITH (isstrict);
+
+CREATE FUNCTION relation_size (name) RETURNS bigint
+    AS '@MODULE_FILENAME@', 'relation_size'
+    LANGUAGE C WITH (isstrict);