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);