Andreas Pflug wrote:

 From an idea of Bruce, the attached patch implements the function
 pg_tablespace_databases(oid) RETURNS SETOF oid
 which delivers as set of database oids having objects in the selected
 tablespace, enabling an admin to examine only the databases affecting
 the tablespace for objects instead of scanning all of them.

initdb forced

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 3c23f43a59f19bfb70bf75e9c104f1ee51933669..8a624614e8d196b0dc9730c9fa31f35c3f8ccfe8 100644 (file)
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -1,5 +1,5 @@
 
 
@@ -7232,6 +7232,10 @@ SELECT pg_type_is_visible('myschema.widget'::regtype);
     pg_get_serial_sequence
    
 
+   
+    pg_tablespace_databases
+   
+
   
     lists functions that
    extract information from the system catalogs.
@@ -7325,6 +7329,11 @@ SELECT pg_type_is_visible('myschema.widget'::regtype);
        get name of the sequence that a serial or bigserial column
        uses
       
+      
+       pg_tablespace_databases(tablespace_oid)
+       setof oid
+       get set of database oids that have objects in the tablespace
+      
      
     
    
@@ -7362,6 +7371,16 @@ SELECT pg_type_is_visible('myschema.widget'::regtype);
    NULL is returned if the column does not have a sequence attached.
   
 
+  
+  pg_tablespace_databases allows usage examination of a
+  tablespace. It will return a set of database oids, that have objects
+  stored in the tablespace. If this function returns any row, the
+  tablespace is assumed not to be empty and cannot be dropped. To
+  display the actual objects populating the tablespace, you will need
+  to connect to the databases returned by 
+  pg_tablespace_databases to query pg_class.
+  
+
    
     obj_description
    

diff --git a/src/backend/commands/tablespace.c b/src/backend/commands/tablespace.c
index 847985456f7007ea2f91064646c3318fefeafd7e..875fb1cae8a8a57dc0fcad827cc9f187b9c5ba52 100644 (file)
--- a/src/backend/commands/tablespace.c
+++ b/src/backend/commands/tablespace.c
@@ -45,7 +45,7 @@
  *
  *
  * IDENTIFICATION
- *   $PostgreSQL: pgsql/src/backend/commands/tablespace.c,v 1.4 2004/06/25 21:55:53 tgl Exp $
+ *   $PostgreSQL: pgsql/src/backend/commands/tablespace.c,v 1.5 2004/07/02 18:59:22 joe Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -315,7 +315,7 @@ CreateTableSpace(CreateTableSpaceStmt *stmt)
    /*
     * All seems well, create the symlink
     */
-   linkloc = (char *) palloc(strlen(DataDir) + 16 + 10 + 1);
+   linkloc = (char *) palloc(strlen(DataDir) + 11 + 10 + 1);
    sprintf(linkloc, "%s/pg_tblspc/%u", DataDir, tablespaceoid);
 
    if (symlink(location, linkloc) < 0)

diff --git a/src/backend/utils/adt/misc.c b/src/backend/utils/adt/misc.c
index 8ab6953cb02c151148a9fabc449b0b9c157128b9..0cc315c6205e2d8717c93716e702146e65646ecc 100644 (file)
--- a/src/backend/utils/adt/misc.c
+++ b/src/backend/utils/adt/misc.c
@@ -8,7 +8,7 @@
  *
  *
  * IDENTIFICATION
- *   $PostgreSQL: pgsql/src/backend/utils/adt/misc.c,v 1.34 2004/06/02 21:29:29 momjian Exp $
+ *   $PostgreSQL: pgsql/src/backend/utils/adt/misc.c,v 1.35 2004/07/02 18:59:22 joe Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -16,11 +16,16 @@
 
 #include 
 #include 
+#include 
 
 #include "commands/dbcommands.h"
 #include "miscadmin.h"
 #include "storage/sinval.h"
+#include "storage/fd.h"
 #include "utils/builtins.h"
+#include "funcapi.h"
+#include "catalog/pg_type.h"
+#include "catalog/pg_tablespace.h"
 
 
 /*
@@ -103,3 +108,97 @@ pg_cancel_backend(PG_FUNCTION_ARGS)
 {
    PG_RETURN_INT32(pg_signal_backend(PG_GETARG_INT32(0),SIGINT));
 }
+
+
+typedef struct 
+{
+   char *location;
+   DIR *dirdesc;
+} ts_db_fctx;
+
+Datum pg_tablespace_databases(PG_FUNCTION_ARGS)
+{
+   FuncCallContext *funcctx;
+   struct dirent *de;
+   ts_db_fctx *fctx;
+
+   if (SRF_IS_FIRSTCALL())
+   {
+       MemoryContext oldcontext;
+       Oid tablespaceOid=PG_GETARG_OID(0);
+
+       funcctx=SRF_FIRSTCALL_INIT();
+       oldcontext = MemoryContextSwitchTo(funcctx->multi_call_memory_ctx);
+
+       fctx = palloc(sizeof(ts_db_fctx));
+
+       /*
+        * size = path length + tablespace dirname length
+        *        + 2 dir sep chars + oid + terminator
+        */
+       fctx->location = (char*) palloc(strlen(DataDir) + 11 + 10 + 1);
+       if (tablespaceOid == GLOBALTABLESPACE_OID)
+       {
+           fctx->dirdesc = NULL;
+           ereport(NOTICE,
+                   (errcode(ERRCODE_WARNING),
+                    errmsg("global tablespace never has databases.")));
+       }
+       else
+       {
+           if (tablespaceOid == DEFAULTTABLESPACE_OID)
+               sprintf(fctx->location, "%s/base", DataDir);
+           else
+               sprintf(fctx->location, "%s/pg_tblspc/%u", DataDir,
+                                                          tablespaceOid);
+       
+           fctx->dirdesc = AllocateDir(fctx->location);
+
+           if (!fctx->dirdesc)  /* not a tablespace */
+               ereport(NOTICE,
+                       (errcode(ERRCODE_WARNING),
+                        errmsg("%d is no tablespace oid.", tablespaceOid)));
+       }
+       funcctx->user_fctx = fctx;
+       MemoryContextSwitchTo(oldcontext);
+   }
+
+   funcctx=SRF_PERCALL_SETUP();
+   fctx = (ts_db_fctx*) funcctx->user_fctx;
+
+   if (!fctx->dirdesc)  /* not a tablespace */
+       SRF_RETURN_DONE(funcctx);
+
+   while ((de = readdir(fctx->dirdesc)) != NULL)
+   {
+       char *subdir;
+       DIR *dirdesc;
+
+       Oid datOid = atol(de->d_name);
+       if (!datOid)
+           continue;
+
+       /* size = path length + dir sep char + file name + terminator */
+       subdir = palloc(strlen(fctx->location) + 1 + strlen(de->d_name) + 1);
+       sprintf(subdir, "%s/%s", fctx->location, de->d_name);
+       dirdesc = AllocateDir(subdir);
+       if (dirdesc)
+       {
+           while ((de = readdir(dirdesc)) != 0)
+           {
+               if (strcmp(de->d_name, ".") && strcmp(de->d_name, ".."))
+                   break;
+           }
+           pfree(subdir);
+           FreeDir(dirdesc);
+
+           if (!de)   /* database subdir is empty; don't report tablespace as used */
+               continue;
+       }
+
+       SRF_RETURN_NEXT(funcctx, ObjectIdGetDatum(datOid));
+   }
+
+   FreeDir(fctx->dirdesc);
+   SRF_RETURN_DONE(funcctx);
+}

diff --git a/src/include/catalog/catversion.h b/src/include/catalog/catversion.h
index b6f98778628edc1fb971e5533fa89d2ba78b65d9..98e554e759992b7892526c4cc9c7c60cb7939a02 100644 (file)
--- a/src/include/catalog/catversion.h
+++ b/src/include/catalog/catversion.h
@@ -37,7 +37,7 @@
  * Portions Copyright (c) 1996-2003, PostgreSQL Global Development Group
  * Portions Copyright (c) 1994, Regents of the University of California
  *
- * $PostgreSQL: pgsql/src/include/catalog/catversion.h,v 1.241 2004/07/01 00:51:39 tgl Exp $
+ * $PostgreSQL: pgsql/src/include/catalog/catversion.h,v 1.242 2004/07/02 18:59:24 joe Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -53,6 +53,6 @@
  */
 
 /*                         yyyymmddN */
-#define CATALOG_VERSION_NO 200406261
+#define CATALOG_VERSION_NO 200407021
 
 #endif

diff --git a/src/include/catalog/pg_proc.h b/src/include/catalog/pg_proc.h
index 489fa9ca9baa5a5c250c65b681bab154364fb4bc..8d2485c168d5393379ae9f3c8bf283b5cea38f30 100644 (file)
--- a/src/include/catalog/pg_proc.h
+++ b/src/include/catalog/pg_proc.h
@@ -7,7 +7,7 @@
  * Portions Copyright (c) 1996-2003, PostgreSQL Global Development Group
  * Portions Copyright (c) 1994, Regents of the University of California
  *
- * $PostgreSQL: pgsql/src/include/catalog/pg_proc.h,v 1.339 2004/06/25 17:20:28 tgl Exp $
+ * $PostgreSQL: pgsql/src/include/catalog/pg_proc.h,v 1.340 2004/07/02 18:59:24 joe Exp $
  *
  * NOTES
  *   The script catalog/genbki.sh reads this file and generates .bki
@@ -3595,6 +3595,9 @@ DESCR("bitwise-and bit aggregate");
 DATA(insert OID = 2243 ( bit_or                           PGNSP PGUID 12 t f f f i 1 1560 "1560" _null_ aggregate_dummy - _null_));
 DESCR("bitwise-or bit aggregate");
 
+DATA(insert OID = 2554(  pg_tablespace_databases       PGNSP PGUID 12 f f t t s 1 26 "26" _null_ pg_tablespace_databases - _null_));
+DESCR("returns database oids in a tablespace");
+
 /*
  * Symbolic values for provolatile column: these indicate whether the result
  * of a function is dependent *only* on the values of its explicit arguments,

diff --git a/src/include/utils/builtins.h b/src/include/utils/builtins.h
index 99974cdec126497952244e71e125c0b3f720576d..c18ad551e485a988f883aa52f583196a6b586493 100644 (file)
--- a/src/include/utils/builtins.h
+++ b/src/include/utils/builtins.h
@@ -7,7 +7,7 @@
  * Portions Copyright (c) 1996-2003, PostgreSQL Global Development Group
  * Portions Copyright (c) 1994, Regents of the University of California
  *
- * $PostgreSQL: pgsql/src/include/utils/builtins.h,v 1.244 2004/06/25 17:20:29 tgl Exp $
+ * $PostgreSQL: pgsql/src/include/utils/builtins.h,v 1.245 2004/07/02 18:59:25 joe Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -356,6 +356,7 @@ extern Datum nonnullvalue(PG_FUNCTION_ARGS);
 extern Datum current_database(PG_FUNCTION_ARGS);
 extern Datum pg_terminate_backend(PG_FUNCTION_ARGS);
 extern Datum pg_cancel_backend(PG_FUNCTION_ARGS);
+extern Datum pg_tablespace_databases(PG_FUNCTION_ARGS);
 
 /* not_in.c */
 extern Datum int4notin(PG_FUNCTION_ARGS);