src/backend/catalog/pg_namespace.c

   1 /*-------------------------------------------------------------------------
   2  *
   3  * pg_namespace.c
   4  *        routines to support manipulation of the pg_namespace relation
   5  *
   6  * Portions Copyright (c) 1996-2020, PostgreSQL Global Development Group
   7  * Portions Copyright (c) 1994, Regents of the University of California
   8  *
   9  *
  10  * IDENTIFICATION
  11  *        src/backend/catalog/pg_namespace.c
  12  *
  13  *-------------------------------------------------------------------------
  14  */
  15 #include "postgres.h"
  16
  17 #include "access/htup_details.h"
  18 #include "access/table.h"
  19 #include "catalog/catalog.h"
  20 #include "catalog/dependency.h"
  21 #include "catalog/indexing.h"
  22 #include "catalog/objectaccess.h"
  23 #include "catalog/pg_namespace.h"
  24 #include "utils/builtins.h"
  25 #include "utils/rel.h"
  26 #include "utils/syscache.h"
  27
  28
  29 /* ----------------
  30  * NamespaceCreate
  31  *
  32  * Create a namespace (schema) with the given name and owner OID.
  33  *
  34  * If isTemp is true, this schema is a per-backend schema for holding
  35  * temporary tables.  Currently, it is used to prevent it from being
  36  * linked as a member of any active extension.  (If someone does CREATE
  37  * TEMP TABLE in an extension script, we don't want the temp schema to
  38  * become part of the extension). And to avoid checking for default ACL
  39  * for temp namespace (as it is not necessary).
  40  * ---------------
  41  */
  42 Oid
  43 NamespaceCreate(const char *nspName, Oid ownerId, bool isTemp)
  44 {
  45         Relation        nspdesc;
  46         HeapTuple       tup;
  47         Oid                     nspoid;
  48         bool            nulls[Natts_pg_namespace];
  49         Datum           values[Natts_pg_namespace];
  50         NameData        nname;
  51         TupleDesc       tupDesc;
  52         ObjectAddress myself;
  53         int                     i;
  54         Acl                *nspacl;
  55
  56         /* sanity checks */
  57         if (!nspName)
  58                 elog(ERROR, "no namespace name supplied");
  59
  60         /* make sure there is no existing namespace of same name */
  61         if (SearchSysCacheExists1(NAMESPACENAME, PointerGetDatum(nspName)))
  62                 ereport(ERROR,
  63                                 (errcode(ERRCODE_DUPLICATE_SCHEMA),
  64                                  errmsg("schema \"%s\" already exists", nspName)));
  65
  66         if (!isTemp)
  67                 nspacl = get_user_default_acl(OBJECT_SCHEMA, ownerId,
  68                                                                           InvalidOid);
  69         else
  70                 nspacl = NULL;
  71
  72         nspdesc = table_open(NamespaceRelationId, RowExclusiveLock);
  73         tupDesc = nspdesc->rd_att;
  74
  75         /* initialize nulls and values */
  76         for (i = 0; i < Natts_pg_namespace; i++)
  77         {
  78                 nulls[i] = false;
  79                 values[i] = (Datum) NULL;
  80         }
  81
  82         nspoid = GetNewOidWithIndex(nspdesc, NamespaceOidIndexId,
  83                                                                 Anum_pg_namespace_oid);
  84         values[Anum_pg_namespace_oid - 1] = ObjectIdGetDatum(nspoid);
  85         namestrcpy(&nname, nspName);
  86         values[Anum_pg_namespace_nspname - 1] = NameGetDatum(&nname);
  87         values[Anum_pg_namespace_nspowner - 1] = ObjectIdGetDatum(ownerId);
  88         if (nspacl != NULL)
  89                 values[Anum_pg_namespace_nspacl - 1] = PointerGetDatum(nspacl);
  90         else
  91                 nulls[Anum_pg_namespace_nspacl - 1] = true;
  92
  93
  94         tup = heap_form_tuple(tupDesc, values, nulls);
  95
  96         CatalogTupleInsert(nspdesc, tup);
  97         Assert(OidIsValid(nspoid));
  98
  99         table_close(nspdesc, RowExclusiveLock);
 100
 101         /* Record dependencies */
 102         myself.classId = NamespaceRelationId;
 103         myself.objectId = nspoid;
 104         myself.objectSubId = 0;
 105
 106         /* dependency on owner */
 107         recordDependencyOnOwner(NamespaceRelationId, nspoid, ownerId);
 108
 109         /* dependences on roles mentioned in default ACL */
 110         recordDependencyOnNewAcl(NamespaceRelationId, nspoid, 0, ownerId, nspacl);
 111
 112         /* dependency on extension ... but not for magic temp schemas */
 113         if (!isTemp)
 114                 recordDependencyOnCurrentExtension(&myself, false);
 115
 116         /* Post creation hook for new schema */
 117         InvokeObjectPostCreateHook(NamespaceRelationId, nspoid, 0);
 118
 119         return nspoid;
 120 }