Remove ATPrepSetStatistics

It was once possible to do ALTER TABLE ... SET STATISTICS on system
tables without allow_sytem_table_mods.  This was changed apparently by
accident between PostgreSQL 9.1 and 9.2, but a code comment still
claimed this was possible.  Without that functionality, having a
separate ATPrepSetStatistics() is useless, so use the generic
ATSimplePermissions() instead and move the remaining custom code into
ATExecSetStatistics().

Reviewed-by: Tom Lane <tgl@sss.pgh.pa.us>
Discussion: https://www.postgresql.org/message-id/flat/cc8d2648-a0ec-7a86-13e5-db473484e19e%402ndquadrant.com

diff --git a/src/backend/commands/tablecmds.c b/src/backend/commands/tablecmds.c
index 5440eb90153d10b5081408194d19988df3a66b16..daa80ec4aa0bee57abbf444935146e1f9f13c86f 100644 (file)
--- a/src/backend/commands/tablecmds.c
+++ b/src/backend/commands/tablecmds.c
@@ -386,8 +386,6 @@ static ObjectAddress ATExecAddIdentity(Relation rel, const char *colName,
 static ObjectAddress ATExecSetIdentity(Relation rel, const char *colName,
                                       Node *def, LOCKMODE lockmode);
 static ObjectAddress ATExecDropIdentity(Relation rel, const char *colName, bool missing_ok, LOCKMODE lockmode);
-static void ATPrepSetStatistics(Relation rel, const char *colName, int16 colNum,
-                               Node *newValue, LOCKMODE lockmode);
 static ObjectAddress ATExecSetStatistics(Relation rel, const char *colName, int16 colNum,
                                         Node *newValue, LOCKMODE lockmode);
 static ObjectAddress ATExecSetOptions(Relation rel, const char *colName,
@@ -3948,9 +3946,9 @@ ATPrepCmd(List **wqueue, Relation rel, AlterTableCmd *cmd,
            pass = AT_PASS_COL_ATTRS;
            break;
        case AT_SetStatistics:  /* ALTER COLUMN SET STATISTICS */
+           ATSimplePermissions(rel, ATT_TABLE | ATT_MATVIEW | ATT_INDEX | ATT_PARTITIONED_INDEX | ATT_FOREIGN_TABLE);
            ATSimpleRecursion(wqueue, rel, cmd, recurse, lockmode);
-           /* Performs own permission checks */
-           ATPrepSetStatistics(rel, cmd->name, cmd->num, cmd->def, lockmode);
+           /* No command-specific prep needed */
            pass = AT_PASS_MISC;
            break;
        case AT_SetOptions:     /* ALTER COLUMN SET ( options ) */
@@ -6702,26 +6700,18 @@ ATExecDropIdentity(Relation rel, const char *colName, bool missing_ok, LOCKMODE
 
 /*
  * ALTER TABLE ALTER COLUMN SET STATISTICS
+ *
+ * Return value is the address of the modified column
  */
-static void
-ATPrepSetStatistics(Relation rel, const char *colName, int16 colNum, Node *newValue, LOCKMODE lockmode)
+static ObjectAddress
+ATExecSetStatistics(Relation rel, const char *colName, int16 colNum, Node *newValue, LOCKMODE lockmode)
 {
-   /*
-    * We do our own permission checking because (a) we want to allow SET
-    * STATISTICS on indexes (for expressional index columns), and (b) we want
-    * to allow SET STATISTICS on system catalogs without requiring
-    * allowSystemTableMods to be turned on.
-    */
-   if (rel->rd_rel->relkind != RELKIND_RELATION &&
-       rel->rd_rel->relkind != RELKIND_MATVIEW &&
-       rel->rd_rel->relkind != RELKIND_INDEX &&
-       rel->rd_rel->relkind != RELKIND_PARTITIONED_INDEX &&
-       rel->rd_rel->relkind != RELKIND_FOREIGN_TABLE &&
-       rel->rd_rel->relkind != RELKIND_PARTITIONED_TABLE)
-       ereport(ERROR,
-               (errcode(ERRCODE_WRONG_OBJECT_TYPE),
-                errmsg("\"%s\" is not a table, materialized view, index, or foreign table",
-                       RelationGetRelationName(rel))));
+   int         newtarget;
+   Relation    attrelation;
+   HeapTuple   tuple;
+   Form_pg_attribute attrtuple;
+   AttrNumber  attnum;
+   ObjectAddress address;
 
    /*
     * We allow referencing columns by numbers only for indexes, since table
@@ -6734,25 +6724,6 @@ ATPrepSetStatistics(Relation rel, const char *colName, int16 colNum, Node *newVa
                (errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
                 errmsg("cannot refer to non-index column by number")));
 
-   /* Permissions checks */
-   if (!pg_class_ownercheck(RelationGetRelid(rel), GetUserId()))
-       aclcheck_error(ACLCHECK_NOT_OWNER, get_relkind_objtype(rel->rd_rel->relkind),
-                      RelationGetRelationName(rel));
-}
-
-/*
- * Return value is the address of the modified column
- */
-static ObjectAddress
-ATExecSetStatistics(Relation rel, const char *colName, int16 colNum, Node *newValue, LOCKMODE lockmode)
-{
-   int         newtarget;
-   Relation    attrelation;
-   HeapTuple   tuple;
-   Form_pg_attribute attrtuple;
-   AttrNumber  attnum;
-   ObjectAddress address;
-
    Assert(IsA(newValue, Integer));
    newtarget = intVal(newValue);