Disallow modifying statistics on system columns.

Reported-by: Heikki Linnakangas
Discussion: https://postgr.es/m/df3e1c41-4e6c-40ad-9636-98deefe488cd@iki.fi

diff --git a/src/backend/statistics/attribute_stats.c b/src/backend/statistics/attribute_stats.c
index 686f2e639c66adb9d6bae69ac148134eec7d5adc..b97ba7b0c0c062fa8bfe725e310a8ab15bcfe272 100644 (file)
--- a/src/backend/statistics/attribute_stats.c
+++ b/src/backend/statistics/attribute_stats.c
@@ -167,6 +167,13 @@ attribute_statistics_update(FunctionCallInfo fcinfo, int elevel)
    stats_check_required_arg(fcinfo, attarginfo, ATTNAME_ARG);
    attname = PG_GETARG_NAME(ATTNAME_ARG);
    attnum = get_attnum(reloid, NameStr(*attname));
+
+   if (attnum < 0)
+       ereport(ERROR,
+               (errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
+                errmsg("cannot modify statistics on system column \"%s\"",
+                       NameStr(*attname))));
+
    if (attnum == InvalidAttrNumber)
        ereport(ERROR,
                (errcode(ERRCODE_UNDEFINED_COLUMN),
@@ -882,6 +889,13 @@ pg_clear_attribute_stats(PG_FUNCTION_ARGS)
    stats_check_required_arg(fcinfo, attarginfo, ATTNAME_ARG);
    attname = PG_GETARG_NAME(ATTNAME_ARG);
    attnum = get_attnum(reloid, NameStr(*attname));
+
+   if (attnum < 0)
+       ereport(ERROR,
+               (errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
+                errmsg("cannot clear statistics on system column \"%s\"",
+                       NameStr(*attname))));
+
    if (attnum == InvalidAttrNumber)
        ereport(ERROR,
                (errcode(ERRCODE_UNDEFINED_COLUMN),

diff --git a/src/test/regress/expected/stats_import.out b/src/test/regress/expected/stats_import.out
index 9186fc01ecc46321483e4b86c34f761435dc4669..aab862c97c717ebbeaf10e68ad8891082ec51680 100644 (file)
--- a/src/test/regress/expected/stats_import.out
+++ b/src/test/regress/expected/stats_import.out
@@ -195,6 +195,15 @@ SELECT pg_catalog.pg_set_attribute_stats(
     avg_width => 2::integer,
     n_distinct => 0.3::real);
 ERROR:  "relation" cannot be NULL
+-- error: attribute is system column
+SELECT pg_catalog.pg_set_attribute_stats(
+    relation => 'stats_import.test'::regclass,
+    attname => 'xmin'::name,
+    inherited => false::boolean,
+    null_frac => 0.1::real,
+    avg_width => 2::integer,
+    n_distinct => 0.3::real);
+ERROR:  cannot modify statistics on system column "xmin"
 -- error: attname doesn't exist
 SELECT pg_catalog.pg_set_attribute_stats(
     relation => 'stats_import.test'::regclass,
@@ -204,6 +213,12 @@ SELECT pg_catalog.pg_set_attribute_stats(
     avg_width => 2::integer,
     n_distinct => 0.3::real);
 ERROR:  column "nope" of relation "test" does not exist
+-- error: attribute is system column
+SELECT pg_catalog.pg_clear_attribute_stats(
+    relation => 'stats_import.test'::regclass,
+    attname => 'ctid'::name,
+    inherited => false::boolean);
+ERROR:  cannot clear statistics on system column "ctid"
 -- error: attname doesn't exist
 SELECT pg_catalog.pg_clear_attribute_stats(
     relation => 'stats_import.test'::regclass,

diff --git a/src/test/regress/sql/stats_import.sql b/src/test/regress/sql/stats_import.sql
index c7d5e017d9004d7b30e529f5a5962c93f39d6027..31455b58c1dac7f3b254ec2e87b2e73af6d00c43 100644 (file)
--- a/src/test/regress/sql/stats_import.sql
+++ b/src/test/regress/sql/stats_import.sql
@@ -145,6 +145,15 @@ SELECT pg_catalog.pg_set_attribute_stats(
     avg_width => 2::integer,
     n_distinct => 0.3::real);
 
+-- error: attribute is system column
+SELECT pg_catalog.pg_set_attribute_stats(
+    relation => 'stats_import.test'::regclass,
+    attname => 'xmin'::name,
+    inherited => false::boolean,
+    null_frac => 0.1::real,
+    avg_width => 2::integer,
+    n_distinct => 0.3::real);
+
 -- error: attname doesn't exist
 SELECT pg_catalog.pg_set_attribute_stats(
     relation => 'stats_import.test'::regclass,
@@ -154,6 +163,12 @@ SELECT pg_catalog.pg_set_attribute_stats(
     avg_width => 2::integer,
     n_distinct => 0.3::real);
 
+-- error: attribute is system column
+SELECT pg_catalog.pg_clear_attribute_stats(
+    relation => 'stats_import.test'::regclass,
+    attname => 'ctid'::name,
+    inherited => false::boolean);
+
 -- error: attname doesn't exist
 SELECT pg_catalog.pg_clear_attribute_stats(
     relation => 'stats_import.test'::regclass,