Again update C comments for pg_attribute.attislocal

diff --git a/src/include/catalog/pg_attribute.h b/src/include/catalog/pg_attribute.h
index 1bd42a8410fca60cf3a66539ff62076f6e4df322..391d5687730d59f16b7212f95c13c0ebdaba7f18 100644 (file)
--- a/src/include/catalog/pg_attribute.h
+++ b/src/include/catalog/pg_attribute.h
@@ -137,9 +137,13 @@ CATALOG(pg_attribute,1249) BKI_BOOTSTRAP BKI_WITHOUT_OIDS BKI_ROWTYPE_OID(75) BK
        bool            attisdropped;
 
        /*
-        * Has a local definition (hence, do not drop when attinhcount is 0)
-        * This is set and remains set if the column was _ever_
-        * local/not-inherited, e.g. this can be set by ALTER TABLE NO INHERIT.
+        * This flag specifies whether this column has ever had a local
+        * definition.  It is set for normal non-inherited columns, but also
+        * for columns that are inherited from parents if also explicitly listed
+        * in CREATE TABLE INHERITS.  It is also set when inheritance is removed
+        * from a table with ALTER TABLE NO INHERIT.  If the flag is set, the
+        * column is not dropped by a parent's DROP COLUMN even if this causes
+        * the column's attinhcount to become zero.
         */
        bool            attislocal;