diff options
| -rw-r--r-- | src/include/catalog/pg_attribute.h | 10 |
1 files changed, 7 insertions, 3 deletions
diff --git a/src/include/catalog/pg_attribute.h b/src/include/catalog/pg_attribute.h index 1bd42a8410f..391d5687730 100644 --- 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; |