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+/*-------------------------------------------------------------------------
+ *
+ * pg_description.h
+ * definition of the "description" system catalog (pg_description)
+ *
+ * Because the contents of this table are taken from the *.dat files
+ * of other catalogs, there is no pg_description.dat file. The initial
+ * contents are assembled by genbki.pl and loaded during initdb.
+ *
+ * NOTE: an object is identified by the OID of the row that primarily
+ * defines the object, plus the OID of the table that that row appears in.
+ * For example, a function is identified by the OID of its pg_proc row
+ * plus the pg_class OID of table pg_proc. This allows unique identification
+ * of objects without assuming that OIDs are unique across tables.
+ *
+ * Since attributes don't have OIDs of their own, we identify an attribute
+ * comment by the objoid+classoid of its parent table, plus an "objsubid"
+ * giving the attribute column number. "objsubid" must be zero in a comment
+ * for a table itself, so that it is distinct from any column comment.
+ * Currently, objsubid is unused and zero for all other kinds of objects,
+ * but perhaps it might be useful someday to associate comments with
+ * constituent elements of other kinds of objects (arguments of a function,
+ * for example).
+ *
+ *
+ * Portions Copyright (c) 1996-2020, PostgreSQL Global Development Group
+ * Portions Copyright (c) 1994, Regents of the University of California
+ *
+ * src/include/catalog/pg_description.h
+ *
+ * NOTES
+ * The Catalog.pm module reads this file and derives schema
+ * information.
+ *
+ *-------------------------------------------------------------------------
+ */
+#ifndef PG_DESCRIPTION_H
+#define PG_DESCRIPTION_H
+
+#include "catalog/genbki.h"
+#include "catalog/pg_description_d.h"
+
+/* ----------------
+ * pg_description definition. cpp turns this into
+ * typedef struct FormData_pg_description
+ * ----------------
+ */
+CATALOG(pg_description,2609,DescriptionRelationId)
+{
+ Oid objoid; /* OID of object itself */
+ Oid classoid; /* OID of table containing object */
+ int32 objsubid; /* column number, or 0 if not used */
+
+#ifdef CATALOG_VARLEN /* variable-length fields start here */
+ text description BKI_FORCE_NOT_NULL; /* description of object */
+#endif
+} FormData_pg_description;
+
+/* ----------------
+ * Form_pg_description corresponds to a pointer to a tuple with
+ * the format of pg_description relation.
+ * ----------------
+ */
+typedef FormData_pg_description * Form_pg_description;
+
+#endif /* PG_DESCRIPTION_H */