pg_type.h

PostgreSQL 8.1.4的源码 适用于Linux下的开源数据库系统

/*-------------------------------------------------------------------------
 *
 * pg_type.h
 *	  definition of the system "type" relation (pg_type)
 *	  along with the relation's initial contents.
 *
 *
 * Portions Copyright (c) 1996-2005, PostgreSQL Global Development Group
 * Portions Copyright (c) 1994, Regents of the University of California
 *
 * $PostgreSQL: pgsql/src/include/catalog/pg_type.h,v 1.166.2.1 2005/11/22 18:23:27 momjian Exp $
 *
 * NOTES
 *	  the genbki.sh script reads this file and generates .bki
 *	  information from the DATA() statements.
 *
 *-------------------------------------------------------------------------
 */
#ifndef PG_TYPE_H
#define PG_TYPE_H

#include "nodes/nodes.h"

/* ----------------
 *		postgres.h contains the system type definitions and the
 *		CATALOG(), BKI_BOOTSTRAP and DATA() sugar words so this file
 *		can be read by both genbki.sh and the C compiler.
 * ----------------
 */

/* ----------------
 *		pg_type definition.  cpp turns this into
 *		typedef struct FormData_pg_type
 *
 *		Some of the values in a pg_type instance are copied into
 *		pg_attribute instances.  Some parts of Postgres use the pg_type copy,
 *		while others use the pg_attribute copy, so they must match.
 *		See struct FormData_pg_attribute for details.
 * ----------------
 */
#define TypeRelationId	1247

CATALOG(pg_type,1247) BKI_BOOTSTRAP
{
	NameData	typname;		/* type name */
	Oid			typnamespace;	/* OID of namespace containing this type */
	Oid			typowner;		/* type owner */

	/*
	 * For a fixed-size type, typlen is the number of bytes we use to
	 * represent a value of this type, e.g. 4 for an int4.	But for a
	 * variable-length type, typlen is negative.  We use -1 to indicate a
	 * "varlena" type (one that has a length word), -2 to indicate a
	 * null-terminated C string.
	 */
	int2		typlen;

	/*
	 * typbyval determines whether internal Postgres routines pass a value of
	 * this type by value or by reference.	typbyval had better be FALSE if
	 * the length is not 1, 2, or 4 (or 8 on 8-byte-Datum machines).
	 * Variable-length types are always passed by reference. Note that
	 * typbyval can be false even if the length would allow pass-by-value;
	 * this is currently true for type float4, for example.
	 */
	bool		typbyval;

	/*
	 * typtype is 'b' for a basic type, 'c' for a complex type (ie a table's
	 * rowtype), 'd' for a domain type, or 'p' for a pseudo type.
	 *
	 * If typtype is 'c', typrelid is the OID of the class' entry in pg_class.
	 */
	char		typtype;

	/*
	 * If typisdefined is false, the entry is only a placeholder (forward
	 * reference).	We know the type name, but not yet anything else about it.
	 */
	bool		typisdefined;

	char		typdelim;		/* delimiter for arrays of this type */

	Oid			typrelid;		/* 0 if not a complex type */

	/*
	 * If typelem is not 0 then it identifies another row in pg_type. The
	 * current type can then be subscripted like an array yielding values of
	 * type typelem. A non-zero typelem does not guarantee this type to be a
	 * "real" array type; some ordinary fixed-length types can also be
	 * subscripted (e.g., name, point). Variable-length types can *not* be
	 * turned into pseudo-arrays like that. Hence, the way to determine
	 * whether a type is a "true" array type is if:
	 *
	 * typelem != 0 and typlen == -1.
	 */
	Oid			typelem;

	/*
	 * I/O conversion procedures for the datatype.
	 */
	regproc		typinput;		/* text format (required) */
	regproc		typoutput;
	regproc		typreceive;		/* binary format (optional) */
	regproc		typsend;

	/*
	 * Custom ANALYZE procedure for the datatype (0 selects the default).
	 */
	regproc		typanalyze;

	/* ----------------
	 * typalign is the alignment required when storing a value of this
	 * type.  It applies to storage on disk as well as most
	 * representations of the value inside Postgres.  When multiple values
	 * are stored consecutively, such as in the representation of a
	 * complete row on disk, padding is inserted before a datum of this
	 * type so that it begins on the specified boundary.  The alignment
	 * reference is the beginning of the first datum in the sequence.
	 *
	 * 'c' = CHAR alignment, ie no alignment needed.
	 * 's' = SHORT alignment (2 bytes on most machines).
	 * 'i' = INT alignment (4 bytes on most machines).
	 * 'd' = DOUBLE alignment (8 bytes on many machines, but by no means all).
	 *
	 * See include/utils/memutils.h for the macros that compute these
	 * alignment requirements.
	 *
	 * NOTE: for types used in system tables, it is critical that the
	 * size and alignment defined in pg_type agree with the way that the
	 * compiler will lay out the field in a struct representing a table row.
	 * ----------------
	 */
	char		typalign;

	/* ----------------
	 * typstorage tells if the type is prepared for toasting and what
	 * the default strategy for attributes of this type should be.
	 *
	 * 'p' PLAIN	  type not prepared for toasting
	 * 'e' EXTERNAL   external storage possible, don't try to compress
	 * 'x' EXTENDED   try to compress and store external if required
	 * 'm' MAIN		  like 'x' but try to keep in main tuple
	 * ----------------
	 */
	char		typstorage;

	/*
	 * This flag represents a "NOT NULL" constraint against this datatype.
	 *
	 * If true, the attnotnull column for a corresponding table column using
	 * this datatype will always enforce the NOT NULL constraint.
	 *
	 * Used primarily for domain types.
	 */
	bool		typnotnull;

	/*
	 * Domains use typbasetype to show the base (or complex) type that the
	 * domain is based on.	Zero if the type is not a domain.
	 */
	Oid			typbasetype;

	/*
	 * Domains use typtypmod to record the typmod to be applied to their base
	 * type (-1 if base type does not use a typmod).  -1 if this type is not a
	 * domain.
	 */
	int4		typtypmod;

	/*
	 * typndims is the declared number of dimensions for an array domain type
	 * (i.e., typbasetype is an array type; the domain's typelem will match
	 * the base type's typelem).  Otherwise zero.
	 */
	int4		typndims;

	/*
	 * If typdefaultbin is not NULL, it is the nodeToString representation of
	 * a default expression for the type.  Currently this is only used for
	 * domains.
	 */
	text		typdefaultbin;	/* VARIABLE LENGTH FIELD */

	/*
	 * typdefault is NULL if the type has no associated default value. If
	 * typdefaultbin is not NULL, typdefault must contain a human-readable
	 * version of the default expression represented by typdefaultbin. If
	 * typdefaultbin is NULL and typdefault is not, then typdefault is the
	 * external representation of the type's default value, which may be fed
	 * to the type's input converter to produce a constant.
	 */
	text		typdefault;		/* VARIABLE LENGTH FIELD */

} FormData_pg_type;

/* ----------------
 *		Form_pg_type corresponds to a pointer to a row with
 *		the format of pg_type relation.
 * ----------------
 */
typedef FormData_pg_type *Form_pg_type;

/* ----------------
 *		compiler constants for pg_type
 * ----------------
 */
#define Natts_pg_type					23
#define Anum_pg_type_typname			1
#define Anum_pg_type_typnamespace		2
#define Anum_pg_type_typowner			3
#define Anum_pg_type_typlen				4
#define Anum_pg_type_typbyval			5
#define Anum_pg_type_typtype			6
#define Anum_pg_type_typisdefined		7
#define Anum_pg_type_typdelim			8
#define Anum_pg_type_typrelid			9
#define Anum_pg_type_typelem			10
#define Anum_pg_type_typinput			11
#define Anum_pg_type_typoutput			12
#define Anum_pg_type_typreceive			13
#define Anum_pg_type_typsend			14
#define Anum_pg_type_typanalyze			15
#define Anum_pg_type_typalign			16
#define Anum_pg_type_typstorage			17
#define Anum_pg_type_typnotnull			18
#define Anum_pg_type_typbasetype		19
#define Anum_pg_type_typtypmod			20
#define Anum_pg_type_typndims			21
#define Anum_pg_type_typdefaultbin		22
#define Anum_pg_type_typdefault			23


/* ----------------
 *		initial contents of pg_type
 * ----------------
 */

/* keep the following ordered by OID so that later changes can be made easier*/

/* Make sure the typlen, typbyval, and typalign values here match the initial
   values for attlen, attbyval, and attalign in both places in pg_attribute.h
   for every instance.
*/

/* OIDS 1 - 99 */
DATA(insert OID = 16 (	bool	   PGNSP PGUID	1 t b t \054 0	 0 boolin boolout boolrecv boolsend - c p f 0 -1 0 _null_ _null_ ));
DESCR("boolean, 'true'/'false'");
#define BOOLOID			16

DATA(insert OID = 17 (	bytea	   PGNSP PGUID -1 f b t \054 0	0 byteain byteaout bytearecv byteasend - i x f 0 -1 0 _null_ _null_ ));
DESCR("variable-length string, binary values escaped");
#define BYTEAOID		17

DATA(insert OID = 18 (	char	   PGNSP PGUID	1 t b t \054 0	 0 charin charout charrecv charsend - c p f 0 -1 0 _null_ _null_ ));
DESCR("single character");
#define CHAROID			18

DATA(insert OID = 19 (	name	   PGNSP PGUID NAMEDATALEN f b t \054 0 18 namein nameout namerecv namesend - i p f 0 -1 0 _null_ _null_ ));
DESCR("63-character type for storing system identifiers");
#define NAMEOID			19

DATA(insert OID = 20 (	int8	   PGNSP PGUID	8 f b t \054 0	 0 int8in int8out int8recv int8send - d p f 0 -1 0 _null_ _null_ ));
DESCR("~18 digit integer, 8-byte storage");
#define INT8OID			20

DATA(insert OID = 21 (	int2	   PGNSP PGUID	2 t b t \054 0	 0 int2in int2out int2recv int2send - s p f 0 -1 0 _null_ _null_ ));
DESCR("-32 thousand to 32 thousand, 2-byte storage");
#define INT2OID			21

DATA(insert OID = 22 (	int2vector PGNSP PGUID -1 f b t \054 0	21 int2vectorin int2vectorout int2vectorrecv int2vectorsend - i p f 0 -1 0 _null_ _null_ ));
DESCR("array of int2, used in system tables");
#define INT2VECTOROID	22

DATA(insert OID = 23 (	int4	   PGNSP PGUID	4 t b t \054 0	 0 int4in int4out int4recv int4send - i p f 0 -1 0 _null_ _null_ ));
DESCR("-2 billion to 2 billion integer, 4-byte storage");
#define INT4OID			23

DATA(insert OID = 24 (	regproc    PGNSP PGUID	4 t b t \054 0	 0 regprocin regprocout regprocrecv regprocsend - i p f 0 -1 0 _null_ _null_ ));
DESCR("registered procedure");
#define REGPROCOID		24

DATA(insert OID = 25 (	text	   PGNSP PGUID -1 f b t \054 0	0 textin textout textrecv textsend - i x f 0 -1 0 _null_ _null_ ));
DESCR("variable-length string, no limit specified");
#define TEXTOID			25

DATA(insert OID = 26 (	oid		   PGNSP PGUID	4 t b t \054 0	 0 oidin oidout oidrecv oidsend - i p f 0 -1 0 _null_ _null_ ));
DESCR("object identifier(oid), maximum 4 billion");
#define OIDOID			26

DATA(insert OID = 27 (	tid		   PGNSP PGUID	6 f b t \054 0	 0 tidin tidout tidrecv tidsend - s p f 0 -1 0 _null_ _null_ ));
DESCR("(Block, offset), physical location of tuple");
#define TIDOID		27

DATA(insert OID = 28 (	xid		   PGNSP PGUID	4 t b t \054 0	 0 xidin xidout xidrecv xidsend - i p f 0 -1 0 _null_ _null_ ));
DESCR("transaction id");
#define XIDOID 28

DATA(insert OID = 29 (	cid		   PGNSP PGUID	4 t b t \054 0	 0 cidin cidout cidrecv cidsend - i p f 0 -1 0 _null_ _null_ ));
DESCR("command identifier type, sequence in transaction id");