#include "access/tupdesc.h"
#include "catalog/pg_am.h"
#include "catalog/pg_class.h"
#include "catalog/pg_index.h"
#include "fmgr.h"
#include "rewrite/prs2lock.h"
#include "storage/block.h"
#include "storage/relfilenode.h"

Clases
struct	LockRelId
struct	LockInfoData
struct	Trigger
struct	TriggerDesc
struct	PgStat_Info
struct	RelationAmInfo
struct	RelationData
'defines'
#define	TRIGGER_NUM_EVENT_CLASSES 3
#define	RelationIsValid(relation) PointerIsValid(relation)
#define	InvalidRelation ((Relation) NULL)
#define	RelationHasReferenceCountZero(relation) ((bool)((relation)->rd_refcnt == 0))
#define	RelationGetForm(relation) ((relation)->rd_rel)
#define	RelationGetRelid(relation) ((relation)->rd_id)
#define	RelationGetNumberOfAttributes(relation) ((relation)->rd_rel->relnatts)
#define	RelationGetDescr(relation) ((relation)->rd_att)
#define	RelationGetRelationName(relation) (NameStr((relation)->rd_rel->relname))
#define	RelationGetNamespace(relation) ((relation)->rd_rel->relnamespace)
#define	RelationOpenSmgr(relation)
#define	RelationCloseSmgr(relation)
#define	RELATION_IS_LOCAL(relation)
'typedefs'
typedef struct LockRelId	LockRelId
typedef struct LockInfoData	LockInfoData
typedef LockInfoData *	LockInfo
typedef struct Trigger	Trigger
typedef struct TriggerDesc	TriggerDesc
typedef struct PgStat_Info	PgStat_Info
typedef struct RelationAmInfo	RelationAmInfo
typedef struct RelationData	RelationData
typedef RelationData *	Relation
typedef Relation *	RelationPtr
Funciones
void	RelationIncrementReferenceCount (Relation rel)
void	RelationDecrementReferenceCount (Relation rel)

Documentación de los 'defines'

#define InvalidRelation ((Relation) NULL)

#define RELATION_IS_LOCAL ( relation )

Valor:

((relation)->rd_istemp || \
         (relation)->rd_createSubid != InvalidSubTransactionId)

#define RelationCloseSmgr ( relation )

Valor:

do { \
                if ((relation)->rd_smgr != NULL) \
                { \
                        smgrclose((relation)->rd_smgr); \
                        Assert((relation)->rd_smgr == NULL); \
                } \
        } while (0)

#define RelationGetDescr ( relation ) ((relation)->rd_att)

#define RelationGetForm ( relation ) ((relation)->rd_rel)

#define RelationGetNamespace ( relation ) ((relation)->rd_rel->relnamespace)

#define RelationGetNumberOfAttributes ( relation ) ((relation)->rd_rel->relnatts)

#define RelationGetRelationName ( relation ) (NameStr((relation)->rd_rel->relname))

#define RelationGetRelid ( relation ) ((relation)->rd_id)

#define RelationHasReferenceCountZero ( relation ) ((bool)((relation)->rd_refcnt == 0))

#define RelationIsValid ( relation ) PointerIsValid(relation)

#define RelationOpenSmgr ( relation )

Valor:

do { \
                if ((relation)->rd_smgr == NULL) \
                        smgrsetowner(&((relation)->rd_smgr), smgropen((relation)->rd_node)); \
        } while (0)

#define TRIGGER_NUM_EVENT_CLASSES 3