postgres/src/include/catalog/heap.h

/*-------------------------------------------------------------------------
 *
 * heap.h
 *	  prototypes for functions in backend/catalog/heap.c
 *
 *
 * Portions Copyright (c) 1996-2001, PostgreSQL Global Development Group
 * Portions Copyright (c) 1994, Regents of the University of California
 *
 * $Id: heap.h,v 1.43 2002/03/07 16:35:38 momjian Exp $
 *
 *-------------------------------------------------------------------------
 */
#ifndef HEAP_H
#define HEAP_H

#include "catalog/pg_attribute.h"
#include "utils/rel.h"

typedef struct RawColumnDefault
{
	AttrNumber	attnum;			/* attribute to attach default to */
	Node	   *raw_default;	/* default value (untransformed parse
								 * tree) */
} RawColumnDefault;

extern Oid	RelnameFindRelid(const char *relname);

extern Relation heap_create(char *relname, TupleDesc tupDesc,
			bool istemp, bool storage_create,
			bool allow_system_table_mods);

extern void heap_storage_create(Relation rel);

extern Oid heap_create_with_catalog(char *relname, TupleDesc tupdesc,
						 char relkind, bool relhasoids, bool istemp,
						 bool allow_system_table_mods);

extern void heap_drop_with_catalog(const char *relname,
					   bool allow_system_table_mods);

extern void heap_truncate(char *relname);

extern void AddRelationRawConstraints(Relation rel,
						  List *rawColDefaults,
						  List *rawConstraints);

extern int	RemoveCheckConstraint(Relation rel, const char *constrName, bool inh);

extern Form_pg_attribute SystemAttributeDefinition(AttrNumber attno,
						  bool relhasoids);

extern Form_pg_attribute SystemAttributeByName(const char *attname,
					  bool relhasoids);

#endif   /* HEAP_H */
More cleanups of the include files - centralizing to simplify the -I's required to compile 30 years ago			`/*-------------------------------------------------------------------------`
			`*`
Change my-function-name-- to my_function_name, and optimizer renames. 27 years ago			`* heap.h`
Consolidate tables of known system attributes into one table. 25 years ago			`* prototypes for functions in backend/catalog/heap.c`
More cleanups of the include files - centralizing to simplify the -I's required to compile 30 years ago			`*`
			`*`
Change Copyright from PostgreSQL, Inc to PostgreSQL Global Development Group. 25 years ago			`* Portions Copyright (c) 1996-2001, PostgreSQL Global Development Group`
Add: * Portions Copyright (c) 1996-2000, PostgreSQL, Inc to all files copyright Regents of Berkeley. Man, that's a lot of files. 26 years ago			`* Portions Copyright (c) 1994, Regents of the University of California`
More cleanups of the include files - centralizing to simplify the -I's required to compile 30 years ago			`*`
Back out domain patch until it works properly. 24 years ago			`* $Id: heap.h,v 1.43 2002/03/07 16:35:38 momjian Exp $`
More cleanups of the include files - centralizing to simplify the -I's required to compile 30 years ago			`*`
			`*-------------------------------------------------------------------------`
			`*/`
			`#ifndef HEAP_H`
			`#define HEAP_H`

Rewrite of planner statistics-gathering code. ANALYZE is now available as a separate statement (though it can still be invoked as part of VACUUM, too). pg_statistic redesigned to be more flexible about what statistics are stored. ANALYZE now collects a list of several of the most common values, not just one, plus a histogram (not just the min and max values). Random sampling is used to make the process reasonably fast even on very large tables. The number of values and histogram bins collected is now user-settable via an ALTER TABLE command. There is more still to do; the new stats are not being used everywhere they could be in the planner. But the remaining changes for this project should be localized, and the behavior is already better than before. A not-very-related change is that sorting now makes use of btree comparison routines if it can find one, rather than invoking '<' twice. 25 years ago			`#include "catalog/pg_attribute.h"`
Change #include's to use <> and "" as appropriate. 27 years ago			`#include "utils/rel.h"`
clean this one 30 years ago
Reimplement parsing and storage of default expressions and constraint expressions in CREATE TABLE. There is no longer an emasculated expression syntax for these things; it's full a_expr for constraints, and b_expr for defaults (unfortunately the fact that NOT NULL is a part of the column constraint syntax causes a shift/reduce conflict if you try a_expr. Oh well --- at least parenthesized boolean expressions work now). Also, stored expression for a column default is not pre-coerced to the column type; we rely on transformInsertStatement to do that when the default is actually used. This means "f1 datetime default 'now'" behaves the way people usually expect it to. BTW, all the support code is now there to implement ALTER TABLE ADD CONSTRAINT and ALTER TABLE ADD COLUMN with a default value. I didn't actually teach ALTER TABLE to call it, but it wouldn't be much work. 27 years ago			`typedef struct RawColumnDefault`
			`{`
			`AttrNumber attnum; /* attribute to attach default to */`
Ye-old pgindent run. Same 4-space tabs. 26 years ago			`Node raw_default; / default value (untransformed parse`
			`* tree) */`
Reimplement parsing and storage of default expressions and constraint expressions in CREATE TABLE. There is no longer an emasculated expression syntax for these things; it's full a_expr for constraints, and b_expr for defaults (unfortunately the fact that NOT NULL is a part of the column constraint syntax causes a shift/reduce conflict if you try a_expr. Oh well --- at least parenthesized boolean expressions work now). Also, stored expression for a column default is not pre-coerced to the column type; we rely on transformInsertStatement to do that when the default is actually used. This means "f1 datetime default 'now'" behaves the way people usually expect it to. BTW, all the support code is now there to implement ALTER TABLE ADD CONSTRAINT and ALTER TABLE ADD COLUMN with a default value. I didn't actually teach ALTER TABLE to call it, but it wouldn't be much work. 27 years ago			`} RawColumnDefault;`

Ye-old pgindent run. Same 4-space tabs. 26 years ago			`extern Oid RelnameFindRelid(const char *relname);`
Reimplement nodeMaterial to use a temporary BufFile (or even memory, if the materialized tupleset is small enough) instead of a temporary relation. This was something I was thinking of doing anyway for performance, and Jan says he needs it for TOAST because he doesn't want to cope with toasting noname relations. With this change, the 'noname table' support in heap.c is dead code, and I have accordingly removed it. Also clean up 'noname' plan handling in planner --- nonames are either sort or materialize plans, and it seems less confusing to handle them separately under those names. 26 years ago
			`extern Relation heap_create(char *relname, TupleDesc tupDesc,`
pgindent run. Make it all clean. 25 years ago			`bool istemp, bool storage_create,`
			`bool allow_system_table_mods);`
Make toast-table creation and deletion work somewhat reliably. Don't go through pg_exec_query_dest(), but directly to the execution routines. Also, extend parameter lists so that there's no need to change the global setting of allowSystemTableMods, a hack that was certain to cause trouble in the event of any error. 26 years ago
Make DROP TABLE rollback-able: postpone physical file delete until commit. (WAL logging for this is not done yet, however.) Clean up a number of really crufty things that are no longer needed now that DROP behaves nicely. Make temp table mapper do the right things when drop or rename affecting a temp table is rolled back. Also, remove "relation modified while in use" error check, in favor of locking tables at first reference and holding that lock throughout the statement. 25 years ago			`extern void heap_storage_create(Relation rel);`
More cleanups of the include files - centralizing to simplify the -I's required to compile 30 years ago
Ye-old pgindent run. Same 4-space tabs. 26 years ago			`extern Oid heap_create_with_catalog(char *relname, TupleDesc tupdesc,`
Make OIDs optional, per discussions in pghackers. WITH OIDS is still the default, but OIDS are removed from many system catalogs that don't need them. Some interesting side effects: TOAST pointers are 20 bytes not 32 now; pg_description has a three-column key instead of one. Bugs fixed in passing: BINARY cursors work again; pg_class.relhaspkey has some usefulness; pg_dump dumps comments on indexes, rules, and triggers in a valid order. initdb forced. 25 years ago			`char relkind, bool relhasoids, bool istemp,`
pgindent run. Make it all clean. 25 years ago			`bool allow_system_table_mods);`
Make toast-table creation and deletion work somewhat reliably. Don't go through pg_exec_query_dest(), but directly to the execution routines. Also, extend parameter lists so that there's no need to change the global setting of allowSystemTableMods, a hack that was certain to cause trouble in the event of any error. 26 years ago
			`extern void heap_drop_with_catalog(const char *relname,`
pgindent run. Make it all clean. 25 years ago			`bool allow_system_table_mods);`
More cleanups of the include files - centralizing to simplify the -I's required to compile 30 years ago
Add TRUNCATE command, with psql help and sgml additions. 27 years ago			`extern void heap_truncate(char *relname);`
More cleanups of the include files - centralizing to simplify the -I's required to compile 30 years ago
Reimplement parsing and storage of default expressions and constraint expressions in CREATE TABLE. There is no longer an emasculated expression syntax for these things; it's full a_expr for constraints, and b_expr for defaults (unfortunately the fact that NOT NULL is a part of the column constraint syntax causes a shift/reduce conflict if you try a_expr. Oh well --- at least parenthesized boolean expressions work now). Also, stored expression for a column default is not pre-coerced to the column type; we rely on transformInsertStatement to do that when the default is actually used. This means "f1 datetime default 'now'" behaves the way people usually expect it to. BTW, all the support code is now there to implement ALTER TABLE ADD CONSTRAINT and ALTER TABLE ADD COLUMN with a default value. I didn't actually teach ALTER TABLE to call it, but it wouldn't be much work. 27 years ago			`extern void AddRelationRawConstraints(Relation rel,`
Ye-old pgindent run. Same 4-space tabs. 26 years ago			`List *rawColDefaults,`
			`List *rawConstraints);`
Reimplement parsing and storage of default expressions and constraint expressions in CREATE TABLE. There is no longer an emasculated expression syntax for these things; it's full a_expr for constraints, and b_expr for defaults (unfortunately the fact that NOT NULL is a part of the column constraint syntax causes a shift/reduce conflict if you try a_expr. Oh well --- at least parenthesized boolean expressions work now). Also, stored expression for a column default is not pre-coerced to the column type; we rely on transformInsertStatement to do that when the default is actually used. This means "f1 datetime default 'now'" behaves the way people usually expect it to. BTW, all the support code is now there to implement ALTER TABLE ADD CONSTRAINT and ALTER TABLE ADD COLUMN with a default value. I didn't actually teach ALTER TABLE to call it, but it wouldn't be much work. 27 years ago
pgindent run on all C files. Java run to follow. initdb/regression tests pass. 25 years ago			`extern int RemoveCheckConstraint(Relation rel, const char *constrName, bool inh);`
Attached is my patch that adds DROP CONSTRAINT support to PostgreSQL. I basically want your guys feedback. I have sprinkled some of my q's thru the text delimited with the @@ symbol. It seems to work perfectly. [ Removed @@ comments because patch was reviewed. ] At the moment it does CHECK constraints only, with inheritance. However, due to the problem mentioned before with the mismatching between inherited constraints it may be wise to disable the inheritance feature for a while. it is written in an extensible fashion to support future dropping of other types of constraint, and is well documented. Please send me your comments, check my use of locking, updating of indices, use of ERROR and NOTICE, etc. and I will rework the patch based on feedback until everyone is happy with it... Christopher Kings 25 years ago
Make OIDs optional, per discussions in pghackers. WITH OIDS is still the default, but OIDS are removed from many system catalogs that don't need them. Some interesting side effects: TOAST pointers are 20 bytes not 32 now; pg_description has a three-column key instead of one. Bugs fixed in passing: BINARY cursors work again; pg_class.relhaspkey has some usefulness; pg_dump dumps comments on indexes, rules, and triggers in a valid order. initdb forced. 25 years ago			`extern Form_pg_attribute SystemAttributeDefinition(AttrNumber attno,`
pgindent run on all C files. Java run to follow. initdb/regression tests pass. 25 years ago			`bool relhasoids);`
Rewrite of planner statistics-gathering code. ANALYZE is now available as a separate statement (though it can still be invoked as part of VACUUM, too). pg_statistic redesigned to be more flexible about what statistics are stored. ANALYZE now collects a list of several of the most common values, not just one, plus a histogram (not just the min and max values). Random sampling is used to make the process reasonably fast even on very large tables. The number of values and histogram bins collected is now user-settable via an ALTER TABLE command. There is more still to do; the new stats are not being used everywhere they could be in the planner. But the remaining changes for this project should be localized, and the behavior is already better than before. A not-very-related change is that sorting now makes use of btree comparison routines if it can find one, rather than invoking '<' twice. 25 years ago
Consolidate tables of known system attributes into one table. 25 years ago			`extern Form_pg_attribute SystemAttributeByName(const char *attname,`
pgindent run on all C files. Java run to follow. initdb/regression tests pass. 25 years ago			`bool relhasoids);`
Another pgindent run. Fixes enum indenting, and improves #endif spacing. Also adds space for one-line comments. 24 years ago
New pgindent run with fixes suggested by Tom. Patch manually reviewed, initdb/regression tests pass. 24 years ago			`#endif /* HEAP_H */`