postgres/src/include/catalog/heap.h

/*-------------------------------------------------------------------------
 *
 * heap.h
 *	  prototypes for functions in backend/catalog/heap.c
 *
 *
 * Portions Copyright (c) 1996-2002, PostgreSQL Global Development Group
 * Portions Copyright (c) 1994, Regents of the University of California
 *
 * $Id: heap.h,v 1.58 2002/11/09 23:56:39 momjian Exp $
 *
 *-------------------------------------------------------------------------
 */
#ifndef HEAP_H
#define HEAP_H

#include "catalog/pg_attribute.h"
#include "nodes/parsenodes.h"
#include "parser/parse_node.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 Relation heap_create(const char *relname,
			Oid relnamespace,
			TupleDesc tupDesc,
			bool shared_relation,
			bool storage_create,
			bool allow_system_table_mods);

extern void heap_storage_create(Relation rel);

extern Oid heap_create_with_catalog(const char *relname,
						 Oid relnamespace,
						 TupleDesc tupdesc,
						 char relkind,
						 bool shared_relation,
						 char ateoxact, 
						 bool allow_system_table_mods);

extern void heap_drop_with_catalog(Oid rid);

extern void heap_truncate(Oid rid);

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

extern Node *cookDefault(ParseState *pstate,
			Node *raw_default,
			Oid atttypid,
			int32 atttypmod,
			char *attname);

extern int RemoveRelConstraints(Relation rel, const char *constrName,
					 DropBehavior behavior);

extern void DeleteRelationTuple(Oid relid);
extern void DeleteAttributeTuples(Oid relid);
extern void RemoveAttributeById(Oid relid, AttrNumber attnum);
extern void RemoveAttrDefault(Oid relid, AttrNumber attnum,
				  DropBehavior behavior, bool complain);
extern void RemoveAttrDefaultById(Oid attrdefId);

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			`*`
			`*`
Update copyright to 2002. 24 years ago			`* Portions Copyright (c) 1996-2002, 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			`*`
Add code to handle [ON COMMIT { PRESERVE ROWS \| DELETE ROWS \| DROP }] for temp tables. Gavin Sherry 23 years ago			`* $Id: heap.h,v 1.58 2002/11/09 23:56:39 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"`
Add DOMAIN support. Includes manual pages and regression tests, from Rod Taylor. 24 years ago			`#include "nodes/parsenodes.h"`
			`#include "parser/parse_node.h"`
Change #include's to use <> and "" as appropriate. 27 years ago			`#include "utils/rel.h"`
clean this one 30 years ago
pg_class has a relnamespace column. You can create and access tables in schemas other than the system namespace; however, there's no search path yet, and not all operations work yet on tables outside the system namespace. 24 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;`

Reimplement temp tables using schemas. The temp table map is history; temp table entries in pg_class have the names the user would expect. 24 years ago			`extern Relation heap_create(const char *relname,`
			`Oid relnamespace,`
pg_class has a relnamespace column. You can create and access tables in schemas other than the system namespace; however, there's no search path yet, and not all operations work yet on tables outside the system namespace. 24 years ago			`TupleDesc tupDesc,`
Support toasting of shared system relations, and provide toast tables for pg_database, pg_shadow, pg_group, all of which now have potentially-long fields. Along the way, get rid of SharedSystemRelationNames list: shared rels are now identified in their include/pg_catalog/*.h files by a BKI_SHARED_RELATION macro, while indexes and toast rels inherit sharedness automatically from their parent table. Fix some bugs with failure to detoast pg_group.grolist during ALTER GROUP. 24 years ago			`bool shared_relation,`
Reimplement temp tables using schemas. The temp table map is history; temp table entries in pg_class have the names the user would expect. 24 years ago			`bool storage_create,`
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
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
Reimplement temp tables using schemas. The temp table map is history; temp table entries in pg_class have the names the user would expect. 24 years ago			`extern Oid heap_create_with_catalog(const char *relname,`
			`Oid relnamespace,`
pg_class has a relnamespace column. You can create and access tables in schemas other than the system namespace; however, there's no search path yet, and not all operations work yet on tables outside the system namespace. 24 years ago			`TupleDesc tupdesc,`
Reimplement temp tables using schemas. The temp table map is history; temp table entries in pg_class have the names the user would expect. 24 years ago			`char relkind,`
Support toasting of shared system relations, and provide toast tables for pg_database, pg_shadow, pg_group, all of which now have potentially-long fields. Along the way, get rid of SharedSystemRelationNames list: shared rels are now identified in their include/pg_catalog/*.h files by a BKI_SHARED_RELATION macro, while indexes and toast rels inherit sharedness automatically from their parent table. Fix some bugs with failure to detoast pg_group.grolist during ALTER GROUP. 24 years ago			`bool shared_relation,`
Add code to handle [ON COMMIT { PRESERVE ROWS \| DELETE ROWS \| DROP }] for temp tables. Gavin Sherry 23 years ago			`char ateoxact,`
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
Second phase of committing Rod Taylor's pg_depend/pg_constraint patch. pg_relcheck is gone; CHECK, UNIQUE, PRIMARY KEY, and FOREIGN KEY constraints all have real live entries in pg_constraint. pg_depend exists, and RESTRICT/CASCADE options work on most kinds of DROP; however, pg_depend is not yet very well populated with dependencies. (Most of the ones that are present at this point just replace formerly hardwired associations, such as the implicit drop of a relation's pg_type entry when the relation is dropped.) Need to add more logic to create dependency entries, improve pg_dump to dump constraints in place of indexes and triggers, and add some regression tests. 24 years ago			`extern void heap_drop_with_catalog(Oid rid);`
More cleanups of the include files - centralizing to simplify the -I's required to compile 30 years ago
pg_type has a typnamespace column; system now supports creating types in different namespaces. Also, cleanup work on relation namespace support: drop, alter, rename commands work for tables in non-default namespaces. 24 years ago			`extern void heap_truncate(Oid rid);`
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
Code review for DOMAIN patch. 24 years ago			`extern Node cookDefault(ParseState pstate,`
pgindent run. 24 years ago			`Node *raw_default,`
			`Oid atttypid,`
			`int32 atttypmod,`
			`char *attname);`
Add DOMAIN support. Includes manual pages and regression tests, from Rod Taylor. 24 years ago
pgindent run. 24 years ago			`extern int RemoveRelConstraints(Relation rel, const char *constrName,`
			`DropBehavior behavior);`
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
In DeleteAttributeTuples, use a single indexscan instead of the multiple scans that will most likely be caused by SearchSysCache probes. Also, share some code between index deletion and table deletion. 24 years ago			`extern void DeleteRelationTuple(Oid relid);`
			`extern void DeleteAttributeTuples(Oid relid);`
ALTER TABLE DROP COLUMN works. Patch by Christopher Kings-Lynne, code review by Tom Lane. Remaining issues: functions that take or return tuple types are likely to break if one drops (or adds!) a column in the table defining the type. Need to think about what to do here. Along the way: some code review for recent COPY changes; mark system columns attnotnull = true where appropriate, per discussion a month ago. 24 years ago			`extern void RemoveAttributeById(Oid relid, AttrNumber attnum);`
Use the dependency mechanism to manage column defaults. We need this so that dependencies in default expressions (on operators, functions, etc) can be expressed properly. 24 years ago			`extern void RemoveAttrDefault(Oid relid, AttrNumber attnum,`
pgindent run. 24 years ago			`DropBehavior behavior, bool complain);`
Use the dependency mechanism to manage column defaults. We need this so that dependencies in default expressions (on operators, functions, etc) can be expressed properly. 24 years ago			`extern void RemoveAttrDefaultById(Oid attrdefId);`
In DeleteAttributeTuples, use a single indexscan instead of the multiple scans that will most likely be caused by SearchSysCache probes. Also, share some code between index deletion and table deletion. 24 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 */`