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.

2 files changed, 60 insertions, 59 deletions

diff --git a/src/interfaces/ecpg/preproc/keywords.c b/src/interfaces/ecpg/preproc/keywords.c
index 5614a34b0fe..c03880f497d 100644
--- a/src/interfaces/ecpg/preproc/keywords.c
+++ b/src/interfaces/ecpg/preproc/keywords.c
@@ -8,7 +8,7 @@
  *
  *
  * IDENTIFICATION
- *	  $Header: /cvsroot/pgsql/src/interfaces/ecpg/preproc/keywords.c,v 1.39 2001/03/22 04:01:21 momjian Exp $
+ *	  $Header: /cvsroot/pgsql/src/interfaces/ecpg/preproc/keywords.c,v 1.40 2001/05/07 00:43:26 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -238,6 +238,7 @@ static ScanKeyword ScanKeywords[] = {
 	{"some", SOME},
 	{"start", START},
 	{"statement", STATEMENT},
+	{"statistics", STATISTICS},
 	{"stdin", STDIN},
 	{"stdout", STDOUT},
 	{"substring", SUBSTRING},
diff --git a/src/interfaces/ecpg/preproc/preproc.y b/src/interfaces/ecpg/preproc/preproc.y
index 345efb6576e..91708bd91fa 100644
--- a/src/interfaces/ecpg/preproc/preproc.y
+++ b/src/interfaces/ecpg/preproc/preproc.y
@@ -134,7 +134,7 @@ make_name(void)
 
 %union {
 	double                  dval;
-        int                     ival;
+	int                     ival;
 	char *                  str;
 	struct when             action;
 	struct index		index;
@@ -224,7 +224,7 @@ make_name(void)
 		NONE, NOTHING, NOTIFY, NOTNULL, OFFSET, OIDS,
 		OPERATOR, OWNER, PASSWORD, PROCEDURAL, REINDEX, RENAME, RESET,
 		RETURNS, ROW, RULE, SEQUENCE, SERIAL, SETOF, SHARE,
-		SHOW, START, STATEMENT, STDIN, STDOUT, SYSID TEMP,
+		SHOW, START, STATEMENT, STATISTICS, STDIN, STDOUT, SYSID TEMP,
 		TEMPLATE, TOAST, TRUNCATE, TRUSTED, UNLISTEN, UNTIL, VACUUM,
 		VALID, VERBOSE, VERSION
 
@@ -285,7 +285,7 @@ make_name(void)
 %type  <str>    file_name AexprConst ParamNo c_expr ConstTypename
 %type  <str>	in_expr_nodes a_expr b_expr TruncateStmt CommentStmt
 %type  <str> 	opt_indirection expr_list extract_list extract_arg
-%type  <str>	position_list substr_list substr_from alter_column_action
+%type  <str>	position_list substr_list substr_from alter_column_default
 %type  <str>	trim_list in_expr substr_for attr attrs drop_behavior
 %type  <str>	Typename SimpleTypename Generic Numeric generic opt_float opt_numeric
 %type  <str> 	opt_decimal Character character opt_varying opt_charset
@@ -293,7 +293,7 @@ make_name(void)
 %type  <str>	row_expr row_descriptor row_list ConstDatetime opt_chain
 %type  <str>	SelectStmt into_clause OptTemp ConstraintAttributeSpec
 %type  <str>	opt_table opt_all sort_clause sortby_list ConstraintAttr 
-%type  <str>	sortby OptUseOp opt_inh_star relation_name_list name_list
+%type  <str>	sortby OptUseOp relation_name_list name_list
 %type  <str>	group_clause having_clause from_clause opt_distinct
 %type  <str>	join_outer where_clause relation_expr sub_type opt_arg
 %type  <str>	opt_column_list insert_rest InsertStmt OptimizableStmt
@@ -301,8 +301,8 @@ make_name(void)
 %type  <str>    NotifyStmt columnElem copy_dirn UnlistenStmt copy_null
 %type  <str>    copy_delimiter ListenStmt CopyStmt copy_file_name opt_binary
 %type  <str>    opt_with_copy FetchStmt direction fetch_how_many from_in
-%type  <str>    ClosePortalStmt DropStmt VacuumStmt opt_verbose func_arg
-%type  <str>    opt_analyze opt_va_list va_list ExplainStmt index_params
+%type  <str>    ClosePortalStmt DropStmt VacuumStmt AnalyzeStmt opt_verbose func_arg
+%type  <str>    analyze_keyword opt_name_list ExplainStmt index_params
 %type  <str>    index_list func_index index_elem opt_class access_method_clause
 %type  <str>    index_opt_unique IndexStmt func_return ConstInterval
 %type  <str>    func_args_list func_args opt_with ProcedureStmt def_arg
@@ -329,7 +329,7 @@ make_name(void)
 %type  <str>	opt_cursor opt_lmode ConstraintsSetStmt comment_tg AllConst
 %type  <str>	case_expr when_clause_list case_default case_arg when_clause
 %type  <str>    select_clause opt_select_limit select_limit_value ConstraintTimeSpec
-%type  <str>    select_offset_value ReindexStmt join_type opt_only opt_boolean
+%type  <str>    select_offset_value ReindexStmt join_type opt_boolean
 %type  <str>	join_qual update_list AlterSchemaStmt joined_table
 %type  <str>	opt_level opt_lock lock_type users_in_new_group_clause
 %type  <str>    OptConstrFromTable comment_op OptTempTableName StringConst
@@ -447,6 +447,7 @@ stmt:  AlterSchemaStmt 			{ output_statement($1, 0, NULL, connection); }
 		| CreatedbStmt		{ output_statement($1, 0, NULL, connection); }
 		| DropdbStmt		{ output_statement($1, 0, NULL, connection); }
 		| VacuumStmt		{ output_statement($1, 0, NULL, connection); }
+		| AnalyzeStmt		{ output_statement($1, 0, NULL, connection); }
 		| VariableSetStmt	{ output_statement($1, 0, NULL, connection); }
 		| VariableShowStmt	{ output_statement($1, 0, NULL, connection); }
 		| VariableResetStmt	{ output_statement($1, 0, NULL, connection); }
@@ -909,39 +910,40 @@ CheckPointStmt: CHECKPOINT     { $$= make_str("checkpoint"); }
 
 /*****************************************************************************
  *
- *		QUERY :
- *
  *	ALTER TABLE variations
  *
  *****************************************************************************/
 
 AlterTableStmt:
-/* ALTER TABLE <name> ADD [COLUMN] <coldef> */
-        ALTER TABLE relation_name opt_inh_star ADD opt_column columnDef
+/* ALTER TABLE <relation> ADD [COLUMN] <coldef> */
+        ALTER TABLE relation_expr ADD opt_column columnDef
+		{
+			$$ = cat_str(5, make_str("alter table"), $3, make_str("add"), $5, $6);
+		}
+/* ALTER TABLE <relation> ALTER [COLUMN] <colname> {SET DEFAULT <expr>|DROP DEFAULT} */
+	| ALTER TABLE relation_expr ALTER opt_column ColId alter_column_default
 		{
-			$$ = cat_str(6, make_str("alter table"), $3, $4, make_str("add"), $6, $7);
+			$$ = cat_str(6, make_str("alter table"), $3, make_str("alter"), $5, $6, $7);
 		}
-/* ALTER TABLE <name> ALTER [COLUMN] <colname> {SET DEFAULT <expr>|DROP
-DEFAULT} */
-	| ALTER TABLE relation_name opt_inh_star ALTER opt_column ColId
-		alter_column_action
+/* ALTER TABLE <relation> ALTER [COLUMN] <colname> SET STATISTICS <Iconst> */
+	| ALTER TABLE relation_expr ALTER opt_column ColId SET STATISTICS Iconst
 		{
-			$$ = cat_str(7, make_str("alter table"), $3, $4, make_str("alter"), $6, $7, $8);
+			$$ = cat_str(7, make_str("alter table"), $3, make_str("alter"), $5, $6, make_str("set statistics"), $9);
 		}
-/* ALTER TABLE <name> DROP [COLUMN] <name> {RESTRICT|CASCADE} */
-	| ALTER TABLE relation_name opt_inh_star DROP opt_column ColId drop_behavior
+/* ALTER TABLE <relation> DROP [COLUMN] <colname> {RESTRICT|CASCADE} */
+	| ALTER TABLE relation_expr DROP opt_column ColId drop_behavior
 		{
-			$$ = cat_str(7, make_str("alter table"), $3, $4, make_str("drop"), $6, $7, $8);
+			$$ = cat_str(6, make_str("alter table"), $3, make_str("drop"), $5, $6, $7);
 		}
-/* ALTER TABLE <name> ADD CONSTRAINT ... */
-	| ALTER TABLE relation_name opt_inh_star ADD TableConstraint
+/* ALTER TABLE <relation> ADD CONSTRAINT ... */
+	| ALTER TABLE relation_expr ADD TableConstraint
 		{
-			$$ = cat_str(5, make_str("alter table"), $3, $4, make_str("add"), $6);
+			$$ = cat_str(4, make_str("alter table"), $3, make_str("add"), $5);
 		}
-/* ALTER TABLE <name> DROP CONSTRAINT ... */
-	| ALTER TABLE relation_name opt_inh_star DROP CONSTRAINT name drop_behavior
+/* ALTER TABLE <relation> DROP CONSTRAINT ... */
+	| ALTER TABLE relation_expr DROP CONSTRAINT name drop_behavior
 		{
-			$$ = cat_str(6, make_str("alter table"), $3, $4, make_str("drop constraint"), $7, $8);
+			$$ = cat_str(5, make_str("alter table"), $3, make_str("drop constraint"), $6, $7);
 		}
 /* ALTER TABLE <name> OWNER TO UserId */     
 	| ALTER TABLE relation_name OWNER TO UserId   
@@ -950,7 +952,7 @@ DEFAULT} */
 		}
 		;
 
-alter_column_action:
+alter_column_default:
         SET DEFAULT a_expr	{ $$ = cat2_str(make_str("set default"), $3); }
         | DROP DEFAULT          { $$ = make_str("drop default"); }
         ;
@@ -1234,10 +1236,6 @@ key_reference:  NO ACTION	{ $$ = make_str("no action"); }
 		| SET NULL_P	{ $$ = make_str("set null"); }
 		;
 
-opt_only: ONLY   	{ $$ = make_str("only"); }
-	| /*EMPTY*/	{ $$ = EMPTY; }
-	;
-
 OptInherit:  INHERITS '(' relation_name_list ')'                { $$ = cat_str(3, make_str("inherits ("), $3, make_str(")")); }
                 | /*EMPTY*/					{ $$ = EMPTY; }
                 ;      
@@ -2013,10 +2011,9 @@ opt_force:      FORCE		{ $$ = make_str("force"); }
  *
  *****************************************************************************/
 
-RenameStmt:  ALTER TABLE relation_name opt_inh_star
-				  RENAME opt_column opt_name TO name
+RenameStmt:  ALTER TABLE relation_expr RENAME opt_column opt_name TO name
 				{
-					$$ = cat_str(8, make_str("alter table"), $3, $4, make_str("rename"), $6, $7, make_str("to"), $9);
+					$$ = cat_str(7, make_str("alter table"), $3, make_str("rename"), $5, $6, make_str("to"), $8);
 				}
 		;
 
@@ -2250,38 +2247,44 @@ ClusterStmt:  CLUSTER index_name ON relation_name
  *
  *		QUERY:
  *				vacuum
+ *				analyze
  *
  *****************************************************************************/
 
-VacuumStmt:  VACUUM opt_verbose opt_analyze
+VacuumStmt:  VACUUM opt_verbose
+				{
+					$$ = cat_str(2, make_str("vacuum"), $2);
+				}
+		| VACUUM opt_verbose relation_name
 				{
 					$$ = cat_str(3, make_str("vacuum"), $2, $3);
 				}
-		| VACUUM opt_verbose opt_analyze relation_name opt_va_list
+		| VACUUM opt_verbose AnalyzeStmt
 				{
-					if ( strlen($5) > 0 && strlen($4) == 0 )
-						mmerror(ET_ERROR, "VACUUM syntax error at or near \"(\"\n\tRelations name must be specified");
-					$$ = cat_str(5, make_str("vacuum"), $2, $3, $4, $5);
+					$$ = cat_str(3, make_str("vacuum"), $2, $3);
 				}
 		;
 
-opt_verbose:  VERBOSE					{ $$ = make_str("verbose"); }
-		| /*EMPTY*/				{ $$ = EMPTY; }
+AnalyzeStmt:  analyze_keyword opt_verbose
+				{
+					$$ = cat_str(2, $1, $2);
+				}
+		| analyze_keyword opt_verbose relation_name opt_name_list
+				{
+					$$ = cat_str(4, $1, $2, $3, $4);
+				}
 		;
 
-opt_analyze:  ANALYZE					{ $$ = make_str("analyze"); }
-		| ANALYSE				{ $$ = make_str("analyse"); }
-		| /*EMPTY*/				{ $$ = EMPTY; }
+analyze_keyword:  ANALYZE					{ $$ = make_str("analyze"); }
+		| ANALYSE							{ $$ = make_str("analyse"); }
 		;
 
-opt_va_list:  '(' va_list ')'				{ $$ = cat_str(3, make_str("("), $2, make_str(")")); }
+opt_verbose:  VERBOSE					{ $$ = make_str("verbose"); }
 		| /*EMPTY*/				{ $$ = EMPTY; }
 		;
 
-va_list:  name
-				{ $$=$1; }
-		| va_list ',' name
-				{ $$=cat_str(3, $1, make_str(","), $3); }
+opt_name_list:  '(' name_list ')'		{ $$ = cat_str(3, make_str("("), $2, make_str(")")); }
+		| /*EMPTY*/				{ $$ = EMPTY; }
 		;
 
 
@@ -2383,9 +2386,9 @@ columnElem:  ColId opt_indirection
  *
  *****************************************************************************/
 
-DeleteStmt:  DELETE FROM opt_only name where_clause
+DeleteStmt:  DELETE FROM relation_expr where_clause
 				{
-					$$ = cat_str(4, make_str("delete from"), $3, $4, $5);
+					$$ = cat_str(3, make_str("delete from"), $3, $4);
 				}
 		;
 
@@ -2416,12 +2419,12 @@ opt_lmode:      SHARE                           { $$ = make_str("share"); }
  *
  *****************************************************************************/
 
-UpdateStmt:  UPDATE opt_only relation_name
+UpdateStmt:  UPDATE relation_expr
 			  SET update_target_list
 			  from_clause
 			  where_clause
 				{
-					$$ = cat_str(7, make_str("update"), $2, $3, make_str("set"), $5, $6, $7);
+					$$ = cat_str(6, make_str("update"), $2, make_str("set"), $4, $5, $6);
 				}
 		;
 
@@ -2667,10 +2670,6 @@ select_offset_value:  	PosIntConst	{
  *	...however, recursive addattr and rename supported.  make special
  *	cases for these.
  */
-opt_inh_star:  '*'					{ $$ = make_str("*"); }
-		| /*EMPTY*/				{ $$ = EMPTY; }
-		;
-
 relation_name_list:  name_list { $$ = $1; };
 
 name_list:  name
@@ -2704,7 +2703,7 @@ opt_for_update_clause: for_update_clause                { $$ = $1; }
 		| /* EMPTY */				{ $$ = EMPTY; }
                 ;
 
-update_list:  OF va_list
+update_list:  OF name_list
               {
 			$$ = cat2_str(make_str("of"), $2);
 	      }
@@ -5028,6 +5027,7 @@ TokenId:  ABSOLUTE			{ $$ = make_str("absolute"); }
 	| SHARE				{ $$ = make_str("share"); }
 	| START				{ $$ = make_str("start"); }
 	| STATEMENT			{ $$ = make_str("statement"); }
+	| STATISTICS		{ $$ = make_str("statistics"); }
 	| STDIN                         { $$ = make_str("stdin"); }
 	| STDOUT                        { $$ = make_str("stdout"); }
 	| SYSID                         { $$ = make_str("sysid"); }