branches/zip: Refuse to use newly created indexes that may lack

history.  This addresses Mantis issue #116.

dict_index_t: Enable the storage of trx_id.

row_prebuilt_t: Make many fields bit-fields to reduce the memory
footprint. Add index_usable.

ha_innobase::change_active_index(): Check if the index is usable and
set prebuilt->index_usable accordingly. Unfortunately, the return
status of this function is ignored by MySQL, and the actual refusal to
use the index must be made in row_search_for_mysql().

row_search_for_mysql(): Return DB_MISSING_HISTORY if
!prebuilt->index_usable.

convert_error_code_to_mysql(): Map DB_MISSING_HISTORY to
HA_ERR_TABLE_DEF_CHANGED.

innodb-index.test: Add a test case where access to a newly created
secondary index must be blocked for old transactions.

rb://100 approved by Heikki Tuuri

ChangeLog

+2009-04-02	The InnoDB Team
+
+	* dict/dict0crea.c, handler/ha_innodb.cc, handler/ha_innodb.h,
+	* include/dict0mem.h, include/row0merge.h, include/row0mysql.h,
+	* mysql-test/innodb-index.result, mysql-test/innodb-index.test,
+	* row/row0merge.c, row/row0sel.c:
+	In consistent reads, refuse to use newly created indexes that may
+	lack history.
+
 2009-03-20	The InnoDB Team
 
 	* buf/buf0buf.c, include/log0recv.h, log/log0recv.c:

dict/dict0crea.c

@@ -561,10 +561,8 @@ dict_build_index_def_step(
 
 	ins_node_set_new_row(node->ind_def, row);
 
-#ifdef ROW_MERGE_IS_INDEX_USABLE
 	/* Note that the index was created by this transaction. */
-	index->trx_id = trx->id;
-#endif /* ROW_MERGE_IS_INDEX_USABLE */
+	index->trx_id = (ib_uint64_t) ut_conv_dulint_to_longlong(trx->id);
 
 	return(DB_SUCCESS);
 }

handler/ha_innodb.cc

@@ -720,6 +720,9 @@ convert_error_code_to_mysql(
 	case DB_FOREIGN_DUPLICATE_KEY:
 		return(HA_ERR_FOREIGN_DUPLICATE_KEY);
 
+	case DB_MISSING_HISTORY:
+		return(HA_ERR_TABLE_DEF_CHANGED);
+
 	case DB_RECORD_NOT_FOUND:
 		return(HA_ERR_NO_ACTIVE_RECORD);
 
@@ -4689,38 +4692,6 @@ ha_innobase::try_semi_consistent_read(bool yes)
 	}
 }
 
-#ifdef ROW_MERGE_IS_INDEX_USABLE
-/**********************************************************************
-Check if an index can be used by the optimizer. */
-UNIV_INTERN
-bool
-ha_innobase::is_index_available(
-/*============================*/
-					/* out: true if available else false*/
-	uint		keynr)		/* in: index number to check */
-{
-	DBUG_ENTER("ha_innobase::is_index_available");
-
-	if (table && keynr != MAX_KEY && table->s->keys > 0) {
-		const dict_index_t*	index;
-		const KEY*		key = table->key_info + keynr;
-
-		ut_ad(user_thd == ha_thd());
-		ut_a(prebuilt->trx == thd_to_trx(user_thd));
-
-		index = dict_table_get_index_on_name(
-			prebuilt->table, key->name);
-
-		if (!row_merge_is_index_usable(prebuilt->trx, index)) {
-
-			DBUG_RETURN(false);
-		}
-	}
-
-	DBUG_RETURN(true);
-}
-#endif /* ROW_MERGE_IS_INDEX_USABLE */
-
 /**********************************************************************
 Initializes a handle to use an index. */
 UNIV_INTERN
@@ -5055,6 +5026,17 @@ ha_innobase::change_active_index(
 		DBUG_RETURN(1);
 	}
 
+	prebuilt->index_usable = row_merge_is_index_usable(prebuilt->trx,
+							   prebuilt->index);
+
+	if (UNIV_UNLIKELY(!prebuilt->index_usable)) {
+		sql_print_warning("InnoDB: insufficient history for index %u",
+				  keynr);
+		/* The caller seems to ignore this.  Thus, we must check
+		this again in row_search_for_mysql(). */
+		DBUG_RETURN(2);
+	}
+
 	ut_a(prebuilt->search_tuple != 0);
 
 	dtuple_set_n_fields(prebuilt->search_tuple, prebuilt->index->n_fields);

handler/ha_innodb.h

@@ -119,14 +119,6 @@ class ha_innobase: public handler
 	void try_semi_consistent_read(bool yes);
 	void unlock_row();
 
-#ifdef ROW_MERGE_IS_INDEX_USABLE
-	/** Check if an index can be used by this transaction.
-	* @param keynr	key number to check
-	* @return	true if available, false if the index
-	*		does not contain old records that exist
-	*		in the read view of this transaction */
-	bool is_index_available(uint keynr);
-#endif /* ROW_MERGE_IS_INDEX_USABLE */
 	int index_init(uint index, bool sorted);
 	int index_end();
 	int index_read(uchar * buf, const uchar * key,

include/dict0mem.h

@@ -279,11 +279,9 @@ struct dict_index_struct{
 				index tree */
 	rw_lock_t	lock;	/* read-write lock protecting the upper levels
 				of the index tree */
-#ifdef ROW_MERGE_IS_INDEX_USABLE
-	dulint		trx_id; /* id of the transaction that created this
-				index, or ut_dulint_zero if the index existed
+	ib_uint64_t	trx_id; /* id of the transaction that created this
+				index, or 0 if the index existed
 				when InnoDB was started up */
-#endif /* ROW_MERGE_IS_INDEX_USABLE */
 #endif /* !UNIV_HOTBACKUP */
 #ifdef UNIV_DEBUG
 	ulint		magic_n;/* magic number */

include/row0merge.h

@@ -152,7 +152,6 @@ row_merge_create_index(
 	dict_table_t*	table,		/* in: the index is on this table */
 	const merge_index_def_t*	/* in: the index definition */
 			index_def);
-#ifdef ROW_MERGE_IS_INDEX_USABLE
 /*************************************************************************
 Check if a transaction can use an index. */
 UNIV_INTERN
@@ -163,7 +162,6 @@ row_merge_is_index_usable(
 					the transaction else FALSE*/
 	const trx_t*		trx,	/* in: transaction */
 	const dict_index_t*	index);	/* in: index to check */
-#endif /* ROW_MERGE_IS_INDEX_USABLE */
 /*************************************************************************
 If there are views that refer to the old table name then we "attach" to
 the new instance of the table else we drop it immediately. */

include/row0mysql.h

@@ -571,52 +571,54 @@ struct row_prebuilt_struct {
 					or ROW_PREBUILT_FREED when the
 					struct has been freed */
 	dict_table_t*	table;		/* Innobase table handle */
+	dict_index_t*	index;		/* current index for a search, if
+					any */
 	trx_t*		trx;		/* current transaction handle */
-	ibool		sql_stat_start;	/* TRUE when we start processing of
+	unsigned	sql_stat_start:1;/* TRUE when we start processing of
 					an SQL statement: we may have to set
 					an intention lock on the table,
 					create a consistent read view etc. */
-	ibool		mysql_has_locked; /* this is set TRUE when MySQL
+	unsigned	mysql_has_locked:1; /* this is set TRUE when MySQL
 					calls external_lock on this handle
 					with a lock flag, and set FALSE when
 					with the F_UNLOCK flag */
-	ibool		clust_index_was_generated;
+	unsigned	clust_index_was_generated:1;
 					/* if the user did not define a
 					primary key in MySQL, then Innobase
 					automatically generated a clustered
 					index where the ordering column is
 					the row id: in this case this flag
 					is set to TRUE */
-	dict_index_t*	index;		/* current index for a search, if
-					any */
-	ulint		read_just_key;	/* set to 1 when MySQL calls
+	unsigned	index_usable:1;	/* caches the value of
+					row_merge_is_index_usable(trx,index) */
+	unsigned	read_just_key:1;/* set to 1 when MySQL calls
 					ha_innobase::extra with the
 					argument HA_EXTRA_KEYREAD; it is enough
 					to read just columns defined in
 					the index (i.e., no read of the
 					clustered index record necessary) */
-	ibool		used_in_HANDLER;/* TRUE if we have been using this
+	unsigned	used_in_HANDLER:1;/* TRUE if we have been using this
 					handle in a MySQL HANDLER low level
 					index cursor command: then we must
 					store the pcur position even in a
 					unique search from a clustered index,
 					because HANDLER allows NEXT and PREV
 					in such a situation */
-	ulint		template_type;	/* ROW_MYSQL_WHOLE_ROW,
+	unsigned	template_type:2;/* ROW_MYSQL_WHOLE_ROW,
 					ROW_MYSQL_REC_FIELDS,
 					ROW_MYSQL_DUMMY_TEMPLATE, or
 					ROW_MYSQL_NO_TEMPLATE */
-	ulint		n_template;	/* number of elements in the
+	unsigned	n_template:10;	/* number of elements in the
 					template */
-	ulint		null_bitmap_len;/* number of bytes in the SQL NULL
+	unsigned	null_bitmap_len:10;/* number of bytes in the SQL NULL
 					bitmap at the start of a row in the
 					MySQL format */
-	ibool		need_to_access_clustered; /* if we are fetching
+	unsigned	need_to_access_clustered:1; /* if we are fetching
 					columns through a secondary index
 					and at least one column is not in
 					the secondary index, then this is
 					set to TRUE */
-	ibool		templ_contains_blob;/* TRUE if the template contains
+	unsigned	templ_contains_blob:1;/* TRUE if the template contains
 					BLOB column(s) */
 	mysql_row_templ_t* mysql_template;/* template used to transform
 					rows fast between MySQL and Innobase

mysql-test/innodb-index.result

@@ -1132,3 +1132,39 @@ t2	CREATE TABLE `t2` (
 ) ENGINE=InnoDB DEFAULT CHARSET=latin1
 DROP TABLE t2;
 DROP TABLE t1;
+CREATE TABLE t1 (a INT, b CHAR(1)) ENGINE=InnoDB;
+INSERT INTO t1 VALUES (3,'a'),(3,'b'),(1,'c'),(0,'d'),(1,'e');
+BEGIN;
+SELECT * FROM t1;
+a	b
+3	a
+3	b
+1	c
+0	d
+1	e
+CREATE INDEX t1a ON t1(a);
+SELECT * FROM t1;
+a	b
+3	a
+3	b
+1	c
+0	d
+1	e
+SELECT * FROM t1 FORCE INDEX(t1a) ORDER BY a;
+ERROR HY000: Table definition has changed, please retry transaction
+SELECT * FROM t1;
+a	b
+3	a
+3	b
+1	c
+0	d
+1	e
+COMMIT;
+SELECT * FROM t1 FORCE INDEX(t1a) ORDER BY a;
+a	b
+0	d
+1	c
+1	e
+3	a
+3	b
+DROP TABLE t1;

mysql-test/innodb-index.test

@@ -509,3 +509,26 @@ SHOW CREATE TABLE t2;
 
 DROP TABLE t2;
 DROP TABLE t1;
+
+connect (a,localhost,root,,);
+connect (b,localhost,root,,);
+connection a;
+CREATE TABLE t1 (a INT, b CHAR(1)) ENGINE=InnoDB;
+INSERT INTO t1 VALUES (3,'a'),(3,'b'),(1,'c'),(0,'d'),(1,'e');
+connection b;
+BEGIN;
+SELECT * FROM t1;
+connection a;
+CREATE INDEX t1a ON t1(a);
+connection b;
+SELECT * FROM t1;
+--error ER_TABLE_DEF_CHANGED
+SELECT * FROM t1 FORCE INDEX(t1a) ORDER BY a;
+SELECT * FROM t1;
+COMMIT;
+SELECT * FROM t1 FORCE INDEX(t1a) ORDER BY a;
+connection default;
+disconnect a;
+disconnect b;
+
+DROP TABLE t1;

row/row0merge.c

@@ -2208,12 +2208,11 @@ row_merge_create_index(
 
 		ut_a(index);
 
-#ifdef ROW_MERGE_IS_INDEX_USABLE
 		/* Note the id of the transaction that created this
 		index, we use it to restrict readers from accessing
 		this index, to ensure read consistency. */
-		index->trx_id = trx->id;
-#endif /* ROW_MERGE_IS_INDEX_USABLE */
+		index->trx_id = (ib_uint64_t)
+			ut_conv_dulint_to_longlong(trx->id);
 	} else {
 		index = NULL;
 	}
@@ -2221,7 +2220,6 @@ row_merge_create_index(
 	return(index);
 }
 
-#ifdef ROW_MERGE_IS_INDEX_USABLE
 /*************************************************************************
 Check if a transaction can use an index. */
 UNIV_INTERN
@@ -2231,13 +2229,11 @@ row_merge_is_index_usable(
 	const trx_t*		trx,	/* in: transaction */
 	const dict_index_t*	index)	/* in: index to check */
 {
-	if (!trx->read_view) {
-		return(TRUE);
-	}
-
-	return(ut_dulint_cmp(index->trx_id, trx->read_view->low_limit_id) < 0);
+	return(!trx->read_view || read_view_sees_trx_id(
+		       trx->read_view,
+		       ut_dulint_create((ulint) (index->trx_id >> 32),
+					(ulint) index->trx_id & 0xFFFFFFFF)));
 }
-#endif /* ROW_MERGE_IS_INDEX_USABLE */
 
 /*************************************************************************
 Drop the old table. */

row/row0sel.c

@@ -3343,6 +3343,11 @@ row_search_for_mysql(
 		return(DB_ERROR);
 	}
 
+	if (UNIV_UNLIKELY(!prebuilt->index_usable)) {
+
+		return(DB_MISSING_HISTORY);
+	}
+
 	if (UNIV_UNLIKELY(prebuilt->magic_n != ROW_PREBUILT_ALLOCATED)) {
 		fprintf(stderr,
 			"InnoDB: Error: trying to free a corrupt\n"