branches/zip: Fast index creation: Remove the ROW_PREBUILT_OBSOLETE nonsense.

Active transactions must not switch table or index definitions on the fly,
for several reasons, including the following:

 * copied indexes do not carry any history or locking information;
   that is, rollbacks, read views, and record locking would be broken

 * huge potential for race conditions, inconsistent reads and writes,
   loss of data, and corruption

Instead of trying to track down if the table was changed during a transaction,
acquire appropriate locks that protect the creation and dropping of indexes.

innodb-index.test: Test the locking of CREATE INDEX and DROP INDEX.  Test
that consistent reads work across dropped indexes.

lock_rec_insert_check_and_lock(): Relax the lock_table_has() assertion.
When inserting a record into an index, the table must be at least IX-locked.
However, when an index is being created, an IS-lock on the table is
sufficient.

row_merge_lock_table(): Add the parameter enum lock_mode mode, which must
be LOCK_X or LOCK_S.

row_merge_drop_table(): Assert that n_mysql_handles_opened == 0.
Unconditionally drop the table.

ha_innobase::add_index(): Acquire an X or S lock on the table, as appropriate.
After acquiring an X lock, assert that n_mysql_handles_opened == 1.
Remove the comments about dropping tables in the background.

ha_innobase::final_drop_index(): Acquire an X lock on the table.

dict_table_t: Remove version_number, to_be_dropped, and prebuilts.
ins_node_t: Remove table_version_number.

enum lock_mode: Move the definition from lock0lock.h to lock0types.h.

ROW_PREBUILT_OBSOLETE, row_update_prebuilt(), row_prebuilt_table_obsolete():
Remove.

row_prebuilt_t: Remove the declaration from row0types.h.

row_drop_table_for_mysql_no_commit(): Always print a warning if a table
was added to the background drop queue.

handler/handler0alter.cc

@@ -704,9 +704,9 @@ ha_innobase::add_index(
 	warnings if row_merge_lock_table() results in a lock wait. */
 	trx_set_dict_operation(trx, TRX_DICT_OP_INDEX_MAY_WAIT);
 
-	/* Acquire an exclusive lock on the table
-	before creating any indexes. */
-	error = row_merge_lock_table(trx, innodb_table);
+	/* Acquire a lock on the table before creating any indexes. */
+	error = row_merge_lock_table(trx, innodb_table,
+				     new_primary ? LOCK_X : LOCK_S);
 
 	if (UNIV_UNLIKELY(error != DB_SUCCESS)) {
 
@@ -719,6 +719,10 @@ ha_innobase::add_index(
 	to drop the original table and rebuild all indexes. */
 
 	if (UNIV_UNLIKELY(new_primary)) {
+		/* This transaction should be the only one
+		operating on the table. */
+		ut_a(innodb_table->n_mysql_handles_opened == 1);
+
 		char*	new_table_name = innobase_create_temporary_tablename(
 			heap, '1', innodb_table->name);
 
@@ -766,11 +770,6 @@ ha_innobase::add_index(
 
 	ut_ad(error == DB_SUCCESS);
 
-	/* Raise version number of the table to track this table's
-	definition changes. */
-
-	indexed_table->version_number++;
-
 	row_mysql_unlock_data_dictionary(trx);
 	dict_locked = FALSE;
 
@@ -782,7 +781,7 @@ ha_innobase::add_index(
 		table lock also on the table that is being created. */
 		ut_ad(indexed_table != innodb_table);
 
-		error = row_merge_lock_table(trx, indexed_table);
+		error = row_merge_lock_table(trx, indexed_table, LOCK_X);
 
 		if (UNIV_UNLIKELY(error != DB_SUCCESS)) {
 
@@ -860,17 +859,10 @@ ha_innobase::add_index(
 			break;
 		}
 
-		row_prebuilt_table_obsolete(innodb_table);
-
 		row_prebuilt_free(prebuilt, TRUE);
 		prebuilt = row_create_prebuilt(indexed_table);
 
-		prebuilt->table->n_mysql_handles_opened++;
-
-		/* Drop the old table if there are no open views
-		referring to it.  If there are such views, we will
-		drop the table when we free the prebuilts and there
-		are no more references to it. */
+		indexed_table->n_mysql_handles_opened++;
 
 		error = row_merge_drop_table(trx, innodb_table);
 		goto convert_error;
@@ -1075,6 +1067,7 @@ ha_innobase::final_drop_index(
 {
 	dict_index_t*	index;		/* Index to be dropped */
 	trx_t*		trx;		/* Transaction */
+	int		err;
 
 	DBUG_ENTER("ha_innobase::final_drop_index");
 	ut_ad(table);
@@ -1105,6 +1098,17 @@ ha_innobase::final_drop_index(
 	the data dictionary will be locked in crash recovery. */
 	trx_set_dict_operation(trx, TRX_DICT_OP_INDEX);
 
+	/* Lock the table exclusively, to ensure that no active
+	transaction depends on an index that is being dropped. */
+	err = convert_error_code_to_mysql(
+		row_merge_lock_table(trx, prebuilt->table, LOCK_X),
+		user_thd);
+
+	if (UNIV_UNLIKELY(err)) {
+
+		goto func_exit;
+	}
+
 	index = dict_table_get_first_index(prebuilt->table);
 
 	while (index) {
@@ -1120,12 +1124,11 @@ ha_innobase::final_drop_index(
 		index = next_index;
 	}
 
-	prebuilt->table->version_number++;
-
 #ifdef UNIV_DEBUG
 	dict_table_check_for_dup_indexes(prebuilt->table);
 #endif
 
+func_exit:
 	trx_commit_for_mysql(trx);
 	row_mysql_unlock_data_dictionary(trx);
 
@@ -1142,5 +1145,5 @@ ha_innobase::final_drop_index(
 
 	srv_active_wake_master_thread();
 
-	DBUG_RETURN(0);
+	DBUG_RETURN(err);
 }

include/dict0mem.h

@@ -24,7 +24,6 @@ Created 1/8/1996 Heikki Tuuri
 #include "lock0types.h"
 #include "hash0hash.h"
 #include "que0types.h"
-#include "row0types.h"
 
 /* Type flags of an index: OR'ing of the flags is allowed to define a
 combination of types */
@@ -312,14 +311,6 @@ struct dict_table_struct{
 				innodb_file_per_table is defined in my.cnf;
 				in Unix this is usually /tmp/..., in Windows
 				\temp\... */
-	unsigned	version_number:32;
-				/* version number of this table definition.
-				Version number is 0 when table is created.
-				Every schema change implemented without
-				creating a new table and copying rows from
-				the old table to new table will increase this
-				number. For example adding or removing index,
-				adding or removing a column. */
 	unsigned	space:32;
 				/* space where the clustered index of the
 				table is placed */
@@ -333,8 +324,6 @@ struct dict_table_struct{
 				calls DISCARD TABLESPACE on this
 				table, and reset to FALSE in IMPORT
 				TABLESPACE */
-	unsigned	to_be_dropped:1; /* if set then this table will
-				dropped when n_mysql_handles_opened is 0 */
 	unsigned	cached:1;/* TRUE if the table object has been added
 				to the dictionary cache */
 	unsigned	flags:8;/* DICT_TF_COMPACT, ... */
@@ -443,9 +432,6 @@ struct dict_table_struct{
 				column. Value must be greater than or equal
 				to 1 */
 	/*----------------------*/
-	UT_LIST_BASE_NODE_T(row_prebuilt_t) prebuilts;
-				/* base node for the prebuilts defined
-				for the table */
 	ulong		n_waiting_or_granted_auto_inc_locks;
 				/* This counter is used to track the number
 				of granted and pending autoinc locks on this

include/lock0lock.h

@@ -25,18 +25,6 @@ extern ibool	lock_print_waits;
 /* Buffer for storing information about the most recent deadlock error */
 extern FILE*	lock_latest_err_file;
 
-/* Basic lock modes */
-enum lock_mode {
-	LOCK_IS = 0,	/* intention shared */
-	LOCK_IX,	/* intention exclusive */
-	LOCK_S,		/* shared */
-	LOCK_X,		/* exclusive */
-	LOCK_AUTO_INC,	/* locks the auto-inc counter of a table
-			in an exclusive mode */
-	LOCK_NONE,	/* this is used elsewhere to note consistent read */
-	LOCK_NUM = LOCK_NONE/* number of lock modes */
-};
-
 /*************************************************************************
 Gets the size of a lock struct. */
 

include/lock0types.h

@@ -13,4 +13,16 @@ Created 5/7/1996 Heikki Tuuri
 typedef struct lock_struct	lock_t;
 typedef struct lock_sys_struct	lock_sys_t;
 
+/* Basic lock modes */
+enum lock_mode {
+	LOCK_IS = 0,	/* intention shared */
+	LOCK_IX,	/* intention exclusive */
+	LOCK_S,		/* shared */
+	LOCK_X,		/* exclusive */
+	LOCK_AUTO_INC,	/* locks the auto-inc counter of a table
+			in an exclusive mode */
+	LOCK_NONE,	/* this is used elsewhere to note consistent read */
+	LOCK_NUM = LOCK_NONE/* number of lock modes */
+};
+
 #endif

include/row0ins.h

@@ -108,11 +108,6 @@ struct ins_node_struct{
 				this should be reset to NULL */
 	UT_LIST_BASE_NODE_T(dtuple_t)
 			entry_list;/* list of entries, one for each index */
-	ulint		table_version_number;
-				/* entry_list is created for this version
-				of the table. If this version is not same
-				as table->version_number, entry_list must
-				be re-created. */
 	byte*		row_id_buf;/* buffer for the row id sys field in row */
 	dulint		trx_id;	/* trx id or the last trx which executed the
 				node */

include/row0merge.h

@@ -20,6 +20,7 @@ Created 13/06/2005 Jan Lindstrom
 #include "read0types.h"
 #include "btr0types.h"
 #include "row0mysql.h"
+#include "lock0types.h"
 
 /* This structure holds index field definitions */
 
@@ -50,7 +51,8 @@ row_merge_lock_table(
 /*=================*/
 					/* out: error code or DB_SUCCESS */
 	trx_t*		trx,		/* in/out: transaction */
-	dict_table_t*	table);		/* in: table to LOCK_X */
+	dict_table_t*	table,		/* in: table to lock */
+	enum lock_mode	mode);		/* in: LOCK_X or LOCK_S */
 /*************************************************************************
 Drop an index from the InnoDB system tables. */
 

include/row0mysql.h

@@ -21,7 +21,7 @@ Created 9/17/2000 Heikki Tuuri
 
 extern ibool row_rollback_on_timeout;
 
-/* typedef struct row_prebuilt_struct row_prebuilt_t; */
+typedef struct row_prebuilt_struct row_prebuilt_t;
 
 /***********************************************************************
 Frees the blob heap in prebuilt when no longer needed. */
@@ -162,22 +162,6 @@ row_update_prebuilt_trx(
 	row_prebuilt_t*	prebuilt,	/* in: prebuilt struct in MySQL
 					handle */
 	trx_t*		trx);		/* in: transaction handle */
-/************************************************************************
-Update a prebuilt struct for a MySQL table handle. */
-
-void
-row_update_prebuilt(
-/*================*/
-	row_prebuilt_t*	prebuilt,	/* in: Innobase table handle */
-	dict_table_t*   table);		/* in: table */
-/*************************************************************************
-Mark all prebuilt structs that use a table obsolete.  They will
-be rebuilt later. */
-
-void
-row_prebuilt_table_obsolete(
-/*========================*/
-	dict_table_t*	table);		/* in: table */
 /*************************************************************************
 Unlocks an AUTO_INC type lock possibly reserved by trx. */
 
@@ -565,7 +549,6 @@ struct mysql_row_templ_struct {
 
 #define ROW_PREBUILT_ALLOCATED	78540783
 #define ROW_PREBUILT_FREED	26423527
-#define ROW_PREBUILT_OBSOLETE	12367541
 
 /* A struct for (sometimes lazily) prebuilt structures in an Innobase table
 handle used within MySQL; these are used to save CPU time. */
@@ -574,9 +557,7 @@ struct row_prebuilt_struct {
 	ulint		magic_n;	/* this magic number is set to
 					ROW_PREBUILT_ALLOCATED when created,
 					or ROW_PREBUILT_FREED when the
-					struct has been freed or
-					ROW_PREBUILT_OBSOLETE when struct
-					needs a rebuilt */
+					struct has been freed */
 	dict_table_t*	table;		/* Innobase table handle */
 	trx_t*		trx;		/* current transaction handle */
 	ibool		sql_stat_start;	/* TRUE when we start processing of

include/row0types.h

@@ -36,8 +36,6 @@ typedef	struct purge_node_struct purge_node_t;
 
 typedef struct row_ext_struct row_ext_t;
 
-typedef struct row_prebuilt_struct row_prebuilt_t;
-
 /* MySQL data types */
 typedef struct st_table TABLE;
 

lock/lock0lock.c

@@ -4880,7 +4880,12 @@ lock_rec_insert_check_and_lock(
 
 	lock_mutex_enter_kernel();
 
-	ut_ad(lock_table_has(trx, index->table, LOCK_IX));
+	/* When inserting a record into an index, the table must be at
+	least IX-locked or we must be building an index, in which case
+	the table must be at least IS-locked. */
+	ut_ad(lock_table_has(trx, index->table, LOCK_IX)
+	      || (*index->name == TEMP_INDEX_PREFIX
+		  && lock_table_has(trx, index->table, LOCK_IS)));
 
 	next_rec_heap_no = page_rec_get_heap_no(next_rec);
 

mysql-test/innodb-index-master.opt

+--innodb_lock_wait_timeout=1

mysql-test/innodb-index.result

@@ -848,4 +848,40 @@ test.t1	check	status	OK
 explain select * from t1 where b like 'adfd%';
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	SIMPLE	t1	range	b	b	769	NULL	11	Using where
+begin;
+select a from t1 limit 1 for update;
+a
+22
+create index t1ba on t1 (b(10),a);
+ERROR HY000: Lock wait timeout exceeded; try restarting transaction
+commit;
+begin;
+select a from t1 limit 1 lock in share mode;
+a
+22
+create index t1ba on t1 (b(10),a);
+drop index t1ba on t1;
+ERROR HY000: Lock wait timeout exceeded; try restarting transaction
+commit;
+explain select a from t1 order by b;
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
+1	SIMPLE	t1	index	NULL	t1ba	16	NULL	60	Using index; Using filesort
+select a,sleep(2+a/100) from t1 order by b limit 3;
+select sleep(1);
+sleep(1)
+0
+drop index t1ba on t1;
+a	sleep(2+a/100)
+22	0
+44	0
+66	0
+explain select a from t1 order by b;
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
+1	SIMPLE	t1	index	NULL	PRIMARY	1028	NULL	60	Using index; Using filesort
+select a from t1 order by b limit 3;
+a
+22
+44
+66
+commit;
 drop table t1;

mysql-test/innodb-index.test

@@ -260,4 +260,57 @@ length(b),b=left(repeat(d,100*a),65535),length(c),c=repeat(d,20*a),d from t1;
 show create table t1;
 check table t1;
 explain select * from t1 where b like 'adfd%';
+
+#
+# Test locking
+#
+connect (a,localhost,root,,);
+connect (b,localhost,root,,);
+connection a;
+begin;
+# Obtain an IX lock on the table
+select a from t1 limit 1 for update;
+connection b;
+# This would require an S lock on the table, conflicting with the IX lock.
+--error ER_LOCK_WAIT_TIMEOUT
+create index t1ba on t1 (b(10),a);
+connection a;
+commit;
+begin;
+# Obtain an IS lock on the table
+select a from t1 limit 1 lock in share mode;
+connection b;
+# This will require an S lock on the table.  No conflict with the IS lock.
+create index t1ba on t1 (b(10),a);
+# This would require an X lock on the table, conflicting with the IS lock.
+--error ER_LOCK_WAIT_TIMEOUT
+drop index t1ba on t1;
+connection a;
+commit;
+explain select a from t1 order by b;
+--send
+select a,sleep(2+a/100) from t1 order by b limit 3;
+
+# The following DROP INDEX will succeed, altough the SELECT above has
+# opened a read view.  However, during the execution of the SELECT,
+# MySQL should hold a table lock that should block the execution
+# of the DROP INDEX below.
+
+connection b;
+select sleep(1);
+drop index t1ba on t1;
+
+# After the index was dropped, subsequent SELECTs will use the same
+# read view, but they should not be accessing the dropped index any more.
+
+connection a;
+reap;
+explain select a from t1 order by b;
+select a from t1 order by b limit 3;
+commit;
+
+connection default;
+disconnect a;
+disconnect b;
+
 drop table t1;

row/row0ins.c

@@ -72,7 +72,6 @@ ins_node_create(
 
 	node->state = INS_NODE_SET_IX_LOCK;
 	node->table = table;
-	node->table_version_number = table->version_number;
 	node->index = NULL;
 	node->entry = NULL;
 

row/row0merge.c

@@ -1648,7 +1648,8 @@ row_merge_lock_table(
 /*=================*/
 					/* out: error code or DB_SUCCESS */
 	trx_t*		trx,		/* in/out: transaction */
-	dict_table_t*	table)		/* in: table to LOCK_X */
+	dict_table_t*	table,		/* in: table to lock */
+	enum lock_mode	mode)		/* in: LOCK_X or LOCK_S */
 {
 	mem_heap_t*	heap;
 	que_thr_t*	thr;
@@ -1657,6 +1658,7 @@ row_merge_lock_table(
 
 	ut_ad(trx);
 	ut_ad(trx->mysql_thread_id == os_thread_get_curr_id());
+	ut_ad(mode == LOCK_X || mode == LOCK_S);
 
 	heap = mem_heap_create(512);
 
@@ -1676,7 +1678,7 @@ row_merge_lock_table(
 	thr->run_node = thr;
 	thr->prev_node = thr->common.parent;
 
-	err = lock_table(0, table, LOCK_X, thr);
+	err = lock_table(0, table, mode, thr);
 
 	trx->error_state = err;
 
@@ -2191,11 +2193,10 @@ row_merge_drop_table(
 		dict_locked = TRUE;
 	}
 
-	/* Drop the table immediately if it is not referenced by MySQL */
-	if (table->n_mysql_handles_opened == 0) {
-		err = row_drop_table_for_mysql_no_commit(table->name, trx,
-							 FALSE);
-	}
+	/* There must be no open transactions on the table. */
+	ut_a(table->n_mysql_handles_opened == 0);
+
+	err = row_drop_table_for_mysql_no_commit(table->name, trx, FALSE);
 
 	if (dict_locked) {
 		row_mysql_unlock_data_dictionary(trx);

row/row0mysql.c

@@ -619,39 +619,9 @@ row_create_prebuilt(
 
 	prebuilt->clust_ref = ref;
 
-	UT_LIST_ADD_LAST(prebuilts, table->prebuilts, prebuilt);
-
 	return(prebuilt);
 }
 
-/************************************************************************
-Update a prebuilt struct for a MySQL table handle. */
-
-void
-row_update_prebuilt(
-/*================*/
-	row_prebuilt_t*	prebuilt,	/* in: Innobase table handle */
-	dict_table_t*   table)		/* in: table */
-{
-	dict_index_t*	clust_index;
-
-	ut_ad(prebuilt && prebuilt->heap && table);
-	ut_ad(prebuilt->magic_n == ROW_PREBUILT_OBSOLETE);
-
-	prebuilt->magic_n = ROW_PREBUILT_ALLOCATED;
-	prebuilt->magic_n2 = ROW_PREBUILT_ALLOCATED;
-
-	clust_index = dict_table_get_first_index(table);
-
-	if (!prebuilt->index) {
-		prebuilt->index = clust_index;
-	}
-
-	if (prebuilt->ins_node) {
-		ins_node_create_entry_list(prebuilt->ins_node);
-	}
-}
-
 /************************************************************************
 Free a prebuilt struct for a MySQL table handle. */
 
@@ -663,8 +633,7 @@ row_prebuilt_free(
 {
 	ulint	i;
 
-	if (UNIV_UNLIKELY(prebuilt->magic_n == ROW_PREBUILT_OBSOLETE)) {
-	} else if (UNIV_UNLIKELY
+	if (UNIV_UNLIKELY
 	    (prebuilt->magic_n != ROW_PREBUILT_ALLOCATED
 	     || prebuilt->magic_n2 != ROW_PREBUILT_ALLOCATED)) {
 
@@ -735,58 +704,9 @@ row_prebuilt_free(
 
 	dict_table_decrement_handle_count(prebuilt->table, dict_locked);
 
-	/* If there were references to this table when a primary index on
-	this table was created then we drop it here since there are no
-	references to it now.*/
-	if (prebuilt->table->to_be_dropped
-	    && prebuilt->table->n_mysql_handles_opened == 0) {
-
-		const char* table_name = prebuilt->table->name;
-
-		if (!row_add_table_to_background_drop_list(table_name)) {
-			ut_print_timestamp(stderr);
-			fputs("  InnoDB: Error: failed trying to add ",
-			      stderr);
-			ut_print_name(stderr, NULL, TRUE, table_name);
-			fputs(" to the background drop list.\n", stderr);
-		}
-	}
-
-	UT_LIST_REMOVE(prebuilts, prebuilt->table->prebuilts, prebuilt);
-
 	mem_heap_free(prebuilt->heap);
 }
 
-/*************************************************************************
-Mark all prebuilt structs that use a table obsolete.  They will
-be rebuilt later. */
-
-void
-row_prebuilt_table_obsolete(
-/*========================*/
-	dict_table_t*	table)		/* in: table */
-{
-	row_prebuilt_t*	prebuilt;
-
-#ifdef UNIV_SYNC_DEBUG
-	ut_ad(rw_lock_own(&dict_operation_lock, RW_LOCK_EX));
-#endif /* UNIV_SYNC_DEBUG */
-	ut_ad(mutex_own(&dict_sys->mutex));
-
-	prebuilt = UT_LIST_GET_FIRST(table->prebuilts);
-
-	while (prebuilt) {
-		prebuilt->magic_n = ROW_PREBUILT_OBSOLETE;
-		prebuilt->magic_n2 = ROW_PREBUILT_OBSOLETE;
-
-		prebuilt = UT_LIST_GET_NEXT(prebuilts, prebuilt);
-	}
-
-	/* This table will be dropped when there are no more references
-	to it */
-	table->to_be_dropped = 1;
-}
-
 /*************************************************************************
 Updates the transaction pointers in query graphs stored in the prebuilt
 struct. */
@@ -1102,7 +1022,6 @@ row_insert_for_mysql(
 	ibool		was_lock_wait;
 	trx_t*		trx		= prebuilt->trx;
 	ins_node_t*	node		= prebuilt->ins_node;
-	dict_table_t*	table;
 
 	ut_ad(trx);
 	ut_ad(trx->mysql_thread_id == os_thread_get_curr_id());
@@ -1125,10 +1044,7 @@ row_insert_for_mysql(
 		return(DB_ERROR);
 	}
 
-	if (UNIV_UNLIKELY(prebuilt->magic_n == ROW_PREBUILT_OBSOLETE)) {
-		row_update_prebuilt(prebuilt, prebuilt->table);
-	} else if (UNIV_UNLIKELY
-		   (prebuilt->magic_n != ROW_PREBUILT_ALLOCATED)) {
+	if (UNIV_UNLIKELY(prebuilt->magic_n != ROW_PREBUILT_ALLOCATED)) {
 		fprintf(stderr,
 			"InnoDB: Error: trying to free a corrupt\n"
 			"InnoDB: table handle. Magic n %lu, table name ",
@@ -1162,14 +1078,6 @@ row_insert_for_mysql(
 	if (node == NULL) {
 		row_get_prebuilt_insert_row(prebuilt);
 		node = prebuilt->ins_node;
-	} else {
-		table = dict_table_get(prebuilt->table->name, FALSE);
-
-		if (prebuilt->ins_node->table_version_number !=
-		    table->version_number) {
-			row_get_prebuilt_insert_row(prebuilt);
-			node = prebuilt->ins_node;
-		}
 	}
 
 	row_mysql_convert_row_to_innobase(node->row, prebuilt, mysql_rec);
@@ -1191,10 +1099,6 @@ row_insert_for_mysql(
 	thr->run_node = node;
 	thr->prev_node = node;
 
-	if (UNIV_UNLIKELY(prebuilt->magic_n == ROW_PREBUILT_OBSOLETE)) {
-		row_update_prebuilt(prebuilt, prebuilt->table);
-	}
-
 	row_ins_step(thr);
 
 	err = trx->error_state;
@@ -1377,10 +1281,7 @@ row_update_for_mysql(
 		return(DB_ERROR);
 	}
 
-	if (UNIV_UNLIKELY(prebuilt->magic_n == ROW_PREBUILT_OBSOLETE)) {
-		row_update_prebuilt(prebuilt, prebuilt->table);
-	} else if (UNIV_UNLIKELY
-		   (prebuilt->magic_n != ROW_PREBUILT_ALLOCATED)) {
+	if (UNIV_UNLIKELY(prebuilt->magic_n != ROW_PREBUILT_ALLOCATED)) {
 		fprintf(stderr,
 			"InnoDB: Error: trying to free a corrupt\n"
 			"InnoDB: table handle. Magic n %lu, table name ",
@@ -1445,10 +1346,6 @@ row_update_for_mysql(
 	thr->run_node = node;
 	thr->prev_node = node;
 
-	if (UNIV_UNLIKELY(prebuilt->magic_n == ROW_PREBUILT_OBSOLETE)) {
-		row_update_prebuilt(prebuilt, prebuilt->table);
-	}
-
 	row_upd_step(thr);
 
 	err = trx->error_state;
@@ -3206,9 +3103,6 @@ row_drop_table_for_mysql_no_commit(
 		added = row_add_table_to_background_drop_list(table->name);
 
 		if (added) {
-			/* Temporary tables can have read views and we don't
-			print any warning. */
-			if (!table->to_be_dropped) {
 			ut_print_timestamp(stderr);
 			fputs("  InnoDB: Warning: MySQL is"
 			      " trying to drop table ", stderr);
@@ -3219,7 +3113,6 @@ row_drop_table_for_mysql_no_commit(
 			      "InnoDB: Adding the table to the"
 			      " background drop queue.\n",
 			      stderr);
-			}
 
 			/* We return DB_SUCCESS to MySQL though the drop will
 			happen lazily later */