Applying InnoDB snapshot

Detailed revision comments:

r6610 | marko | 2010-02-09 13:53:59 +0200 (Tue, 09 Feb 2010) | 17 lines
branches/zip: When dropping temporary indexes and tables at startup,
first load them to the data dictionary cache and use the normal
routines for dropping tables or indexes.  This should reduce the
risk of bugs and also make the code compatible with the upcoming
TablespaceDictionary implementation.

DICT_SYS_INDEXES_NAME_FIELD: The clustered index position of SYS_INDEXES.NAME.

row_merge_drop_temp_indexes(): Scan SYS_INDEXES for tables containing
temporary indexes, and load the tables as needed. Invoke
row_merge_drop_index() to drop the indexes.

row_mysql_drop_temp_tables(): Scan SYS_TABLES for temporary tables,
load them with dict_load_table() and drop them with
row_drop_table_for_mysql().

rb://251, not yet reviewed

storage/innodb_plugin/dict/dict0boot.c

@@ -358,7 +358,7 @@ dict_boot(void)
 	dict_mem_table_add_col(table, heap, "SPACE", DATA_INT, 0, 4);
 	dict_mem_table_add_col(table, heap, "PAGE_NO", DATA_INT, 0, 4);
 
-	/* The '+ 2' below comes from the 2 system fields */
+	/* The '+ 2' below comes from the fields DB_TRX_ID, DB_ROLL_PTR */
 #if DICT_SYS_INDEXES_PAGE_NO_FIELD != 6 + 2
 #error "DICT_SYS_INDEXES_PAGE_NO_FIELD != 6 + 2"
 #endif
@@ -367,6 +367,9 @@ dict_boot(void)
 #endif
 #if DICT_SYS_INDEXES_TYPE_FIELD != 4 + 2
 #error "DICT_SYS_INDEXES_TYPE_FIELD != 4 + 2"
+#endif
+#if DICT_SYS_INDEXES_NAME_FIELD != 1 + 2
+#error "DICT_SYS_INDEXES_NAME_FIELD != 1 + 2"
 #endif
 
 	table->id = DICT_INDEXES_ID;

storage/innodb_plugin/include/dict0boot.h

@@ -137,6 +137,7 @@ clustered index */
 #define DICT_SYS_INDEXES_PAGE_NO_FIELD	 8
 #define DICT_SYS_INDEXES_SPACE_NO_FIELD	 7
 #define DICT_SYS_INDEXES_TYPE_FIELD	 6
+#define DICT_SYS_INDEXES_NAME_FIELD	 3
 
 /* When a row id which is zero modulo this number (which must be a power of
 two) is assigned, the field DICT_HDR_ROW_ID on the dictionary header page is

storage/innodb_plugin/row/row0merge.c

@@ -2031,38 +2031,79 @@ row_merge_drop_temp_indexes(void)
 /*=============================*/
 {
 	trx_t*		trx;
-	ulint		err;
-
-	/* We use the private SQL parser of Innobase to generate the
-	query graphs needed in deleting the dictionary data from system
-	tables in Innobase. Deleting a row from SYS_INDEXES table also
-	frees the file segments of the B-tree associated with the index. */
-	static const char drop_temp_indexes[] =
-		"PROCEDURE DROP_TEMP_INDEXES_PROC () IS\n"
-		"indexid CHAR;\n"
-		"DECLARE CURSOR c IS SELECT ID FROM SYS_INDEXES\n"
-		"WHERE SUBSTR(NAME,0,1)='" TEMP_INDEX_PREFIX_STR "';\n"
-		"BEGIN\n"
-		"\tOPEN c;\n"
-		"\tWHILE 1=1 LOOP\n"
-		"\t\tFETCH c INTO indexid;\n"
-		"\t\tIF (SQL % NOTFOUND) THEN\n"
-		"\t\t\tEXIT;\n"
-		"\t\tEND IF;\n"
-		"\t\tDELETE FROM SYS_FIELDS WHERE INDEX_ID = indexid;\n"
-		"\t\tDELETE FROM SYS_INDEXES WHERE ID = indexid;\n"
-		"\tEND LOOP;\n"
-		"\tCLOSE c;\n"
-		"\tCOMMIT WORK;\n"
-		"END;\n";
+	btr_pcur_t	pcur;
+	mtr_t		mtr;
 
+	/* Load the table definitions that contain partially defined
+	indexes, so that the data dictionary information can be checked
+	when accessing the tablename.ibd files. */
 	trx = trx_allocate_for_background();
 	trx->op_info = "dropping partially created indexes";
 	row_mysql_lock_data_dictionary(trx);
 
-	err = que_eval_sql(NULL, drop_temp_indexes, FALSE, trx);
-	ut_a(err == DB_SUCCESS);
+	mtr_start(&mtr);
+
+	btr_pcur_open_at_index_side(
+		TRUE,
+		dict_table_get_first_index(dict_sys->sys_indexes),
+		BTR_SEARCH_LEAF, &pcur, TRUE, &mtr);
+
+	for (;;) {
+		const rec_t*	rec;
+		const byte*	field;
+		ulint		len;
+		dulint		table_id;
+		dict_table_t*	table;
+
+		btr_pcur_move_to_next_user_rec(&pcur, &mtr);
+
+		if (!btr_pcur_is_on_user_rec(&pcur)) {
+			break;
+		}
 
+		rec = btr_pcur_get_rec(&pcur);
+		field = rec_get_nth_field_old(rec, DICT_SYS_INDEXES_NAME_FIELD,
+					      &len);
+		if (len == UNIV_SQL_NULL || len == 0
+		    || mach_read_from_1(field) != (ulint) TEMP_INDEX_PREFIX) {
+			continue;
+		}
+
+		/* This is a temporary index. */
+
+		field = rec_get_nth_field_old(rec, 0/*TABLE_ID*/, &len);
+		if (len != 8) {
+			/* Corrupted TABLE_ID */
+			continue;
+		}
+
+		table_id = mach_read_from_8(field);
+
+		btr_pcur_store_position(&pcur, &mtr);
+		btr_pcur_commit_specify_mtr(&pcur, &mtr);
+
+		table = dict_load_table_on_id(table_id);
+
+		if (table) {
+			dict_index_t*	index;
+
+			for (index = dict_table_get_first_index(table);
+			     index; index = dict_table_get_next_index(index)) {
+
+				if (*index->name == TEMP_INDEX_PREFIX) {
+					row_merge_drop_index(index, table, trx);
+					trx_commit_for_mysql(trx);
+				}
+			}
+		}
+
+		mtr_start(&mtr);
+		btr_pcur_restore_position(BTR_SEARCH_LEAF,
+					  &pcur, &mtr);
+	}
+
+	btr_pcur_close(&pcur);
+	mtr_commit(&mtr);
 	row_mysql_unlock_data_dictionary(trx);
 	trx_free_for_background(trx);
 }

storage/innodb_plugin/row/row0mysql.c

@@ -3370,88 +3370,79 @@ void
 row_mysql_drop_temp_tables(void)
 /*============================*/
 {
-	trx_t*	trx;
-	ulint	err;
+	trx_t*		trx;
+	btr_pcur_t	pcur;
+	mtr_t		mtr;
+	mem_heap_t*	heap;
 
 	trx = trx_allocate_for_background();
 	trx->op_info = "dropping temporary tables";
 	row_mysql_lock_data_dictionary(trx);
 
-	err = que_eval_sql(
-		NULL,
-		"PROCEDURE DROP_TEMP_TABLES_PROC () IS\n"
-		"table_name CHAR;\n"
-		"table_id CHAR;\n"
-		"foreign_id CHAR;\n"
-		"index_id CHAR;\n"
-		"DECLARE CURSOR c IS SELECT NAME,ID FROM SYS_TABLES\n"
-		"WHERE N_COLS > 2147483647\n"
-		/* N_COLS>>31 is set unless ROW_FORMAT=REDUNDANT,
-		and MIX_LEN may be garbage for those tables */
-		"AND MIX_LEN=(MIX_LEN/2*2+1);\n"
-		/* MIX_LEN & 1 is set for temporary tables */
-#if DICT_TF2_TEMPORARY != 1
-# error "DICT_TF2_TEMPORARY != 1"
-#endif
-		"BEGIN\n"
-		"OPEN c;\n"
-		"WHILE 1=1 LOOP\n"
-		"	FETCH c INTO table_name, table_id;\n"
-		"	IF (SQL % NOTFOUND) THEN\n"
-		"		EXIT;\n"
-		"	END IF;\n"
-		"	WHILE 1=1 LOOP\n"
-		"		SELECT ID INTO index_id\n"
-		"		FROM SYS_INDEXES\n"
-		"		WHERE TABLE_ID = table_id\n"
-		"		LOCK IN SHARE MODE;\n"
-		"		IF (SQL % NOTFOUND) THEN\n"
-		"			EXIT;\n"
-		"		END IF;\n"
-
-		/* Do not drop tables for which there exist
-		foreign key constraints. */
-		"		SELECT ID INTO foreign_id\n"
-		"		FROM SYS_FOREIGN\n"
-		"		WHERE FOR_NAME = table_name\n"
-		"		AND TO_BINARY(FOR_NAME)\n"
-		"		  = TO_BINARY(table_name)\n;"
-		"		IF NOT (SQL % NOTFOUND) THEN\n"
-		"			EXIT;\n"
-		"		END IF;\n"
-
-		"		SELECT ID INTO foreign_id\n"
-		"		FROM SYS_FOREIGN\n"
-		"		WHERE REF_NAME = table_name\n"
-		"		AND TO_BINARY(REF_NAME)\n"
-		"		  = TO_BINARY(table_name)\n;"
-		"		IF NOT (SQL % NOTFOUND) THEN\n"
-		"			EXIT;\n"
-		"		END IF;\n"
-
-		"		DELETE FROM SYS_FIELDS\n"
-		"		WHERE INDEX_ID = index_id;\n"
-		"		DELETE FROM SYS_INDEXES\n"
-		"		WHERE ID = index_id\n"
-		"		AND TABLE_ID = table_id;\n"
-		"	END LOOP;\n"
-		"	DELETE FROM SYS_COLUMNS\n"
-		"	WHERE TABLE_ID = table_id;\n"
-		"	DELETE FROM SYS_TABLES\n"
-		"	WHERE ID = table_id;\n"
-		"END LOOP;\n"
-		"COMMIT WORK;\n"
-		"END;\n"
-		, FALSE, trx);
+	heap = mem_heap_create(200);
 
-	if (err != DB_SUCCESS) {
-		ut_print_timestamp(stderr);
-		fprintf(stderr,
-			"  InnoDB: Failed to drop temporary tables:"
-			" error %lu occurred\n",
-			(ulong) err);
+	mtr_start(&mtr);
+
+	btr_pcur_open_at_index_side(
+		TRUE,
+		dict_table_get_first_index(dict_sys->sys_tables),
+		BTR_SEARCH_LEAF, &pcur, TRUE, &mtr);
+
+	for (;;) {
+		const rec_t*	rec;
+		const byte*	field;
+		ulint		len;
+		const char*	table_name;
+		dict_table_t*	table;
+
+		btr_pcur_move_to_next_user_rec(&pcur, &mtr);
+
+		if (!btr_pcur_is_on_user_rec(&pcur)) {
+			break;
+		}
+
+		rec = btr_pcur_get_rec(&pcur);
+		field = rec_get_nth_field_old(rec, 4/*N_COLS*/, &len);
+		if (len != 4 || !(mach_read_from_4(field) & 0x80000000UL)) {
+			continue;
+		}
+
+		/* Because this is not a ROW_FORMAT=REDUNDANT table,
+		the is_temp flag is valid.  Examine it. */
+
+		field = rec_get_nth_field_old(rec, 7/*MIX_LEN*/, &len);
+		if (len != 4
+		    || !(mach_read_from_4(field) & DICT_TF2_TEMPORARY)) {
+			continue;
+		}
+
+		/* This is a temporary table. */
+		field = rec_get_nth_field_old(rec, 0/*NAME*/, &len);
+		if (len == UNIV_SQL_NULL || len == 0) {
+			/* Corrupted SYS_TABLES.NAME */
+			continue;
+		}
+
+		table_name = mem_heap_strdupl(heap, (const char*) field, len);
+
+		btr_pcur_store_position(&pcur, &mtr);
+		btr_pcur_commit_specify_mtr(&pcur, &mtr);
+
+		table = dict_load_table(table_name);
+
+		if (table) {
+			row_drop_table_for_mysql(table_name, trx, FALSE);
+			trx_commit_for_mysql(trx);
+		}
+
+		mtr_start(&mtr);
+		btr_pcur_restore_position(BTR_SEARCH_LEAF,
+					  &pcur, &mtr);
 	}
 
+	btr_pcur_close(&pcur);
+	mtr_commit(&mtr);
+	mem_heap_free(heap);
 	row_mysql_unlock_data_dictionary(trx);
 	trx_free_for_background(trx);
 }