MDEV-18878 Purge: Optimize away futile table lookups

If a table has been dropped, rebuilt, or its tablespace has been
discarded or the table is corrupted, it does not make sense to
look up that table again while purging old undo log records.

purge_node_t::purge_node_t(): Replaces row_purge_node_create().

que_common_t::que_common_t(): Constructor.

row_import_update_index_root(): Remove the constant parameter
dict_locked=true, and update the table->def_trx_id in the cache.

purge_node_t::unavailable_table_id: The latest unavailable table ID,
to avoid future lookups.

purge_node_t::def_trx_id: The latest modification of the table
identified by unavailable_table_id, or TRX_ID_MAX.

purge_node_t::is_skipped(): Determine if a table should be skipped.

purge_node_t::skip(): Note that a table should be skipped.

storage/innobase/include/que0que.h

@@ -1,7 +1,7 @@
 /*****************************************************************************
 
 Copyright (c) 1996, 2016, Oracle and/or its affiliates. All Rights Reserved.
-Copyright (c) 2017, 2018, MariaDB Corporation.
+Copyright (c) 2017, 2019, MariaDB Corporation.
 
 This program is free software; you can redistribute it and/or modify it under
 the terms of the GNU General Public License as published by the Free Software
@@ -460,39 +460,6 @@ struct que_fork_t{
 /* Flag which is ORed to control structure statement node types */
 #define QUE_NODE_CONTROL_STAT	1024
 
-/* Query graph node types */
-#define	QUE_NODE_LOCK		1
-#define	QUE_NODE_INSERT		2
-#define QUE_NODE_UPDATE		4
-#define	QUE_NODE_CURSOR		5
-#define	QUE_NODE_SELECT		6
-#define	QUE_NODE_AGGREGATE	7
-#define QUE_NODE_FORK		8
-#define QUE_NODE_THR		9
-#define QUE_NODE_UNDO		10
-#define QUE_NODE_COMMIT		11
-#define QUE_NODE_ROLLBACK	12
-#define QUE_NODE_PURGE		13
-#define QUE_NODE_CREATE_TABLE	14
-#define QUE_NODE_CREATE_INDEX	15
-#define QUE_NODE_SYMBOL		16
-#define QUE_NODE_RES_WORD	17
-#define QUE_NODE_FUNC		18
-#define QUE_NODE_ORDER		19
-#define QUE_NODE_PROC		(20 + QUE_NODE_CONTROL_STAT)
-#define QUE_NODE_IF		(21 + QUE_NODE_CONTROL_STAT)
-#define QUE_NODE_WHILE		(22 + QUE_NODE_CONTROL_STAT)
-#define QUE_NODE_ASSIGNMENT	23
-#define QUE_NODE_FETCH		24
-#define QUE_NODE_OPEN		25
-#define QUE_NODE_COL_ASSIGNMENT	26
-#define QUE_NODE_FOR		(27 + QUE_NODE_CONTROL_STAT)
-#define QUE_NODE_RETURN		28
-#define QUE_NODE_ROW_PRINTF	29
-#define QUE_NODE_ELSIF		30
-#define QUE_NODE_CALL		31
-#define QUE_NODE_EXIT		32
-
 #include "que0que.ic"
 
 #endif

storage/innobase/include/que0types.h

@@ -1,6 +1,7 @@
 /*****************************************************************************
 
 Copyright (c) 1996, 2009, Oracle and/or its affiliates. All Rights Reserved.
+Copyright (c) 2019, MariaDB Corporation.
 
 This program is free software; you can redistribute it and/or modify it under
 the terms of the GNU General Public License as published by the Free Software
@@ -36,6 +37,39 @@ typedef	struct que_fork_t	que_t;
 
 struct que_thr_t;
 
+/* Query graph node types */
+#define	QUE_NODE_LOCK		1
+#define	QUE_NODE_INSERT		2
+#define QUE_NODE_UPDATE		4
+#define	QUE_NODE_CURSOR		5
+#define	QUE_NODE_SELECT		6
+#define	QUE_NODE_AGGREGATE	7
+#define QUE_NODE_FORK		8
+#define QUE_NODE_THR		9
+#define QUE_NODE_UNDO		10
+#define QUE_NODE_COMMIT		11
+#define QUE_NODE_ROLLBACK	12
+#define QUE_NODE_PURGE		13
+#define QUE_NODE_CREATE_TABLE	14
+#define QUE_NODE_CREATE_INDEX	15
+#define QUE_NODE_SYMBOL		16
+#define QUE_NODE_RES_WORD	17
+#define QUE_NODE_FUNC		18
+#define QUE_NODE_ORDER		19
+#define QUE_NODE_PROC		(20 + QUE_NODE_CONTROL_STAT)
+#define QUE_NODE_IF		(21 + QUE_NODE_CONTROL_STAT)
+#define QUE_NODE_WHILE		(22 + QUE_NODE_CONTROL_STAT)
+#define QUE_NODE_ASSIGNMENT	23
+#define QUE_NODE_FETCH		24
+#define QUE_NODE_OPEN		25
+#define QUE_NODE_COL_ASSIGNMENT	26
+#define QUE_NODE_FOR		(27 + QUE_NODE_CONTROL_STAT)
+#define QUE_NODE_RETURN		28
+#define QUE_NODE_ROW_PRINTF	29
+#define QUE_NODE_ELSIF		30
+#define QUE_NODE_CALL		31
+#define QUE_NODE_EXIT		32
+
 /* Common struct at the beginning of each query graph node; the name of this
 substruct must be 'common' */
 
@@ -51,6 +85,11 @@ struct que_common_t{
 				symbol node or a function node, then we
 				have to free the data field in val
 				explicitly */
+
+	/** Constructor */
+	que_common_t(ulint type, que_node_t* parent)
+		: type(type), parent(parent), brother(), val(), val_buf_size()
+	{}
 };
 
 #endif

storage/innobase/include/row0import.h

@@ -1,7 +1,7 @@
 /*****************************************************************************
 
 Copyright (c) 2012, 2016, Oracle and/or its affiliates. All Rights Reserved.
-Copyright (c) 2017, MariaDB Corporation.
+Copyright (c) 2017, 2019, MariaDB Corporation.
 
 This program is free software; you can redistribute it and/or modify it under
 the terms of the GNU General Public License as published by the Free Software
@@ -63,22 +63,13 @@ row_import_update_discarded_flag(
 						dict_sys_t:: mutex. */
 	MY_ATTRIBUTE((nonnull, warn_unused_result));
 
-/*****************************************************************//**
-Update the (space, root page) of a table's indexes from the values
-in the data dictionary.
+/** Update the root page numbers and tablespace ID of a table.
+@param[in,out]	trx	dictionary transaction
+@param[in,out]	table	persistent table
+@param[in]	reset	whether to reset the fields to FIL_NULL
 @return DB_SUCCESS or error code */
 dberr_t
-row_import_update_index_root(
-/*=========================*/
-	trx_t*			trx,		/*!< in/out: transaction that
-						covers the update */
-	const dict_table_t*	table,		/*!< in: Table for which we want
-						to set the root page_no */
-	bool			reset,		/*!< in: if true then set to
-						FIL_NUL */
-	bool			dict_locked)	/*!< in: Set to true if the
-						caller already owns the
-						dict_sys_t:: mutex. */
+row_import_update_index_root(trx_t* trx, dict_table_t* table, bool reset)
 	MY_ATTRIBUTE((nonnull, warn_unused_result));
 
 #endif /* row0import_h */

storage/innobase/include/row0purge.h

@@ -1,7 +1,7 @@
 /*****************************************************************************
 
 Copyright (c) 1997, 2016, Oracle and/or its affiliates. All Rights Reserved.
-Copyright (c) 2017, MariaDB Corporation.
+Copyright (c) 2017, 2019, MariaDB Corporation.
 
 This program is free software; you can redistribute it and/or modify it under
 the terms of the GNU General Public License as published by the Free Software
@@ -35,16 +35,6 @@ Created 3/14/1997 Heikki Tuuri
 #include "ut0vec.h"
 #include "row0mysql.h"
 
-/** Create a purge node to a query graph.
-@param[in]	parent	parent node, i.e., a thr node
-@param[in]	heap	memory heap where created
-@return own: purge node */
-purge_node_t*
-row_purge_node_create(
-	que_thr_t*	parent,
-	mem_heap_t*	heap)
-	MY_ATTRIBUTE((warn_unused_result));
-
 /** Determines if it is possible to remove a secondary index entry.
 Removal is possible if the secondary index entry does not refer to any
 not delete marked version of a clustered index record where DB_TRX_ID
@@ -102,6 +92,13 @@ struct purge_node_t{
 
 	ulint		rec_type;/*!< undo log record type: TRX_UNDO_INSERT_REC,
 				... */
+private:
+	/** latest unavailable table ID (do not bother looking up again) */
+	table_id_t	unavailable_table_id;
+	/** the latest modification of the table definition identified by
+	unavailable_table_id, or TRX_ID_MAX */
+	trx_id_t	def_trx_id;
+public:
 	dict_table_t*	table;	/*!< table where purge is done */
 
 	ulint		cmpl_info;/* compiler analysis info of an update */
@@ -131,6 +128,12 @@ struct purge_node_t{
 	It resets after processing each undo log record. */
 	purge_vcol_info_t	vcol_info;
 
+	/** Constructor */
+	explicit purge_node_t(que_thr_t* parent) :
+		common(QUE_NODE_PURGE, parent), heap(mem_heap_create(256)),
+		done(TRUE)
+	{}
+
 #ifdef UNIV_DEBUG
 	/***********************************************************//**
 	Validate the persisent cursor. The purge node has two references
@@ -146,6 +149,24 @@ struct purge_node_t{
 	computation.
 	@return true if the table failed to open. */
 	bool vcol_op_failed() const { return !vcol_info.validate(); }
+
+	/** Determine if a table should be skipped in purge.
+	@param[in]	table_id	table identifier
+	@return	whether to skip the table lookup and processing */
+	bool is_skipped(table_id_t id) const
+	{
+		return id == unavailable_table_id && trx_id <= def_trx_id;
+	}
+
+	/** Remember that a table should be skipped in purge.
+	@param[in]	id	table identifier
+	@param[in]	limit	last transaction for which to skip */
+	void skip(table_id_t id, trx_id_t limit)
+	{
+		DBUG_ASSERT(limit >= trx_id || !srv_safe_truncate);
+		unavailable_table_id = id;
+		def_trx_id = limit;
+	}
 };
 
 #endif

storage/innobase/row/row0import.cc

@@ -1,7 +1,7 @@
 /*****************************************************************************
 
 Copyright (c) 2012, 2016, Oracle and/or its affiliates. All Rights Reserved.
-Copyright (c) 2015, 2018, MariaDB Corporation.
+Copyright (c) 2015, 2019, MariaDB Corporation.
 
 This program is free software; you can redistribute it and/or modify it under
 the terms of the GNU General Public License as published by the Free Software
@@ -3064,23 +3064,13 @@ row_import_read_cfg(
 	return(err);
 }
 
-/*****************************************************************//**
-Update the <space, root page> of a table's indexes from the values
-in the data dictionary.
+/** Update the root page numbers and tablespace ID of a table.
+@param[in,out]	trx	dictionary transaction
+@param[in,out]	table	persistent table
+@param[in]	reset	whether to reset the fields to FIL_NULL
 @return DB_SUCCESS or error code */
 dberr_t
-row_import_update_index_root(
-/*=========================*/
-	trx_t*			trx,		/*!< in/out: transaction that
-						covers the update */
-	const dict_table_t*	table,		/*!< in: Table for which we want
-						to set the root page_no */
-	bool			reset,		/*!< in: if true then set to
-						FIL_NUL */
-	bool			dict_locked)	/*!< in: Set to true if the
-						caller already owns the
-						dict_sys_t:: mutex. */
-
+row_import_update_index_root(trx_t* trx, dict_table_t* table, bool reset)
 {
 	const dict_index_t*	index;
 	que_t*			graph = 0;
@@ -3096,9 +3086,7 @@ row_import_update_index_root(
 		"WHERE TABLE_ID = :table_id AND ID = :index_id;\n"
 		"END;\n"};
 
-	if (!dict_locked) {
-		mutex_enter(&dict_sys->mutex);
-	}
+	table->def_trx_id = trx->id;
 
 	for (index = dict_table_get_first_index(table);
 	     index != 0;
@@ -3173,10 +3161,6 @@ row_import_update_index_root(
 
 	que_graph_free(graph);
 
-	if (!dict_locked) {
-		mutex_exit(&dict_sys->mutex);
-	}
-
 	return(err);
 }
 
@@ -4118,7 +4102,7 @@ row_import_for_mysql(
 	row_mysql_lock_data_dictionary(trx);
 
 	/* Update the root pages of the table's indexes. */
-	err = row_import_update_index_root(trx, table, false, true);
+	err = row_import_update_index_root(trx, table, false);
 
 	if (err != DB_SUCCESS) {
 		return(row_import_error(prebuilt, trx, err));

storage/innobase/row/row0mysql.cc

@@ -2940,7 +2940,7 @@ row_discard_tablespace(
 	}
 
 	/* Update the index root pages in the system tables, on disk */
-	err = row_import_update_index_root(trx, table, true, true);
+	err = row_import_update_index_root(trx, table, true);
 
 	if (err != DB_SUCCESS) {
 		return(err);