row0umod.c 19.2 KB
Newer Older
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96
/******************************************************
Undo modify of a row

(c) 1997 Innobase Oy

Created 2/27/1997 Heikki Tuuri
*******************************************************/

#include "row0umod.h"

#ifdef UNIV_NONINL
#include "row0umod.ic"
#endif

#include "dict0dict.h"
#include "dict0boot.h"
#include "trx0undo.h"
#include "trx0roll.h"
#include "btr0btr.h"
#include "mach0data.h"
#include "row0undo.h"
#include "row0vers.h"
#include "trx0trx.h"
#include "trx0rec.h"
#include "row0row.h"
#include "row0upd.h"
#include "que0que.h"
#include "log0log.h"

/* Considerations on undoing a modify operation.
(1) Undoing a delete marking: all index records should be found. Some of
them may have delete mark already FALSE, if the delete mark operation was
stopped underway, or if the undo operation ended prematurely because of a
system crash.
(2) Undoing an update of a delete unmarked record: the newer version of
an updated secondary index entry should be removed if no prior version
of the clustered index record requires its existence. Otherwise, it should
be delete marked.
(3) Undoing an update of a delete marked record. In this kind of update a
delete marked clustered index record was delete unmarked and possibly also
some of its fields were changed. Now, it is possible that the delete marked
version has become obsolete at the time the undo is started. */

/***************************************************************
Checks if also the previous version of the clustered index record was
modified or inserted by the same transaction, and its undo number is such
that it should be undone in the same rollback. */
UNIV_INLINE
ibool
row_undo_mod_undo_also_prev_vers(
/*=============================*/
				/* out: TRUE if also previous modify or
				insert of this row should be undone */
 	undo_node_t*	node,	/* in: row undo node */
	que_thr_t*	thr,	/* in: query thread */
	dulint*		undo_no)/* out: the undo number */
{
	trx_undo_rec_t*	undo_rec;
	ibool		ret;
	trx_t*		trx;

	UT_NOT_USED(thr);

	trx = node->trx;
	
	if (0 != ut_dulint_cmp(node->new_trx_id, trx->id)) {

		return(FALSE);
	}

	undo_rec = trx_undo_get_undo_rec_low(node->new_roll_ptr, node->heap);

	*undo_no = trx_undo_rec_get_undo_no(undo_rec);

	if (ut_dulint_cmp(trx->roll_limit, *undo_no) <= 0) {
		ret = TRUE;
	} else {
		ret = FALSE;
	}
	
	return(ret);
}
	
/***************************************************************
Undoes a modify in a clustered index record. */
static
ulint
row_undo_mod_clust_low(
/*===================*/
				/* out: DB_SUCCESS, DB_FAIL, or error code:
				we may run out of file space */
	undo_node_t*	node,	/* in: row undo node */
	que_thr_t*	thr,	/* in: query thread */
	mtr_t*		mtr,	/* in: mtr */
	ulint		mode)	/* in: BTR_MODIFY_LEAF or BTR_MODIFY_TREE */
{
97
	big_rec_t*	dummy_big_rec;
98 99 100 101 102 103 104 105 106 107 108 109
	btr_pcur_t*	pcur;
	btr_cur_t*	btr_cur;
	ulint		err;
	ibool		success;

	pcur = &(node->pcur);
	btr_cur = btr_pcur_get_btr_cur(pcur);

	success = btr_pcur_restore_position(mode, pcur, mtr);

	ut_ad(success);

110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138
	if (mode == BTR_MODIFY_LEAF) {

		err = btr_cur_optimistic_update(BTR_NO_LOCKING_FLAG
					| BTR_NO_UNDO_LOG_FLAG
					| BTR_KEEP_SYS_FLAG,
					btr_cur, node->update,
					node->cmpl_info, thr, mtr);
	} else {
		ut_ad(mode == BTR_MODIFY_TREE);

		err = btr_cur_pessimistic_update(BTR_NO_LOCKING_FLAG
					| BTR_NO_UNDO_LOG_FLAG
					| BTR_KEEP_SYS_FLAG,
					btr_cur, &dummy_big_rec, node->update,
					node->cmpl_info, thr, mtr);
	}

	return(err);
}
		
/***************************************************************
Removes a clustered index record after undo if possible. */
static
ulint
row_undo_mod_remove_clust_low(
/*==========================*/
				/* out: DB_SUCCESS, DB_FAIL, or error code:
				we may run out of file space */
	undo_node_t*	node,	/* in: row undo node */
unknown's avatar
unknown committed
139
	que_thr_t*	thr __attribute__((unused)), /* in: query thread */
140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157
	mtr_t*		mtr,	/* in: mtr */
	ulint		mode)	/* in: BTR_MODIFY_LEAF or BTR_MODIFY_TREE */
{
	btr_pcur_t*	pcur;
	btr_cur_t*	btr_cur;
	ulint		err;
	ibool		success;
	
	pcur = &(node->pcur);
	btr_cur = btr_pcur_get_btr_cur(pcur);

	success = btr_pcur_restore_position(mode, pcur, mtr);

	if (!success) {

		return(DB_SUCCESS);
	}

158 159 160 161 162
	/* Find out if we can remove the whole clustered index record */

	if (node->rec_type == TRX_UNDO_UPD_DEL_REC
	    && !row_vers_must_preserve_del_marked(node->new_trx_id, mtr)) {

163
		/* Ok, we can remove */
164
	} else {
165
		return(DB_SUCCESS);
166 167 168
	}
	    
	if (mode == BTR_MODIFY_LEAF) {
169
		success = btr_cur_optimistic_delete(btr_cur, mtr);
170

171 172
		if (success) {
			err = DB_SUCCESS;
173
		} else {
174
			err = DB_FAIL;
175 176 177 178
		}
	} else {
		ut_ad(mode == BTR_MODIFY_TREE);

179 180 181 182 183
		/* Note that since this operation is analogous to purge,
		we can free also inherited externally stored fields:
		hence the last FALSE in the call below */

		btr_cur_pessimistic_delete(&err, FALSE, btr_cur, FALSE, mtr);
184

185 186 187
		/* The delete operation may fail if we have little
		file space left: TODO: easiest to crash the database
		and restart with more file space */
188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240
	}

	return(err);
}
		
/***************************************************************
Undoes a modify in a clustered index record. Sets also the node state for the
next round of undo. */
static
ulint
row_undo_mod_clust(
/*===============*/
				/* out: DB_SUCCESS or error code: we may run
				out of file space */
	undo_node_t*	node,	/* in: row undo node */
	que_thr_t*	thr)	/* in: query thread */
{
	btr_pcur_t*	pcur;
	mtr_t		mtr;
	ulint		err;
	ibool		success;
	ibool		more_vers;
	dulint		new_undo_no;
	
	ut_ad(node && thr);

	/* Check if also the previous version of the clustered index record
	should be undone in this same rollback operation */

	more_vers = row_undo_mod_undo_also_prev_vers(node, thr, &new_undo_no);

	pcur = &(node->pcur);

	mtr_start(&mtr);

	/* Try optimistic processing of the record, keeping changes within
	the index page */

	err = row_undo_mod_clust_low(node, thr, &mtr, BTR_MODIFY_LEAF);

	if (err != DB_SUCCESS) {
		btr_pcur_commit_specify_mtr(pcur, &mtr);

		/* We may have to modify tree structure: do a pessimistic
		descent down the index tree */

		mtr_start(&mtr);

		err = row_undo_mod_clust_low(node, thr, &mtr, BTR_MODIFY_TREE);
	}

	btr_pcur_commit_specify_mtr(pcur, &mtr);

241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263
	if (err == DB_SUCCESS && node->rec_type == TRX_UNDO_UPD_DEL_REC) {
	
		mtr_start(&mtr);

		err = row_undo_mod_remove_clust_low(node, thr, &mtr,
							BTR_MODIFY_LEAF);
		if (err != DB_SUCCESS) {
			btr_pcur_commit_specify_mtr(pcur, &mtr);

			/* We may have to modify tree structure: do a
			pessimistic descent down the index tree */

			mtr_start(&mtr);

			err = row_undo_mod_remove_clust_low(node, thr, &mtr,
							BTR_MODIFY_TREE);
		}

		btr_pcur_commit_specify_mtr(pcur, &mtr);
	}

	node->state = UNDO_NODE_FETCH_NEXT;
	
264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290 291 292 293 294 295 296 297 298 299 300 301 302 303
 	trx_undo_rec_release(node->trx, node->undo_no);

	if (more_vers && err == DB_SUCCESS) {

		/* Reserve the undo log record to the prior version after
		committing &mtr: this is necessary to comply with the latching
		order, as &mtr may contain the fsp latch which is lower in
		the latch hierarchy than trx->undo_mutex. */

		success = trx_undo_rec_reserve(node->trx, new_undo_no);

		if (success) {
			node->state = UNDO_NODE_PREV_VERS;
		}
	}

	return(err);
}

/***************************************************************
Delete marks or removes a secondary index entry if found. */
static
ulint
row_undo_mod_del_mark_or_remove_sec_low(
/*====================================*/
				/* out: DB_SUCCESS, DB_FAIL, or
				DB_OUT_OF_FILE_SPACE */
	undo_node_t*	node,	/* in: row undo node */
	que_thr_t*	thr,	/* in: query thread */
	dict_index_t*	index,	/* in: index */
	dtuple_t*	entry,	/* in: index entry */
	ulint		mode)	/* in: latch mode BTR_MODIFY_LEAF or
				BTR_MODIFY_TREE */	
{
	ibool		found;
	btr_pcur_t	pcur;
	btr_cur_t*	btr_cur;
	ibool		success;
	ibool		old_has;
	ulint		err;
unknown's avatar
Merge  
unknown committed
304 305
	mtr_t		mtr;
	mtr_t		mtr_vers;
306 307 308 309 310 311 312 313 314 315 316 317 318 319 320 321 322 323 324 325 326 327 328 329 330
	
	log_free_check();
	mtr_start(&mtr);
	
	found = row_search_index_entry(index, entry, mode, &pcur, &mtr);

	btr_cur = btr_pcur_get_btr_cur(&pcur);

	if (!found) {
		/* Not found */

		btr_pcur_close(&pcur);
		mtr_commit(&mtr);

		return(DB_SUCCESS);
	}

	/* We should remove the index record if no prior version of the row,
	which cannot be purged yet, requires its existence. If some requires,
	we should delete mark the record. */

	mtr_start(&mtr_vers);
		
	success = btr_pcur_restore_position(BTR_SEARCH_LEAF, &(node->pcur),
								&mtr_vers);
unknown's avatar
Merge  
unknown committed
331
	ut_a(success);
332 333 334 335 336 337 338 339 340 341 342 343 344 345 346 347 348 349 350 351 352
		
	old_has = row_vers_old_has_index_entry(FALSE,
					btr_pcur_get_rec(&(node->pcur)),
					&mtr_vers, index, entry);
	if (old_has) {
		err = btr_cur_del_mark_set_sec_rec(BTR_NO_LOCKING_FLAG,
						btr_cur, TRUE, thr, &mtr);
		ut_ad(err == DB_SUCCESS);
	} else {
		/* Remove the index record */

		if (mode == BTR_MODIFY_LEAF) {		
			success = btr_cur_optimistic_delete(btr_cur, &mtr);
			if (success) {
				err = DB_SUCCESS;
			} else {
				err = DB_FAIL;
			}
		} else {
			ut_ad(mode == BTR_MODIFY_TREE);

353
			btr_cur_pessimistic_delete(&err, FALSE, btr_cur,
unknown's avatar
Merge  
unknown committed
354
								TRUE, &mtr);
355 356 357 358 359 360 361 362 363 364 365 366 367 368 369

			/* The delete operation may fail if we have little
			file space left: TODO: easiest to crash the database
			and restart with more file space */
		}
	}

	btr_pcur_commit_specify_mtr(&(node->pcur), &mtr_vers);
	btr_pcur_close(&pcur);
	mtr_commit(&mtr);

	return(err);
}

/***************************************************************
unknown's avatar
unknown committed
370 371 372 373 374 375 376 377
Delete marks or removes a secondary index entry if found.
NOTE that if we updated the fields of a delete-marked secondary index record
so that alphabetically they stayed the same, e.g., 'abc' -> 'aBc', we cannot
return to the original values because we do not know them. But this should
not cause problems because in row0sel.c, in queries we always retrieve the
clustered index record or an earlier version of it, if the secondary index
record through which we do the search is delete-marked. */
static
378 379 380 381 382 383 384 385 386 387 388 389 390 391 392 393 394 395 396 397 398 399 400 401
ulint
row_undo_mod_del_mark_or_remove_sec(
/*================================*/
				/* out: DB_SUCCESS or DB_OUT_OF_FILE_SPACE */
	undo_node_t*	node,	/* in: row undo node */
	que_thr_t*	thr,	/* in: query thread */
	dict_index_t*	index,	/* in: index */
	dtuple_t*	entry)	/* in: index entry */
{
	ulint	err;
	
	err = row_undo_mod_del_mark_or_remove_sec_low(node, thr, index,
 						entry, BTR_MODIFY_LEAF);
	if (err == DB_SUCCESS) {

		return(err);
	}

	err = row_undo_mod_del_mark_or_remove_sec_low(node, thr, index,
 						entry, BTR_MODIFY_TREE);
 	return(err);
}

/***************************************************************
unknown's avatar
unknown committed
402 403 404 405
Delete unmarks a secondary index entry which must be found. It might not be
delete-marked at the moment, but it does not harm to unmark it anyway. We also
need to update the fields of the secondary index record if we updated its
fields but alphabetically they stayed the same, e.g., 'abc' -> 'aBc'. */
406
static
unknown's avatar
unknown committed
407 408 409 410 411 412 413
ulint
row_undo_mod_del_unmark_sec_and_undo_update(
/*========================================*/
				/* out: DB_FAIL or DB_SUCCESS or
				DB_OUT_OF_FILE_SPACE */
	ulint		mode,	/* in: search mode: BTR_MODIFY_LEAF or
				BTR_MODIFY_TREE */
414 415 416 417
	que_thr_t*	thr,	/* in: query thread */
	dict_index_t*	index,	/* in: index */
	dtuple_t*	entry)	/* in: index entry */
{
unknown's avatar
unknown committed
418
	mem_heap_t*	heap;
419
	btr_pcur_t	pcur;
unknown's avatar
unknown committed
420 421
	upd_t*		update;
	ulint		err		= DB_SUCCESS;
422
	ibool		found;
unknown's avatar
unknown committed
423
	big_rec_t*	dummy_big_rec;
unknown's avatar
Merge  
unknown committed
424
	mtr_t		mtr;
425 426 427 428

	log_free_check();
	mtr_start(&mtr);
	
unknown's avatar
unknown committed
429 430
	found = row_search_index_entry(index, entry, mode, &pcur, &mtr);

431
	if (!found) {
432 433 434 435 436 437 438 439 440 441 442 443
		fputs("InnoDB: error in sec index entry del undo in\n"
			"InnoDB: ", stderr);
		dict_index_name_print(stderr, index);
		fputs("\n"
			"InnoDB: tuple ", stderr);
		dtuple_print(stderr, entry);
		fputs("\n"
			"InnoDB: record ", stderr);
		rec_print(stderr, btr_pcur_get_rec(&pcur));
		putc('\n', stderr);
		trx_print(stderr, thr_get_trx(thr));
		fputs("\n"
444
"InnoDB: Submit a detailed bug report to http://bugs.mysql.com\n", stderr);
445
	} else {
446
		btr_cur_t*	btr_cur = btr_pcur_get_btr_cur(&pcur);
447 448

	        err = btr_cur_del_mark_set_sec_rec(BTR_NO_LOCKING_FLAG,
449
						btr_cur, FALSE, thr, &mtr);
unknown's avatar
unknown committed
450 451 452 453
	        ut_a(err == DB_SUCCESS);
		heap = mem_heap_create(100);

		update = row_upd_build_sec_rec_difference_binary(index, entry,
454
					btr_cur_get_rec(btr_cur), heap);
unknown's avatar
unknown committed
455 456 457 458 459 460 461 462 463 464 465 466 467 468 469 470 471 472 473 474 475 476 477
	        if (upd_get_n_fields(update) == 0) {

			/* Do nothing */
		
		} else if (mode == BTR_MODIFY_LEAF) {
                	/* Try an optimistic updating of the record, keeping
			changes within the page */

                	err = btr_cur_optimistic_update(BTR_KEEP_SYS_FLAG
							| BTR_NO_LOCKING_FLAG,
 						btr_cur, update, 0, thr, &mtr);
                	if (err == DB_OVERFLOW || err == DB_UNDERFLOW) {
                        	err = DB_FAIL;
                	}
       		} else  {
                	ut_a(mode == BTR_MODIFY_TREE);
                	err = btr_cur_pessimistic_update(BTR_KEEP_SYS_FLAG
							| BTR_NO_LOCKING_FLAG,
						btr_cur, &dummy_big_rec,
						update, 0, thr, &mtr);
        	}			

		mem_heap_free(heap);
478
	}
479 480 481

	btr_pcur_close(&pcur);
	mtr_commit(&mtr);
unknown's avatar
unknown committed
482 483

	return(err);
484 485 486 487 488 489 490 491 492 493 494 495 496 497 498 499 500 501 502 503 504 505 506 507 508 509 510 511 512 513 514 515 516 517 518 519 520 521 522 523 524 525 526 527 528 529 530
}

/***************************************************************
Undoes a modify in secondary indexes when undo record type is UPD_DEL. */
static
ulint
row_undo_mod_upd_del_sec(
/*=====================*/
				/* out: DB_SUCCESS or DB_OUT_OF_FILE_SPACE */
	undo_node_t*	node,	/* in: row undo node */
	que_thr_t*	thr)	/* in: query thread */
{
	mem_heap_t*	heap;
	dtuple_t*	entry;
	dict_index_t*	index;
	ulint		err;
	
	heap = mem_heap_create(1024);

	while (node->index != NULL) {
		index = node->index;

		entry = row_build_index_entry(node->row, index, heap);

		err = row_undo_mod_del_mark_or_remove_sec(node, thr, index,
								entry);
		if (err != DB_SUCCESS) {

			mem_heap_free(heap);

			return(err);
		}
									
		node->index = dict_table_get_next_index(node->index);
	}

	mem_heap_free(heap);

	return(DB_SUCCESS);
}

/***************************************************************
Undoes a modify in secondary indexes when undo record type is DEL_MARK. */
static
ulint
row_undo_mod_del_mark_sec(
/*======================*/
unknown's avatar
unknown committed
531
				/* out: DB_SUCCESS or DB_OUT_OF_FILE_SPACE */
532 533 534 535 536 537
	undo_node_t*	node,	/* in: row undo node */
	que_thr_t*	thr)	/* in: query thread */
{
	mem_heap_t*	heap;
	dtuple_t*	entry;
	dict_index_t*	index;
unknown's avatar
unknown committed
538
	ulint		err;
539 540 541 542 543 544 545 546

	heap = mem_heap_create(1024);

	while (node->index != NULL) {
		index = node->index;

		entry = row_build_index_entry(node->row, index, heap);
		
unknown's avatar
unknown committed
547 548
		err = row_undo_mod_del_unmark_sec_and_undo_update(
						BTR_MODIFY_LEAF,
549
						thr, index, entry);
unknown's avatar
unknown committed
550 551 552
		if (err == DB_FAIL) {
			err = row_undo_mod_del_unmark_sec_and_undo_update(
						BTR_MODIFY_TREE,
553
						thr, index, entry);
unknown's avatar
unknown committed
554 555 556 557 558 559 560 561
		}

		if (err != DB_SUCCESS) {

			mem_heap_free(heap);

			return(err);
		}
562 563 564 565 566 567 568 569 570 571 572 573 574 575 576

		node->index = dict_table_get_next_index(node->index);
	}

	mem_heap_free(heap);	

	return(DB_SUCCESS);
}

/***************************************************************
Undoes a modify in secondary indexes when undo record type is UPD_EXIST. */
static
ulint
row_undo_mod_upd_exist_sec(
/*=======================*/
unknown's avatar
unknown committed
577
				/* out: DB_SUCCESS or DB_OUT_OF_FILE_SPACE */
578 579 580 581 582 583 584 585 586 587 588 589 590 591 592 593 594 595 596
	undo_node_t*	node,	/* in: row undo node */
	que_thr_t*	thr)	/* in: query thread */
{
	mem_heap_t*	heap;
	dtuple_t*	entry;
	dict_index_t*	index;
	ulint		err;

	if (node->cmpl_info & UPD_NODE_NO_ORD_CHANGE) {
		/* No change in secondary indexes */
	
		return(DB_SUCCESS);
	}
	
	heap = mem_heap_create(1024);

	while (node->index != NULL) {
		index = node->index;

597
		if (row_upd_changes_ord_field_binary(node->row, node->index,
598 599 600 601 602
							node->update)) {

			/* Build the newest version of the index entry */
			entry = row_build_index_entry(node->row, index, heap);

unknown's avatar
unknown committed
603 604 605 606 607 608 609 610 611 612
			/* NOTE that if we updated the fields of a
			delete-marked secondary index record so that
			alphabetically they stayed the same, e.g.,
			'abc' -> 'aBc', we cannot return to the original
			values because we do not know them. But this should
			not cause problems because in row0sel.c, in queries
			we always retrieve the clustered index record or an
			earlier version of it, if the secondary index record
			through which we do the search is delete-marked. */

613
			err = row_undo_mod_del_mark_or_remove_sec(node, thr,
unknown's avatar
unknown committed
614
								index, entry);
615 616 617 618 619
			if (err != DB_SUCCESS) {
				mem_heap_free(heap);

				return(err);
			}
unknown's avatar
unknown committed
620

621 622
			/* We may have to update the delete mark in the
			secondary index record of the previous version of
unknown's avatar
unknown committed
623 624 625 626
			the row. We also need to update the fields of
			the secondary index record if we updated its fields
			but alphabetically they stayed the same, e.g.,
			'abc' -> 'aBc'. */
627 628

			row_upd_index_replace_new_col_vals(entry, index,
unknown's avatar
unknown committed
629
							node->update, NULL);
unknown's avatar
unknown committed
630 631
			err = row_undo_mod_del_unmark_sec_and_undo_update(
						BTR_MODIFY_LEAF,
632
						thr, index, entry);
unknown's avatar
unknown committed
633 634 635 636
			if (err == DB_FAIL) {
				err =
				   row_undo_mod_del_unmark_sec_and_undo_update(
						BTR_MODIFY_TREE,
637
						thr, index, entry);
unknown's avatar
unknown committed
638
			}
639

unknown's avatar
unknown committed
640 641 642 643 644
			if (err != DB_SUCCESS) {
				mem_heap_free(heap);

				return(err);
			}
645 646 647 648 649 650 651 652 653 654 655 656 657 658 659 660 661 662 663 664 665 666 667 668 669 670 671 672
		}

		node->index = dict_table_get_next_index(node->index);
	}

	mem_heap_free(heap);

	return(DB_SUCCESS);
}

/***************************************************************
Parses the row reference and other info in a modify undo log record. */
static
void
row_undo_mod_parse_undo_rec(
/*========================*/
	undo_node_t*	node,	/* in: row undo node */
	que_thr_t*	thr)	/* in: query thread */
{
	dict_index_t*	clust_index;
	byte*		ptr;
	dulint		undo_no;
	dulint		table_id;
	dulint		trx_id;
	dulint		roll_ptr;
	ulint		info_bits;
	ulint		type;
	ulint		cmpl_info;
673
	ibool		dummy_extern;
674 675 676 677
	
	ut_ad(node && thr);
	
	ptr = trx_undo_rec_get_pars(node->undo_rec, &type, &cmpl_info,
678
					&dummy_extern, &undo_no, &table_id);
679 680 681 682
	node->rec_type = type;
	
	node->table = dict_table_get_on_id(table_id, thr_get_trx(thr));

683 684 685 686 687 688 689 690
	/* TODO: other fixes associated with DROP TABLE + rollback in the
	same table by another user */

	if (node->table == NULL) {
	        /* Table was dropped */
	        return;
	}

691 692 693 694 695 696 697 698 699 700 701 702 703 704 705 706 707 708 709 710 711 712 713 714 715 716 717 718 719 720 721 722 723 724
	clust_index = dict_table_get_first_index(node->table);

	ptr = trx_undo_update_rec_get_sys_cols(ptr, &trx_id, &roll_ptr,
								&info_bits);

	ptr = trx_undo_rec_get_row_ref(ptr, clust_index, &(node->ref),
								node->heap);

	trx_undo_update_rec_get_update(ptr, clust_index, type, trx_id,
					roll_ptr, info_bits, node->heap,
					&(node->update));
	node->new_roll_ptr = roll_ptr;
	node->new_trx_id = trx_id;
	node->cmpl_info = cmpl_info;
}
	
/***************************************************************
Undoes a modify operation on a row of a table. */

ulint
row_undo_mod(
/*=========*/
				/* out: DB_SUCCESS or error code */
	undo_node_t*	node,	/* in: row undo node */
	que_thr_t*	thr)	/* in: query thread */
{
	ibool	found;
	ulint	err;
	
	ut_ad(node && thr);
	ut_ad(node->state == UNDO_NODE_MODIFY);

	row_undo_mod_parse_undo_rec(node, thr);

725
	if (node->table == NULL) {
726
		found = FALSE;
727
	} else {
728
		found = row_undo_search_clust_to_pcur(node);
729
	}
730 731 732

	if (!found) {
		/* It is already undone, or will be undone by another query
733
		thread, or table was dropped */
734
	
735
	        trx_undo_rec_release(node->trx, node->undo_no);
736 737 738 739 740 741 742 743 744 745 746 747 748 749 750 751 752 753 754 755 756 757 758 759 760 761 762 763 764
		node->state = UNDO_NODE_FETCH_NEXT;

		return(DB_SUCCESS);
	}

	node->index = dict_table_get_next_index(
				dict_table_get_first_index(node->table));

	if (node->rec_type == TRX_UNDO_UPD_EXIST_REC) {
		
		err = row_undo_mod_upd_exist_sec(node, thr);

	} else if (node->rec_type == TRX_UNDO_DEL_MARK_REC) {

		err = row_undo_mod_del_mark_sec(node, thr);
	} else {
		ut_ad(node->rec_type == TRX_UNDO_UPD_DEL_REC);
		err = row_undo_mod_upd_del_sec(node, thr);
	}

	if (err != DB_SUCCESS) {

		return(err);
	}
	
	err = row_undo_mod_clust(node, thr);
	
	return(err);
}