[RP006] Reverts wrong changes for Adaptive Hash Index

Reverts BAD performance changes for AHI. The Bug #31750840 ADAPTIVE HASH INDEX(AHI) BUILDING CAUSING CONTENTION ON BTR_SEARCH_LATCHES Bug #33601434 InnoDB: AHI-related fields n_fields, n_bytes, left_side should be atomically set are basically wrong. Just intorducing performance regression of AHI... The AHI search is optimistic trial before normal b-tree search. If succeeds, can skip normal b-tree search. So, the most important for AHI performance is "turn-around time", has priority over "concurrent scale" or "search consistency", to minimize the trial overhead and basically limited concurrency of hash indexes. AHI limits concurrency for minimize each waiting time of "turn-around time", basically. But the BAD changes increased "turn-around time" much, and cannot get concurrency enogh than that. Just introducing regression in total. And AHI has enough result check at the end of search, and fail to search is acceptable. But the BAD changes introduced useless cosistency keeping and its overhead for "turn-around time". In addition, the BAD changes seem to contain bad code for some kinds of PGO build. Even non-AHI path, performance regression detected, lower throughput than normal build. Such no merit and only risky code should be eliminated. Reverts the followings whole as possible as we can. > commit 78e695d > Author: Marcin Babij <marcin.babij@oracle.com> > Date: Fri Apr 1 00:29:48 2022 +0200 > > Bug #31750840 ADAPTIVE HASH INDEX(AHI) BUILDING CAUSING CONTENTION ON BTR_SEARCH_LATCHES > commit d7114b1 > Author: Marcin Babij <marcin.babij@oracle.com> > Date: Fri Aug 12 17:01:16 2022 +0200 > > Bug #33601434 InnoDB: AHI-related fields n_fields, n_bytes, left_side should be atomically set and also reverted bug fix introduced by the above BAD changes. Because not needed now. > commit 1392643 > Author: Yasufumi Kinoshita <yasufumi.kinoshita@oracle.com> > Date: Mon Dec 12 16:26:57 2022 +0900 > > Bug#34544595: btr_search_hash_table_validate() has race condition with btr_search_disable() > commit 8c944fc > Author: Ramakrishnan Kamalakannan <ramakrishnan.kamalakannan@oracle.com> > Date: Fri Aug 18 08:49:34 2023 +0200 > > Bug#35037114 Server crash in old_index != nullptr at my_server_abort

Author: buildup-db

mysql-test/suite/innodb/r/disable_ahi_other_blocks.result

@@ -6075,8 +6075,8 @@ ER_IB_MSG_179
 ER_IB_MSG_180
  eng "%s"
 
-ER_IB_LONG_AHI_DISABLE_WAIT
- eng "Waited for %u secs for hash index ref_count (%zu) to drop to 0. index: \"%s\" table: \"%s\""
+ER_IB_MSG_181
+ eng "%s"
 
 ER_IB_MSG_182
  eng "%s"

mysql-test/suite/innodb/t/disable_ahi_other_blocks-master.opt

@@ -1552,7 +1552,7 @@ rec_t *btr_root_raise_and_insert(
  lock_prdt_rec_move(new_block, root_block);
  }
 
- btr_search_update_hash_on_move(new_block, root_block, index);
+ btr_search_move_or_delete_hash_entries(new_block, root_block, index);
  }
 
  /* If this is a pessimistic insert which is actually done to
@@ -2508,7 +2508,7 @@ rec_t *btr_page_split_and_insert(
  new_page + PAGE_NEW_INFIMUM);
  }
 
- btr_search_update_hash_on_move(new_block, block, cursor->index);
+ btr_search_move_or_delete_hash_entries(new_block, block, cursor->index);
 
  /* Delete the records from the source page. */
 
@@ -2549,7 +2549,7 @@ rec_t *btr_page_split_and_insert(
 
  ut_ad(!dict_index_is_spatial(index));
 
- btr_search_update_hash_on_move(new_block, block, cursor->index);
+ btr_search_move_or_delete_hash_entries(new_block, block, cursor->index);
 
  /* Delete the records from the source page. */
 
@@ -2936,7 +2936,7 @@ static buf_block_t *btr_lift_page_up(
  lock_prdt_rec_move(father_block, block);
  }
 
- btr_search_update_hash_on_move(father_block, block, index);
+ btr_search_move_or_delete_hash_entries(father_block, block, index);
  }
 
  if (!dict_table_is_locking_disabled(index->table)) {

mysql-test/suite/innodb/t/disable_ahi_other_blocks.test

@@ -688,6 +688,7 @@ void btr_cur_search_to_nth_level(
 
  DBUG_TRACE;
 
+ btr_search_t *info;
  mem_heap_t *heap = nullptr;
  ulint offsets_[REC_OFFS_NORMAL_SIZE];
  ulint *offsets = offsets_;
@@ -770,13 +771,15 @@ void btr_cur_search_to_nth_level(
  cursor->flag = BTR_CUR_BINARY;
  cursor->index = index;
 
+ info = btr_search_get_info(index);
+
 #ifdef UNIV_SEARCH_PERF_STAT
  info->n_searches++;
 #endif
  /* Use of AHI is disabled for intrinsic table as these tables re-use
  the index-id and AHI validation is based on index-id. */
  if (rw_lock_get_writer(btr_get_search_latch(index)) == RW_LOCK_NOT_LOCKED &&
- latch_mode <= BTR_MODIFY_LEAF && index->search_info->last_hash_succ &&
+ latch_mode <= BTR_MODIFY_LEAF && info->last_hash_succ &&
  !index->disable_ahi && !estimate
 #ifdef PAGE_CUR_LE_OR_EXTENDS
  && mode != PAGE_CUR_LE_OR_EXTENDS
@@ -786,7 +789,7 @@ void btr_cur_search_to_nth_level(
  btr_search_enabled below, and btr_search_guess_on_hash()
  will have to check it again. */
  && UNIV_LIKELY(btr_search_enabled) && !modify_external &&
- btr_search_guess_on_hash(tuple, mode, latch_mode, cursor,
+ btr_search_guess_on_hash(index, info, tuple, mode, latch_mode, cursor,
  has_search_latch, mtr)) {
 
  /* Search using the hash index succeeded */
@@ -958,10 +961,10 @@ void btr_cur_search_to_nth_level(
 retry_page_get:
  ut_ad(n_blocks < BTR_MAX_LEVELS);
  tree_savepoints[n_blocks] = mtr_set_savepoint(mtr);
- block = buf_page_get_gen(
- page_id, page_size, rw_latch,
- (height == ULINT_UNDEFINED ? index->search_info->root_guess : nullptr),
- fetch, {file, line}, mtr);
+ block =
+ buf_page_get_gen(page_id, page_size, rw_latch,
+  (height == ULINT_UNDEFINED ? info->root_guess : nullptr),
+  fetch, {file, line}, mtr);
 
  tree_blocks[n_blocks] = block;
 
@@ -1130,7 +1133,7 @@ void btr_cur_search_to_nth_level(
  rtr_get_mbr_from_tuple(tuple, &cursor->rtr_info->mbr);
  }
 
- index->search_info->root_guess = block;
+ info->root_guess = block;
  }
 
  if (height == 0) {
@@ -1657,7 +1660,7 @@ void btr_cur_search_to_nth_level(
  btr_search_build_page_hash_index() before building a
  page hash index, while holding search latch. */
  if (btr_search_enabled && !index->disable_ahi) {
- btr_search_info_update(cursor);
+ btr_search_info_update(index, cursor);
  }
  ut_ad(cursor->up_match != ULINT_UNDEFINED || mode != PAGE_CUR_GE);
  ut_ad(cursor->up_match != ULINT_UNDEFINED || mode != PAGE_CUR_LE);
@@ -3337,6 +3340,7 @@ dberr_t btr_cur_update_in_place(ulint flags, btr_cur_t *cursor, ulint *offsets,
  rec_t *rec;
  roll_ptr_t roll_ptr = 0;
  bool was_delete_marked;
+ bool is_hashed;
 
  rec = btr_cur_get_rec(cursor);
  index = cursor->index;
@@ -3394,7 +3398,9 @@ dberr_t btr_cur_update_in_place(ulint flags, btr_cur_t *cursor, ulint *offsets,
  was_delete_marked =
  rec_get_deleted_flag(rec, page_is_comp(buf_block_get_frame(block)));
 
- if (block->ahi.index.load() != nullptr) {
+ is_hashed = (block->index != nullptr);
+
+ if (is_hashed) {
  /* TO DO: Can we skip this if none of the fields
  index->search_info->curr_n_fields
  are being updated? */
@@ -3409,11 +3415,17 @@ dberr_t btr_cur_update_in_place(ulint flags, btr_cur_t *cursor, ulint *offsets,
  /* Remove possible hash index pointer to this record */
  btr_search_update_hash_on_delete(cursor);
  }
+
+ rw_lock_x_lock(btr_get_search_latch(index), UT_LOCATION_HERE);
  }
 
- block->ahi.validate();
+ assert_block_ahi_valid(block);
  row_upd_rec_in_place(rec, index, offsets, update, page_zip);
 
+ if (is_hashed) {
+ rw_lock_x_unlock(btr_get_search_latch(index));
+ }
+
  btr_cur_update_in_place_log(flags, rec, index, update, trx_id, roll_ptr, mtr);
 
  if (was_delete_marked &&