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Reduce the size of btr_search_t from 13 machine words to 7. This
structure is reserved for every index in the data dictionary cache. (Bug #20877) We could shrink the structure further to three 32-bit words or two 64-bit words by turning the remaining fields to bit-fields. Unfortunately, the fields are not protected by any mutex, and thus we would better keep each field aligned to a machine word. btr_search_t, buf_block_t: Rename "ulint side" to "ibool left_side". Remove BTR_SEARCH_LEFT_SIDE and BTR_SEARCH_RIGHT_SIDE, and also rename some local variables and function parameters from "ulint side" to "ibool left_side". btr_search_t: Remove the unused fields last_search, n_direction, direction, and modify_clock. Remove the unused constants BTR_SEA_NO_DIRECTION, BTR_SEA_LEFT, BTR_SEA_RIGHT, and BTR_SEA_SAME_REC. btr_search_t: Remove magic_n unless #defined UNIV_DEBUG. Turn an assertion about the magic number into a debug assertion.
This commit is contained in:
marko
parent
0e79b32012
commit
0efd5d663e
4 changed files with 61 additions and 84 deletions
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@ -74,7 +74,7 @@ btr_search_build_page_hash_index(
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ulint n_fields,/* in: hash this many full fields */
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ulint n_bytes,/* in: hash this many bytes from the next
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field */
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ulint side); /* in: hash for searches from this side */
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ibool left_side);/* in: hash for searches from left side? */
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/*********************************************************************
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This function should be called before reserving any btr search mutex, if
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@ -157,10 +157,10 @@ btr_search_info_create(
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info = mem_heap_alloc(heap, sizeof(btr_search_t));
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#ifdef UNIV_DEBUG
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info->magic_n = BTR_SEARCH_MAGIC_N;
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#endif /* UNIV_DEBUG */
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info->last_search = NULL;
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info->n_direction = 0;
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info->root_guess = NULL;
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info->hash_analysis = 0;
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@ -179,7 +179,7 @@ btr_search_info_create(
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info->n_fields = 1;
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info->n_bytes = 0;
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info->side = BTR_SEARCH_LEFT_SIDE;
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info->left_side = TRUE;
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return(info);
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}
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@ -224,7 +224,7 @@ btr_search_info_update_hash(
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hash prefix */
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if (info->n_fields >= n_unique && cursor->up_match >= n_unique) {
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increment_potential:
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info->n_hash_potential++;
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return;
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@ -233,8 +233,7 @@ btr_search_info_update_hash(
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cmp = ut_pair_cmp(info->n_fields, info->n_bytes,
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cursor->low_match, cursor->low_bytes);
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if ((info->side == BTR_SEARCH_LEFT_SIDE && cmp <= 0)
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|| (info->side == BTR_SEARCH_RIGHT_SIDE && cmp > 0)) {
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if (info->left_side ? cmp <= 0 : cmp > 0) {
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goto set_new_recomm;
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}
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@ -242,16 +241,11 @@ btr_search_info_update_hash(
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cmp = ut_pair_cmp(info->n_fields, info->n_bytes,
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cursor->up_match, cursor->up_bytes);
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if ((info->side == BTR_SEARCH_LEFT_SIDE && cmp > 0)
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|| (info->side == BTR_SEARCH_RIGHT_SIDE && cmp <= 0)) {
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if (info->left_side ? cmp <= 0 : cmp > 0) {
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goto set_new_recomm;
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goto increment_potential;
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}
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info->n_hash_potential++;
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return;
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set_new_recomm:
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/* We have to set a new recommendation; skip the hash analysis
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for a while to avoid unnecessary CPU time usage when there is no
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@ -269,7 +263,7 @@ set_new_recomm:
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info->n_fields = 1;
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info->n_bytes = 0;
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info->side = BTR_SEARCH_LEFT_SIDE;
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info->left_side = TRUE;
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} else if (cmp > 0) {
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info->n_hash_potential = 1;
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@ -288,7 +282,7 @@ set_new_recomm:
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info->n_bytes = cursor->low_bytes + 1;
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}
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info->side = BTR_SEARCH_LEFT_SIDE;
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info->left_side = TRUE;
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} else {
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info->n_hash_potential = 1;
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@ -306,7 +300,7 @@ set_new_recomm:
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info->n_bytes = cursor->up_bytes + 1;
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}
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info->side = BTR_SEARCH_RIGHT_SIDE;
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info->left_side = FALSE;
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}
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}
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@ -336,18 +330,18 @@ btr_search_update_block_hash_info(
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info->last_hash_succ = FALSE;
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ut_a(block->magic_n == BUF_BLOCK_MAGIC_N);
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ut_a(info->magic_n == BTR_SEARCH_MAGIC_N);
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ut_ad(info->magic_n == BTR_SEARCH_MAGIC_N);
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if ((block->n_hash_helps > 0)
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&& (info->n_hash_potential > 0)
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&& (block->n_fields == info->n_fields)
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&& (block->n_bytes == info->n_bytes)
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&& (block->side == info->side)) {
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&& (block->left_side == info->left_side)) {
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if ((block->is_hashed)
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&& (block->curr_n_fields == info->n_fields)
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&& (block->curr_n_bytes == info->n_bytes)
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&& (block->curr_side == info->side)) {
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&& (block->curr_left_side == info->left_side)) {
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/* The search would presumably have succeeded using
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the hash index */
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@ -360,7 +354,7 @@ btr_search_update_block_hash_info(
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block->n_hash_helps = 1;
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block->n_fields = info->n_fields;
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block->n_bytes = info->n_bytes;
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block->side = info->side;
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block->left_side = info->left_side;
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}
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#ifdef UNIV_DEBUG
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@ -378,7 +372,7 @@ btr_search_update_block_hash_info(
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> 2 * page_get_n_recs(block->frame))
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|| (block->n_fields != block->curr_n_fields)
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|| (block->n_bytes != block->curr_n_bytes)
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|| (block->side != block->curr_side)) {
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|| (block->left_side != block->curr_left_side)) {
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/* Build a new hash index on the page */
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@ -422,7 +416,7 @@ btr_search_update_hash_ref(
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&& (info->n_hash_potential > 0)
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&& (block->curr_n_fields == info->n_fields)
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&& (block->curr_n_bytes == info->n_bytes)
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&& (block->curr_side == info->side)) {
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&& (block->curr_left_side == info->left_side)) {
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mem_heap_t* heap = NULL;
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ulint offsets_[REC_OFFS_NORMAL_SIZE];
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*offsets_ = (sizeof offsets_) / sizeof *offsets_;
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@ -512,7 +506,7 @@ btr_search_info_update_slow(
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params = mem_alloc(3 * sizeof(ulint));
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params[0] = block->n_fields;
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params[1] = block->n_bytes;
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params[2] = block->side;
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params[2] = block->left_side;
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/* Make sure the compiler cannot deduce the values and do
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optimizations */
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@ -1102,7 +1096,7 @@ btr_search_build_page_hash_index(
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ulint n_fields,/* in: hash this many full fields */
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ulint n_bytes,/* in: hash this many bytes from the next
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field */
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ulint side) /* in: hash for searches from this side */
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ibool left_side)/* in: hash for searches from left side? */
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{
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hash_table_t* table;
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buf_block_t* block;
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@ -1136,7 +1130,7 @@ btr_search_build_page_hash_index(
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if (block->is_hashed && ((block->curr_n_fields != n_fields)
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|| (block->curr_n_bytes != n_bytes)
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|| (block->curr_side != side))) {
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|| (block->curr_left_side != left_side))) {
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rw_lock_s_unlock(&btr_search_latch);
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@ -1191,7 +1185,7 @@ btr_search_build_page_hash_index(
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fold = rec_fold(rec, offsets, n_fields, n_bytes, tree_id);
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if (side == BTR_SEARCH_LEFT_SIDE) {
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if (left_side) {
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folds[n_cached] = fold;
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recs[n_cached] = rec;
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@ -1203,7 +1197,7 @@ btr_search_build_page_hash_index(
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if (page_rec_is_supremum(next_rec)) {
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if (side == BTR_SEARCH_RIGHT_SIDE) {
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if (!left_side) {
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folds[n_cached] = fold;
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recs[n_cached] = rec;
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@ -1221,7 +1215,7 @@ btr_search_build_page_hash_index(
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if (fold != next_fold) {
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/* Insert an entry into the hash index */
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if (side == BTR_SEARCH_LEFT_SIDE) {
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if (left_side) {
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folds[n_cached] = next_fold;
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recs[n_cached] = next_rec;
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@ -1243,7 +1237,7 @@ btr_search_build_page_hash_index(
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if (block->is_hashed && ((block->curr_n_fields != n_fields)
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|| (block->curr_n_bytes != n_bytes)
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|| (block->curr_side != side))) {
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|| (block->curr_left_side != left_side))) {
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goto exit_func;
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}
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@ -1252,7 +1246,7 @@ btr_search_build_page_hash_index(
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block->curr_n_fields = n_fields;
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block->curr_n_bytes = n_bytes;
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block->curr_side = side;
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block->curr_left_side = left_side;
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block->index = index;
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for (i = 0; i < n_cached; i++) {
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@ -1291,7 +1285,7 @@ btr_search_move_or_delete_hash_entries(
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buf_block_t* new_block;
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ulint n_fields;
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ulint n_bytes;
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ulint side;
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ibool left_side;
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block = buf_block_align(page);
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new_block = buf_block_align(new_page);
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@ -1319,22 +1313,23 @@ btr_search_move_or_delete_hash_entries(
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n_fields = block->curr_n_fields;
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n_bytes = block->curr_n_bytes;
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side = block->curr_side;
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left_side = block->curr_left_side;
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new_block->n_fields = block->curr_n_fields;
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new_block->n_bytes = block->curr_n_bytes;
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new_block->side = block->curr_side;
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new_block->left_side = left_side;
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rw_lock_s_unlock(&btr_search_latch);
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ut_a(n_fields + n_bytes > 0);
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btr_search_build_page_hash_index(index, new_page, n_fields,
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n_bytes, side);
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n_bytes, left_side);
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#if 1 /* TODO: safe to remove? */
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ut_a(n_fields == block->curr_n_fields);
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ut_a(n_bytes == block->curr_n_bytes);
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ut_a(side == block->curr_side);
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ut_a(left_side == block->curr_left_side);
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#endif
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return;
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}
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@ -1428,7 +1423,7 @@ btr_search_update_hash_node_on_insert(
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if ((cursor->flag == BTR_CUR_HASH)
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&& (cursor->n_fields == block->curr_n_fields)
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&& (cursor->n_bytes == block->curr_n_bytes)
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&& (block->curr_side == BTR_SEARCH_RIGHT_SIDE)) {
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&& !block->curr_left_side) {
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table = btr_search_sys->hash_index;
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@ -1465,7 +1460,7 @@ btr_search_update_hash_on_insert(
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ulint next_fold = 0; /* remove warning (??? bug ???) */
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ulint n_fields;
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ulint n_bytes;
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ulint side;
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ibool left_side;
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ibool locked = FALSE;
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mem_heap_t* heap = NULL;
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ulint offsets_[REC_OFFS_NORMAL_SIZE];
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@ -1495,7 +1490,7 @@ btr_search_update_hash_on_insert(
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n_fields = block->curr_n_fields;
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n_bytes = block->curr_n_bytes;
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side = block->curr_side;
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left_side = block->curr_left_side;
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ins_rec = page_rec_get_next(rec);
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next_rec = page_rec_get_next(ins_rec);
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@ -1516,7 +1511,7 @@ btr_search_update_hash_on_insert(
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n_fields + (n_bytes > 0), &heap);
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fold = rec_fold(rec, offsets, n_fields, n_bytes, tree_id);
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} else {
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if (side == BTR_SEARCH_LEFT_SIDE) {
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if (left_side) {
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rw_lock_x_lock(&btr_search_latch);
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@ -1537,7 +1532,7 @@ btr_search_update_hash_on_insert(
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locked = TRUE;
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}
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if (side == BTR_SEARCH_RIGHT_SIDE) {
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if (!left_side) {
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ha_insert_for_fold(table, fold, rec);
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} else {
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ha_insert_for_fold(table, ins_fold, ins_rec);
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@ -1547,7 +1542,7 @@ btr_search_update_hash_on_insert(
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check_next_rec:
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if (page_rec_is_supremum(next_rec)) {
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if (side == BTR_SEARCH_RIGHT_SIDE) {
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if (!left_side) {
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if (!locked) {
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rw_lock_x_lock(&btr_search_latch);
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@ -1570,7 +1565,7 @@ check_next_rec:
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locked = TRUE;
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}
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if (side == BTR_SEARCH_RIGHT_SIDE) {
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if (!left_side) {
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ha_insert_for_fold(table, ins_fold, ins_rec);
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/*
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@ -1680,7 +1675,7 @@ btr_search_validate(void)
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(void*) page, (ulong) block->is_hashed,
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(ulong) block->curr_n_fields,
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(ulong) block->curr_n_bytes,
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(ulong) block->curr_side);
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(ulong) block->curr_left_side);
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if (n_page_dumps < 20) {
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buf_page_print(page);
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@ -1583,7 +1583,7 @@ buf_page_init_for_backup_restore(
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block->is_hashed = FALSE;
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block->n_fields = 1;
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block->n_bytes = 0;
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block->side = BTR_SEARCH_LEFT_SIDE;
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block->left_side = TRUE;
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block->file_page_was_freed = FALSE;
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}
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@ -1650,7 +1650,7 @@ buf_page_init(
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block->is_hashed = FALSE;
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block->n_fields = 1;
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block->n_bytes = 0;
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block->side = BTR_SEARCH_LEFT_SIDE;
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block->left_side = TRUE;
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block->file_page_was_freed = FALSE;
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}
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@ -134,48 +134,34 @@ btr_search_validate(void);
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/*======================*/
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/* out: TRUE if ok */
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/* Search info directions */
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#define BTR_SEA_NO_DIRECTION 1
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#define BTR_SEA_LEFT 2
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#define BTR_SEA_RIGHT 3
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#define BTR_SEA_SAME_REC 4
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/* The search info struct in an index */
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struct btr_search_struct{
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ulint magic_n; /* magic number */
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/* The following 4 fields are currently not used: */
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rec_t* last_search; /* pointer to the lower limit record of the
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previous search; NULL if not known */
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ulint n_direction; /* number of consecutive searches in the
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same direction */
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ulint direction; /* BTR_SEA_NO_DIRECTION, BTR_SEA_LEFT,
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BTR_SEA_RIGHT, BTR_SEA_SAME_REC,
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or BTR_SEA_SAME_PAGE */
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dulint modify_clock; /* value of modify clock at the time
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last_search was stored */
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/*----------------------*/
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/* The following 4 fields are not protected by any latch: */
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/* The following fields are not protected by any latch.
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Unfortunately, this means that they must be aligned to
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the machine word, i.e., they cannot be turned into bit-fields. */
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page_t* root_guess; /* the root page frame when it was last time
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fetched, or NULL */
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ulint hash_analysis; /* when this exceeds a certain value, the
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hash analysis starts; this is reset if no
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ulint hash_analysis; /* when this exceeds BTR_SEARCH_HASH_ANALYSIS,
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the hash analysis starts; this is reset if no
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success noticed */
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ibool last_hash_succ; /* TRUE if the last search would have
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succeeded, or did succeed, using the hash
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index; NOTE that the value here is not exact:
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it is not calculated for every search, and the
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calculation itself is not always accurate! */
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ulint n_hash_potential;/* number of consecutive searches which would
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have succeeded, or did succeed, using the hash
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index */
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ulint n_hash_potential;
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/* number of consecutive searches
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which would have succeeded, or did succeed,
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using the hash index;
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the range is 0 .. BTR_SEARCH_BUILD_LIMIT + 5 */
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/*----------------------*/
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ulint n_fields; /* recommended prefix length for hash search:
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number of full fields */
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ulint n_bytes; /* recommended prefix: number of bytes in
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an incomplete field */
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ulint side; /* BTR_SEARCH_LEFT_SIDE or
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BTR_SEARCH_RIGHT_SIDE, depending on whether
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an incomplete field;
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cf. BTR_PAGE_MAX_REC_SIZE */
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ibool left_side; /* TRUE or FALSE, depending on whether
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the leftmost record of several records with
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the same prefix should be indexed in the
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hash index */
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|
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@ -188,10 +174,12 @@ struct btr_search_struct{
|
|||
far */
|
||||
ulint n_searches; /* number of searches */
|
||||
#endif /* UNIV_SEARCH_PERF_STAT */
|
||||
#ifdef UNIV_DEBUG
|
||||
ulint magic_n; /* magic number */
|
||||
# define BTR_SEARCH_MAGIC_N 1112765
|
||||
#endif /* UNIV_DEBUG */
|
||||
};
|
||||
|
||||
#define BTR_SEARCH_MAGIC_N 1112765
|
||||
|
||||
/* The hash index system */
|
||||
|
||||
typedef struct btr_search_sys_struct btr_search_sys_t;
|
||||
|
|
@ -229,9 +217,6 @@ is no hope in building a hash index. */
|
|||
|
||||
#define BTR_SEARCH_HASH_ANALYSIS 17
|
||||
|
||||
#define BTR_SEARCH_LEFT_SIDE 1
|
||||
#define BTR_SEARCH_RIGHT_SIDE 2
|
||||
|
||||
/* Limit of consecutive searches for trying a search shortcut on the search
|
||||
pattern */
|
||||
|
||||
|
|
|
|||
|
|
@ -825,8 +825,7 @@ struct buf_block_struct{
|
|||
search: number of full fields */
|
||||
ulint n_bytes; /* recommended prefix: number of bytes
|
||||
in an incomplete field */
|
||||
ulint side; /* BTR_SEARCH_LEFT_SIDE or
|
||||
BTR_SEARCH_RIGHT_SIDE, depending on
|
||||
ibool left_side; /* TRUE or FALSE, depending on
|
||||
whether the leftmost record of several
|
||||
records with the same prefix should be
|
||||
indexed in the hash index */
|
||||
|
|
@ -851,9 +850,7 @@ struct buf_block_struct{
|
|||
ulint curr_n_fields; /* prefix length for hash indexing:
|
||||
number of full fields */
|
||||
ulint curr_n_bytes; /* number of bytes in hash indexing */
|
||||
ulint curr_side; /* BTR_SEARCH_LEFT_SIDE or
|
||||
BTR_SEARCH_RIGHT_SIDE in hash
|
||||
indexing */
|
||||
ibool curr_left_side; /* TRUE or FALSE in hash indexing */
|
||||
dict_index_t* index; /* Index for which the adaptive
|
||||
hash index has been created. */
|
||||
/* 6. Debug fields */
|
||||
|
|
|
|||
Loading…
Reference in a new issue