Assertion `tmp >= 0' failed in best_access_path

commit b254844ed197cfe0b305ff37442b03a4573ee931

Author: Monty

Date:   Tue May 31 17:36:32 2022 +0300

    Improve pruning in greedy_search by sorting tables during search

    MDEV-28073 Slow query performance in MariaDB when using many tables

SET histogram_type= JSON_HB;

CREATE TABLE t1 (a varchar(1)) ENGINE=MyISAM;

INSERT INTO t1 VALUES ('o'),('s'),('j'),('s'),('y'),('s'),('l'),

  ('q'),('x'),('m'),('t'),('d'),('v'),('j'),('p'),('t'),('b'),('q');

CREATE TABLE t2 (b varchar(1), c int, KEY(b), KEY(c)) ENGINE=MyISAM;

INSERT INTO t2 VALUES ('r',NULL),('a',NULL),('r',1);

ANALYZE TABLE t1, t2 PERSISTENT FOR ALL;

SELECT * FROM t1 JOIN t2 ON a = b WHERE a > 'y' AND c != 9;

DROP TABLE t1, t2;

sql/sql_select.cc:8324: void best_access_path(JOIN*, JOIN_TAB*, table_map, const POSITION*, uint, bool, double, POSITION*, POSITION*): Assertion `tmp >= 0' failed.

220617 21:53:29 [ERROR] mysqld got signal 6 ;

#7  0x00007f3d62e4d662 in __GI___assert_fail (assertion=0x56272d6d1b2f "tmp >= 0", file=0x56272d6d00c0 "/data/src/preview-10.10-MDEV-28852-optimizer-gcov-Jun17/sql/sql_select.cc", line=8324, function=0x56272d6d1a28 "void best_access_path(JOIN*, JOIN_TAB*, table_map, const POSITION*, uint, bool, double, POSITION*, POSITION*)") at assert.c:101

No locals.

#8  0x000056272bf2dca3 in best_access_path (join=0x7f3d4c0187e0, s=0x7f3d4c064700, remaining_tables=2, join_positions=0x7f3d4c064cd8, idx=1, disable_jbuf=false, record_count=1.7976931348623153e+308, pos=0x7f3d4c0653d8, loose_scan_pos=0x7f3d4c0654d8) at /data/src/preview-10.10-MDEV-28852-optimizer-gcov-Jun17/sql/sql_select.cc:8324

        rows = inf

        access_cost_factor = 0

        found_part = 1

        key = 0

        keyinfo = 0x7f3d4c05a060

        key_parts = 1

        notnull_part = 1

        found_ref = 1

        ft_key = false

        ref_or_null_part = 0

        key_flags = 64

        const_part = 0

        all_parts = 1

        trace_access_idx = {<Json_writer_struct> = {_vptr.Json_writer_struct = 0x56272e01c308 <vtable for Json_writer_object+16>, my_writer = 0x0, context = {writer = 0x0}, closed = false}, <No data fields>}

        keyuse = 0x7f3d4c065ce8

        max_key_part = 4294967295

        start_key = 0x7f3d4c065c90

        table = 0x7f3d4c203538

        best_records = 1.7976931348623157e+308

        thd = 0x7f3d4c000db8

        use_cond_selectivity = 4

        best_key = 0x0

        best_max_key_part = 0

        found_constraint = 1 '\001'

        best = 1.7976931348623157e+308

        best_time = 1.7976931348623157e+308

        records = 1.5

        best_ref_depends_map = 0

        key_dependent = 0

        best_filter = 0x0

        tmp = -nan(0x8000000000000)

        rec = 10

        best_uses_jbuf = false

        eq_join_set = 0x7f3d4c2036c8

        hj_start_key = 0x0

        spl_plan = 0x0

        filter = 0x7f3d4c066628

        cause = 0x0

        best_type = JT_UNKNOWN

        type = JT_REF

        loose_scan_opt = {try_loosescan = false, bound_sj_equalities = 0, handled_sj_equalities = 0, loose_scan_keyparts = 0, max_loose_keypart = 0, part1_conds_met = false, quick_uses_applicable_index = 0, quick_max_loose_keypart = 0, best_loose_scan_key = 0, best_loose_scan_cost = 1.7976931348623157e+308, best_loose_scan_records = 0, best_loose_scan_start_key = 0x0, best_max_loose_keypart = 0, best_ref_depend_map = 0}

        _db_stack_frame_ = {func = 0x56272d6d1e22 "get_plans_for_tables", file = 0x56272d6d00c0 "/data/src/preview-10.10-MDEV-28852-optimizer-gcov-Jun17/sql/sql_select.cc", level = 2147483662, line = -1, prev = 0x7f3d5d7f5d40}

        trace_wrapper = {<Json_writer_struct> = {_vptr.Json_writer_struct = 0x56272e01c308 <vtable for Json_writer_object+16>, my_writer = 0x0, context = {writer = 0x0}, closed = false}, <No data fields>}

        trace_paths = {<Json_writer_struct> = {_vptr.Json_writer_struct = 0x56272e01c2e8 <vtable for Json_writer_array+16>, my_writer = 0x0, context = {writer = 0x0}, closed = false}, <No data fields>}

        __PRETTY_FUNCTION__ = "void best_access_path(JOIN*, JOIN_TAB*, table_map, const POSITION*, uint, bool, double, POSITION*, POSITION*)"

        trace_access_scan = {<Json_writer_struct> = {_vptr.Json_writer_struct = 0x56272e01c308 <vtable for Json_writer_object+16>, my_writer = 0x0, context = {writer = 0x0}, closed = false}, <No data fields>}

#9  0x000056272bf354d3 in get_costs_for_tables (join=0x7f3d4c0187e0, remaining_tables=2, idx=1, record_count=1.7976931348623153e+308, trace_one_table=0x7f3d5d7f5ef0, pos=0x7f3d4c064ca8, store_position=0x7f3d5d7f5e28, allowed_tables=0x7f3d5d7f5e38, stop_on_eq_ref=false) at /data/src/preview-10.10-MDEV-28852-optimizer-gcov-Jun17/sql/sql_select.cc:10036

        wrapper = {<Json_writer_struct> = {_vptr.Json_writer_struct = 0x56272e01c308 <vtable for Json_writer_object+16>, my_writer = 0x0, context = {writer = 0x0}, closed = false}, <No data fields>}

        real_table_bit = 2

        thd = 0x7f3d4c000db8

        sort_position = 0x7f3d4c0653d8

        sort_end = 0x7f3d5d7f5db0

        s = 0x7f3d4c064700

        found_tables = 0

        found_eq_ref = false

        disable_jbuf = false

        _db_stack_frame_ = {func = 0x56272d6d1f70 "best_extension_by_limited_search", file = 0x56272d6d00c0 "/data/src/preview-10.10-MDEV-28852-optimizer-gcov-Jun17/sql/sql_select.cc", level = 2147483661, line = -1, prev = 0x7f3d5d7f5ed0}

        __PRETTY_FUNCTION__ = "bool get_costs_for_tables(JOIN*, table_map, uint, double, Json_writer_object*, JOIN_TAB**, SORT_POSITION**, table_map*, bool)"

#10 0x000056272bf36387 in best_extension_by_limited_search (join=0x7f3d4c0187e0, remaining_tables=2, idx=1, record_count=1.7976931348623153e+308, read_time=3.5953862697246305e+307, search_depth=61, prune_level=2, use_cond_selectivity=4, processed_eq_ref_tables=0x7f3d5d7f5ff0) at /data/src/preview-10.10-MDEV-28852-optimizer-gcov-Jun17/sql/sql_select.cc:10299

        table_map = 2

        trace_one_table = {<Json_writer_struct> = {_vptr.Json_writer_struct = 0x56272e01c308 <vtable for Json_writer_object+16>, my_writer = 0x0, context = {writer = 0x0}, closed = false}, <No data fields>}

        best_ref = 0x7f3d4c064ca8

        arr = {<Json_writer_struct> = {_vptr.Json_writer_struct = 0x56272e01c2e8 <vtable for Json_writer_array+16>, my_writer = 0x0, context = {writer = 0x0}, closed = false}, <No data fields>}

        thd = 0x7f3d4c000db8

        s = 0x4c064cb0

        best_record_count = 1.7976931348623157e+308

        best_read_time = 1.7976931348623157e+308

        best_res = SEARCH_OK

        tables_left = 1

        found_tables = 0

        accepted_tables = 32512

        found_eq_ref_tables = 0

        used_eq_ref_table = 0

        allowed_tables = 2

        allowed_current_tables = 2

        sort = 0x7f3d5d7f5db0

        sort_end = 0x7f3d5d7f5db0

        _db_stack_frame_ = {func = 0x56272d6d1f70 "best_extension_by_limited_search", file = 0x56272d6d00c0 "/data/src/preview-10.10-MDEV-28852-optimizer-gcov-Jun17/sql/sql_select.cc", level = 2147483660, line = -1, prev = 0x7f3d5d7f60a0}

        __PRETTY_FUNCTION__ = "enum_best_search best_extension_by_limited_search(JOIN*, table_map, uint, double, double, uint, uint, uint, table_map*)"

#11 0x000056272bf3751f in best_extension_by_limited_search (join=0x7f3d4c0187e0, remaining_tables=3, idx=0, record_count=1, read_time=0, search_depth=62, prune_level=2, use_cond_selectivity=4, processed_eq_ref_tables=0x7f3d5d7f6178) at /data/src/preview-10.10-MDEV-28852-optimizer-gcov-Jun17/sql/sql_select.cc:10446

        trace_rest = {<Json_writer_struct> = {_vptr.Json_writer_struct = 0x56272e01c2e8 <vtable for Json_writer_array+16>, my_writer = 0x0, context = {writer = 0x0}, closed = false}, <No data fields>}

        trace_one_table = {<Json_writer_struct> = {_vptr.Json_writer_struct = 0x56272e01c308 <vtable for Json_writer_object+16>, my_writer = 0x0, context = {writer = 0x0}, closed = false}, <No data fields>}

        filter_cmp_gain = 0

        pushdown_cond_selectivity = 1

        real_table_bit = 1

        current_record_count = 1.7976931348623153e+308

        current_read_time = 3.5953862697246305e+307

        partial_join_cardinality = 1.7976931348623153e+308

        position = 0x7f3d4c064cd8

        loose_scan_pos = 0x7f3d4c0652d8

        pos = 0x7f3d5d7f5f70

        thd = 0x7f3d4c000db8

        s = 0x7f3d4c064348

        best_record_count = 1.7976931348623153e+308

        best_read_time = 3.5953862697246305e+307

        best_res = 1275071712

        tables_left = 2

        found_tables = 2

        accepted_tables = 1

        found_eq_ref_tables = 0

        used_eq_ref_table = 0

        allowed_tables = 3

        allowed_current_tables = 3

        sort = 0x7f3d5d7f5f70

        sort_end = 0x7f3d5d7f5f90

        _db_stack_frame_ = {func = 0x56272d6d1d33 "greedy_search", file = 0x56272d6d00c0 "/data/src/preview-10.10-MDEV-28852-optimizer-gcov-Jun17/sql/sql_select.cc", level = 2147483659, line = -1, prev = 0x7f3d5d7f61b0}

        __PRETTY_FUNCTION__ = "enum_best_search best_extension_by_limited_search(JOIN*, table_map, uint, double, double, uint, uint, uint, table_map*)"

#12 0x000056272bf322c9 in greedy_search (join=0x7f3d4c0187e0, remaining_tables=3, search_depth=62, prune_level=2, use_cond_selectivity=4) at /data/src/preview-10.10-MDEV-28852-optimizer-gcov-Jun17/sql/sql_select.cc:9282

        is_interleave_error = false

        pos = 0x7f3d5d7f61c0

        record_count = 1

        read_time = 0

        idx = 0

        best_idx = 0

        size_remain = 2

        usable_tables = 3

        eq_ref_tables = 0

        best_pos = {table = 0x0, records_read = 0, cond_selectivity = 0, read_time = 0, prefix_record_count = 0, prefix_cost = 2.7519649000858304e-314, key = 0x0, spl_plan = 0x0, range_rowid_filter_info = 0x0, ref_depend_map = 0, key_dependent = 0, dups_producing_tables = 0, inner_tables_handled_with_other_sjs = 0, dups_weedout_picker = {<Semi_join_strategy_picker> = {_vptr.Semi_join_strategy_picker = 0x56272e03ad80 <vtable for Duplicate_weedout_picker+16>}, first_dupsweedout_table = 61, dupsweedout_tables = 0, is_used = false}, firstmatch_picker = {<Semi_join_strategy_picker> = {_vptr.Semi_join_strategy_picker = 0x56272e03adc0 <vtable for Firstmatch_picker+16>}, first_firstmatch_table = 61, first_firstmatch_rtbl = 139901538362208, firstmatch_need_tables = 139901538362032, is_used = false}, loosescan_picker = {<Semi_join_strategy_picker> = {_vptr.Semi_join_strategy_picker = 0x56272e03ae00 <vtable for LooseScan_picker+16>}, first_loosescan_table = 61, loosescan_need_tables = 0, loosescan_key = 1568629600, loosescan_parts = 32573, is_used = false}, sjmat_picker = {<Semi_join_strategy_picker> = {_vptr.Semi_join_strategy_picker = 0x56272e03ae40 <vtable for Sj_materialization_picker+16>}, is_used = false, sjm_scan_last_inner = 0, sjm_scan_need_tables = 0}, sj_strategy = SJ_OPT_NONE, type = JT_UNKNOWN, n_sj_tables = 0, use_join_buffer = false}

        best_table = 0x56272d73ce4f

        n_tables = 2

        _db_stack_frame_ = {func = 0x56272d6d1c2f "choose_plan", file = 0x56272d6d00c0 "/data/src/preview-10.10-MDEV-28852-optimizer-gcov-Jun17/sql/sql_select.cc", level = 2147483658, line = -1, prev = 0x7f3d5d7f6320}

        __PRETTY_FUNCTION__ = "bool greedy_search(JOIN*, table_map, uint, uint, uint)"

#13 0x000056272bf30ea5 in choose_plan (join=0x7f3d4c0187e0, join_tables=3) at /data/src/preview-10.10-MDEV-28852-optimizer-gcov-Jun17/sql/sql_select.cc:8847

        search_depth = 62

        prune_level = 2

        use_cond_selectivity = 4

        straight_join = false

        thd = 0x7f3d4c000db8

        _db_stack_frame_ = {func = 0x56272d6d137b "make_join_statistics", file = 0x56272d6d00c0 "/data/src/preview-10.10-MDEV-28852-optimizer-gcov-Jun17/sql/sql_select.cc", level = 2147483657, line = -1, prev = 0x7f3d5d7f6570}

        jtab_sort_func = 0x56272bf3130f <join_tab_cmp(void const*, void const*, void const*)>

        wrapper = {<Json_writer_struct> = {_vptr.Json_writer_struct = 0x56272e01c308 <vtable for Json_writer_object+16>, my_writer = 0x0, context = {writer = 0x0}, closed = false}, <No data fields>}

        trace_plan = {<Json_writer_struct> = {_vptr.Json_writer_struct = 0x56272e01c2e8 <vtable for Json_writer_array+16>, my_writer = 0x0, context = {writer = 0x0}, closed = false}, <No data fields>}

        __PRETTY_FUNCTION__ = "bool choose_plan(JOIN*, table_map)"

#14 0x000056272bf2213b in make_join_statistics (join=0x7f3d4c0187e0, tables_list=@0x7f3d4c015750: {<base_list> = {<Sql_alloc> = {<No data fields>}, first = 0x7f3d4c018db8, last = 0x7f3d4c018dc8, elements = 2}, <No data fields>}, keyuse_array=0x7f3d4c018b20) at /data/src/preview-10.10-MDEV-28852-optimizer-gcov-Jun17/sql/sql_select.cc:5968

        records = 1

        unit = 0x7f3d4c0051e8

        error = 0

        table = 0x7f3d4c203538

        i = 2

        table_count = 2

        const_count = 0

        key = 0

        sort_space = 6

        found_const_table_map = 0

        all_table_map = 3

        const_ref = {buffer = {0}}

        eq_part = {buffer = {1}}

        has_expensive_keyparts = false

        table_vector = 0x7f3d4c064cb8

        stat = 0x7f3d4c064348

        stat_end = 0x7f3d4c064ab8

        s = 0x7f3d4c064ab8

        stat_ref = 0x7f3d4c064ab8

        stat_vector = 0x7f3d4c064ca0

        keyuse = 0x7f3d4c065ce8

        start_keyuse = 0x7f3d4c065c90

        outer_join = 0

        no_rows_const_tables = 0

        sargables = 0x7f3d4c065c80

        ti = {<base_list_iterator> = {list = 0x7f3d4c015750, el = 0x56272ed103e0 <end_of_list>, prev = 0x7f3d4c018dc8, current = 0x56272ed103e0 <end_of_list>}, <No data fields>}

        tables = 0x0

        thd = 0x7f3d4c000db8

        _db_stack_frame_ = {func = 0x56272d6d085d "JOIN::optimize_inner", file = 0x56272d6d00c0 "/data/src/preview-10.10-MDEV-28852-optimizer-gcov-Jun17/sql/sql_select.cc", level = 2147483656, line = -1, prev = 0x7f3d5d7f66c0}

        ref_changed = 0

        __PRETTY_FUNCTION__ = "bool make_join_statistics(JOIN*, List<TABLE_LIST>&, DYNAMIC_ARRAY*)"

#15 0x000056272bf0b1cc in JOIN::optimize_inner (this=0x7f3d4c0187e0) at /data/src/preview-10.10-MDEV-28852-optimizer-gcov-Jun17/sql/sql_select.cc:2511

        _db_stack_frame_ = {func = 0x56272d6d12ff "mysql_select", file = 0x56272d6d00c0 "/data/src/preview-10.10-MDEV-28852-optimizer-gcov-Jun17/sql/sql_select.cc", level = 2147483655, line = -1, prev = 0x7f3d5d7f6820}

        trace_wrapper = {<Json_writer_struct> = {_vptr.Json_writer_struct = 0x56272e01c308 <vtable for Json_writer_object+16>, my_writer = 0x0, context = {writer = 0x0}, closed = false}, <No data fields>}

        trace_prepare = {<Json_writer_struct> = {_vptr.Json_writer_struct = 0x56272e01c308 <vtable for Json_writer_object+16>, my_writer = 0x0, context = {writer = 0x0}, closed = false}, <No data fields>}

        trace_steps = {<Json_writer_struct> = {_vptr.Json_writer_struct = 0x56272e01c2e8 <vtable for Json_writer_array+16>, my_writer = 0x0, context = {writer = 0x0}, closed = false}, <No data fields>}

        sel = 0x7f3d4c015538

        eq_list = {<base_list> = {<Sql_alloc> = {<No data fields>}, first = 0x56272ed103e0 <end_of_list>, last = 0x7f3d5d7f66a0, elements = 0}, <No data fields>}

        ignore_on_expr = false

        __PRETTY_FUNCTION__ = "int JOIN::optimize_inner()"

#16 0x000056272bf068f9 in JOIN::optimize (this=0x7f3d4c0187e0) at /data/src/preview-10.10-MDEV-28852-optimizer-gcov-Jun17/sql/sql_select.cc:1850

        res = 0

        init_state = JOIN::NOT_OPTIMIZED

#17 0x000056272bf1c20b in mysql_select (thd=0x7f3d4c000db8, tables=0x7f3d4c015b10, fields=@0x7f3d4c0157d8: {<base_list> = {<Sql_alloc> = {<No data fields>}, first = 0x7f3d4c015ac8, last = 0x7f3d4c019178, elements = 3}, <No data fields>}, conds=0x7f3d4c017d28, og_num=0, order=0x0, group=0x0, having=0x0, proc_param=0x0, select_options=2147748608, result=0x7f3d4c0187b8, unit=0x7f3d4c0051e8, select_lex=0x7f3d4c015538) at /data/src/preview-10.10-MDEV-28852-optimizer-gcov-Jun17/sql/sql_select.cc:5038

        err = 0

        free_join = true

        _db_stack_frame_ = {func = 0x56272d6d01d0 "handle_select", file = 0x56272d6d00c0 "/data/src/preview-10.10-MDEV-28852-optimizer-gcov-Jun17/sql/sql_select.cc", level = 2147483654, line = -1, prev = 0x7f3d5d7f68e0}

        join = 0x7f3d4c0187e0

#18 0x000056272befcedf in handle_select (thd=0x7f3d4c000db8, lex=0x7f3d4c005110, result=0x7f3d4c0187b8, setup_tables_done_option=0) at /data/src/preview-10.10-MDEV-28852-optimizer-gcov-Jun17/sql/sql_select.cc:583

        unit = 0x7f3d4c0051e8

        res = false

        select_lex = 0x7f3d4c015538

        _db_stack_frame_ = {func = 0x56272d6bb8a8 "mysql_execute_command", file = 0x56272d6bab40 "/data/src/preview-10.10-MDEV-28852-optimizer-gcov-Jun17/sql/sql_parse.cc", level = 2147483653, line = -1, prev = 0x7f3d5d7f6f30}

#19 0x000056272be5384a in execute_sqlcom_select (thd=0x7f3d4c000db8, all_tables=0x7f3d4c015b10) at /data/src/preview-10.10-MDEV-28852-optimizer-gcov-Jun17/sql/sql_parse.cc:6260

        save_protocol = 0x0

        lex = 0x7f3d4c005110

        result = 0x7f3d4c0187b8

        res = false

        __PRETTY_FUNCTION__ = "bool execute_sqlcom_select(THD*, TABLE_LIST*)"

#20 0x000056272be4029f in mysql_execute_command (thd=0x7f3d4c000db8, is_called_from_prepared_stmt=false) at /data/src/preview-10.10-MDEV-28852-optimizer-gcov-Jun17/sql/sql_parse.cc:3944

        privileges_requested = SELECT_ACL

        res = 0

        up_result = 0

        lex = 0x7f3d4c005110

        select_lex = 0x7f3d4c015538

        first_table = 0x7f3d4c015b10

        all_tables = 0x7f3d4c015b10

        unit = 0x7f3d4c0051e8

        have_table_map_for_update = false

        rpl_filter = 0x56272e021310 <vtable for Internal_error_handler+16>

        _db_stack_frame_ = {func = 0x56272d6bcc3f "mysql_parse", file = 0x56272d6bab40 "/data/src/preview-10.10-MDEV-28852-optimizer-gcov-Jun17/sql/sql_parse.cc", level = 2147483652, line = -1, prev = 0x7f3d5d7f7380}

        __PRETTY_FUNCTION__ = "int mysql_execute_command(THD*, bool)"

        ots = {ctx = 0x7f3d4c004da8, traceable = false}

        orig_binlog_format = BINLOG_FORMAT_MIXED

        orig_current_stmt_binlog_format = BINLOG_FORMAT_STMT

#21 0x000056272be5cc04 in mysql_parse (thd=0x7f3d4c000db8, rawbuf=0x7f3d4c015460 "SELECT * FROM t1 JOIN t2 ON a = b WHERE a > 'y' AND c != 9", length=58, parser_state=0x7f3d5d7f7500) at /data/src/preview-10.10-MDEV-28852-optimizer-gcov-Jun17/sql/sql_parse.cc:8036

        found_semicolon = 0x0

        error = 32573

        lex = 0x7f3d4c005110

        err = false

        _db_stack_frame_ = {func = 0x56272d6bb0e9 "dispatch_command", file = 0x56272d6bab40 "/data/src/preview-10.10-MDEV-28852-optimizer-gcov-Jun17/sql/sql_parse.cc", level = 2147483651, line = -1, prev = 0x7f3d5d7f74e0}

        __PRETTY_FUNCTION__ = "void mysql_parse(THD*, char*, uint, Parser_state*)"

#22 0x000056272be33f05 in dispatch_command (command=COM_QUERY, thd=0x7f3d4c000db8, packet=0x7f3d4c00b9e9 "SELECT * FROM t1 JOIN t2 ON a = b WHERE a > 'y' AND c != 9", packet_length=58, blocking=true) at /data/src/preview-10.10-MDEV-28852-optimizer-gcov-Jun17/sql/sql_parse.cc:1894

        packet_end = 0x7f3d4c01549a ""

        parser_state = {m_lip = {lookahead_token = -1, lookahead_yylval = 0x0, m_thd = 0x7f3d4c000db8, m_ptr = 0x7f3d4c01549b "\004", m_tok_start = 0x7f3d4c01549b "\004", m_tok_end = 0x7f3d4c01549b "\004", m_end_of_query = 0x7f3d4c01549a "", m_tok_start_prev = 0x7f3d4c01549a "", m_buf = 0x7f3d4c015460 "SELECT * FROM t1 JOIN t2 ON a = b WHERE a > 'y' AND c != 9", m_buf_length = 58, m_echo = true, m_echo_saved = false, m_cpp_buf = 0x7f3d4c0154f8 "SELECT * FROM t1 JOIN t2 ON a = b WHERE a > 'y' AND c != 9", m_cpp_ptr = 0x7f3d4c015532 "", m_cpp_tok_start = 0x7f3d4c015532 "", m_cpp_tok_start_prev = 0x7f3d4c015532 "", m_cpp_tok_end = 0x7f3d4c015532 "", m_body_utf8 = 0x0, m_body_utf8_ptr = 0x14c000cb8 <error: Cannot access memory at address 0x14c000cb8>, m_cpp_utf8_processed_ptr = 0x0, next_state = MY_LEX_END, found_semicolon = 0x0, ignore_space = false, stmt_prepare_mode = false, multi_statements = true, yylineno = 1, m_digest = 0x0, in_comment = NO_COMMENT, in_comment_saved = (unknown: 0x10000), m_cpp_text_start = 0x7f3d4c015531 "9", m_cpp_text_end = 0x7f3d4c015532 "", m_underscore_cs = 0x0}, m_yacc = {yacc_yyss = 0x0, yacc_yyvs = 0x0, m_set_signal_info = {m_item = {0x0 <repeats 13 times>}}, m_lock_type = TL_READ_DEFAULT, m_mdl_type = MDL_SHARED_READ}, m_digest_psi = 0x7f3d4c004b38}

        net = 0x7f3d4c0010f0

        error = false

        do_end_of_statement = true

        _db_stack_frame_ = {func = 0x56272d6bad6d "do_command", file = 0x56272d6bab40 "/data/src/preview-10.10-MDEV-28852-optimizer-gcov-Jun17/sql/sql_parse.cc", level = 2147483650, line = -1, prev = 0x7f3d5d7f7dc0}

        drop_more_results = false

        __PRETTY_FUNCTION__ = "dispatch_command_return dispatch_command(enum_server_command, THD*, char*, uint, bool)"

        __FUNCTION__ = "dispatch_command"

        res = <optimized out>

#23 0x000056272be310de in do_command (thd=0x7f3d4c000db8, blocking=true) at /data/src/preview-10.10-MDEV-28852-optimizer-gcov-Jun17/sql/sql_parse.cc:1407

        return_value = DISPATCH_COMMAND_SUCCESS

        packet = 0x7f3d4c00b9e8 "\003SELECT * FROM t1 JOIN t2 ON a = b WHERE a > 'y' AND c != 9"

        packet_length = 59

        net = 0x7f3d4c0010f0

        command = COM_QUERY

        _db_stack_frame_ = {func = 0x56272db40749 "?func", file = 0x56272db4074f "?file", level = 2147483649, line = -1, prev = 0x0}

        __PRETTY_FUNCTION__ = "dispatch_command_return do_command(THD*, bool)"

        __FUNCTION__ = "do_command"

#24 0x000056272c19b9f7 in do_handle_one_connection (connect=0x562731f08f78, put_in_cache=true) at /data/src/preview-10.10-MDEV-28852-optimizer-gcov-Jun17/sql/sql_connect.cc:1418

        create_user = true

        thr_create_utime = 1914121414503

        thd = 0x7f3d4c000db8

        __PRETTY_FUNCTION__ = "void do_handle_one_connection(CONNECT*, bool)"

#25 0x000056272c19b1fe in handle_one_connection (arg=0x562731f0b958) at /data/src/preview-10.10-MDEV-28852-optimizer-gcov-Jun17/sql/sql_connect.cc:1312

        connect = 0x562731f0b958

#26 0x000056272caa9fe7 in pfs_spawn_thread (arg=0x562731f08ae8) at /data/src/preview-10.10-MDEV-28852-optimizer-gcov-Jun17/storage/perfschema/pfs.cc:2201

        typed_arg = 0x562731f08ae8

        user_arg = 0x562731f0b958

        user_start_routine = 0x56272c19b149 <handle_one_connection(void*)>

        pfs = 0x7f3d627415c0

        klass = 0x562731941540

#27 0x00007f3d63317ea7 in start_thread (arg=<optimized out>) at pthread_create.c:477

        ret = <optimized out>

        pd = <optimized out>

        unwind_buf = {cancel_jmp_buf = {{jmp_buf = {139901538371328, -2832153553564932155, 140736454476238, 140736454476239, 139901538369408, 311296, 2794643718716975045, 2794744409914927045}, mask_was_saved = 0}}, priv = {pad = {0x0, 0x0, 0x0, 0x0}, data = {prev = 0x0, cleanup = 0x0, canceltype = 0}}}

        not_first_call = 0

#28 0x00007f3d62f16def in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:95