#4  <signal handler called>
#5  0x08383dcb in JOIN::print_explain (this=0xa0f0258, result=0x9ff0560, 
    explain_flags=0 '\000', on_the_fly=true, need_tmp_table=false, need_order=false, 
    distinct=false, message=0x0) at sql_select.cc:21264
#6  0x081e8fa7 in st_select_lex::print_explain (this=0x9fd4818, output=0x9ff0560, 
    explain_flags=0 '\000') at sql_lex.cc:3773
#7  0x081e9109 in st_select_lex_unit::print_explain (this=0x9fd4524, output=0x9ff0560, 
    explain_flags=0 '\000') at sql_lex.cc:3824
#8  0x082bd29f in Show_explain_request::get_explain_data (arg=0x943d1694)
    at sql_class.cc:3042
#9  0x0850ae24 in Apc_target::process_apc_requests (this=0x9fd433c) at my_apc.cc:255
#10 0x0850a875 in Apc_target::disable (this=0x9fd433c) at my_apc.cc:83
#11 0x08357d43 in JOIN::exec (this=0xa0f0258) at sql_select.cc:2134
#12 0x0835ac4f in mysql_select (thd=0x9fd2d30, rref_pointer_array=0x9fd4958, 
    tables=0xa0ef240, wild_num=1, fields=..., conds=0xa0f00a0, og_num=0, order=0x0, 
    group=0x0, having=0x0, proc_param=0x0, select_options=2147764736, result=0xa0f0240, 
    unit=0x9fd4524, select_lex=0x9fd4818) at sql_select.cc:3031
#13 0x0835277f in handle_select (thd=0x9fd2d30, lex=0x9fd44c8, result=0xa0f0240, 
    setup_tables_done_option=0) at sql_select.cc:332
#14 0x082ed586 in execute_sqlcom_select (thd=0x9fd2d30, all_tables=0xa0ef240)
    at sql_parse.cc:5178
#15 0x082e480b in mysql_execute_command (thd=0x9fd2d30) at sql_parse.cc:2285
#16 0x082efbc1 in mysql_parse (thd=0x9fd2d30, 
    rawbuf=0xa0ef078 "SELECT * FROM A WHERE ( 5, 78 ) IN ( SELECT `a1`, MAX(`a1`) FROM A GROUP BY `a1` )", length=82, found_semicolon=0x9438a234) at sql_parse.cc:6179
#17 0x082e244b in dispatch_command (command=COM_QUERY, thd=0x9fd2d30, packet=0xa0e9709 "", 
    packet_length=82) at sql_parse.cc:1229
#18 0x082e18f5 in do_command (thd=0x9fd2d30) at sql_parse.cc:924
#19 0x082de7e1 in handle_one_connection (arg=0x9fd2d30) at sql_connect.cc:1218
#20 0xb774bb25 in start_thread () from /lib/libpthread.so.0

revision-id: psergey@askmonty.org-20120516162254-kxt6xh902iqb6rsc
date: 2012-05-16 20:22:54 +0400
revno: 3513

1 PRIMARY <subquery2> const distinct_key distinct_key 8  1
1 PRIMARY A ALL     20 Using join buffer (flat, BNL join)
2 MATERIALIZED A index  a1 4  20 Using index

1 PRIMARY <subquery2> const distinct_key distinct_key 8 const,const 1
1 PRIMARY A ALL     20 Using join buffer (flat, BNL join)
2 MATERIALIZED A index  a1 4  20 Using index

perl runall.pl \
--threads=2 \
--duration=600 \
--queries=100M \
--skip-gendata \
--grammar=test.yy \
--basedir=<your basedir>

thread1_init:
  DROP TABLE IF EXISTS A; CREATE TABLE A ( `pk` INT NOT NULL PRIMARY KEY, `a1` INT NOT NULL, KEY(`a1`) ) ENGINE=MyISAM ; INSERT INTO A VALUES (1,5),(2,4),(3,6),(4,9),(5,2),(6,8),(7,4),(8,8),(9,0),(10,43),(11,23),(12,3),(13,45),(14,16),(15,2),(16,33),(17,2),(18,5),(19,9),(20,2);

query:
  SELECT * FROM A WHERE ( 5, 78 ) IN ( SELECT `a1`, MAX(`a1`) FROM A GROUP BY `a1` ) ;

thread2_init:
  SET @con_id = CONNECTION_ID()-1;

thread2:
  SHOW EXPLAIN FOR @con_id ;