Server version: 10.11.9-MariaDB-log source revision: 284489576611aebc565c052d344d06eb3f40e31a

key_buffer_size=1048576

read_buffer_size=131072

max_used_connections=1

max_threads=153

thread_count=8

It is possible that mysqld could use up to 

key_buffer_size + (read_buffer_size + sort_buffer_size)*max_threads = 63839 K  bytes of memory

Hope that's ok; if not, decrease some variables in the equation.

Thread pointer: 0x3ff80000c58

Attempting backtrace. You can use the following information to find out

where mysqld died. If you see no messages after this, something went

terribly wrong...

stack_bottom = 0x3ffa5e7ebd8 thread_stack 0x49000

mysys/stacktrace.c:215(my_print_stacktrace)[0x2aa09ee40d6]

sql/signal_handler.cc:239(handle_fatal_signal)[0x2aa099dd306]

[0x3ffa5e7c9d6]

sql/sql_analyze_stmt.h:172(JOIN::exec())[0x2aa097f0082]

sql/sql_select.cc:5203(mysql_select(THD*, TABLE_LIST*, List<Item>&, Item*, unsigned int, st_order*, st_order*, Item*, st_order*, unsigned long long, select_result*, st_select_lex_unit*, st_select_lex*))[0x2aa097ee3f6]

sql/sql_select.cc:29496(mysql_explain_union(THD*, st_select_lex_unit*, select_result*))[0x2aa097eee9a]

sql/sql_select.cc:29450(select_describe(JOIN*, bool, bool, bool, char const*) [clone .isra.534])[0x2aa097eefa0]

sql/sql_select.cc:4905(JOIN::exec_inner())[0x2aa097ef9c2]

sql/sql_select.cc:4722(JOIN::exec())[0x2aa097f00a2]

sql/sql_select.cc:5203(mysql_select(THD*, TABLE_LIST*, List<Item>&, Item*, unsigned int, st_order*, st_order*, Item*, st_order*, unsigned long long, select_result*, st_select_lex_unit*, st_select_lex*))[0x2aa097ee3f6]

sql/sql_select.cc:29496(mysql_explain_union(THD*, st_select_lex_unit*, select_result*))[0x2aa097eee9a]

sql/sql_parse.cc:6324(execute_sqlcom_select(THD*, TABLE_LIST*))[0x2aa0976d1c4]

sql/sql_parse.cc:6126(mysql_execute_command(THD*, bool))[0x2aa09777fa8]

sql/sql_parse.cc:8146(mysql_parse(THD*, char*, unsigned int, Parser_state*))[0x2aa09767830]

sql/sql_parse.cc:1866(dispatch_command(enum_server_command, THD*, char*, unsigned int, bool))[0x2aa09773ff4]

sql/sql_parse.cc:1408(do_command(THD*, bool))[0x2aa09775ffc]

sql/sql_connect.cc:1417(do_handle_one_connection(CONNECT*, bool))[0x2aa098a22d4]

sql/sql_connect.cc:1323(handle_one_connection)[0x2aa098a269a]

perfschema/pfs.cc:2204(pfs_spawn_thread)[0x2aa09bfa2a6]

/lib64/libpthread.so.0(+0x80de)[0x3ffa66080de]

/lib64/libc.so.6(+0x28b42)[0x3ffa6028b42]

[0x0]

Trying to get some variables.

Some pointers may be invalid and cause the dump to abort.

Query (0x3ff80010ba0): EXPLAIN FORMAT=JSON SELECT * FROM t1

GROUP BY b

HAVING (SELECT MAX(b) FROM t1) = a AND a + b = 3