Elena Stepanova added a comment - 2020-02-01 23:06 Thanks, it's very helpful, it means we can rule out some recent changes in 10.4.12. Can you by any chance try the same query directly from the command-line client, without the connector (as a plain query and, if it doesn't work, as a prepared statement)?

Trevor Simonton added a comment - 2020-02-01 23:16 I tried that and it didn't seem to have the same issue in the CLI I just downgraded to 10.3.16 and the issue is gone. So it's somewhere between 10.3.16 and 10.4.12 I can try continuing a binary search at some point but for now i might just hang onto 10.3.16 and give debugging this a break

Elena Stepanova added a comment - 2020-02-01 23:20 Thanks for your investigation, we'll try to reproduce it. As I understand, you have only one record in the table, right? Would you be able to share the contents, just in case it turns out to be important? If you don't want to make it public, you can send it by email or upload to ftp.askmonty.org/private. You can also obfuscate the parts of it which you don't want to share.

markus makela added a comment - 2020-02-03 13:35 In MDEV-17334 I reported a crash and at the request of elenst tested with this query. It produce the following stacktrace: 200203 13:34:34 [ERROR] mysqld got signal 11 ; This could be because you hit a bug. It is also possible that this binary or one of the libraries it was linked against is corrupt, improperly built, or misconfigured. This error can also be caused by malfunctioning hardware. To report this bug, see https://mariadb.com/kb/en/reporting-bugs We will try our best to scrape up some info that will hopefully help diagnose the problem, but since we have already crashed, something is definitely wrong and this may fail. Server version: 10.4.12-MariaDB-1:10.4.12+maria~bionic-log key_buffer_size=134217728 read_buffer_size=2097152 max_used_connections=5 max_threads=10002 thread_count=12 It is possible that mysqld could use up to key_buffer_size + (read_buffer_size + sort_buffer_size)*max_threads = 61830494 K bytes of memory Hope that's ok; if not, decrease some variables in the equation. Thread pointer: 0x7f3cdc000c08 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 = 0x7f3d6c1c3dd8 thread_stack 0x49000 mysqld(my_print_stacktrace+0x2e)[0x55e52067fc3e] mysqld(handle_fatal_signal+0x515)[0x55e5200f3cf5] /lib/x86_64-linux-gnu/libpthread.so.0(+0x12890)[0x7f3d75cd1890] mysqld(_Z19append_query_stringPK15charset_info_stP6StringPKcmb+0x61)[0x55e5201e8901] mysqld(_ZNK10Item_param19value_query_val_strEP3THDP6String+0xb6)[0x55e520114fc6] mysqld(_ZThn144_N10Item_param14append_for_logEP3THDP6String+0x7b)[0x55e5201154db] mysqld(+0x677377)[0x55e51fef6377] mysqld(_ZN18Prepared_statement14set_parametersEP6StringPhS2_+0xe1)[0x55e51fef9de1] mysqld(_ZN18Prepared_statement12execute_loopEP6StringbPhS2_+0x35)[0x55e51fefbcc5] mysqld(+0x67da72)[0x55e51fefca72] mysqld(_Z19mysqld_stmt_executeP3THDPcj+0x25)[0x55e51fefcb15] mysqld(_Z16dispatch_command19enum_server_commandP3THDPcjbb+0xe35)[0x55e51fee8da5] mysqld(_Z10do_commandP3THD+0x148)[0x55e51feeabe8] mysqld(_Z24do_handle_one_connectionP7CONNECT+0x25e)[0x55e51ffc6dae] mysqld(handle_one_connection+0x3d)[0x55e51ffc6e6d] /lib/x86_64-linux-gnu/libpthread.so.0(+0x76db)[0x7f3d75cc66db] /lib/x86_64-linux-gnu/libc.so.6(clone+0x3f)[0x7f3d746e888f] Trying to get some variables. Some pointers may be invalid and cause the dump to abort. Query (0x0): Connection ID (thread ID): 13 Status: NOT_KILLED Optimizer switch: index_merge=on,index_merge_union=on,index_merge_sort_union=on,index_merge_intersection=on,index_merge_sort_intersection=off,engine_condition_pushdown=off,index_condition_pushdown=on,derived_merge=on,derived_with_keys=on,firstmatch=on,loosescan=on,materialization=on,in_to_exists=on,semijoin=on,partial_match_rowid_merge=on,partial_match_table_scan=on,subquery_cache=on,mrr=off,mrr_cost_based=off,mrr_sort_keys=off,outer_join_with_cache=on,semijoin_with_cache=on,join_cache_incremental=on,join_cache_hashed=on,join_cache_bka=on,optimize_join_buffer_size=on,table_elimination=on,extended_keys=on,exists_to_in=on,orderby_uses_equalities=on,condition_pushdown_for_derived=on,split_materialized=on,condition_pushdown_for_subquery=on,rowid_filter=on,condition_pushdown_from_having=on The manual page at http://dev.mysql.com/doc/mysql/en/crashing.html contains information that should help you find out what is causing the crash. Writing a core file... Working directory at /var/lib/mysql Resource Limits: Limit Soft Limit Hard Limit Units Max cpu time unlimited unlimited seconds Max file size unlimited unlimited bytes Max data size unlimited unlimited bytes Max stack size 8388608 unlimited bytes Max core file size unlimited unlimited bytes Max resident set unlimited unlimited bytes Max processes 1048576 1048576 processes Max open files 1048576 1048576 files Max locked memory 65536 65536 bytes Max address space unlimited unlimited bytes Max file locks unlimited unlimited locks Max pending signals 127226 127226 signals Max msgqueue size 819200 819200 bytes Max nice priority 0 0 Max realtime priority 0 0 Max realtime timeout unlimited unlimited us Core pattern: |/usr/lib/systemd/systemd-coredump %P %u %g %s %t %c %h %e

Elena Stepanova added a comment - 2020-02-05 14:47 - edited Just found out that we had a very similar report before, MDEV-20261 (also MythTV, same query). I've finally managed to install MythTV and make it work up to the point where it causes the crash. Added a test case to MDEV-20261 , I suggest we continue tracking the problem there.