mariadb table doesn t exist in engine

version: windows x64 mariadb 10.4.7.

Before i do it, mariadb is work well.

Here is what i done:

I try to dump database data, but i get an error.

mysqldump -uxxx -pxxxx agilor_ws > ag.sql

error message

unknown variable 'character_set_client=utf8mb'

So, i try to change my.ini file, i update many times and restart mariadb many times (start success but mysqldump error), i just change character code, like utf8mb to utf8mb4, or utf8mb4 to utf8, and still get that error message.

Finally i rollback my.ini and remove charater_set_client=utf8mb under [mysqldump], and it worked. I successfully dump the data.

Here is my.ini finally look like.

[client]
plugin-dir=D:/mariadb-10.4.7-winx64/lib/plugin
default-character-set=utf8mb4

[mysqld]
datadir=D:/mariadb-10.4.7-winx64/data
character-set-client-handshake = false
character_set_server = utf8mb4
character_set_filesystem = binary
character_set_client = utf8mb4
collation_server = utf8mb4_unicode_ci
init_connect='SET NAMES utf8mb4'

[mysqldump]
# character_set_client=utf8mb

[mysql]
default-character-set=utf8mb4

And now, the real problem was happend. When i type select * from control_point, i get an error table control_point doesn t exist in engine. The table is in database building_control, it has nothing to do with the database agilor_ws i just exported.

I follow this tutorial to try restore the control_point table use control_point.ibd file.

http://www.chriscalender.com/recovering-an-innodb-table-from-only-an-ibd-file/

I use method #1 in that tutorial.

First, i install mariadb in an new machine.

create database test1;
use test1

CREATE TABLE IF NOT EXISTS `test1`.`control_point` (
  `id` CHAR(32) NOT NULL,
  `path` VARCHAR(200) NULL,
  `control_path` VARCHAR(200) NULL,
  `title` VARCHAR(20) NULL,
  `enabled` TINYINT(1) NULL,
  `control_point_template_id` CHAR(32) NOT NULL,
  `device_id` CHAR(32) NOT NULL,
  `connector_id` CHAR(32) NOT NULL,
  PRIMARY KEY (`id`))
ENGINE = InnoDB;

ALTER TABLE control_point DISCARD TABLESPACE;

And the file control_point.ibd is removed when i execute the command.

I copy the control_point.ibd file from server into test1 folder.

ALTER TABLE control_point IMPORT TABLESPACE;

When i execute this command, i get an error ERROR 2013 (HY000): Lost connection to MySQL server during query.

And mariadb server is down.

Here is the mysql log.

2020-06-10 18:29:35 8 [Note] InnoDB: Sync to disk
2020-06-10 18:29:35 8 [Note] InnoDB: Sync to disk - done!
2020-06-10 18:29:35 8 [Warning] InnoDB: Table `test1`.`control_point` should have 1 indexes but the tablespace has 5 indexes
2020-06-10 18:29:35 8 [Note] InnoDB: Phase I - Update all pages
2020-06-10 18:29:35 8 [Note] InnoDB: Sync to disk
2020-06-10 18:29:35 8 [Note] InnoDB: Sync to disk - done!
2020-06-10 18:29:35 8 [Note] InnoDB: Phase III - Flush changes to disk
2020-06-10 18:29:35 8 [Note] InnoDB: Phase IV - Flush complete
2020-06-10 18:29:35 8 [ERROR] InnoDB: Table `test1`.`control_point` is missing instant ALTER metadata
200610 18:29:35 [ERROR] mysqld got exception 0xc0000005 ;
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: 10.4.7-MariaDB
key_buffer_size=134217728
read_buffer_size=131072
max_used_connections=3
max_threads=65537
thread_count=7
It is possible that mysqld could use up to 
key_buffer_size + (read_buffer_size + sort_buffer_size)*max_threads = 136383 K  bytes of memory
Hope that's ok; if not, decrease some variables in the equation.

Thread pointer: 0x237d8a82528
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...
mysqld.exe!ha_innobase::discard_or_import_tablespace()[ha_innodb.cc:12867]
mysqld.exe!mysql_discard_or_import_tablespace()[sql_table.cc:5945]
mysqld.exe!Sql_cmd_discard_import_tablespace::execute()[sql_alter.cc:543]
mysqld.exe!mysql_execute_command()[sql_parse.cc:6108]
mysqld.exe!mysql_parse()[sql_parse.cc:7913]
mysqld.exe!dispatch_command()[sql_parse.cc:1845]
mysqld.exe!do_command()[sql_parse.cc:1359]
mysqld.exe!threadpool_process_request()[threadpool_common.cc:359]
mysqld.exe!tp_callback()[threadpool_common.cc:186]
ntdll.dll!TpReleaseWait()
ntdll.dll!RtlInitializeResource()
KERNEL32.DLL!BaseThreadInitThunk()
ntdll.dll!RtlUserThreadStart()

Trying to get some variables.
Some pointers may be invalid and cause the dump to abort.
Query (0x237d8a8f810): ALTER TABLE control_point IMPORT TABLESPACE
Connection ID (thread ID): 8
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 at D:\tools\MariaDB 10.4\data\

Is there other way to recover control_point table data from control_point.ibd file?