the best way to update sql_joined_field in main+delta schema

[jacentsao]

use Main+ delta schema and sql_joined field together。

tables key columns :

main_table: id bigint, name string, updated_at timestamp
join_table: id bigint, main_table_id bigint, code string, updated_at timestamp 

one main_table record will have many join_table records.

# in manticore.conf
source main {
  ...
  sql_query_pre = REPLACE INTO deltabreaker SET index_name = 'main', created_at = NOW()
  sql_query =  SELECT id, name, UNIX_TIMESTAMP(updated_at) AS updated FROM main_table WHERE  updated_at  >=FROM_UNIXTIME($start) AND updated_at  <=FROM_UNIXTIME($end)
  sql_query_range  = SELECT ( SELECT UNIX_TIMESTAMP(MIN(updated_at)) FROM main_table) min, ( SELECT UNIX_TIMESTAMP(created_at)-1 FROM deltabreaker WHERE index_name='main') max
  sql_query_post_index = REPLACE INTO deltabreaker set index_name = 'delta', created_at = (SELECT created_at FROM deltabreaker t WHERE index_name='main')
  ...
  sql_attr_timestamp = updated
  sql_joined_field= codes from query; SELECT main_table_id , code FROM join_table
}

source delta : main {
  sql_query_pre =
  sql_query_range = SELECT ( SELECT UNIX_TIMESTAMP(created_at) FROM deltabreaker WHERE index_name='delta') min, UNIX_TIMESTAMP() max
  sql_query_killlist = SELECT id FROM main_table WHERE updated_at >=  (SELECT created_at FROM deltabreaker WHERE index_name='delta')
}

table main {
  path = /var/lib/manticore/main
  source = main
}

table delta {
  path = /var/lib/manticore/delta
  source = delta
  killlist_target = main:kl
}

problem: the join_table can update the code independently without update the main_table, what's the best way to sync data from mysql to manticoresearch plain table in plain mode? to update related main_table's updated_at column when join_table is updated or any other solution? Many thanks for your suggestion.

[jacentsao]

or append search main_table_idfrom join_table

sql_query =  SELECT id, name, UNIX_TIMESTAMP(updated_at) AS updated FROM main_table WHERE  (updated_at  >=FROM_UNIXTIME($start) AND updated_at  <=FROM_UNIXTIME($end)) \
 or id in (SELECT distinct(main_table_id) from join_table WHERE  updated_at  >=FROM_UNIXTIME($start) AND updated_at  <=FROM_UNIXTIME($end) )