Thanks @datenschuft . Our situation is similar (migrated from MySQL to PostgreSQL a while ago). However even after commenting out the mentioned line in /opt/zammad/db/migrate/20230726082734_smime_meta_information_table.rb, zammad run rails db:migrate RAILS_ENV=production fails with a long trace:
$ zammad run rails db:migrate RAILS_ENV=production
== 20230726082734 SMIMEMetaInformationTable: migrating ========================
-- change_table(:smime_certificates)
rails aborted!
StandardError: An error has occurred, this and all later migrations canceled:
No indexes found on smime_certificates with the options provided.
/opt/zammad/vendor/bundle/ruby/3.1.0/gems/activerecord-6.1.7.6/lib/active_record/connection_adapters/abstract/schema_statements.rb:1411:in `index_name_for_remove'
/opt/zammad/vendor/bundle/ruby/3.1.0/gems/activerecord-6.1.7.6/lib/active_record/connection_adapters/postgresql/schema_statements.rb:470:in `remove_index'
/opt/zammad/vendor/bundle/ruby/3.1.0/gems/activerecord-6.1.7.6/lib/active_record/connection_adapters/abstract/schema_definitions.rb:711:in `remove_index'
/opt/zammad/db/migrate/20230726082734_smime_meta_information_table.rb:24:in `remove_columns'
/opt/zammad/db/migrate/20230726082734_smime_meta_information_table.rb:15:in `block in migrate_table'
/opt/zammad/vendor/bundle/ruby/3.1.0/gems/activerecord-6.1.7.6/lib/active_record/connection_adapters/abstract/schema_statements.rb:490:in `change_table'
/opt/zammad/vendor/bundle/ruby/3.1.0/gems/activerecord-6.1.7.6/lib/active_record/migration.rb:929:in `block in method_missing'
/opt/zammad/vendor/bundle/ruby/3.1.0/gems/activerecord-6.1.7.6/lib/active_record/migration.rb:897:in `block in say_with_time'
/opt/zammad/vendor/ruby-3.1.3/lib/ruby/3.1.0/benchmark.rb:296:in `measure'
/opt/zammad/vendor/bundle/ruby/3.1.0/gems/activerecord-6.1.7.6/lib/active_record/migration.rb:897:in `say_with_time'
/opt/zammad/vendor/bundle/ruby/3.1.0/gems/activerecord-6.1.7.6/lib/active_record/migration.rb:918:in `method_missing'
/opt/zammad/db/migrate/20230726082734_smime_meta_information_table.rb:14:in `migrate_table'
/opt/zammad/db/migrate/20230726082734_smime_meta_information_table.rb:8:in `change'
/opt/zammad/vendor/bundle/ruby/3.1.0/gems/activerecord-6.1.7.6/lib/active_record/migration.rb:867:in `exec_migration'
/opt/zammad/vendor/bundle/ruby/3.1.0/gems/activerecord-6.1.7.6/lib/active_record/migration.rb:851:in `block (2 levels) in migrate'
/opt/zammad/vendor/ruby-3.1.3/lib/ruby/3.1.0/benchmark.rb:296:in `measure'
/opt/zammad/vendor/bundle/ruby/3.1.0/gems/activerecord-6.1.7.6/lib/active_record/migration.rb:850:in `block in migrate'
/opt/zammad/vendor/bundle/ruby/3.1.0/gems/activerecord-6.1.7.6/lib/active_record/connection_adapters/abstract/connection_pool.rb:462:in `with_connection'
/opt/zammad/vendor/bundle/ruby/3.1.0/gems/activerecord-6.1.7.6/lib/active_record/migration.rb:849:in `migrate'
/opt/zammad/vendor/bundle/ruby/3.1.0/gems/activerecord-6.1.7.6/lib/active_record/migration.rb:1037:in `migrate'
/opt/zammad/vendor/bundle/ruby/3.1.0/gems/activerecord-6.1.7.6/lib/active_record/migration.rb:1329:in `block in execute_migration_in_transaction'
/opt/zammad/vendor/bundle/ruby/3.1.0/gems/activerecord-6.1.7.6/lib/active_record/migration.rb:1380:in `block in ddl_transaction'
/opt/zammad/vendor/bundle/ruby/3.1.0/gems/activerecord-6.1.7.6/lib/active_record/connection_adapters/abstract/database_statements.rb:320:in `block in transaction'
/opt/zammad/vendor/bundle/ruby/3.1.0/gems/activerecord-6.1.7.6/lib/active_record/connection_adapters/abstract/transaction.rb:319:in `block in within_new_transaction'
/opt/zammad/vendor/bundle/ruby/3.1.0/gems/activesupport-6.1.7.6/lib/active_support/concurrency/load_interlock_aware_monitor.rb:26:in `block (2 levels) in synchronize'
/opt/zammad/vendor/bundle/ruby/3.1.0/gems/activesupport-6.1.7.6/lib/active_support/concurrency/load_interlock_aware_monitor.rb:25:in `handle_interrupt'
/opt/zammad/vendor/bundle/ruby/3.1.0/gems/activesupport-6.1.7.6/lib/active_support/concurrency/load_interlock_aware_monitor.rb:25:in `block in synchronize'
/opt/zammad/vendor/bundle/ruby/3.1.0/gems/activesupport-6.1.7.6/lib/active_support/concurrency/load_interlock_aware_monitor.rb:21:in `handle_interrupt'
/opt/zammad/vendor/bundle/ruby/3.1.0/gems/activesupport-6.1.7.6/lib/active_support/concurrency/load_interlock_aware_monitor.rb:21:in `synchronize'
/opt/zammad/vendor/bundle/ruby/3.1.0/gems/activerecord-6.1.7.6/lib/active_record/connection_adapters/abstract/transaction.rb:317:in `within_new_transaction'
/opt/zammad/vendor/bundle/ruby/3.1.0/gems/activerecord-6.1.7.6/lib/active_record/connection_adapters/abstract/database_statements.rb:320:in `transaction'
/opt/zammad/vendor/bundle/ruby/3.1.0/gems/activerecord-6.1.7.6/lib/active_record/transactions.rb:209:in `transaction'
/opt/zammad/vendor/bundle/ruby/3.1.0/gems/activerecord-6.1.7.6/lib/active_record/migration.rb:1380:in `ddl_transaction'
/opt/zammad/vendor/bundle/ruby/3.1.0/gems/activerecord-6.1.7.6/lib/active_record/migration.rb:1328:in `execute_migration_in_transaction'
/opt/zammad/vendor/bundle/ruby/3.1.0/gems/activerecord-6.1.7.6/lib/active_record/migration.rb:1302:in `each'
/opt/zammad/vendor/bundle/ruby/3.1.0/gems/activerecord-6.1.7.6/lib/active_record/migration.rb:1302:in `migrate_without_lock'
/opt/zammad/vendor/bundle/ruby/3.1.0/gems/activerecord-6.1.7.6/lib/active_record/migration.rb:1251:in `block in migrate'
/opt/zammad/vendor/bundle/ruby/3.1.0/gems/activerecord-6.1.7.6/lib/active_record/migration.rb:1401:in `block in with_advisory_lock'
/opt/zammad/vendor/bundle/ruby/3.1.0/gems/activerecord-6.1.7.6/lib/active_record/migration.rb:1416:in `block in with_advisory_lock_connection'
/opt/zammad/vendor/bundle/ruby/3.1.0/gems/activerecord-6.1.7.6/lib/active_record/connection_adapters/abstract/connection_pool.rb:462:in `with_connection'
/opt/zammad/vendor/bundle/ruby/3.1.0/gems/activerecord-6.1.7.6/lib/active_record/migration.rb:1416:in `with_advisory_lock_connection'
/opt/zammad/vendor/bundle/ruby/3.1.0/gems/activerecord-6.1.7.6/lib/active_record/migration.rb:1397:in `with_advisory_lock'
/opt/zammad/vendor/bundle/ruby/3.1.0/gems/activerecord-6.1.7.6/lib/active_record/migration.rb:1251:in `migrate'
/opt/zammad/vendor/bundle/ruby/3.1.0/gems/activerecord-6.1.7.6/lib/active_record/migration.rb:1086:in `up'
/opt/zammad/vendor/bundle/ruby/3.1.0/gems/activerecord-6.1.7.6/lib/active_record/migration.rb:1061:in `migrate'
/opt/zammad/vendor/bundle/ruby/3.1.0/gems/activerecord-6.1.7.6/lib/active_record/tasks/database_tasks.rb:237:in `migrate'
/opt/zammad/vendor/bundle/ruby/3.1.0/gems/activerecord-6.1.7.6/lib/active_record/railties/databases.rake:92:in `block (3 levels) in <main>'
/opt/zammad/vendor/bundle/ruby/3.1.0/gems/activerecord-6.1.7.6/lib/active_record/railties/databases.rake:90:in `each'
/opt/zammad/vendor/bundle/ruby/3.1.0/gems/activerecord-6.1.7.6/lib/active_record/railties/databases.rake:90:in `block (2 levels) in <main>'
/opt/zammad/vendor/bundle/ruby/3.1.0/gems/rake-13.0.6/lib/rake/task.rb:281:in `block in execute'
/opt/zammad/vendor/bundle/ruby/3.1.0/gems/rake-13.0.6/lib/rake/task.rb:281:in `each'
/opt/zammad/vendor/bundle/ruby/3.1.0/gems/rake-13.0.6/lib/rake/task.rb:281:in `execute'
/opt/zammad/vendor/bundle/ruby/3.1.0/gems/rake-13.0.6/lib/rake/task.rb:219:in `block in invoke_with_call_chain'
/opt/zammad/vendor/bundle/ruby/3.1.0/gems/rake-13.0.6/lib/rake/task.rb:199:in `synchronize'
/opt/zammad/vendor/bundle/ruby/3.1.0/gems/rake-13.0.6/lib/rake/task.rb:199:in `invoke_with_call_chain'
/opt/zammad/vendor/bundle/ruby/3.1.0/gems/rake-13.0.6/lib/rake/task.rb:188:in `invoke'
/opt/zammad/vendor/bundle/ruby/3.1.0/gems/rake-13.0.6/lib/rake/application.rb:160:in `invoke_task'
/opt/zammad/vendor/bundle/ruby/3.1.0/gems/rake-13.0.6/lib/rake/application.rb:116:in `block (2 levels) in top_level'
/opt/zammad/vendor/bundle/ruby/3.1.0/gems/rake-13.0.6/lib/rake/application.rb:116:in `each'
/opt/zammad/vendor/bundle/ruby/3.1.0/gems/rake-13.0.6/lib/rake/application.rb:116:in `block in top_level'
/opt/zammad/vendor/bundle/ruby/3.1.0/gems/rake-13.0.6/lib/rake/application.rb:125:in `run_with_threads'
/opt/zammad/vendor/bundle/ruby/3.1.0/gems/rake-13.0.6/lib/rake/application.rb:110:in `top_level'
/opt/zammad/vendor/bundle/ruby/3.1.0/gems/railties-6.1.7.6/lib/rails/commands/rake/rake_command.rb:24:in `block (2 levels) in perform'
/opt/zammad/vendor/bundle/ruby/3.1.0/gems/rake-13.0.6/lib/rake/application.rb:186:in `standard_exception_handling'
/opt/zammad/vendor/bundle/ruby/3.1.0/gems/railties-6.1.7.6/lib/rails/commands/rake/rake_command.rb:24:in `block in perform'
/opt/zammad/vendor/bundle/ruby/3.1.0/gems/rake-13.0.6/lib/rake/rake_module.rb:59:in `with_application'
/opt/zammad/vendor/bundle/ruby/3.1.0/gems/railties-6.1.7.6/lib/rails/commands/rake/rake_command.rb:18:in `perform'
/opt/zammad/vendor/bundle/ruby/3.1.0/gems/railties-6.1.7.6/lib/rails/command.rb:50:in `invoke'
/opt/zammad/vendor/bundle/ruby/3.1.0/gems/railties-6.1.7.6/lib/rails/commands.rb:18:in `<main>'
/opt/zammad/vendor/bundle/ruby/3.1.0/gems/bootsnap-1.16.0/lib/bootsnap/load_path_cache/core_ext/kernel_require.rb:32:in `require'
/opt/zammad/vendor/bundle/ruby/3.1.0/gems/bootsnap-1.16.0/lib/bootsnap/load_path_cache/core_ext/kernel_require.rb:32:in `require'
/opt/zammad/bin/rails:5:in `<main>'
Caused by:
ArgumentError: No indexes found on smime_certificates with the options provided.
/opt/zammad/vendor/bundle/ruby/3.1.0/gems/activerecord-6.1.7.6/lib/active_record/connection_adapters/abstract/schema_statements.rb:1411:in `index_name_for_remove'
/opt/zammad/vendor/bundle/ruby/3.1.0/gems/activerecord-6.1.7.6/lib/active_record/connection_adapters/postgresql/schema_statements.rb:470:in `remove_index'
/opt/zammad/vendor/bundle/ruby/3.1.0/gems/activerecord-6.1.7.6/lib/active_record/connection_adapters/abstract/schema_definitions.rb:711:in `remove_index'
/opt/zammad/db/migrate/20230726082734_smime_meta_information_table.rb:24:in `remove_columns'
/opt/zammad/db/migrate/20230726082734_smime_meta_information_table.rb:15:in `block in migrate_table'
/opt/zammad/vendor/bundle/ruby/3.1.0/gems/activerecord-6.1.7.6/lib/active_record/connection_adapters/abstract/schema_statements.rb:490:in `change_table'
/opt/zammad/vendor/bundle/ruby/3.1.0/gems/activerecord-6.1.7.6/lib/active_record/migration.rb:929:in `block in method_missing'
/opt/zammad/vendor/bundle/ruby/3.1.0/gems/activerecord-6.1.7.6/lib/active_record/migration.rb:897:in `block in say_with_time'
/opt/zammad/vendor/ruby-3.1.3/lib/ruby/3.1.0/benchmark.rb:296:in `measure'
/opt/zammad/vendor/bundle/ruby/3.1.0/gems/activerecord-6.1.7.6/lib/active_record/migration.rb:897:in `say_with_time'
/opt/zammad/vendor/bundle/ruby/3.1.0/gems/activerecord-6.1.7.6/lib/active_record/migration.rb:918:in `method_missing'
/opt/zammad/db/migrate/20230726082734_smime_meta_information_table.rb:14:in `migrate_table'
/opt/zammad/db/migrate/20230726082734_smime_meta_information_table.rb:8:in `change'
/opt/zammad/vendor/bundle/ruby/3.1.0/gems/activerecord-6.1.7.6/lib/active_record/migration.rb:867:in `exec_migration'
/opt/zammad/vendor/bundle/ruby/3.1.0/gems/activerecord-6.1.7.6/lib/active_record/migration.rb:851:in `block (2 levels) in migrate'
/opt/zammad/vendor/ruby-3.1.3/lib/ruby/3.1.0/benchmark.rb:296:in `measure'
/opt/zammad/vendor/bundle/ruby/3.1.0/gems/activerecord-6.1.7.6/lib/active_record/migration.rb:850:in `block in migrate'
/opt/zammad/vendor/bundle/ruby/3.1.0/gems/activerecord-6.1.7.6/lib/active_record/connection_adapters/abstract/connection_pool.rb:462:in `with_connection'
/opt/zammad/vendor/bundle/ruby/3.1.0/gems/activerecord-6.1.7.6/lib/active_record/migration.rb:849:in `migrate'
/opt/zammad/vendor/bundle/ruby/3.1.0/gems/activerecord-6.1.7.6/lib/active_record/migration.rb:1037:in `migrate'
/opt/zammad/vendor/bundle/ruby/3.1.0/gems/activerecord-6.1.7.6/lib/active_record/migration.rb:1329:in `block in execute_migration_in_transaction'
/opt/zammad/vendor/bundle/ruby/3.1.0/gems/activerecord-6.1.7.6/lib/active_record/migration.rb:1380:in `block in ddl_transaction'
/opt/zammad/vendor/bundle/ruby/3.1.0/gems/activerecord-6.1.7.6/lib/active_record/connection_adapters/abstract/database_statements.rb:320:in `block in transaction'
/opt/zammad/vendor/bundle/ruby/3.1.0/gems/activerecord-6.1.7.6/lib/active_record/connection_adapters/abstract/transaction.rb:319:in `block in within_new_transaction'
/opt/zammad/vendor/bundle/ruby/3.1.0/gems/activesupport-6.1.7.6/lib/active_support/concurrency/load_interlock_aware_monitor.rb:26:in `block (2 levels) in synchronize'
/opt/zammad/vendor/bundle/ruby/3.1.0/gems/activesupport-6.1.7.6/lib/active_support/concurrency/load_interlock_aware_monitor.rb:25:in `handle_interrupt'
/opt/zammad/vendor/bundle/ruby/3.1.0/gems/activesupport-6.1.7.6/lib/active_support/concurrency/load_interlock_aware_monitor.rb:25:in `block in synchronize'
/opt/zammad/vendor/bundle/ruby/3.1.0/gems/activesupport-6.1.7.6/lib/active_support/concurrency/load_interlock_aware_monitor.rb:21:in `handle_interrupt'
/opt/zammad/vendor/bundle/ruby/3.1.0/gems/activesupport-6.1.7.6/lib/active_support/concurrency/load_interlock_aware_monitor.rb:21:in `synchronize'
/opt/zammad/vendor/bundle/ruby/3.1.0/gems/activerecord-6.1.7.6/lib/active_record/connection_adapters/abstract/transaction.rb:317:in `within_new_transaction'
/opt/zammad/vendor/bundle/ruby/3.1.0/gems/activerecord-6.1.7.6/lib/active_record/connection_adapters/abstract/database_statements.rb:320:in `transaction'
/opt/zammad/vendor/bundle/ruby/3.1.0/gems/activerecord-6.1.7.6/lib/active_record/transactions.rb:209:in `transaction'
/opt/zammad/vendor/bundle/ruby/3.1.0/gems/activerecord-6.1.7.6/lib/active_record/migration.rb:1380:in `ddl_transaction'
/opt/zammad/vendor/bundle/ruby/3.1.0/gems/activerecord-6.1.7.6/lib/active_record/migration.rb:1328:in `execute_migration_in_transaction'
/opt/zammad/vendor/bundle/ruby/3.1.0/gems/activerecord-6.1.7.6/lib/active_record/migration.rb:1302:in `each'
/opt/zammad/vendor/bundle/ruby/3.1.0/gems/activerecord-6.1.7.6/lib/active_record/migration.rb:1302:in `migrate_without_lock'
/opt/zammad/vendor/bundle/ruby/3.1.0/gems/activerecord-6.1.7.6/lib/active_record/migration.rb:1251:in `block in migrate'
/opt/zammad/vendor/bundle/ruby/3.1.0/gems/activerecord-6.1.7.6/lib/active_record/migration.rb:1401:in `block in with_advisory_lock'
/opt/zammad/vendor/bundle/ruby/3.1.0/gems/activerecord-6.1.7.6/lib/active_record/migration.rb:1416:in `block in with_advisory_lock_connection'
/opt/zammad/vendor/bundle/ruby/3.1.0/gems/activerecord-6.1.7.6/lib/active_record/connection_adapters/abstract/connection_pool.rb:462:in `with_connection'
/opt/zammad/vendor/bundle/ruby/3.1.0/gems/activerecord-6.1.7.6/lib/active_record/migration.rb:1416:in `with_advisory_lock_connection'
/opt/zammad/vendor/bundle/ruby/3.1.0/gems/activerecord-6.1.7.6/lib/active_record/migration.rb:1397:in `with_advisory_lock'
/opt/zammad/vendor/bundle/ruby/3.1.0/gems/activerecord-6.1.7.6/lib/active_record/migration.rb:1251:in `migrate'
/opt/zammad/vendor/bundle/ruby/3.1.0/gems/activerecord-6.1.7.6/lib/active_record/migration.rb:1086:in `up'
/opt/zammad/vendor/bundle/ruby/3.1.0/gems/activerecord-6.1.7.6/lib/active_record/migration.rb:1061:in `migrate'
/opt/zammad/vendor/bundle/ruby/3.1.0/gems/activerecord-6.1.7.6/lib/active_record/tasks/database_tasks.rb:237:in `migrate'
/opt/zammad/vendor/bundle/ruby/3.1.0/gems/activerecord-6.1.7.6/lib/active_record/railties/databases.rake:92:in `block (3 levels) in <main>'
/opt/zammad/vendor/bundle/ruby/3.1.0/gems/activerecord-6.1.7.6/lib/active_record/railties/databases.rake:90:in `each'
/opt/zammad/vendor/bundle/ruby/3.1.0/gems/activerecord-6.1.7.6/lib/active_record/railties/databases.rake:90:in `block (2 levels) in <main>'
/opt/zammad/vendor/bundle/ruby/3.1.0/gems/rake-13.0.6/lib/rake/task.rb:281:in `block in execute'
/opt/zammad/vendor/bundle/ruby/3.1.0/gems/rake-13.0.6/lib/rake/task.rb:281:in `each'
/opt/zammad/vendor/bundle/ruby/3.1.0/gems/rake-13.0.6/lib/rake/task.rb:281:in `execute'
/opt/zammad/vendor/bundle/ruby/3.1.0/gems/rake-13.0.6/lib/rake/task.rb:219:in `block in invoke_with_call_chain'
/opt/zammad/vendor/bundle/ruby/3.1.0/gems/rake-13.0.6/lib/rake/task.rb:199:in `synchronize'
/opt/zammad/vendor/bundle/ruby/3.1.0/gems/rake-13.0.6/lib/rake/task.rb:199:in `invoke_with_call_chain'
/opt/zammad/vendor/bundle/ruby/3.1.0/gems/rake-13.0.6/lib/rake/task.rb:188:in `invoke'
/opt/zammad/vendor/bundle/ruby/3.1.0/gems/rake-13.0.6/lib/rake/application.rb:160:in `invoke_task'
/opt/zammad/vendor/bundle/ruby/3.1.0/gems/rake-13.0.6/lib/rake/application.rb:116:in `block (2 levels) in top_level'
/opt/zammad/vendor/bundle/ruby/3.1.0/gems/rake-13.0.6/lib/rake/application.rb:116:in `each'
/opt/zammad/vendor/bundle/ruby/3.1.0/gems/rake-13.0.6/lib/rake/application.rb:116:in `block in top_level'
/opt/zammad/vendor/bundle/ruby/3.1.0/gems/rake-13.0.6/lib/rake/application.rb:125:in `run_with_threads'
/opt/zammad/vendor/bundle/ruby/3.1.0/gems/rake-13.0.6/lib/rake/application.rb:110:in `top_level'
/opt/zammad/vendor/bundle/ruby/3.1.0/gems/railties-6.1.7.6/lib/rails/commands/rake/rake_command.rb:24:in `block (2 levels) in perform'
/opt/zammad/vendor/bundle/ruby/3.1.0/gems/rake-13.0.6/lib/rake/application.rb:186:in `standard_exception_handling'
/opt/zammad/vendor/bundle/ruby/3.1.0/gems/railties-6.1.7.6/lib/rails/commands/rake/rake_command.rb:24:in `block in perform'
/opt/zammad/vendor/bundle/ruby/3.1.0/gems/rake-13.0.6/lib/rake/rake_module.rb:59:in `with_application'
/opt/zammad/vendor/bundle/ruby/3.1.0/gems/railties-6.1.7.6/lib/rails/commands/rake/rake_command.rb:18:in `perform'
/opt/zammad/vendor/bundle/ruby/3.1.0/gems/railties-6.1.7.6/lib/rails/command.rb:50:in `invoke'
/opt/zammad/vendor/bundle/ruby/3.1.0/gems/railties-6.1.7.6/lib/rails/commands.rb:18:in `<main>'
/opt/zammad/vendor/bundle/ruby/3.1.0/gems/bootsnap-1.16.0/lib/bootsnap/load_path_cache/core_ext/kernel_require.rb:32:in `require'
/opt/zammad/vendor/bundle/ruby/3.1.0/gems/bootsnap-1.16.0/lib/bootsnap/load_path_cache/core_ext/kernel_require.rb:32:in `require'
/opt/zammad/bin/rails:5:in `<main>'
Tasks: TOP => db:migrate
(See full trace by running task with --trace)
$
And the listed migrations are still pending.
To make it worse, since a recent upgrade to the latest 6.1.0-1701845240.5a81e629.centos7 (yum upgrade zammad), our triggers have stopped working 
. So any hint on how to fix this unfortunate situation are highly appreciated.