•Each replication channel copies global replication filters to its channel specific replication filters if no channel specific replication filter of this type is configured. 

•Each channel uses its channel specific replication filters to filter the replication stream. 

The syntax to create channel specific replication filters extends the existing SQL statements and command options. When a replication channel is not specified the global replication filter is configured to ensure backwards compatibility. The CHANGE REPLICATION FILTER  statement supports the FOR CHANNEL  clause to configure channel specific filters online. The --replicate- *  command options to configure filters can specify a replication channel using the form -- replicate- filter_type = channel_name : filter_details . For example, suppose channels channel_1  and channel_2  exist before the server starts, starting the replica with the command line options --replicate-do-db=db1 --replicate-do-db=channel_1:db2 --replicate-do- db=db3 --replicate-ignore-db=db4 --replicate-ignore-db=channel_2:db5  would result in: 

• Global replication filters : do_db=db1,db3, ignore_db=db4 

• Channel specific filters on channel_1 : do_db=db2 ignore_db=db4 

• Channel specific filters on channel_2 : do_db=db1,db3 ignore_db=db5 

To monitor the replication filters in such a setup use the replication_applier_global_filters  and replication_applier_filters  tables. 

## Configuring Channel Specific Replication Filters at Startup 

The replication filter related command options can take an optional channel  followed by a colon, followed by the filter specification. The first colon is interpreted as a separator, subsequent colons are interpreted as literal colons. The following command options support channel specific replication filters using this format: 

• --replicate-do-db= channel : database_id 

• --replicate-ignore-db= channel : database_id 

• --replicate-do-table= channel : table_id 

• --replicate-ignore-table= channel : table_id 

• --replicate-rewrite-db= channel : db1-db2 

• --replicate-wild-do-table= channel : table regexid 

• --replicate-wild-ignore-table= channel : table regexid 

If you use a colon but do not specify a channel  for the filter option, for example --replicate-do- db=: database_id , the option configures the replication filter for the default replication channel. The default replication channel is the replication channel which always exists once replication has been started, and differs from multi-source replication channels which you create manually. When neither the colon nor a channel  is specified the option configures the global replication filters, for example --replicate-do- db= database_id  configures the global --replicate-do-db  filter. 

If you configure multiple rewrite-db= from_name -> to_name  options with the same from_name database, all filters are added together (put into the rewrite_do  list) and the first one takes effect. 

## Changing Channel Specific Replication Filters Online 

In addition to the --replicate-*  options, replication filters can be configured using the CHANGE REPLICATION FILTER  statement. This removes the need to restart the server, but the replication SQL 

