pg_recvlogical

Function

pg_recvlogical connects to a specified DN to create and delete logical replication slots, obtains the intermediate result of logic decoding from the DN continuously in real time, and outputs the result to a file or in standard mode.

Syntax

pg_recvlogical [OPTION]...

Logical replication slot behavior parameters are mandatory and must be specified. Other parameters are optional. If you do not specify them, the default values will be read.

Parameter Description

• Logical replication slot behavior parameters (mandatory):

  • --create

    Creates a logical replication slot.

  • --start

    Starts the flow replication of a logic replication slot.

  • --drop

    Deletes a logical replication slot.

• Connection options:

  • -d, --dbname=DBNAME

    Connects to the target database.

  • -h, --host=HOSTNAME

    Specifies the name or socket of the connected host.

  • -p, --port=PORT

    Specifies the HA port number for connecting to the target DN.

  • -U, --username=NAME

    Specifies the user name for connecting to the target database.

  • -w, --no-password

    Performs connection without a password.

  • -W, --password

    Performs connection with a specified password.

• Replication parameters:

  • -F --fsync-interval=INTERVAL

    Specifies an interval for synchronizing data to the target output file.

    The unit is s. The default value is 10.

  • -o, --option=NAME[=VALUE]

    Adds parameters to the output plug-in of a logical replication slot.

    The values are include-xids, skip-empty-xacts, and include-timestamp.

    For details, see “SQL Reference > Functions and Operators > System Administration Functions > Logical Replication Functions > options” in the Developer Guide.

  • -P, --plugin=PLUGIN

    Specifies the logical replication slot output plug-in.

    The default value is mppdb_decoding.

  • -s, --status-interval=INTERVAL

    Specifies an interval for sending heartbeat packets.

    The unit is s. The default value is 10.

  • -S, --slot=SLOT

    Specifies the name of a logical replication slot.

  • -I, --startpos=PTR

    LSN location of the initial replication when an existing logical replication slot is used

• Other parameters:

  • -f, --file=FILE

    Specifies the output file.

    If - is used, data is output to stdout.

  • -n, --no-loop

    If this parameter is specified, the system does not retry after the connection fails.

  • -v, --verbose

    Displays detailed information.

  • -V, --version

    Displays the version and exits immediately.

  • -?, --help

    Displays help information and exits immediately.

Examples

1. Create a logical replication slot named test_slot.

   pg_recvlogical -d postgres -S test_slot -p 26000 --create
   

2. Enable stream decoding, and use stdout for output.

   pg_recvlogical -d postgres -S test_slot -p 26000 --start -v -f -
   pg_recvlogical: starting log streaming at 0/0 (slot test_slot)
   pg_recvlogical: initiated streaming
   pg_recvlogical: confirming write up to 0/0, flush to 0/0 (slot test_slot)
   pg_recvlogical: confirming write up to 0/2A342E8, flush to 0/2A342E8 (slot test_slot)
   pg_recvlogical: confirming write up to 0/2A34320, flush to 0/2A34320 (slot test_slot)
   pg_recvlogical: confirming write up to 0/2A34320, flush to 0/2A34320 (slot test_slot)
   BEGIN 16039
   table public.t: INSERT: a[integer]:4 b[integer]:4
   COMMIT 16039
   pg_recvlogical: confirming write up to 0/2A34450, flush to 0/2A34450 (slot test_slot)
   pg_recvlogical: confirming write up to 0/2A34450, flush to 0/2A34450 (slot test_slot)
   

3. Delete the logical replication slot.

   pg_recvlogical -d postgres -S test_slot -p 26000 --drop