PostgreSQL 9.4.0 Documentation
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# pg_recvlogical

## Name

pg_recvlogical -- control PostgreSQL logical decoding streams

## Synopsis

`pg_recvlogical` [`option`...]

## Description

`pg_recvlogical` controls logical decoding replication slots and streams data from such replication slots.

It creates a replication-mode connection, so it is subject to the same constraints as pg_receivexlog, plus those for logical replication (see Chapter 46).

## Options

At least one of the following options must be specified to select an action:

`--create-slot`

  Create a new logical replication slot with the name specified by `--slot`, using the output plugin specified by `--plugin`, for the database specified by `--dbname`.

`--drop-slot`

  Drop the replication slot with the name specified by `--slot`, then exit.

`--start`

  Begin streaming changes from the logical replication slot specified by `--slot`, continuing until terminated by a signal. If the server side change stream ends with a server shutdown or disconnect, retry in a loop unless `--no-loop` is specified.

  The stream format is determined by the output plugin specified when the slot was created.

  The connection must be to the same database used to create the slot.

`--create-slot` and `--start` can be specified together. `--drop-slot` cannot be combined with another action.

The following command-line options control the location and format of the output and other replication behavior:

`-f `filename``
`--file=`filename``

  Write received and decoded transaction data into this file. Use `-` for stdout.

`-F `interval_seconds``
`--fsync-interval=`interval_seconds``

  Specifies how often pg_recvlogical should issue `fsync()` calls to ensure the output file is safely flushed to disk.

  The server will occasionally request the client to perform a flush and report the flush position to the server. This setting is in addition to that, to perform flushes more frequently.

  Specifying an interval of `0` disables issuing `fsync()` calls altogether, while still reporting progress to the server. In this case, data could be lost in the event of a crash.

`-I `lsn``
`--startpos=`lsn``

  In `--start` mode, start replication from the given LSN. For details on the effect of this, see the documentation in Chapter 46 and Section 49.3. Ignored in other modes.

`-n`
`--no-loop`

  When the connection to the server is lost, do not retry in a loop, just exit.

`-o `name`[=`value`]`
`--option=`name`[=`value`]`

  Pass the option `name` to the output plugin with, if specified, the option value `value`. Which options exist and their effects depends on the used output plugin.

`-P `plugin``
`--plugin=`plugin``

  When creating a slot, use the specified logical decoding output plugin. See Chapter 46. This option has no effect if the slot already exists.

`-s `interval_seconds``
`--status-interval=`interval_seconds``

  This option has the same effect as the option of the same name in pg_receivexlog. See the description there.

`-S `slot_name``
`--slot=`slot_name``

  In `--start` mode, use the existing logical replication slot named `slot_name`. In `--create-slot` mode, create the slot with this name. In `--drop-slot` mode, delete the slot with this name.

`-v`
`--verbose`

  Enables verbose mode.

The following command-line options control the database connection parameters.

`-d `database``
`--dbname=`database``

  The database to connect to. See the description of the actions for what this means in detail. This can be a libpq connection string; see Section 31.1.1 for more information. Defaults to user name.

`-h `hostname-or-ip``
`--host=`hostname-or-ip``

  Specifies the host name of the machine on which the server is running. If the value begins with a slash, it is used as the directory for the Unix domain socket. The default is taken from the `PGHOST` environment variable, if set, else a Unix domain socket connection is attempted.

`-p `port``
`--port=`port``

  Specifies the TCP port or local Unix domain socket file extension on which the server is listening for connections. Defaults to the `PGPORT` environment variable, if set, or a compiled-in default.

`-U `user``
`--username=`user``

  Username to connect as. Defaults to current operating system user name.

`-w`
`--no-password`

  Never issue a password prompt. If the server requires password authentication and a password is not available by other means such as a `.pgpass` file, the connection attempt will fail. This option can be useful in batch jobs and scripts where no user is present to enter a password.

`-W`
`--password`

  Force pg_recvlogical to prompt for a password before connecting to a database.

  This option is never essential, since pg_recvlogical will automatically prompt for a password if the server demands password authentication. However, pg_recvlogical will waste a connection attempt finding out that the server wants a password. In some cases it is worth typing `-W` to avoid the extra connection attempt.

The following additional options are available:

`-V`
`--version`

  Print the pg_recvlogical version and exit.

`-?`
`--help`

  Show help about pg_recvlogical command line arguments, and exit.

## Environment

This utility, like most other PostgreSQL utilities, uses the environment variables supported by libpq (see Section 31.14).

## Examples

See Section 46.1 for an example.

## See Also

pg_receivexlog

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