pg_recvlogical(1) - phpMan

PG_RECVLOGICAL(1) PostgreSQL 14.15 Documentation PG_RECVLOGICAL(1)

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_receivewal(1), plus those for logical replication (see Chapter 49).

pg_recvlogical has no equivalent to the logical decoding SQL interface's peek and get
modes. It sends replay confirmations for data lazily as it receives it and on clean exit.
To examine pending data on a slot without consuming it, use pg_logical_slot_peek_changes.

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:

-E lsn
--endpos=lsn
In --start mode, automatically stop replication and exit with normal exit status 0
when receiving reaches the specified LSN. If specified when not in --start mode, an
error is raised.

If there's a record with LSN exactly equal to lsn, the record will be output.

The --endpos option is not aware of transaction boundaries and may truncate output
partway through a transaction. Any partially output transaction will not be consumed
and will be replayed again when the slot is next read from. Individual messages are
never truncated.

-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 49 and Section 53.4. Ignored in other modes.

--if-not-exists
Do not error out when --create-slot is specified and a slot with the specified name
already exists.

-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 49. 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_receivewal(1).
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 dbname
--dbname=dbname
The database to connect to. See the description of the actions for what this means in
detail. The dbname can be a connection string. If so, connection string parameters
will override any conflicting command line options. Defaults to the 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
User name 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 34.15).

The environment variable PG_COLOR specifies whether to use color in diagnostic messages.
Possible values are always, auto and never.

NOTES
pg_recvlogical will preserve group permissions on the received WAL files if group
permissions are enabled on the source cluster.

EXAMPLES
See Section 49.1 for an example.