pg_recvlogicalpg_recvlogical1Applicationpg_recvlogicalcontrol PostgreSQL logical decoding streamspg_recvlogicaloptionDescriptionpg_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 , plus those for logical
replication (see ).
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.
In the absence of fatal errors, pg_recvlogical
will run until terminated by the SIGINT
(ControlC)
or SIGTERM signal.
Options
At least one of the following options must be specified to select an action:
Create a new logical replication slot with the name specified by
, using the output plugin specified by
, for the database specified
by .
The can be specified with
to enable decoding of prepared transactions.
Drop the replication slot with the name specified
by , then exit.
Begin streaming changes from the logical replication slot specified
by , continuing until terminated by a
signal. If the server side change stream ends with a server shutdown
or disconnect, retry in a loop unless
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.
and can be
specified together. cannot be combined with
another action.
The following command-line options control the location and format of the
output and other replication behavior:
In mode, automatically stop replication
and exit with normal exit status 0 when receiving reaches the
specified LSN. If specified when not in
mode, an error is raised.
If there's a record with LSN exactly equal to lsn,
the record will be output.
The 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.
Write received and decoded transaction data into this
file. Use - for stdout.
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.
In mode, start replication from the given
LSN. For details on the effect of this, see the documentation
in
and . Ignored in other modes.
Do not error out when is specified
and a slot with the specified name already exists.
When the connection to the server is lost, do not retry in a loop, just exit.
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.
When creating a slot, use the specified logical decoding output
plugin. See . This option has no
effect if the slot already exists.
This option has the same effect as the option of the same name
in . See the description there.
In mode, use the existing logical replication slot named
slot_name. In
mode, create the slot with this name. In
mode, delete the slot with this name.
Enables decoding of prepared transactions. This option may only be specified with
Enables verbose mode.
The following command-line options control the database connection parameters.
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.
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.
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.
User name to connect as. Defaults to current operating system user
name.
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.
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 to avoid the extra
connection attempt.
The following additional options are available:
Print the pg_recvlogical version and exit.
Show help about pg_recvlogical command line
arguments, and exit.
Exit Statuspg_recvlogical will exit with status 0 when
terminated by the SIGINT or
SIGTERM signal. (That is the
normal way to end it. Hence it is not an error.) For fatal errors or
other signals, the exit status will be nonzero.
Environment
This utility, like most other PostgreSQL utilities,
uses the environment variables supported by libpq
(see ).
The environment variable PG_COLOR specifies whether to use
color in diagnostic messages. Possible values are
always, auto and
never.
Notespg_recvlogical will preserve group permissions on
the received WAL files if group permissions are enabled on the source
cluster.
Examples
See for an example.
See Also