pg_recvlogical
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 aspg_receivexlog, plus those for logical replication (seeChapter 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:
- -ffilename
--file=filename Write received and decoded transaction data into this file. Use- for stdout.
- -Finterval_seconds
--fsync-interval=interval_seconds Specifies how oftenpg_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 of0 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.- -Ilsn
--startpos=lsn In--start mode, start replication from the given LSN. For details on the effect of this, see the documentation inChapter 46 andSection 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.
- -oname[=value]
--option=name[=value] Pass the optionname to the output plugin with, if specified, the option valuevalue. Which options exist and their effects depends on the used output plugin.
- -Pplugin
--plugin=plugin When creating a slot, use the specified logical decoding output plugin. SeeChapter 46. This option has no effect if the slot already exists.
- -sinterval_seconds
--status-interval=interval_seconds This option has the same effect as the option of the same name inpg_receivexlog. See the description there.
- -Sslot_name
--slot=slot_name In--start mode, use the existing logical replication slot namedslot_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.
- -ddatabase
--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; seeSection 31.1.1 for more information. Defaults to user name.
- -hhostname-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 thePGHOST environment variable, if set, else a Unix domain socket connection is attempted.
- -pport
--port=port Specifies the TCP port or local Unix domain socket file extension on which the server is listening for connections. Defaults to thePGPORT environment variable, if set, or a compiled-in default.
- -Uuser
--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 Forcepg_recvlogical to prompt for a password before connecting to a database.
This option is never essential, sincepg_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 thepg_recvlogical version and exit.
- -?
--help Show help aboutpg_recvlogical command line arguments, and exit.
Environment
This utility, like most otherPostgreSQL utilities, uses the environment variables supported bylibpq (seeSection 31.14).