Module: Pgoutput::Client::Commands Private

Defined in:
lib/pgoutput/client/commands.rb

Overview

This module is part of a private API. You should avoid using this module if possible, as it may be removed or be changed in the future.

SQL command builders for PostgreSQL replication-mode commands.

PostgreSQL replication commands are issued on a connection opened with the replication parameter enabled. The methods in this module render the small command subset needed by pgoutput-client and rely on Configuration to validate identifier-like values before interpolation.

Class Method Summary collapse

Class Method Details

.create_replication_slot(configuration) ⇒ String

This method is part of a private API. You should avoid using this method if possible, as it may be removed or be changed in the future.

Render a CREATE_REPLICATION_SLOT command.

Temporary slots are requested only when Pgoutput::Client::Configuration#temporary_slot is true.

Examples:

Permanent slot

Commands.create_replication_slot(config)
# => "CREATE_REPLICATION_SLOT cdc_slot LOGICAL pgoutput"

Parameters:

Returns:

  • (String) —

    SQL command suitable for PG::Connection#exec



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# File 'lib/pgoutput/client/commands.rb', line 27

def create_replication_slot(configuration)
  temporary = configuration.temporary_slot ? " TEMPORARY" : ""
  "CREATE_REPLICATION_SLOT #{configuration.slot_name}#{temporary} LOGICAL #{configuration.plugin}"
end

.drop_replication_slot(configuration) ⇒ String

This method is part of a private API. You should avoid using this method if possible, as it may be removed or be changed in the future.

Render a DROP_REPLICATION_SLOT command.

Parameters:

Returns:

  • (String) —

    SQL command suitable for PG::Connection#exec



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# File 'lib/pgoutput/client/commands.rb', line 36

def drop_replication_slot(configuration)
  "DROP_REPLICATION_SLOT #{configuration.slot_name}"
end

.start_replication(configuration) ⇒ String

This method is part of a private API. You should avoid using this method if possible, as it may be removed or be changed in the future.

Render a START_REPLICATION SLOT ... LOGICAL ... command.

The command includes the pgoutput options required by PostgreSQL: proto_version and publication_names. Optional pgoutput switches such as binary and messages are emitted only when enabled.

Parameters:

Returns:

  • (String) —

    SQL command suitable for PG::Connection#exec



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# File 'lib/pgoutput/client/commands.rb', line 48

def start_replication(configuration)
  options = {
    "proto_version" => configuration.proto_version.to_s,
    "publication_names" => configuration.publication_names.join(","),
    "binary" => configuration.binary ? "true" : nil,
    "messages" => configuration.messages ? "true" : nil
  }.compact

  rendered_options = options.map { |key, value| %("#{key}" '#{value}') }.join(", ")

  "START_REPLICATION SLOT #{configuration.slot_name} LOGICAL #{configuration.start_lsn_string} (#{rendered_options})"
end