<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd"> <HTML ><HEAD ><TITLE >Logical Decoding Output Writers</TITLE ><META NAME="GENERATOR" CONTENT="Modular DocBook HTML Stylesheet Version 1.79"><LINK REV="MADE" HREF="mailto:pgsql-docs@postgresql.org"><LINK REL="HOME" TITLE="PostgreSQL 9.6.15 Documentation" HREF="index.html"><LINK REL="UP" TITLE="Logical Decoding" HREF="logicaldecoding.html"><LINK REL="PREVIOUS" TITLE="Logical Decoding Output Plugins" HREF="logicaldecoding-output-plugin.html"><LINK REL="NEXT" TITLE="Synchronous Replication Support for Logical Decoding" HREF="logicaldecoding-synchronous.html"><LINK REL="STYLESHEET" TYPE="text/css" HREF="stylesheet.css"><META HTTP-EQUIV="Content-Type" CONTENT="text/html; charset=ISO-8859-1"><META NAME="creation" CONTENT="2019-08-11T16:06:51"></HEAD ><BODY CLASS="SECT1" ><DIV CLASS="NAVHEADER" ><TABLE SUMMARY="Header navigation table" WIDTH="100%" BORDER="0" CELLPADDING="0" CELLSPACING="0" ><TR ><TH COLSPAN="4" ALIGN="center" VALIGN="bottom" ><A HREF="index.html" >PostgreSQL 9.6.15 Documentation</A ></TH ></TR ><TR ><TD WIDTH="10%" ALIGN="left" VALIGN="top" ><A TITLE="Logical Decoding Output Plugins" HREF="logicaldecoding-output-plugin.html" ACCESSKEY="P" >Prev</A ></TD ><TD WIDTH="10%" ALIGN="left" VALIGN="top" ><A HREF="logicaldecoding.html" ACCESSKEY="U" >Up</A ></TD ><TD WIDTH="60%" ALIGN="center" VALIGN="bottom" >Chapter 47. Logical Decoding</TD ><TD WIDTH="20%" ALIGN="right" VALIGN="top" ><A TITLE="Synchronous Replication Support for Logical Decoding" HREF="logicaldecoding-synchronous.html" ACCESSKEY="N" >Next</A ></TD ></TR ></TABLE ><HR ALIGN="LEFT" WIDTH="100%"></DIV ><DIV CLASS="SECT1" ><H1 CLASS="SECT1" ><A NAME="LOGICALDECODING-WRITER" >47.7. Logical Decoding Output Writers</A ></H1 ><P > It is possible to add more output methods for logical decoding. For details, see <TT CLASS="FILENAME" >src/backend/replication/logical/logicalfuncs.c</TT >. Essentially, three functions need to be provided: one to read WAL, one to prepare writing output, and one to write the output (see <A HREF="logicaldecoding-output-plugin.html#LOGICALDECODING-OUTPUT-PLUGIN-OUTPUT" >Section 47.6.5</A >). </P ></DIV ><DIV CLASS="NAVFOOTER" ><HR ALIGN="LEFT" WIDTH="100%"><TABLE SUMMARY="Footer navigation table" WIDTH="100%" BORDER="0" CELLPADDING="0" CELLSPACING="0" ><TR ><TD WIDTH="33%" ALIGN="left" VALIGN="top" ><A HREF="logicaldecoding-output-plugin.html" ACCESSKEY="P" >Prev</A ></TD ><TD WIDTH="34%" ALIGN="center" VALIGN="top" ><A HREF="index.html" ACCESSKEY="H" >Home</A ></TD ><TD WIDTH="33%" ALIGN="right" VALIGN="top" ><A HREF="logicaldecoding-synchronous.html" ACCESSKEY="N" >Next</A ></TD ></TR ><TR ><TD WIDTH="33%" ALIGN="left" VALIGN="top" >Logical Decoding Output Plugins</TD ><TD WIDTH="34%" ALIGN="center" VALIGN="top" ><A HREF="logicaldecoding.html" ACCESSKEY="U" >Up</A ></TD ><TD WIDTH="33%" ALIGN="right" VALIGN="top" >Synchronous Replication Support for Logical Decoding</TD ></TR ></TABLE ></DIV ></BODY ></HTML >