diff options
| author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-05-04 12:19:15 +0000 |
|---|---|---|
| committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-05-04 12:19:15 +0000 |
| commit | 6eb9c5a5657d1fe77b55cc261450f3538d35a94d (patch) | |
| tree | 657d8194422a5daccecfd42d654b8a245ef7b4c8 /doc/src/sgml/html/protocol-logicalrep-message-formats.html | |
| parent | Initial commit. (diff) | |
| download | postgresql-13-upstream.tar.xz postgresql-13-upstream.zip | |
Adding upstream version 13.4.upstream/13.4upstream
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'doc/src/sgml/html/protocol-logicalrep-message-formats.html')
| -rw-r--r-- | doc/src/sgml/html/protocol-logicalrep-message-formats.html | 311 |
1 files changed, 311 insertions, 0 deletions
diff --git a/doc/src/sgml/html/protocol-logicalrep-message-formats.html b/doc/src/sgml/html/protocol-logicalrep-message-formats.html new file mode 100644 index 0000000..c164e3d --- /dev/null +++ b/doc/src/sgml/html/protocol-logicalrep-message-formats.html @@ -0,0 +1,311 @@ +<?xml version="1.0" encoding="UTF-8" standalone="no"?> +<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd"><html xmlns="http://www.w3.org/1999/xhtml"><head><meta http-equiv="Content-Type" content="text/html; charset=UTF-8" /><title>52.9. Logical Replication Message Formats</title><link rel="stylesheet" type="text/css" href="stylesheet.css" /><link rev="made" href="pgsql-docs@lists.postgresql.org" /><meta name="generator" content="DocBook XSL Stylesheets V1.79.1" /><link rel="prev" href="protocol-error-fields.html" title="52.8. Error and Notice Message Fields" /><link rel="next" href="protocol-changes.html" title="52.10. Summary of Changes since Protocol 2.0" /></head><body id="docContent" class="container-fluid col-10"><div xmlns="http://www.w3.org/TR/xhtml1/transitional" class="navheader"><table width="100%" summary="Navigation header"><tr><th colspan="5" align="center">52.9. Logical Replication Message Formats</th></tr><tr><td width="10%" align="left"><a accesskey="p" href="protocol-error-fields.html" title="52.8. Error and Notice Message Fields">Prev</a> </td><td width="10%" align="left"><a accesskey="u" href="protocol.html" title="Chapter 52. Frontend/Backend Protocol">Up</a></td><th width="60%" align="center">Chapter 52. Frontend/Backend Protocol</th><td width="10%" align="right"><a accesskey="h" href="index.html" title="PostgreSQL 13.4 Documentation">Home</a></td><td width="10%" align="right"> <a accesskey="n" href="protocol-changes.html" title="52.10. Summary of Changes since Protocol 2.0">Next</a></td></tr></table><hr></hr></div><div class="sect1" id="PROTOCOL-LOGICALREP-MESSAGE-FORMATS"><div class="titlepage"><div><div><h2 class="title" style="clear: both">52.9. Logical Replication Message Formats</h2></div></div></div><p> +This section describes the detailed format of each logical replication message. +These messages are returned either by the replication slot SQL interface or are +sent by a walsender. In case of a walsender they are encapsulated inside the replication +protocol WAL messages as described in <a class="xref" href="protocol-replication.html" title="52.4. Streaming Replication Protocol">Section 52.4</a> +and generally obey same message flow as physical replication. +</p><div class="variablelist"><dl class="variablelist"><dt><span class="term"> +Begin +</span></dt><dd><p> + +</p><div class="variablelist"><dl class="variablelist"><dt><span class="term"> + Byte1('B') +</span></dt><dd><p> + Identifies the message as a begin message. +</p></dd><dt><span class="term"> + Int64 +</span></dt><dd><p> + The final LSN of the transaction. +</p></dd><dt><span class="term"> + Int64 +</span></dt><dd><p> + Commit timestamp of the transaction. The value is in number + of microseconds since PostgreSQL epoch (2000-01-01). +</p></dd><dt><span class="term"> + Int32 +</span></dt><dd><p> + Xid of the transaction. +</p></dd></dl></div><p> +</p></dd><dt><span class="term"> +Commit +</span></dt><dd><p> + +</p><div class="variablelist"><dl class="variablelist"><dt><span class="term"> + Byte1('C') +</span></dt><dd><p> + Identifies the message as a commit message. +</p></dd><dt><span class="term"> + Int8 +</span></dt><dd><p> + Flags; currently unused (must be 0). +</p></dd><dt><span class="term"> + Int64 +</span></dt><dd><p> + The LSN of the commit. +</p></dd><dt><span class="term"> + Int64 +</span></dt><dd><p> + The end LSN of the transaction. +</p></dd><dt><span class="term"> + Int64 +</span></dt><dd><p> + Commit timestamp of the transaction. The value is in number + of microseconds since PostgreSQL epoch (2000-01-01). +</p></dd></dl></div><p> +</p></dd><dt><span class="term"> +Origin +</span></dt><dd><p> + +</p><div class="variablelist"><dl class="variablelist"><dt><span class="term"> + Byte1('O') +</span></dt><dd><p> + Identifies the message as an origin message. +</p></dd><dt><span class="term"> + Int64 +</span></dt><dd><p> + The LSN of the commit on the origin server. +</p></dd><dt><span class="term"> + String +</span></dt><dd><p> + Name of the origin. +</p></dd></dl></div><p> +</p><p> + Note that there can be multiple Origin messages inside a single transaction. +</p></dd><dt><span class="term"> +Relation +</span></dt><dd><p> + +</p><div class="variablelist"><dl class="variablelist"><dt><span class="term"> + Byte1('R') +</span></dt><dd><p> + Identifies the message as a relation message. +</p></dd><dt><span class="term"> + Int32 +</span></dt><dd><p> + ID of the relation. +</p></dd><dt><span class="term"> + String +</span></dt><dd><p> + Namespace (empty string for <code class="literal">pg_catalog</code>). +</p></dd><dt><span class="term"> + String +</span></dt><dd><p> + Relation name. +</p></dd><dt><span class="term"> + Int8 +</span></dt><dd><p> + Replica identity setting for the relation (same as + <code class="structfield">relreplident</code> in <code class="structname">pg_class</code>). +</p></dd><dt><span class="term"> + Int16 +</span></dt><dd><p> + Number of columns. +</p></dd></dl></div><p> + Next, the following message part appears for each column (except generated columns): +</p><div class="variablelist"><dl class="variablelist"><dt><span class="term"> + Int8 +</span></dt><dd><p> + Flags for the column. Currently can be either 0 for no flags + or 1 which marks the column as part of the key. +</p></dd><dt><span class="term"> + String +</span></dt><dd><p> + Name of the column. +</p></dd><dt><span class="term"> + Int32 +</span></dt><dd><p> + ID of the column's data type. +</p></dd><dt><span class="term"> + Int32 +</span></dt><dd><p> + Type modifier of the column (<code class="structfield">atttypmod</code>). +</p></dd></dl></div><p> +</p></dd><dt><span class="term"> +Type +</span></dt><dd><p> + +</p><div class="variablelist"><dl class="variablelist"><dt><span class="term"> + Byte1('Y') +</span></dt><dd><p> + Identifies the message as a type message. +</p></dd><dt><span class="term"> + Int32 +</span></dt><dd><p> + ID of the data type. +</p></dd><dt><span class="term"> + String +</span></dt><dd><p> + Namespace (empty string for <code class="literal">pg_catalog</code>). +</p></dd><dt><span class="term"> + String +</span></dt><dd><p> + Name of the data type. +</p></dd></dl></div><p> +</p></dd><dt><span class="term"> +Insert +</span></dt><dd><p> + +</p><div class="variablelist"><dl class="variablelist"><dt><span class="term"> + Byte1('I') +</span></dt><dd><p> + Identifies the message as an insert message. +</p></dd><dt><span class="term"> + Int32 +</span></dt><dd><p> + ID of the relation corresponding to the ID in the relation + message. +</p></dd><dt><span class="term"> + Byte1('N') +</span></dt><dd><p> + Identifies the following TupleData message as a new tuple. +</p></dd><dt><span class="term"> + TupleData +</span></dt><dd><p> + TupleData message part representing the contents of new tuple. +</p></dd></dl></div><p> +</p></dd><dt><span class="term"> +Update +</span></dt><dd><p> + +</p><div class="variablelist"><dl class="variablelist"><dt><span class="term"> + Byte1('U') +</span></dt><dd><p> + Identifies the message as an update message. +</p></dd><dt><span class="term"> + Int32 +</span></dt><dd><p> + ID of the relation corresponding to the ID in the relation + message. +</p></dd><dt><span class="term"> + Byte1('K') +</span></dt><dd><p> + Identifies the following TupleData submessage as a key. + This field is optional and is only present if + the update changed data in any of the column(s) that are + part of the REPLICA IDENTITY index. +</p></dd><dt><span class="term"> + Byte1('O') +</span></dt><dd><p> + Identifies the following TupleData submessage as an old tuple. + This field is optional and is only present if table in which + the update happened has REPLICA IDENTITY set to FULL. +</p></dd><dt><span class="term"> + TupleData +</span></dt><dd><p> + TupleData message part representing the contents of the old tuple + or primary key. Only present if the previous 'O' or 'K' part + is present. +</p></dd><dt><span class="term"> + Byte1('N') +</span></dt><dd><p> + Identifies the following TupleData message as a new tuple. +</p></dd><dt><span class="term"> + TupleData +</span></dt><dd><p> + TupleData message part representing the contents of a new tuple. +</p></dd></dl></div><p> +</p><p> + The Update message may contain either a 'K' message part or an 'O' message part + or neither of them, but never both of them. +</p></dd><dt><span class="term"> +Delete +</span></dt><dd><p> + +</p><div class="variablelist"><dl class="variablelist"><dt><span class="term"> + Byte1('D') +</span></dt><dd><p> + Identifies the message as a delete message. +</p></dd><dt><span class="term"> + Int32 +</span></dt><dd><p> + ID of the relation corresponding to the ID in the relation + message. +</p></dd><dt><span class="term"> + Byte1('K') +</span></dt><dd><p> + Identifies the following TupleData submessage as a key. + This field is present if the table in which the delete has + happened uses an index as REPLICA IDENTITY. +</p></dd><dt><span class="term"> + Byte1('O') +</span></dt><dd><p> + Identifies the following TupleData message as an old tuple. + This field is present if the table in which the delete + happened has REPLICA IDENTITY set to FULL. +</p></dd><dt><span class="term"> + TupleData +</span></dt><dd><p> + TupleData message part representing the contents of the old tuple + or primary key, depending on the previous field. +</p></dd></dl></div><p> +</p><p> + The Delete message may contain either a 'K' message part or an 'O' message part, + but never both of them. +</p></dd><dt><span class="term"> +Truncate +</span></dt><dd><p> + +</p><div class="variablelist"><dl class="variablelist"><dt><span class="term"> + Byte1('T') +</span></dt><dd><p> + Identifies the message as a truncate message. +</p></dd><dt><span class="term"> + Int32 +</span></dt><dd><p> + Number of relations +</p></dd><dt><span class="term"> + Int8 +</span></dt><dd><p> + Option bits for <code class="command">TRUNCATE</code>: + 1 for <code class="literal">CASCADE</code>, 2 for <code class="literal">RESTART IDENTITY</code> +</p></dd><dt><span class="term"> + Int32 +</span></dt><dd><p> + ID of the relation corresponding to the ID in the relation + message. This field is repeated for each relation. +</p></dd></dl></div><p> +</p></dd></dl></div><p> + +The following message parts are shared by the above messages. + +</p><div class="variablelist"><dl class="variablelist"><dt><span class="term"> +TupleData +</span></dt><dd><p> + +</p><div class="variablelist"><dl class="variablelist"><dt><span class="term"> + Int16 +</span></dt><dd><p> + Number of columns. +</p></dd></dl></div><p> + Next, one of the following submessages appears for each column (except generated columns): +</p><div class="variablelist"><dl class="variablelist"><dt><span class="term"> + Byte1('n') +</span></dt><dd><p> + Identifies the data as NULL value. +</p></dd></dl></div><p> + Or +</p><div class="variablelist"><dl class="variablelist"><dt><span class="term"> + Byte1('u') +</span></dt><dd><p> + Identifies unchanged TOASTed value (the actual value is not + sent). +</p></dd></dl></div><p> + Or +</p><div class="variablelist"><dl class="variablelist"><dt><span class="term"> + Byte1('t') +</span></dt><dd><p> + Identifies the data as text formatted value. +</p></dd><dt><span class="term"> + Int32 +</span></dt><dd><p> + Length of the column value. +</p></dd><dt><span class="term"> + Byte<em class="replaceable"><code>n</code></em> +</span></dt><dd><p> + The value of the column, in text format. (A future release + might support additional formats.) + <em class="replaceable"><code>n</code></em> is the above length. + +</p></dd></dl></div><p> +</p></dd></dl></div></div><div xmlns="http://www.w3.org/TR/xhtml1/transitional" class="navfooter"><hr></hr><table width="100%" summary="Navigation footer"><tr><td width="40%" align="left"><a accesskey="p" href="protocol-error-fields.html" title="52.8. Error and Notice Message Fields">Prev</a> </td><td width="20%" align="center"><a accesskey="u" href="protocol.html" title="Chapter 52. Frontend/Backend Protocol">Up</a></td><td width="40%" align="right"> <a accesskey="n" href="protocol-changes.html" title="52.10. Summary of Changes since Protocol 2.0">Next</a></td></tr><tr><td width="40%" align="left" valign="top">52.8. Error and Notice Message Fields </td><td width="20%" align="center"><a accesskey="h" href="index.html" title="PostgreSQL 13.4 Documentation">Home</a></td><td width="40%" align="right" valign="top"> 52.10. Summary of Changes since Protocol 2.0</td></tr></table></div></body></html>
\ No newline at end of file |