diff options
Diffstat (limited to 'doc/src/sgml/protocol.sgml')
| -rw-r--r-- | doc/src/sgml/protocol.sgml | 150 |
1 files changed, 130 insertions, 20 deletions
diff --git a/doc/src/sgml/protocol.sgml b/doc/src/sgml/protocol.sgml index c4d3853cbf2..cc5c8dc574c 100644 --- a/doc/src/sgml/protocol.sgml +++ b/doc/src/sgml/protocol.sgml @@ -189,7 +189,7 @@ </sect2> <sect2 id="protocol-versions"> - <title>Protocol versions</title> + <title>Protocol Versions</title> <para> The current, latest version of the protocol is version 3.2. However, for @@ -226,7 +226,7 @@ </para> <table id="protocol-versions-table"> - <title>Protocol versions</title> + <title>Protocol Versions</title> <tgroup cols="3"> <thead> @@ -537,6 +537,11 @@ The frontend should not respond to this message, but should continue listening for a ReadyForQuery message. </para> + <para> + The <productname>PostgreSQL</productname> server will always send this + message, but some third party backend implementations of the protocol + that don't support query cancellation are known not to. + </para> </listitem> </varlistentry> @@ -886,6 +891,16 @@ SELCT 1/0;<!-- this typo is intentional --> Errors detected at semantic analysis or later, such as a misspelled table or column name, do not have this effect. </para> + + <para> + Lastly, note that all the statements within the Query message will + observe the same value of <function>statement_timestamp()</function>, + since that timestamp is updated only upon receipt of the Query + message. This will result in them all observing the same + value of <function>transaction_timestamp()</function> as well, + except in cases where the query string ends a previously-started + transaction and begins a new one. + </para> </sect3> </sect2> @@ -2225,6 +2240,8 @@ psql "dbname=postgres replication=database" -c "IDENTIFY_SYSTEM;" <para> The name of the slot to create. Must be a valid replication slot name (see <xref linkend="streaming-replication-slots-manipulation"/>). + The name cannot be <literal>pg_conflict_detection</literal> as it + is reserved for the conflict detection. </para> </listitem> </varlistentry> @@ -2538,8 +2555,8 @@ psql "dbname=postgres replication=database" -c "IDENTIFY_SYSTEM;" </para> <variablelist> - <varlistentry id="protocol-replication-xlogdata"> - <term>XLogData (B)</term> + <varlistentry id="protocol-replication-waldata"> + <term>WALData (B)</term> <listitem> <variablelist> <varlistentry> @@ -2587,11 +2604,11 @@ psql "dbname=postgres replication=database" -c "IDENTIFY_SYSTEM;" </para> <para> - A single WAL record is never split across two XLogData messages. + A single WAL record is never split across two WALData messages. When a WAL record crosses a WAL page boundary, and is therefore already split using continuation records, it can be split at the page boundary. In other words, the first main WAL record and its - continuation records can be sent in different XLogData messages. + continuation records can be sent in different WALData messages. </para> </listitem> </varlistentry> @@ -2643,6 +2660,65 @@ psql "dbname=postgres replication=database" -c "IDENTIFY_SYSTEM;" </variablelist> </listitem> </varlistentry> + + <varlistentry id="protocol-replication-primary-status-update"> + <term>Primary status update (B)</term> + <listitem> + <variablelist> + <varlistentry> + <term>Byte1('s')</term> + <listitem> + <para> + Identifies the message as a primary status update. + </para> + </listitem> + </varlistentry> + + <varlistentry> + <term>Int64</term> + <listitem> + <para> + The latest WAL write position on the server. + </para> + </listitem> + </varlistentry> + + <varlistentry> + <term>Int64</term> + <listitem> + <para> + The oldest transaction ID that is currently in the commit phase on + the server, along with its epoch. The most significant 32 bits are + the epoch. The least significant 32 bits are the transaction ID. + If no transactions are active on the server, this number will be + the next transaction ID to be assigned. + </para> + </listitem> + </varlistentry> + + <varlistentry> + <term>Int64</term> + <listitem> + <para> + The next transaction ID to be assigned on the server, along with + its epoch. The most significant 32 bits are the epoch. The least + significant 32 bits are the transaction ID. + </para> + </listitem> + </varlistentry> + + <varlistentry> + <term>Int64</term> + <listitem> + <para> + The server's system clock at the time of transmission, as + microseconds since midnight on 2000-01-01. + </para> + </listitem> + </varlistentry> + </variablelist> + </listitem> + </varlistentry> </variablelist> <para> @@ -2787,6 +2863,33 @@ psql "dbname=postgres replication=database" -c "IDENTIFY_SYSTEM;" </variablelist> </listitem> </varlistentry> + + <varlistentry id="protocol-replication-standby-wal-status-request"> + <term>Request primary status update (F)</term> + <listitem> + <variablelist> + <varlistentry> + <term>Byte1('p')</term> + <listitem> + <para> + Identifies the message as a request for a primary status update. + </para> + </listitem> + </varlistentry> + + <varlistentry> + <term>Int64</term> + <listitem> + <para> + The client's system clock at the time of transmission, as + microseconds since midnight on 2000-01-01. + </para> + </listitem> + </varlistentry> + </variablelist> + </listitem> + </varlistentry> + </variablelist> </listitem> </varlistentry> @@ -3482,6 +3585,7 @@ psql "dbname=postgres replication=database" -c "IDENTIFY_SYSTEM;" <para> Boolean option to use binary transfer mode. Binary mode is faster than the text mode but slightly less robust. + The default is <literal>off</literal>. </para> </listitem> </varlistentry> @@ -3494,6 +3598,7 @@ psql "dbname=postgres replication=database" -c "IDENTIFY_SYSTEM;" <para> Boolean option to enable sending the messages that are written by <function>pg_logical_emit_message</function>. + The default is <literal>off</literal>. </para> </listitem> </varlistentry> @@ -3504,11 +3609,13 @@ psql "dbname=postgres replication=database" -c "IDENTIFY_SYSTEM;" </term> <listitem> <para> - Boolean option to enable streaming of in-progress transactions. - It accepts an additional value "parallel" to enable sending extra - information with some messages to be used for parallelisation. - Minimum protocol version 2 is required to turn it on. Minimum protocol - version 4 is required for the "parallel" option. + Option to enable streaming of in-progress transactions. Valid values are + <literal>off</literal> (the default), <literal>on</literal> and + <literal>parallel</literal>. The setting <literal>parallel</literal> + enables sending extra information with some messages to be used for + parallelization. Minimum protocol version 2 is required to turn it + <literal>on</literal>. Minimum protocol version 4 is required for the + <literal>parallel</literal> value. </para> </listitem> </varlistentry> @@ -3521,6 +3628,7 @@ psql "dbname=postgres replication=database" -c "IDENTIFY_SYSTEM;" <para> Boolean option to enable two-phase transactions. Minimum protocol version 3 is required to turn it on. + The default is <literal>off</literal>. </para> </listitem> </varlistentry> @@ -3537,6 +3645,7 @@ psql "dbname=postgres replication=database" -c "IDENTIFY_SYSTEM;" to send the changes regardless of their origin. This can be used to avoid loops (infinite replication of the same data) among replication nodes. + The default is <literal>any</literal>. </para> </listitem> </varlistentry> @@ -6081,13 +6190,14 @@ psql "dbname=postgres replication=database" -c "IDENTIFY_SYSTEM;" </varlistentry> <varlistentry> - <term>Int32(196608)</term> + <term>Int32</term> <listitem> <para> The protocol version number. The most significant 16 bits are - the major version number (3 for the protocol described here). - The least significant 16 bits are the minor version number - (0 for the protocol described here). + the major version number. The least significant 16 bits are the minor + version number. As an example protocol version 3.2 is represented as + <literal>196610</literal> in decimal or more clearly as + <literal>0x00030002</literal> in hexadecimal. </para> </listitem> </varlistentry> @@ -7292,8 +7402,8 @@ psql "dbname=postgres replication=database" -c "IDENTIFY_SYSTEM;" <term>Int64 (XLogRecPtr)</term> <listitem> <para> - The LSN of the abort. This field is available since protocol version - 4. + The LSN of the abort operation, present only when streaming is set to parallel. + This field is available since protocol version 4. </para> </listitem> </varlistentry> @@ -7302,9 +7412,9 @@ psql "dbname=postgres replication=database" -c "IDENTIFY_SYSTEM;" <term>Int64 (TimestampTz)</term> <listitem> <para> - Abort timestamp of the transaction. The value is in number - of microseconds since PostgreSQL epoch (2000-01-01). This field is - available since protocol version 4. + Abort timestamp of the transaction, present only when streaming is set to + parallel. The value is in number of microseconds since PostgreSQL epoch (2000-01-01). + This field is available since protocol version 4. </para> </listitem> </varlistentry> |