one session available for the stream.

</para>

<para>

The starting point of the write-ahead log streaming is calculated when

<application>pg_receivewal</application> starts:

<orderedlist>

<listitem>

<para>

First, scan the directory where the WAL segment files are written and

find the newest completed segment file, using as starting point the

beginning of the next WAL segment file. This is calculated independently

on the compression method used to compress each segment.

</para>

</listitem>

<listitem>

<para>

If a starting point cannot be calculated with the previous method,

the latest WAL flush location is used as reported by the server from

a <literal>IDENTIFY_SYSTEM</literal> command.

</para>

</listitem>

</orderedlist>

</para>

<para>

If the connection is lost, or if it cannot be initially established,

with a non-fatal error, <application>pg_receivewal</application> will