<p>I did some testing with a smaller osm.pbf and the PostGres default max_connections of 100 on a many cores processor.<br>
osm2pgsql always fails if option --number-processes is greater than 12.</p>
<p><code>Osm2pgsql failed due to ERROR: Connection to database failed: FATAL:  remaining connection slots are reserved for non-replication superuser connections</code></p>
<p>osm2pgsql version 0.94.0 (64 bit id space)</p>

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