my_own.xml

<?xml version="1.0" encoding="utf-8"?>
<!DOCTYPE Map[
  <!ENTITY db_settings SYSTEM "config/db_settings.inc.xml">
]>
<Map srs="+proj=merc +a=6378137 +b=6378137 +lat_ts=0.0 +lon_0=0.0 +x_0=0.0 +y_0=0 +k=1.0 +units=m +nadgrids=@null +no_defs +over" background-color="transparent" minimum-version="0.7.2">
<Style name="my_own">
    <Rule>
      <MaxScaleDenominator>200000</MaxScaleDenominator>
      <LineSymbolizer stroke-linejoin="round" stroke="#F00" stroke-width="2" stroke-linecap="round" stroke-opacity="0.6"/></Rule>
</Style>

  <Layer name="my_own" status="on" srs="+proj=merc +a=6378137 +b=6378137 +lat_ts=0.0 +lon_0=0.0 +x_0=0.0 +y_0=0 +k=1.0 +units=m +nadgrids=@null +no_defs +over">
    <StyleName>my_own</StyleName>
    <Datasource>
	&db_settings;
      <Parameter name="table">
      (select way from planet_osm_line where tags ? 'validate:my_own') as ways
      </Parameter>
    </Datasource>
  </Layer>

</Map>