prob-set-cardinality</a> </li><li> <a href="tech.v3.dataset.reductions.html#var-reducer">reducer</a> </li><li> <a href="tech.v3.dataset.reductions.html#var-reducer-.3Ecolumn-reducer">reducer-&gt;column-reducer</a> </li><li> <a href="tech.v3.dataset.reductions.html#var-reservoir-dataset">reservoir-dataset</a> </li><li> <a href="tech.v3.dataset.reductions.html#var-reservoir-desc-stat">reservoir-desc-stat</a> </li><li> <a href="tech.v3.dataset.reductions.html#var-row-count">row-count</a> </li><li> <a href="tec