Issue #3548313 by ericpoir, klausi, liam morland, dmitry.korhov, rick...

      $this->sqlFields["base_table.$id_field"] = ['base_table', $id_field];

    }

    // Use max and group by to only return the latest revision in the most

    // optimal way.

    // Use a subquery with MAX() to only return the latest revision in the most

    // optimal way. Note that this query is extremely performance-sensitive and

    // changes here need to be tested on a database where there are many

    // revisions and many entities.

    if ($this->latestRevision && $revision_field) {

      // Fetch all latest revision ids in a sub-query.

      $revision_subquery = $this->connection->select($base_table, 'base_table');

      $revision_subquery->addExpression("MAX(base_table.$revision_field)");

      $revision_subquery->groupBy("base_table.$id_field");

      $revision_subquery = $this->connection->select($base_table, 'subquery_base_table');

      $revision_subquery->addExpression("MAX(subquery_base_table.$revision_field)");

      $revision_subquery->where("base_table.$id_field = subquery_base_table.$id_field");

      // Restrict results only to latest ids.

      $this->sqlQuery->condition("base_table.$revision_field", $revision_subquery, 'IN');