final WriterPrel prel = (WriterPrel) initialPrel.copy(initialPrel.getTraitSet(), ImmutableList.<RelNode>of(input));
final RelCollation collation = getCollation(prel.getTraitSet(), sortKeys);
final WriterPrel writer = new WriterPrel(prel.getCluster(), prel.getTraitSet(), changeDetection, prel.getCreateTableEntry(), prel.getExpectedInboundRowType());
return writer;
final RelCollation collation = getCollation(prel.getTraitSet(), sortKeys);
final Prel sort = new SortPrel(input.getCluster(), input.getTraitSet().plus(collation), input, collation);
final WriterPrel writer = new WriterPrel(prel.getCluster(), prel.getTraitSet(), changeDetectionPrel, prel.getCreateTableEntry(), prel.getExpectedInboundRowType());
return writer;
final RelCollation collation = getCollation(prel.getTraitSet(), getFieldIndices(options.getSortColumns(), input.getRowType()));
final Prel sort = new SortPrel(input.getCluster(), input.getTraitSet().plus(collation), input, collation);
final WriterPrel writer = new WriterPrel(prel.getCluster(), prel.getTraitSet(), sort, prel.getCreateTableEntry(), prel.getExpectedInboundRowType());
return writer;