// 1. Fragment unique id.
// 2. Summary: currently contains number of records written.
MaterializedField fragmentIdField = MaterializedField.create(SchemaPath.getSimplePath("Fragment"), Types.required(MinorType.VARCHAR));
MaterializedField summaryField = MaterializedField.create(SchemaPath.getSimplePath("Number of records written"), Types.required(MinorType.BIGINT));
VarCharVector fragmentIdVector = (VarCharVector) TypeHelper.getNewVector(fragmentIdField, context.getAllocator());
AllocationHelper.allocate(fragmentIdVector, 1, TypeHelper.getSize(Types.required(MinorType.VARCHAR)));
BigIntVector summaryVector = (BigIntVector) TypeHelper.getNewVector(summaryField, context.getAllocator());
AllocationHelper.allocate(summaryVector, 1, TypeHelper.getSize(Types.required(MinorType.VARCHAR)));
container.add(fragmentIdVector);
container.add(summaryVector);
container.buildSchema(BatchSchema.SelectionVectorMode.NONE);
fragmentIdVector.getMutator().setSafe(0, fragmentUniqueId.getBytes());
fragmentIdVector.getMutator().setValueCount(1);
summaryVector.getMutator().setSafe(0, counter);
summaryVector.getMutator().setValueCount(1);
container.setRecordCount(1);
processed = true;