@Override
	boolean hasRecord(Field field) throws IOException {
		IndexField indexField =
			indexKeyType.newIndexField(field, getPrimaryTableKeyType().getMinValue());
		DBFieldIterator iter = indexTable.fieldKeyIterator(indexField);
		while (iter.hasNext()) {
			IndexField f = (IndexField) iter.next();
			if (!f.hasSameIndexValue(indexField)) {
				return false;
			}
			if (indexField.usesTruncatedFieldValue()) {
				// Must check actual record if index value was truncated
				DBRecord rec = primaryTable.getRecord(f.getPrimaryKey());
				Field val = rec.getField(indexColumn);
				if (!field.equals(val)) {
					continue; // skip
				}
			}
			return true;
		}
		return false;
	}
Delete all primary records which have the current
index value (lastKey).
@see db.DBFieldIterator#delete()
Ghidra/Framework/DB/src/main/java/db/FieldIndexTable.java