IndexedEncoding minEntry = new IndexedEncoding(header.types, header.minimaRecordOffset, buffer);
double max = Double.MIN_VALUE, min=Double.MAX_VALUE;
long cursor = header.dataTableOffset;
while(cursor < buffer.fileSize()) {
IndexedEncoding entry = new IndexedEncoding(header.types, cursor, buffer);
cursor += header.recordLength;
max = Math.max(max, (Double) entry.get(0));
min = Math.min(min, (Double) entry.get(0));
}