import heapq

from datetime import datetime

def sort_dates_limited_memory(records):

"""

Sorts a list of date records using a min-heap for limited memory.

Args:

records: A list of records, where each record contains a date value.

Assumes each record has a 'date' attribute that is a datetime object.

Returns:

A list of records sorted by date in ascending order.

"""

if not records:

return []

heap = [] # Min-heap to store records

result = []

# Initialize the heap with the first record

heapq.heappush(heap, (records[0].date, records[0]))

for i in range(1, len(records)):

# Compare the current record's date with the smallest date in the heap

date, record = heapq.heappop(heap)

if records[i].date > date:

# Current record is later than the smallest date in the heap

heapq.heappush(heap, (records[i].date, records[i]))

else:

# Current record is earlier than or equal to the smallest date in the heap

heapq.heappush(heap, (date, record))

heapq.heappush(heap, (records[i].date, records[i]))

# Extract records from the heap in sorted order

while heap:

date, record = heapq.heappop(heap)

result.append(record)

return result