Pagination hugawanya kundi kubwa la matokeo katika kurasa tofauti, ili usipakie maelfu ya records kwa wakati mmoja. Ni jambo la lazima kwa performance na utumiaji. Django hutoa class ya Paginator kwa templates/views, na DRF hutoa pagination ya ndani kwa APIs.
# ❌ loading everything — slow, memory-heavy, bad UX with thousands of rows
articles = Article.objects.()
from django.core.paginator import Paginator
def article_list(request):
articles = Article.objects.all().order_by("-created_at") # ORDER matters for consistent pages
paginator = Paginator(articles, 20) # 20 items per page
page_number = request.GET.get("page") # ?page=2
page_obj = paginator.get_page(page_number) # the requested page
return render(request, "list.html", {"page_obj": page_obj})
<!-- in the template -->
{% for article in page_obj %}
<h2>{{ article.title }}</h2>
{% endfor %}
{% if page_obj.has_previous %}<a href="?page={{ page_obj.previous_page_number }}">Prev</a>{% endif %}
Page {{ page_obj.number }} of {{ page_obj.paginator.num_pages }}
{% if page_obj.has_next %}<a href="?page={{ page_obj.next_page_number }}">Next</a>{% endif %}
Paginator hukata queryset katika kurasa na get_page() hurudisha page object yenye navigation helpers (has_next, next_page_number, n.k.) — kumbuka huongeza LIMIT/OFFSET kwenye query, hivyo ukurasa mmoja tu huletwa kutoka kwenye database.
# global default in settings.py
REST_FRAMEWORK = {
"DEFAULT_PAGINATION_CLASS": "rest_framework.pagination.PageNumberPagination",
"PAGE_SIZE": 20,
}
# now list endpoints are automatically paginated, returning:
# { "count": 1000, "next": "...?page=3", "previous": "...?page=1", "results": [...] }
DRF hu-paginate list endpoints kiotomatiki mara baada ya kusanidiwa, ikirudisha page metadata (count, next/previous links) pamoja na matokeo — clients husafiri kupitia URLs zilizotolewa.
PageNumberPagination → ?page=2 (simple page numbers)
LimitOffsetPagination → ?limit=20&offset=40 (flexible offsets)
CursorPagination → opaque cursor; consistent & performant for large/changing data
(avoids OFFSET performance issues on huge datasets)
⚠️ OFFSET-based pagination (page/offset) gets SLOWER on deep pages of huge tables
(the DB must skip OFFSET rows). For very large datasets, CURSOR pagination
(keyset, using a WHERE on an indexed column) is far more efficient.
⚠️ Always ORDER BY a stable field, or pages can be inconsistent/repeat items.
Pagination ni jambo la lazima kwa kujenga applications zenye performance na zinazoweza kutumika zinazoshughulikia data za kiasi halisi — bila yake, listing endpoints na kurasa zinazopakia tables nzima (huenda maelfu au mamilioni ya rows) huwa polepole, zenye memory nyingi, na zisizoweza kutumika, zikilemea database na kuwazidi watumiaji na clients.
Kuelewa pagination ni maarifa ya kivitendo ya kila siku: Paginator ya Django hushughulikia views/templates za kawaida (ikikata querysets katika kurasa zenye navigation helpers, ikileta ukurasa mmoja tu kwa ufanisi kupitia LIMIT/OFFSET), na pagination ya ndani ya DRF hushughulikia APIs (ikipaginate list endpoints kiotomatiki kwa metadata na navigation links mara baada ya kusanidiwa) — zote zinahitajika kutegemea kama unajenga kurasa zinazo-render kwenye server au APIs.
Kujua jinsi ya kutekeleza pagination katika muktadha zote mbili ni jambo la lazima kwa karibu kipengele chochote cha kuorodhesha data.
Hoja ya performance ni maarifa yenye thamani hasa ya kiwango cha senior: standard OFFSET-based pagination hudhoofika kwenye kurasa za kina za tables kubwa sana (database lazima iruke rows zote zilizotangulia), hivyo cursor (keyset) pagination ndicho chaguo lenye ufanisi kwa datasets kubwa au zinazobadilika kwa kasi, na kila wakati kuagiza kwa field thabiti ni jambo la lazima kuepuka matokeo yasiyo thabiti au yaliyorudiwa katika kurasa.
Kuelewa mechanics za msingi (Paginator, DRF pagination classes) na mambo haya ya performance (OFFSET dhidi ya cursor pagination, ordering thabiti) ni muhimu kwa kujenga applications zinazobaki haraka na sahihi kadiri data inavyokua — pagination ni hitaji lililoenea, na kuifanya vizuri, hasa kwa kiwango kikubwa, ni ujuzi wa kivitendo unaoathiri moja kwa moja performance ya application na uzoefu wa mtumiaji.