Django

Django QuerySet高效读取百万行数据

291 words
How to fetch millions of rows from DataBase by Django Queryset in a memory efficient way? Below is a solution that chunks the QuerySets so they’re only keeping a small subset in memory.While this is somewhat heavier on the database (multiple queries) it seriously reduces the memory usage. Example import gc def lazy_fetch_iterator(table, start_pk=0, chunk_size=1000, *args, **kwargs): """ Get the entire rows of a table by iterating over Django QuerySets

Django QuerySet缓存和迭代器

527 words
Lazy QuerySet A queryset in Django represents a number of rows in the database, optionally filtered by a query. For example, the following code represents all people in the database whose first name is ‘Dave’: person_set = Person.objects.filter(first_name="Dave") The above code doesn’t run any database queries. You can can take the person_set and apply additional filters, or pass

Django数据库连接池

4025 words
数据库长连接 长连接是指程序之间的连接在建立之后,就一直打开,被后续程序重用。使用长连接的初衷是减少连接的开销。 先看看官方文档是怎么讲Djan

Django数据库分表

2087 words
Django ORM没有提供默认的分表功能,给访问分表的数据库带来的不变。那么Django分表怎么实现呢? 分析Django ORM 在实现具体的方案之前,我们先