如何在 Django 迁移中创建 GIN 索引

问题描述

在 Django 中，从 1.11 版开始，我们有一个用于 PostgreSQL 的类 GinIndex (https://docs.djangoproject.com/en/1.11/ref/contrib/postgres/indexes/).我想创建一个迁移，在我添加到我的一个表中的 VectorSearchField 上构建这样的索引.到目前为止，我尝试简单地将 db_index=True 添加到 VectorSearchField，但是失败了，因为它试图创建一个 B-Tree 索引(我认为)和VectorSearchField 值太长.

In Django, since version 1.11 we have a class for PostgreSQL GinIndex (https://docs.djangoproject.com/en/1.11/ref/contrib/postgres/indexes/). I'd like to create a migration that constructs such index on a VectorSearchField I added to one of my tables. So far, I've tried to simply add db_index=True to the VectorSearchField, but that fails, because it tries to create a B-Tree index (I think) and the VectorSearchField values are too long.

我设法通过运行 migrations.RunSQL() 迁移来创建我想要的索引:

I managed to create the index I want by running a migrations.RunSQL() migration with:

CREATE INDEX entryline_sv_index ON entryline USING GIN (sv);

但是，我想，既然 Django 中有一个特殊的 GinIndex 类，也许有一种方法可以在不执行原始 SQL 的情况下创建这样的索引?

However, I guess, since there is a special GinIndex class in Django, maybe there is a way to create such index without executing raw SQL?

这是一个模型类:

import django.contrib.postgres.search as pg_search

class EntryLine(models.Model):
    speaker = models.CharField(max_length=512, db_index=True)
    text = models.TextField()
    sv = pg_search.SearchVectorField(null=True)  # I want a GIN index on this field.

知道如何在迁移中为 sv 字段正确创建索引吗?还是执行 CREATE INDEX ... 查询是最好的方式?

Any idea how to properly create an index for sv field in a migration? Or is executing the CREATE INDEX ... query the best way?

推荐答案

还没有机会将我的旧手动 CREATE INDEX 代码迁移到 1.11 中引入的新系统中 但我的理解是

Haven't yet had a chance to migrate my old manual CREATE INDEX codes to the new system introduced in 1.11 but my understanding is

from django.contrib.postgres.indexes import GinIndex
import django.contrib.postgres.search as pg_search

class EntryLine(models.Model):
    speaker = models.CharField(max_length=512, db_index=True)
    text = models.TextField()
    sv = pg_search.SearchVectorField(null=True)
    class Meta:
        indexes = [GinIndex(fields=['sv'])]

是必需的.不再需要使用原始 SQL CREATE INDEX 语句.

Is what's required. Raw SQL CREATE INDEX statements need not be used any more.

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