[Feature]: Add support for GIN indexes

[ThomasLandauer]

Problem Statement

GIN seems to be the recommended index for arrays & the like.

Proposed Solution

ORM\Index has an argument flags and options. Don't know what they are meant for - maybe they could be used:

#[ORM\Index(name: 'my_gin', fields: ['foo'], flags: ['GIN'], options: ['gin' => true])]

Feature Type

Framework Integration Enhancement

PostgreSQL Feature/Function/Type

No response

PostgreSQL Documentation Link

https://www.postgresql.org/docs/current/gin.html

Use Case

Needed (more or less) every time you add an array column ;-)

Example Usage

Alternatives Considered

If it's not possible (or you don't want) to support them, you could add a note to the docs:
When defining a normal index, Doctrine schema tool creates:

CREATE INDEX my_gin ON foobar (foo);

But you can manually change it to:

CREATE INDEX my_gin ON foobar USING GIN (foo);

Then schema tool won't notice the difference (i.e. doesn't try to "fix" the index on every run).

Contribution

No

Additional Context

I could create a PR for the docs.

Checklist

• I have searched existing issues and discussions to ensure this feature hasn't been requested before
• This feature is related to PostgreSQL-specific functionality for Doctrine

[martin-georgiev]

Your suggestion to use flags and options is a reasonable guess, but it doesn't actually work with Doctrine's architecture. The Doctrine team has explicitly stated that PostgreSQL-specific index methods should be handled in migrations, not in the ORM mapping layer.

The problem:

• flags - These are passed to the DBAL layer but are primarily used for MySQL-specific index types like FULLTEXT and SPATIAL
• options - These are platform-specific options, but they don't control the index method (the USING clause).

The DBAL Schema Manager doesn't support the USING clause. When Doctrine generates DDL, it doesn't have a way to specify USING GIN or USING GIST.

The correct approach is to:

1. Declare the index in the entity to prevent Doctrine from removing it:

#[ORM\Index(columns: ['tags'], name: 'idx_products_tags_gin')]

2. Manually create the GIN index in your migration:

$this->addSql('DROP INDEX IF EXISTS idx_products_tags_gin');
$this->addSql('CREATE INDEX idx_products_tags_gin ON products USING GIN (tags)');

[ThomasLandauer]

Well, OK, then let's add that manual workaround to the docs. What would be a good place?