docs: add support for partial indexes (filtered indexes)

apps/docs/content/docs/orm/prisma-migrate/getting-started.mdx

@@ -155,13 +155,18 @@ To include [unsupported database features](/orm/prisma-migrate/workflows/unsuppo
 - Open the `migration.sql` file generated in the [Create a baseline migration](#create-a-baseline-migration) section.
 - Modify the generated SQL. For example:
 
-  - If the changes are minor, you can append additional custom SQL to the generated migration. The following example creates a partial index:
+  - If the changes are minor, you can append additional custom SQL to the generated migration. The following example creates a trigger function:
 
 ```sql title="migration.sql"
 /* Generated migration SQL */
 
-CREATE UNIQUE INDEX tests_success_constraint ON posts (subject, target) -- [!code ++]
-  WHERE success; -- [!code ++]
+CREATE OR REPLACE FUNCTION notify_on_insert() -- [!code ++]
+RETURNS TRIGGER AS $$ -- [!code ++]
+BEGIN -- [!code ++]
+  PERFORM pg_notify('new_record', NEW.id::text); -- [!code ++]
+  RETURN NEW; -- [!code ++]
+END; -- [!code ++]
+$$ LANGUAGE plpgsql; -- [!code ++]
 ```
 
   - If the changes are significant, it can be easier to replace the entire migration file with the result of a database dump:

apps/docs/content/docs/orm/prisma-migrate/workflows/development-and-production.mdx

@@ -63,7 +63,7 @@ Sometimes, you need to modify a migration **before applying it**. For example:
 - You want to introduce a significant refactor, such as changing blog post tags from a `String[]` to a `Tag[]`
 - You want to [rename a field](/orm/prisma-migrate/workflows/customizing-migrations#example-rename-a-field) (by default, Prisma Migrate will drop the existing field)
 - You want to [change the direction of a 1-1 relationship](/orm/prisma-migrate/workflows/customizing-migrations#example-change-the-direction-of-a-1-1-relation)
-- You want to add features that cannot be represented in Prisma Schema Language - such as a partial index or a stored procedure.
+- You want to add features that cannot be represented in Prisma Schema Language - such as a stored procedure or a trigger.
 
 The `--create-only` command allows you to create a migration without applying it:
 

apps/docs/content/docs/orm/prisma-migrate/workflows/native-database-types.mdx

@@ -90,7 +90,7 @@ For type mappings organized by database provider, see:
 
 ## Handling unsupported database features
 
-Prisma Migrate cannot automatically create database features that have no equivalent in Prisma Schema Language (PSL). For example, there is currently no way to define a stored procedure or a partial index in PSL. However, there are ways to add unsupported features to your database with Prisma Migrate:
+Prisma Migrate cannot automatically create database features that have no equivalent in Prisma Schema Language (PSL). For example, there is currently no way to define a stored procedure or a trigger in PSL. However, there are ways to add unsupported features to your database with Prisma Migrate:
 
 - [Handle unsupported field types](/orm/prisma-schema/data-model/unsupported-database-features#unsupported-field-types) (like `circle`)
 - [Handle unsupported features](/orm/prisma-schema/data-model/unsupported-database-features#unsupported-database-features), like stored procedures

apps/docs/content/docs/orm/prisma-migrate/workflows/unsupported-database-features.mdx

@@ -11,12 +11,13 @@ Prisma Migrate uses the Prisma schema to determine what features to create in th
 - Stored procedures
 - Triggers
 - Views
-- Partial indexes
 
 To add an unsupported feature to your database, you must [customize a migration](/orm/prisma-migrate/workflows/customizing-migrations) to include that feature before you apply it.
 
 :::tip
-The Prisma schema is able to represent [unsupported field types](/orm/prisma-schema/data-model/unsupported-database-features#unsupported-field-types) and [native database functions](/orm/prisma-migrate/workflows/native-database-functions).
+Partial indexes are now supported in Prisma Schema Language via the `where` argument on `@@index`, `@@unique`, and `@unique`. See [Configuring partial indexes](/orm/prisma-schema/data-model/indexes#configuring-partial-indexes-with-where) for details. You no longer need to customize migrations for partial indexes.
+
+The Prisma schema is also able to represent [unsupported field types](/orm/prisma-schema/data-model/unsupported-database-features#unsupported-field-types) and [native database functions](/orm/prisma-migrate/workflows/native-database-functions).
 :::
 
 :::warning
@@ -34,12 +35,16 @@ To customize a migration to include an unsupported feature:
 npx prisma migrate dev --create-only
 ```
 
-- Open the generated `migration.sql` file and add the unsupported feature - for example, a partial index:
+- Open the generated `migration.sql` file and add the unsupported feature - for example, a trigger function:
 
 ```sql title="migration.sql"
-CREATE UNIQUE INDEX tests_success_constraint
-  ON posts (subject, target)
-  WHERE success;
+CREATE OR REPLACE FUNCTION notify_on_insert()
+RETURNS TRIGGER AS $$
+BEGIN
+  PERFORM pg_notify('new_record', NEW.id::text);
+  RETURN NEW;
+END;
+$$ LANGUAGE plpgsql;
 ```
 
 - Apply the migration:

apps/docs/content/docs/orm/prisma-schema/data-model/indexes.mdx

@@ -494,6 +494,167 @@ model Post {
 }
 ```
 
+### Configuring partial indexes with `where`
+
+The `where` argument allows you to define [partial indexes](https://www.postgresql.org/docs/current/indexes-partial.html) (also known as filtered indexes). A partial index only includes rows that match a specified condition, which reduces the index size and improves both write performance and query performance for the indexed subset of data.
+
+The `where` argument is available on the `@unique`, `@@unique` and `@@index` attributes. It requires the `partialIndexes` Preview feature.
+
+:::note
+
+Partial indexes are supported on **PostgreSQL**, **SQLite**, **SQL Server**, and **CockroachDB**. They are **not** supported on MySQL.
+
+:::
+
+#### Enabling the `partialIndexes` Preview feature
+
+To use partial indexes, add the `partialIndexes` feature flag to the `generator` block of your `schema.prisma` file:
+
+```prisma title="schema.prisma" showLineNumbers
+generator client {
+  provider        = "prisma-client"
+  output          = "./generated"
+  previewFeatures = ["partialIndexes"]
+}
+```
+
+#### Raw SQL syntax with `raw()`
+
+You can define a partial index with a raw SQL predicate string using the `raw()` function. This approach supports any valid SQL `WHERE` expression that your database accepts:
+
+```prisma title="schema.prisma" showLineNumbers
+model User {
+  id        Int       @id
+  email     String
+  status    String
+  deletedAt DateTime?
+
+  @@unique([email], where: raw("status = 'active'"))
+  @@index([email], where: raw("\"deletedAt\" IS NULL"))
+}
+```
+
+This generates SQL like:
+
+**PostgreSQL:**
+
+```sql
+CREATE UNIQUE INDEX "User_email_key" ON "User" ("email") WHERE (status = 'active');
+CREATE INDEX "User_email_idx" ON "User" ("email") WHERE ("deletedAt" IS NULL);
+```
+
+**SQLite:**
+
+```sql
+CREATE UNIQUE INDEX "User_email_key" ON "User" ("email") WHERE status = 'active';
+CREATE INDEX "User_email_idx" ON "User" ("email") WHERE "deletedAt" IS NULL;
+```
+
+**SQL Server:**
+
+```sql
+CREATE UNIQUE NONCLUSTERED INDEX [User_email_key] ON [dbo].[User]([email]) WHERE ([status]='active');
+CREATE NONCLUSTERED INDEX [User_email_idx] ON [dbo].[User]([email]) WHERE ([deletedAt] IS NULL);
+```
+
+The `raw()` syntax can be used with any SQL expression your database supports, making it the most flexible option.
+
+#### Object literal syntax (type-safe alternative)
+
+You can also define partial indexes using an object literal syntax, which provides type-safety by validating field names and value types against your Prisma schema:
+
+```prisma title="schema.prisma" showLineNumbers
+model Post {
+  id        Int      @id
+  title     String
+  published Boolean
+
+  @@index([title], where: { published: true })
+  @@unique([title], where: { published: true })
+}
+```
+
+The object literal syntax supports the following value types:
+
+| Value type       | Example                                  | Notes                                                  |
+| ---------------- | ---------------------------------------- | ------------------------------------------------------ |
+| `Boolean`        | `{ active: true }`, `{ deleted: false }` | For `Boolean` fields                                   |
+| `String`         | `{ status: "active" }`                   | For `String`, `DateTime`, and `Enum` fields            |
+| `Number`         | `{ priority: 1 }`, `{ score: 1.5 }`      | For `Int`, `BigInt`, `Float`, and `Decimal` fields     |
+| `null`           | `{ deletedAt: null }`                    | Translates to `IS NULL`. Works with any nullable field |
+| `{ not: value }` | `{ deletedAt: { not: null } }`           | Negation. Translates to `IS NOT NULL` or `!= value`    |
+
+You can combine multiple conditions in a single object:
+
+```prisma title="schema.prisma" showLineNumbers
+model User {
+  id        Int       @id
+  email     String
+  active    Boolean
+  deletedAt DateTime?
+
+  @@unique([email], where: { active: true, deletedAt: null })
+}
+```
+
+:::note
+
+The object literal syntax validates field types. For example, you cannot use a `Boolean` value for a `String` field. For fields with types that are not supported by the object syntax (such as `Unsupported` or composite types), use `raw()` instead.
+
+:::
+
+#### Using `where` with other index arguments
+
+The `where` argument can be combined with other index arguments such as `name` and `map`:
+
+```prisma title="schema.prisma" showLineNumbers
+model User {
+  id     Int    @id
+  email  String
+  status String
+
+  @@unique([email], name: "email_active_unique", map: "idx_email_active", where: raw("status = 'active'"))
+}
+```
+
+#### Database-specific behavior
+
+| Database    | Migrations    | Introspection | Notes                                                                  |
+| ----------- | ------------- | ------------- | ---------------------------------------------------------------------- |
+| PostgreSQL  | Full support  | Full support  | Full predicate support                                                 |
+| SQLite      | Full support  | Full support  | Full predicate support                                                 |
+| SQL Server  | Full support  | Full support  | Filtered indexes via `CREATE INDEX`                                    |
+| CockroachDB | Create only   | Not supported | Cannot introspect predicate text; predicate modifications not detected |
+| MySQL       | Not supported | Not supported | Partial indexes are not supported by the database                      |
+
+:::warning
+
+**CockroachDB limitation**: CockroachDB supports creating partial indexes, but it cannot introspect the predicate text from existing indexes. This means that after initial creation, modifications to the `where` clause (adding, changing, or removing a predicate) will not be detected by Prisma Migrate. The differ skips predicate comparison for CockroachDB to prevent false-positive migrations.
+
+:::
+
+#### Introspection
+
+When you run `prisma db pull` on a database that contains partial indexes, Prisma ORM will:
+
+1. Automatically add `"partialIndexes"` to the `previewFeatures` list in your generator block
+2. Represent the partial index predicate using the `raw()` syntax with the database's normalized form of the SQL expression
+
+For example, a PostgreSQL partial unique index on a single field will be introspected as:
+
+```prisma title="schema.prisma" showLineNumbers
+model User {
+  id     Int    @id
+  email  String @unique(where: raw("(status = 'active'::text)"))
+  status String
+}
+```
+
+:::note
+
+The introspected `raw()` string reflects the database's normalized form of the SQL expression, which may differ from what you originally wrote. For example, PostgreSQL adds parentheses and explicit type casts (e.g., `'active'::text`), SQL Server wraps column names in brackets and adds parentheses (e.g., `([status]='active')`), while SQLite generally preserves the original expression as-is.
+
+:::
 
 ## Full text indexes (MySQL and MongoDB)
 

apps/docs/content/docs/orm/prisma-schema/data-model/unsupported-database-features.mdx

@@ -79,4 +79,10 @@ The `prisma migrate dev` and `prisma db push` command will both create a `positi
 
 ## Unsupported database features
 
-Some features, like SQL views or partial indexes, cannot be represented in the Prisma schema. If your project uses [Prisma Migrate](/orm/prisma-migrate), you must [include unsupported features as part of a migration](/orm/prisma-migrate/workflows/unsupported-database-features) .
+Some features, like SQL views, cannot be represented in the Prisma schema. If your project uses [Prisma Migrate](/orm/prisma-migrate), you must [include unsupported features as part of a migration](/orm/prisma-migrate/workflows/unsupported-database-features) .
+
+:::tip
+
+Partial indexes are now supported in Prisma Schema Language via the `where` argument on `@@index`, `@@unique`, and `@unique`. See [Configuring partial indexes](/orm/prisma-schema/data-model/indexes#configuring-partial-indexes-with-where) for details.
+
+:::

apps/docs/content/docs/orm/reference/database-features.mdx

@@ -53,7 +53,7 @@ These features are _only_ for relational databases. Supported features for NoSQL
 | -------------- | :--------------------------------------: | :---------------------------------------------------------------------------------------------------------: | :-----------: | :------------: |
 | `UNIQUE`       |                    ✔️                    |          [`@unique` and `@@unique`](/orm/prisma-schema/data-model/models#defining-a-unique-field)           |      ✔️       |       ✔️       |
 | `USING`        |             PostgreSQL only              | [`type`](/orm/prisma-schema/data-model/indexes#configuring-the-access-type-of-indexes-with-type-postgresql) |      ✔️       |       ✔️       |
-| `WHERE`        |                    ✔️                    |                                                   Not yet                                                   |      ✔️       |    Not yet     |
+| `WHERE`        |                    ✔️                    |      [`where`](/orm/prisma-schema/data-model/indexes#configuring-partial-indexes-with-where) (Preview)      |      ✔️       |       ✔️       |
 | `(expression)` |                    ✔️                    |                                                   Not yet                                                   |      ✔️       |    Not yet     |
 | `INCLUDE`      | PostgreSQL and Microsoft SQL Server only |                                                   Not yet                                                   |      ✔️       |    Not yet     |
 

apps/docs/content/docs/orm/reference/preview-features/client-preview-features.mdx

@@ -23,6 +23,7 @@ The following [Preview](/orm/more/releases#preview) feature flags are available
 | `strictUndefinedChecks`                                                 | [5.20.0](https://github.com/prisma/prisma/releases/tag/5.20.0) | [Submit feedback](https://github.com/prisma/prisma/discussions/25271) |
 | [`fullTextSearchPostgres`](/v6/orm/prisma-client/queries/full-text-search) | [6.0.0](https://github.com/prisma/prisma/releases/tag/6.0.0)   |   [Submit feedback](https://github.com/prisma/prisma/issues/25773)    |
 | `shardKeys`                                                             | [6.10.0](https://pris.ly/release/6.10.0)                       |      [Submit feedback](https://github.com/prisma/prisma/issues/)      |
+| [`partialIndexes`](/orm/prisma-schema/data-model/indexes)               | [7.4.0](https://pris.ly/release/7.4.0)                         |    [Submit feedback](https://github.com/prisma/prisma/issues/6974)    |
 
 To enable a Preview feature, [add the feature flag to the `generator` block](#enabling-a-prisma-client-preview-feature) in your `schema.prisma` file. [Share your feedback on all Preview features on GitHub](https://github.com/prisma/prisma/issues/3108).