# VECTOR_INDEX_COLUMNS view

The `INFORMATION_SCHEMA.VECTOR_INDEX_COLUMNS` view contains one row for each
vector-indexed column on each table in a dataset.

## Required permissions

To see [vector index](https://docs.cloud.google.com/bigquery/docs/vector-index) metadata, you need the
`bigquery.tables.get` or `bigquery.tables.list` Identity and Access Management (IAM)
permission on the table with the index. Each of the following predefined
IAM roles includes at least one of these permissions:

- `roles/bigquery.admin`
- `roles/bigquery.dataEditor`
- `roles/bigquery.dataOwner`
- `roles/bigquery.dataViewer`
- `roles/bigquery.metadataViewer`
- `roles/bigquery.user`

For more information about BigQuery permissions, see
[Access control with IAM](https://docs.cloud.google.com/bigquery/docs/access-control).

## Schema

When you query the `INFORMATION_SCHEMA.VECTOR_INDEX_COLUMNS` view, the query results contain one row for each indexed column on each table in a dataset.

<br />

The `INFORMATION_SCHEMA.VECTOR_INDEX_COLUMNS` view has the following schema:

| Column name | Data type | Value |
|---|---|---|
| `index_catalog` | `STRING` | The name of the project that contains the dataset. |
| `index_schema` | `STRING` | The name of the dataset that contains the vector index. |
| `table_name` | `STRING` | The name of the table that the vector index is created on. |
| `index_name` | `STRING` | The name of the vector index. |
| `index_column_name` | `STRING` | The name of the indexed column. |
| `index_field_path` | `STRING` | The full path of the expanded indexed field, starting with the column name. Fields are separated by a period. |

For stability, we recommend that you explicitly list columns in your information schema queries instead of
using a wildcard (`SELECT *`). Explicitly listing columns prevents queries from
breaking if the underlying schema changes.

## Scope and syntax

Queries against this view must have a [dataset qualifier](https://docs.cloud.google.com/bigquery/docs/information-schema-intro#syntax). The
following table explains the region scope for this view:

| View Name | Resource scope | Region scope |
|---|---|---|
| `[PROJECT_ID.]DATASET_ID.INFORMATION_SCHEMA.VECTOR_INDEX_COLUMNS` | Dataset level | Dataset location |

<br />

Replace the following:

- Optional: `PROJECT_ID`: the ID of your Google Cloud project. If not specified, the default project is used.
- `DATASET_ID`: the ID of your dataset. For more information, see [Dataset qualifier](https://docs.cloud.google.com/bigquery/docs/information-schema-intro#dataset_qualifier).

  <br />

  <br />

  > [!NOTE]
  > **Note:** You must use [a region qualifier](https://docs.cloud.google.com/bigquery/docs/information-schema-intro#region_qualifier) to query `INFORMATION_SCHEMA` views. The location of the query execution must match the region of the `INFORMATION_SCHEMA` view.

<br />

**Example**

    -- Returns metadata for vector indexes in a single dataset.
    SELECT * FROM myDataset.INFORMATION_SCHEMA.VECTOR_INDEX_COLUMNS;

## Examples

The following query extracts information on columns that have vector indexes:

```googlesql
SELECT table_name, index_name, index_column_name, index_field_path
FROM my_project.dataset.INFORMATION_SCHEMA.VECTOR_INDEX_COLUMNS;
```

The result is similar to the following:

```
+---+---+---+---+
| table_name | index_name | index_column_name | index_field_path |
+---+---+---+---+
| table1     | indexa     | embeddings        | embeddings       |
| table2     | indexb     | vectors           | vectors          |
| table3     | indexc     | vectors           | vectors          |
+---+---+---+---+
```