# Data Description

## Data types

| Data type            | Supported | Notes                         |
| -------------------- | --------- | ----------------------------- |
| `BOOLEAN`            | ✅         | Alias for `TINYINT`           |
| `INTEGER`            | ✅         |                               |
| `TINYINT`            | ✅         |                               |
| `SMALLINT`           | ✅         |                               |
| `MEDIUMINT`          | ✅         |                               |
| `INT`                | ✅         |                               |
| `BIGINT`             | ✅         |                               |
| `DECIMAL`            | ✅         | Max (precision + scale) is 65 |
| `FLOAT`              | ✅         |                               |
| `DOUBLE`             | ✅         |                               |
| `BIT`                | ✅         |                               |
| `DATE`               | ✅         |                               |
| `TIME`               | ✅         |                               |
| `DATETIME`           | ✅         |                               |
| `TIMESTAMP`          | ✅         |                               |
| `YEAR`               | ✅         |                               |
| `CHAR`               | ✅         |                               |
| `VARCHAR`            | ✅         |                               |
| `BINARY`             | ✅         |                               |
| `VARBINARY`          | ✅         |                               |
| `TINYBLOB`           | ✅         |                               |
| `BLOB`               | ✅         |                               |
| `MEDIUMBLOB`         | ✅         |                               |
| `LONGBLOB`           | ✅         |                               |
| `TINYTEXT`           | ✅         |                               |
| `TEXT`               | ✅         |                               |
| `MEDIUMTEXT`         | ✅         |                               |
| `LONGTEXT`           | ✅         |                               |
| `ENUM`               | ✅         |                               |
| `SET`                | ✅         |                               |
| `GEOMETRY`           | ✅         |                               |
| `POINT`              | ✅         |                               |
| `LINESTRING`         | ✅         |                               |
| `POLYGON`            | ✅         |                               |
| `MULTIPOINT`         | ✅         |                               |
| `MULTILINESTRING`    | ✅         |                               |
| `MULTIPOLYGON`       | ✅         |                               |
| `GEOMETRYCOLLECTION` | ✅         |                               |
| `JSON`               | ✅         |                               |

## Constraints

| Component     | Supported | Notes and limitations                                                        |
| ------------- | --------- | ---------------------------------------------------------------------------- |
| Not Null      | ✅         |                                                                              |
| Unique        | ✅         | Unique constraints are supported via creation of indexes with `UNIQUE` keys. |
| Primary Key   | ✅         |                                                                              |
| Check         | ✅         |                                                                              |
| Foreign Key   | ✅         |                                                                              |
| Default Value | ✅         |                                                                              |

## Indexes

| Component            | Supported | Notes and limitations                                                                                                                                          |
| -------------------- | --------- | -------------------------------------------------------------------------------------------------------------------------------------------------------------- |
| Indexes              | ✅         |                                                                                                                                                                |
| Multi-column indexes | ✅         |                                                                                                                                                                |
| Full-text indexes    | 🟠        | Only basic functionality supported. Missing other search modifiers, different text parsers, stopword support, minimum word length adjustments, phrase matching |
| Spatial indexes      | ✅         |                                                                                                                                                                |

## Schema

| Component                | Supported | Notes and limitations                                                                                                          |
| ------------------------ | --------- | ------------------------------------------------------------------------------------------------------------------------------ |
| `ALTER TABLE` statements | 🟠        | Some limitations. See the [supported statements doc](https://docs.dolthub.com/sql-reference/sql-support/supported-statements). |
| Database renames         | ❌         | Database names are read-only, and configured by the server at startup.                                                         |
| Adding tables            | ✅         |                                                                                                                                |
| Dropping tables          | ✅         |                                                                                                                                |
| Table renames            | ✅         |                                                                                                                                |
| Adding views             | ✅         |                                                                                                                                |
| Dropping views           | ✅         |                                                                                                                                |
| View renames             | ❌         |                                                                                                                                |
| Column renames           | ✅         |                                                                                                                                |
| Adding columns           | ✅         |                                                                                                                                |
| Removing columns         | ✅         |                                                                                                                                |
| Reordering columns       | ✅         |                                                                                                                                |
| Adding constraints       | ✅         |                                                                                                                                |
| Removing constraints     | ✅         |                                                                                                                                |
| Creating indexes         | ✅         |                                                                                                                                |
| Index renames            | ✅         |                                                                                                                                |
| Removing indexes         | ✅         |                                                                                                                                |
| `AUTO INCREMENT`         | ✅         |                                                                                                                                |