[Yandex Cloud documentation](../../index.md) > [Yandex DataLens](../index.md) > [Datasets](index.md) > Data type mapping

# Database type and internal Yandex DataLens type mapping table

When you create a dataset, DataLens converts the source data to its own type for streamlined data processing.
This helps DataLens unify the operations with data from different sources.

The table below shows how data types of different databases and DataLens internal data types map.

DataLens | ClickHouse® | PostgreSQL | MySQL | MS SQL | YDB
----- | ----- | ----- | ----- | ----- | -----
**Boolean** | boolean | boolean | bit | bit | boolean
**Date** | date | date | date | date | date<br/>date32
**Date and time** | datetime | timestamp | datetime<br/>timestamp | datetime<br/>datetime2<br/>smalldatetime<br/>datetimeoffset | datetime<br/>datetime64<br/>timestamp<br/>timestamp64
**Fractional number** | float<br/>float32<br/>float64<br/>decimal<sup>*</sup> | real<br/>double precision<br/>numeric | float<br/>double<br/>numeric<br/>decimal<sup>*</sup> | float<br/>real<br/>numeric<br/>decimal<sup>*</sup> | float<br/>double<br/>decimal<sup>*</sup><br/>dynumber
**Integer** | integer<br/>int8<br/>int16<br/>int32<br/>int64<br/>uint8<br/>uint16<br/>uint32<br/>uint64 | smallint<br/>integer<br/>bigint | tinyint<br/>smallint<br/>mediumint<br/>integer<br/>bigint | tinyint<br/>smallint<br/>integer<br/>bigint | int8<br/>int16<br/>int32<br/>int64<br/>uint8<br/>uint16<br/>uint32<br/>uint64<br/>interval<br/>interval64
**String** | string<br/>enum8<br/>enum16 | char<br/>varchar<br/>text<br/>citext<br/> | tinyblob<br/>blob<br/>binary<br/>varbinary<br/>char<br/>varchar<br/>tinytext<br/>text<br/>enum | char<br/>varchar</br>text<br/>nchar<br/>nvarchar<br/>ntext<br/> | string<br/>utf8
**Geopoint** | Set by a formula in DataLens | Set by a formula in DataLens | Set by a formula in DataLens | Set by a formula in DataLens | Set by a formula in DataLens
**Geopolygon** | Set by a formula in DataLens | Set by a formula in DataLens | Set by a formula in DataLens | Set by a formula in DataLens | Set by a formula in DataLens
**Array of integers** | Array(integer)<br/> Array(int8)<br/>Array(int16)<br/>Array(int32)<br/>Array(int64)<br/>Array(uint8)<br/>Array(uint16)<br/>Array(uint32)<br/>Array(uint64) | Array(smallint)<br/>Array(integer)<br/>Array(bigint) | Not supported | Not supported | Not supported:
**Float array** | Array(float32)<br/>Array(float64) | Array(real)<br/>Array(double)<br/>Array(precision)<br/>Array(numeric)| Not supported | Not supported | Not supported:
**Array of strings** | Array(string) | Array(char)<br/>Array(varchar)<br/>Array(text) | Not supported | Not supported | Not supported:

<sup>*</sup> There may be a loss of accuracy when converting data.

_ClickHouse® is a registered trademark of [ClickHouse, Inc](https://clickhouse.com)._