add map to list of unsupported nullable types

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candiduslynx 2023-05-03 17:52:42 +03:00
parent 5c72bdcb29
commit d5ccc99b1c

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@ -8,7 +8,7 @@ sidebar_label: Nullable
Allows to store special marker ([NULL](../../sql-reference/syntax.md)) that denotes “missing value” alongside normal values allowed by `TypeName`. For example, a `Nullable(Int8)` type column can store `Int8` type values, and the rows that do not have a value will store `NULL`. Allows to store special marker ([NULL](../../sql-reference/syntax.md)) that denotes “missing value” alongside normal values allowed by `TypeName`. For example, a `Nullable(Int8)` type column can store `Int8` type values, and the rows that do not have a value will store `NULL`.
For a `TypeName`, you cant use composite data types [Array](../../sql-reference/data-types/array.md) and [Tuple](../../sql-reference/data-types/tuple.md). Composite data types can contain `Nullable` type values, such as `Array(Nullable(Int8))`. For a `TypeName`, you cant use composite data types [Array](../../sql-reference/data-types/array.md), [Map](../../sql-reference/data-types/map.md) and [Tuple](../../sql-reference/data-types/tuple.md). Composite data types can contain `Nullable` type values, such as `Array(Nullable(Int8))`.
A `Nullable` type field cant be included in table indexes. A `Nullable` type field cant be included in table indexes.