PowerCenter uses the following data types in Vertica mappings:

Vertica native data types. Vertica data types appear in Vertica definitions in a mapping.
Transformation data types. Set of data types that appear in the transformations. They are internal data types based on ANSI SQL-92 generic data types, which the PowerCenter Integration Service uses to move data across platforms. They appear in all transformations in a mapping.

When the PowerCenter Integration Service reads source data, it converts the native data types to the comparable transformation data types before transforming the data. When the PowerCenter Integration Service writes to target, it converts the transformation data types to the comparable native data types.