Locale Support
An important aspect of globalization is locale, which is a model and definition of a native-language environment. A locale consists of a number of categories for which country-dependent formatting or other specifications exist. For example, a locale defines date and time formatting conventions, monetary conventions, decimal formatting conventions, and collation (sort) order. Depending on the operating system, a locale may be called a region.
More than one locale can be associated with a particular language, which allows for regional differences. For example, English can have a United States locale and a Great Britain locale.
When executing string functions, PSQL uses the locale of the operating system on which the database engine is running. PSQL uses the locale of the Client when converting data types as requested by the application through one of the PSQL access methods.
For more information, see SET DECIMALSEPARATORCOMMA, Comma as Decimal Separator and SET TIME ZONE in SQL Engine Reference.