37.2. Data Types

|       37.2. Data Types       |                             |                                  |                  |                                                        |
|:----------------------------:|-----------------------------|----------------------------------|------------------|--------------------------------------------------------|
|[Prev](infoschema-schema.html)|[Up](information-schema.html)|Chapter 37. The Information Schema|[Home](index.html)| [Next](infoschema-information-schema-catalog-name.html)|

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## 37.2. Data Types

 The columns of the information schema views use special data types that are defined in the information schema. These are defined as simple domains over ordinary built-in types. You should not use these types for work outside the information schema, but your applications must be prepared for them if they select from the information schema.

 These types are:

`cardinal_number`

 A nonnegative integer.

`character_data`

 A character string (without specific maximum length).

`sql_identifier`

 A character string. This type is used for SQL identifiers, the type `character_data` is used for any other kind of text data.

`time_stamp`

 A domain over the type `timestamp with time zone`

`yes_or_no`

 A character string domain that contains either `YES` or `NO`. This is used to represent Boolean (true/false) data in the information schema. (The information schema was invented before the type `boolean` was added to the SQL standard, so this convention is necessary to keep the information schema backward compatible.)

 Every column in the information schema has one of these five types.

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|:-----------------------------|:---------------------------:|-------------------------------------------------------:|
|       37.1. The Schema       |     [Home](index.html)      |         37.3. `information_schema_catalog_name`        |

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