Using Caché Objects - InterSystems Documentation

15
Streams
Streams are used to create properties containing large (greater than 32K) amounts of data.
Caché contains several stream classes that provide access to different data sources using a
common stream interface defined by the %Stream.Object class. Streams are implemented via
a family of classes that include the following members:
• %Stream.Object — the base class for all stream classes.
• %Library.AbstractStream — base class for all streams that can be used as object properties.
• %Library.GlobalCharacterStream — class for character streams stored in global nodes.
• %Library.GlobalBinaryStream — class for binary streams stored in global nodes.
• %Library.FileCharacterStream — class for character streams stored in an external file.
• %Library.FileBinaryStream — class for binary streams stored in an external file.
• %Library.File — class for manipulating external files as streams.
15.1 Declaring Stream Properties
Caché supports both binary streams and character streams. Binary streams contain the same
sort of data as type %Binary, and are intended for very large binary objects such as pictures.
Similarly, character streams contain the same sort of data as type %String, and are intended
for storing large amounts of text. Character streams, like strings, may undergo a UNICODE
translation within client applications.
Using Caché Objects 133