With the 1811 release you will see a warning message in SAP Cloud Applications Studio like the one below.
This warning is shown when you use the ‘Text’ data type for field definition. It’s an unlimited text data type and allows you to save as much text as you want. Because of the unlimited nature of the data type, certain users save binary content like PDF files or XML or images in this field. The data type is not designed to save such content and because of this it affects the database performance.
In such cases where you want to save PDF files, images etc. its recommended to AttachmentFolder (refer section 188.8.131.52 in the SDK Help Documentation for more on AttachmentFolder). Further, if you wish to store unlimited text then its recommended to use to use the TextCollection DO (refer section 184.108.40.206 in the SDK Help Documentation for more on TextCollection).
We also support text data types with limited character length. It highly recommended that when you define the text fields you one of the following data types.
Field Definition in Custom Objects
Field Definition in Extension Objects
Field Definition in Custom Nodes of an Extension Object