When data from a data connection or an information link is added to the analysis, you have the option to either load all data at once, or to load data on demand only. Your analysis can benefit from on-demand loading when you have access to massive amounts of data, but you only need to work with some parts of the data at a time. When configuring an on-demand data source you can specify conditions based on one or more other data tables to control what to load. You can also start by letting an on-demand data table be the first (or only) data table in the analysis if its input is defined by a document property.
You can edit the on-demand settings from the source view of the Data canvas, including the option to enable on-demand loading for a data source that previously was not loaded on demand: