Capacity Management - Business Connectivity Services limits

Limit	Maximum value	Limit type	Notes
ECT (in-memory)	5,000 per Web server (per tenant)	Boundary	Total number of external content type (ECT) definitions loaded in memory at a given point in time on a Web server.
External system connections	500 per Web server	Boundary	Number of active/open external system connections at a given point in time. The default maximum value is 200; the boundary is 500. This limit is enforced at the Web Server scope, regardless of the kind of external system (for example, database, .NET assembly, and so on) The default maximum is used to restrict the number of connections. An application can specify a larger limit via execution context; the boundary enforces the maximum even for applications that do not respect the default.
Database items returned per request	2,000 per database connector	Threshold	Number of items per request the database connector can return. The default maximum of 2,000 is used by the database connector to restrict the number of result that can be returned per page. The application can specify a larger limit via execution context; the Absolute Max enforces the maximum even for applications that do not respect the default. The boundary for this limit is 1,000,000