With the SQL DATA LENS Server Navigator you see every namespace available on a Caché or IRIS server. You do not have to know a namespace’s name in advance, and you do not have to configure one JDBC connection per namespace by hand. Click a namespace and its tables, views, classes and routines are there.
What the tree tells you
Namespaces are not all alike, and the navigator distinguishes them rather than presenting one flat list. Local and remote namespaces are marked differently, and where a namespace is mapped from another system, the navigator can check whether it actually responds before you try to work in it.
That last case is the useful one. A remote namespace whose target database is down looks identical to a healthy one in a generic client — you find out when a query fails. The availability check turns it into something you can see before you start. It costs a round trip per remote namespace, so it is an option on the connection rather than always on; see setting up a connection for that and the related switches.
What a namespace actually is
A namespace is a collection of data and programs in a virtual workspace. Within a namespace you define the globals that a particular group of people or applications needs. If your accounting department has to use globals that live on different systems or in different directories, you can set up a single namespace that references all the accounting globals and databases across your network.
That indirection is why the namespace list matters more here than a database list would in another product: the namespace tells you what is reachable, not where it is stored. The Global Browser is the view that shows you what sits underneath a given mapping.
Caché and IRIS come with the following predefined namespaces:
%SYS— system management information and utilities.USER— empty at installation, typically used for application development.DOCBOOK— documentation. Present in Caché and in older IRIS installations; recent IRIS releases ship the documentation separately.SAMPLES— sample code and applications. Shipped with Caché; for IRIS, the samples are distributed as separate packages instead.
The InterSystems documentation on namespaces and databases covers the mapping rules in full.
%SYS and the other system namespaces are hidden unless the connection asks for them — see hiding the system objects. To get started, the download page has the current build and the user’s guide the rest.