Spaces

A space is a logical namespace inside a database and a branch. It exists so you can keep unrelated application domains apart without opening a second database.

Every command that touches data takes a --space, and every database starts with one called default. If you never mention spaces, everything you write is in default and this page changes nothing about how Strata behaves for you.

Keys are scoped to the space

The same key in two spaces is two records:

strata kv put k main-value
strata space create analytics
strata kv put k analytics-value --space analytics

strata kv get k returns main-value. strata kv get k --space analytics returns analytics-value. Neither read can see the other’s record, and neither write can clobber it.

That is the whole feature at the data level. What makes it worth having is how it interacts with everything else.

branch default

• spacedefaultk =main-value
• spaceanalyticsk =analytics-value
• spacestagingk =staged-value

one key name · three records · no read crosses a lane

Spaces live inside a branch

A space is not a property of the database. It belongs to the branch it was created on, and it forks and diverges with that branch like any other state.

strata space create shared
strata branch fork default work
strata space create after-fork

work has default and shared, the two that existed when it was forked. It does not have after-fork, because that was created on the parent afterwards. Creating a space on work likewise leaves the parent alone.

Comparisons respect the same boundary. branch diff reports its results grouped by space and by data model, so a change in analytics and a change in default arrive as separate entries rather than as one undifferentiated list.

Reading and writing somewhere else

--space is an override on the command, not a mode you enter:

strata kv list --space analytics
strata json get config '$' --space analytics

Commands that accept a branch and a space accept both independently, so “the analytics space on the work branch” is an ordinary thing to address.

Deleting one is deliberately awkward

Deleting a space that still holds data is refused:

strata space delete analytics

failed_precondition.engine.space_not_empty: product space `analytics`
contains visible data; retry with force=true to delete it

--force deletes the data and then the space. The refusal is the useful part: dropping a namespace is not the kind of thing that should succeed because you forgot what was in it.

Names

Names are permissive. Spaces, mixed case and non-ASCII characters are all accepted. Two things are not: an empty name, and names reserved for the engine’s own use, which fail with invalid_argument.engine.product_space_reserved.

When to use one

Spaces are for separation that is permanent and structural. Two products sharing a database. Application data kept apart from data you imported to analyse. A tenant boundary you want to be sure a query cannot cross.

They are not for separation that is temporary. If you want to change something and decide later whether to keep it, that is a branch, and Branches is the page for it. Spaces sit still; branches are the ones that move.