A declarative schema revision. Applying it converges the database toward the
declared state using only the four closed operations — add/drop a store,
add/remove an index — so applying it once or many times yields the same
result. Drops must be explicit; they are never inferred from omission.
A declarative schema revision. Applying it converges the database toward the declared state using only the four closed operations — add/drop a store, add/remove an index — so applying it once or many times yields the same result. Drops must be explicit; they are never inferred from omission.