wow-query/me.ahoo.wow.query.schema/QueryStorageFacts

QueryStorageFacts

class QueryStorageFacts(val bindings: Map<QueryPathTemplate, QueryValueBindings>, val capabilities: Set<QueryCapability> = emptySet(), val fullProjectionAvailable: Boolean = true, val approximateMetrics: Set<String> = emptySet(), val storage: StorageSupport = StorageSupport.NATIVE, val provisional: Boolean = false)

What a storage proves about one read model, in the storage-neutral vocabulary of capabilities: for each logical path, the capabilities its native structures can execute and the physical location each binds to, with the projection and response locations; and the storage's model-wide support. Which native types, index kinds or mapping options prove a capability is the storage's knowledge; what a logical value must be for a capability to apply at all is the Catalog's (compile).

Constructors

QueryStorageFacts

constructor(bindings: Map<QueryPathTemplate, QueryValueBindings>, capabilities: Set<QueryCapability> = emptySet(), fullProjectionAvailable: Boolean = true, approximateMetrics: Set<String> = emptySet(), storage: StorageSupport = StorageSupport.NATIVE, provisional: Boolean = false)

Properties

approximateMetrics

val approximateMetrics: Set<String>

The metric types (DISTINCT_COUNT, PERCENTILE) the storage estimates rather than computes exactly.

bindings

val bindings: Map<QueryPathTemplate, QueryValueBindings>

capabilities

val capabilities: Set<QueryCapability>

The model-wide capabilities the storage proves, such as a full-text search over the whole record.

fullProjectionAvailable

val fullProjectionAvailable: Boolean

Whether native storage can deliver an unrestricted source projection.

provisional

val provisional: Boolean

Whether the facts describe storage that does not exist yet, such as an index before its first write, from what it will be created with. A provisional schema is never published: the next load asks the storage again, so the schema follows the storage as soon as it exists.

storage

val storage: StorageSupport

How the storage pages and aggregates.

Functions

compile

@JvmOverloads

fun compile(model: QueryModel, logicalSchema: LogicalQuerySchema, profile: QueryModelProfile? = QueryModelProfile.of(model)): QueryModelSchema

Compiles these facts about logicalSchema into the model's schema. The storage-independent capability rules apply here, once for every storage: