Enum foundationdb::options::StreamingMode

#[non_exhaustive]pub enum StreamingMode {
    WantAll,
    Iterator,
    Exact,
    Small,
    Medium,
    Large,
    Serial,
}

Variants (Non-exhaustive)

Non-exhaustive enums could have additional variants added in future. Therefore, when matching against variants of non-exhaustive enums, an extra wildcard arm must be added to account for any future variants.

WantAll

Client intends to consume the entire range and would like it all transferred as early as possible.

Iterator

The default. The client doesn't know how much of the range it is likely to used and wants different performance concerns to be balanced. Only a small portion of data is transferred to the client initially (in order to minimize costs if the client doesn't read the entire range), and as the caller iterates over more items in the range larger batches will be transferred in order to minimize latency. After enough iterations, the iterator mode will eventually reach the same byte limit as WANT_ALL

Exact

Infrequently used. The client has passed a specific row limit and wants that many rows delivered in a single batch. Because of iterator operation in client drivers make request batches transparent to the user, consider WANT_ALL StreamingMode instead. A row limit must be specified if this mode is used.

Small

Infrequently used. Transfer data in batches small enough to not be much more expensive than reading individual rows, to minimize cost if iteration stops early.

Medium

Infrequently used. Transfer data in batches sized in between small and large.

Large

Infrequently used. Transfer data in batches large enough to be, in a high-concurrency environment, nearly as efficient as possible. If the client stops iteration early, some disk and network bandwidth may be wasted. The batch size may still be too small to allow a single client to get high throughput from the database, so if that is what you need consider the SERIAL StreamingMode.

Serial

Transfer data in batches large enough that an individual client can get reasonable read bandwidth from the database. If the client stops iteration early, considerable disk and network bandwidth may be wasted.

Implementations

impl StreamingMode

pub fn code(&self) -> FDBStreamingMode

Trait Implementations

impl Clone for StreamingMode

fn clone(&self) -> StreamingMode

Returns a copy of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl Copy for StreamingMode

impl Debug for StreamingMode

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.