Type of the result record
Primary key used for routing the fast-path read
SQL statement to execute
Parameter values to bind to the SQL statement
Optionaloptions: ReadOptions
Read guarantee for this call. The routed read and the fallback share one session per shard
The first matching row, or null when neither path finds one
Reads the first matching row via key routing, falling back to a global all-shards scan when the routed read misses.
The routed read stays the fast path. The fallback exists for the window where a primary-key -> shard mapping has not been created yet (a brand-new key, an eventually-consistent KV, or a row written directly to a shard), so a single lookup still resolves without the caller wiring their own fanout.