JoinStrategyHint¶
JoinStrategyHint
is an abstraction of join hints.
JoinStrategyHint | displayName | hintAliases |
---|---|---|
BROADCAST | broadcast |
|
NO_BROADCAST_HASH | no_broadcast_hash | |
PREFER_SHUFFLE_HASH | prefer_shuffle_hash | |
SHUFFLE_HASH | shuffle_hash |
|
SHUFFLE_MERGE | merge |
|
SHUFFLE_REPLICATE_NL | shuffle_replicate_nl |
|
JoinStrategyHint
is resolved using ResolveJoinStrategyHints logical resolution rule.
sealed abstract class
JoinStrategyHint
is a Scala sealed abstract class which means that all possible implementations (JoinStrategyHint
s) are all in the same compilation unit (file).
Contract¶
displayName¶
displayName: String
hintAliases¶
hintAliases: Set[String]
Used when:
- ResolveJoinStrategyHints logical resolution rule is executed
JoinStrategyHints¶
JoinStrategyHint
defines strategies
collection of JoinStrategyHint
s for ResolveJoinStrategyHints logical resolution rule: