public static interface BuiltInMetadata.Distribution extends Metadata
If you are an operator consuming a relational expression, which subset of the rows are you seeing? You might be seeing all of them (BROADCAST or SINGLETON), only those whose key column values have a particular hash code (HASH) or only those whose column values have particular values or ranges of values (RANGE).
When a relational expression is partitioned, it is often partitioned among nodes, but it may be partitioned among threads running on the same node.
Modifier and Type | Interface and Description |
---|---|
static interface |
BuiltInMetadata.Distribution.Handler
Handler API.
|
Modifier and Type | Field and Description |
---|---|
static MetadataDef<BuiltInMetadata.Distribution> |
DEF |
Modifier and Type | Method and Description |
---|---|
RelDistribution |
distribution()
Determines how the rows are distributed.
|
static final MetadataDef<BuiltInMetadata.Distribution> DEF
RelDistribution distribution()
Copyright © 2012–2019 The Apache Software Foundation. All rights reserved.