BuiltInMetadata.Memory (Apache Calcite API)

All Superinterfaces:

Metadata

All Known Subinterfaces:

BuiltInMetadata.All

Enclosing class:

BuiltInMetadata
```
public static interface BuiltInMetadata.Memory
extends Metadata
```
Metadata about the memory use of an operator.

Nested Class Summary

Nested Classes
Modifier and Type Interface Description

static interface BuiltInMetadata.Memory.Handler
Handler API.

Field Summary

Fields
Modifier and Type Field Description

static MetadataDef<BuiltInMetadata.Memory> DEF

Method Summary

All Methods Instance Methods Abstract Methods
Modifier and Type	Method	Description
`java.lang.Double`	`cumulativeMemoryWithinPhase()`	Returns the cumulative amount of memory, in bytes, required by the physical operator implementing this relational expression, and all other operators within the same phase, across all splits.
`java.lang.Double`	`cumulativeMemoryWithinPhaseSplit()`	Returns the expected cumulative amount of memory, in bytes, required by the physical operator implementing this relational expression, and all operators within the same phase, within each split.
`java.lang.Double`	`memory()`	Returns the expected amount of memory, in bytes, required by a physical operator implementing this relational expression, across all splits.

Methods inherited from interface org.apache.calcite.rel.metadata.Metadata
rel

- Field Detail
  - DEF
```
static final MetadataDef<BuiltInMetadata.Memory> DEF
```
- Method Detail
  - memory
```
java.lang.Double memory()
```
    Returns the expected amount of memory, in bytes, required by a physical operator implementing this relational expression, across all splits.
    How much memory is used depends very much on the algorithm; for example, an implementation of Aggregate that loads all data into a hash table requires approximately rowCount * averageRowSize bytes, whereas an implementation that assumes that the input is sorted requires only averageRowSize bytes to maintain a single accumulator for each aggregate function.
  - cumulativeMemoryWithinPhase
```
java.lang.Double cumulativeMemoryWithinPhase()
```
    Returns the cumulative amount of memory, in bytes, required by the physical operator implementing this relational expression, and all other operators within the same phase, across all splits.
    
    See Also:
    
    BuiltInMetadata.Parallelism.splitCount()
  - cumulativeMemoryWithinPhaseSplit
```
java.lang.Double cumulativeMemoryWithinPhaseSplit()
```
    Returns the expected cumulative amount of memory, in bytes, required by the physical operator implementing this relational expression, and all operators within the same phase, within each split.
    Basic formula:
    cumulativeMemoryWithinPhaseSplit = cumulativeMemoryWithinPhase / Parallelism.splitCount