BuiltInMetadata.Size (Apache Calcite API)

All Superinterfaces:

Metadata

All Known Subinterfaces:

BuiltInMetadata.All

Enclosing class:

BuiltInMetadata
```
public static interface BuiltInMetadata.Size
extends Metadata
```
Metadata about the size of rows and columns.

Nested Class Summary

Nested Classes
Modifier and Type Interface Description

static interface BuiltInMetadata.Size.Handler
Handler API.

Field Summary

Fields
Modifier and Type Field Description

static MetadataDef<BuiltInMetadata.Size> DEF

Method Summary

All Methods Instance Methods Abstract Methods
Modifier and Type	Method	Description
`java.util.List<java.lang.Double>`	`averageColumnSizes()`	Determines the average size (in bytes) of a value of a column in this relational expression.
`java.lang.Double`	`averageRowSize()`	Determines the average size (in bytes) of a row from this relational expression.

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

- Field Detail
  - DEF
```
static final MetadataDef<BuiltInMetadata.Size> DEF
```
- Method Detail
  - averageRowSize
```
java.lang.Double averageRowSize()
```
    Determines the average size (in bytes) of a row from this relational expression.
    
    Returns:
    
    average size of a row, in bytes, or null if not known
  - averageColumnSizes
```
java.util.List<java.lang.Double> averageColumnSizes()
```
    Determines the average size (in bytes) of a value of a column in this relational expression.
    Null values are included (presumably they occupy close to 0 bytes).
    It is left to the caller to decide whether the size is the compressed size, the uncompressed size, or memory allocation when the value is wrapped in an object in the Java heap. The uncompressed size is probably a good compromise.
    
    Returns:
    
    an immutable list containing, for each column, the average size of a column value, in bytes. Each value or the entire list may be null if the metadata is not available