## Node.write()


Store this node in `sink` ([sverify.io.DeltaSink](io.DeltaSink.md#sverify.io.DeltaSink), [IcebergSink](io.IcebergSink.md#sverify.io.IcebergSink)),


Usage

``` python
Node.write(
    sink,
    *,
    quarantine=None,
)
```


as a cache in the middle of a job or as its output. Each refresh writes it once, upstream first, exactly once per state. Returns the stored node, which transforms read as a versioned source.

Nothing is written until a refresh. Downstream transforms may assume about the stored node what this node's stage proved: the preconditions on its sources are checked there, not again by the stages that read it. Without a [write](Node.write.md#sverify.Node.write), transforms fuse into one plan and the intermediate rows are never stored.


## Parameters


`sink: Sink`  
Where to store the node, such as `DeltaSink(uri)` or `IcebergSink(catalog, identifier)`. A sink stores one node.

`quarantine: Sink | Literal[False] | None = None`  
Where the rows this node's stage sets aside go (`on_violation="quarantine"`, \#184): a [DeltaSink](io.DeltaSink.md#sverify.io.DeltaSink) or [IcebergSink](io.IcebergSink.md#sverify.io.IcebergSink) whose table holds them, False for no quarantine table ([Node.quarantined](Node.quarantined.md#sverify.Node.quarantined) still returns them), or None (the default): a table next to the sink's, its URI or identifier with `_quarantine` appended. Written only when a precondition sets rows aside.


## Returns


`Node`  
The stored node, named by the sink's [name](engines.Dialect.md#sverify.engines.Dialect.name). Refreshing it (or

any node that reads it) writes the sink.


## Raises


`ValueError`  
`sink` already stores a node.


## Examples

With `orders`, `paid` and `doubled` from the [Node](Node.md#sverify.Node) example, in a new directory:

``` python
lake = tempfile.mkdtemp()
p = orders.pipe(paid).write(DeltaSink(f"{lake}/paid"))
r = p.pipe(doubled).write(DeltaSink(f"{lake}/doubled"))
[w.mode for w in r.refresh().writes]  # ['created', 'created']
```