# Google BigQuery Storage v1 API - Class ReadSession (3.19.0)

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    public sealed class ReadSession : IMessage<ReadSession>, IEquatable<ReadSession>, IDeepCloneable<ReadSession>, IBufferMessage, IMessage

Reference documentation and code samples for the Google BigQuery Storage v1 API class ReadSession.

Information about the ReadSession.

## Inheritance

[object](https://learn.microsoft.com/dotnet/api/system.object) \> ReadSession

## Implements

[IMessage](https://cloud.google.com/dotnet/docs/reference/Google.Protobuf/latest/Google.Protobuf.IMessage-1.html)[ReadSession](https://docs.cloud.google.com/dotnet/docs/reference/Google.Cloud.BigQuery.Storage.V1/latest/Google.Cloud.BigQuery.Storage.V1.ReadSession), [IEquatable](https://learn.microsoft.com/dotnet/api/system.iequatable-1)[ReadSession](https://docs.cloud.google.com/dotnet/docs/reference/Google.Cloud.BigQuery.Storage.V1/latest/Google.Cloud.BigQuery.Storage.V1.ReadSession), [IDeepCloneable](https://cloud.google.com/dotnet/docs/reference/Google.Protobuf/latest/Google.Protobuf.IDeepCloneable-1.html)[ReadSession](https://docs.cloud.google.com/dotnet/docs/reference/Google.Cloud.BigQuery.Storage.V1/latest/Google.Cloud.BigQuery.Storage.V1.ReadSession), [IBufferMessage](https://cloud.google.com/dotnet/docs/reference/Google.Protobuf/latest/Google.Protobuf.IBufferMessage.html), [IMessage](https://cloud.google.com/dotnet/docs/reference/Google.Protobuf/latest/Google.Protobuf.IMessage.html)

## Inherited Members

[object.GetHashCode()](https://learn.microsoft.com/dotnet/api/system.object.gethashcode) [object.GetType()](https://learn.microsoft.com/dotnet/api/system.object.gettype) [object.ToString()](https://learn.microsoft.com/dotnet/api/system.object.tostring)

## Namespace

[Google.Cloud.BigQuery.Storage.V1](https://docs.cloud.google.com/dotnet/docs/reference/Google.Cloud.BigQuery.Storage.V1/latest/Google.Cloud.BigQuery.Storage.V1)

## Assembly

Google.Cloud.BigQuery.Storage.V1.dll

## Constructors

### ReadSession()

    public ReadSession()

### ReadSession(ReadSession)

    public ReadSession(ReadSession other)

| **Parameter** ||
|---|---|
| **Name** | **Description** |
| `other` | `https://docs.cloud.google.com/dotnet/docs/reference/Google.Cloud.BigQuery.Storage.V1/latest/Google.Cloud.BigQuery.Storage.V1.ReadSession` |

## Properties

### ArrowSchema

    public ArrowSchema ArrowSchema { get; set; }

Output only. Arrow schema.

| **Property Value** ||
|---|---|
| **Type** | **Description** |
| `https://docs.cloud.google.com/dotnet/docs/reference/Google.Cloud.BigQuery.Storage.V1/latest/Google.Cloud.BigQuery.Storage.V1.ArrowSchema` |   |

### AvroSchema

    public AvroSchema AvroSchema { get; set; }

Output only. Avro schema.

| **Property Value** ||
|---|---|
| **Type** | **Description** |
| `https://docs.cloud.google.com/dotnet/docs/reference/Google.Cloud.BigQuery.Storage.V1/latest/Google.Cloud.BigQuery.Storage.V1.AvroSchema` |   |

### DataFormat

    public DataFormat DataFormat { get; set; }

Immutable. Data format of the output data. DATA_FORMAT_UNSPECIFIED not
supported.

| **Property Value** ||
|---|---|
| **Type** | **Description** |
| `https://docs.cloud.google.com/dotnet/docs/reference/Google.Cloud.BigQuery.Storage.V1/latest/Google.Cloud.BigQuery.Storage.V1.DataFormat` |   |

### EstimatedRowCount

    public long EstimatedRowCount { get; set; }

Output only. An estimate on the number of rows present in this session's
streams. This estimate is based on metadata from the table which might be
incomplete or stale.

| **Property Value** ||
|---|---|
| **Type** | **Description** |
| `https://learn.microsoft.com/dotnet/api/system.int64` |   |

### EstimatedTotalBytesScanned

    public long EstimatedTotalBytesScanned { get; set; }

Output only. An estimate on the number of bytes this session will scan when
all streams are completely consumed. This estimate is based on
metadata from the table which might be incomplete or stale.

| **Property Value** ||
|---|---|
| **Type** | **Description** |
| `https://learn.microsoft.com/dotnet/api/system.int64` |   |

### EstimatedTotalPhysicalFileSize

    public long EstimatedTotalPhysicalFileSize { get; set; }

Output only. A pre-projected estimate of the total physical size of files
(in bytes) that this session will scan when all streams are consumed. This
estimate is independent of the selected columns and can be based on
incomplete or stale metadata from the table. This field is only set for
BigLake tables.

| **Property Value** ||
|---|---|
| **Type** | **Description** |
| `https://learn.microsoft.com/dotnet/api/system.int64` |   |

### ExpireTime

    public Timestamp ExpireTime { get; set; }

Output only. Time at which the session becomes invalid. After this time,
subsequent requests to read this Session will return errors. The
expire_time is automatically assigned and currently cannot be specified or
updated.

| **Property Value** ||
|---|---|
| **Type** | **Description** |
| `https://cloud.google.com/dotnet/docs/reference/Google.Protobuf/latest/Google.Protobuf.WellKnownTypes.Timestamp.html` |   |

### Name

    public string Name { get; set; }

Output only. Unique identifier for the session, in the form
`projects/{project_id}/locations/{location}/sessions/{session_id}`.

| **Property Value** ||
|---|---|
| **Type** | **Description** |
| `https://learn.microsoft.com/dotnet/api/system.string` |   |

### ReadOptions

    public ReadSession.Types.TableReadOptions ReadOptions { get; set; }

Optional. Read options for this session (e.g. column selection, filters).

| **Property Value** ||
|---|---|
| **Type** | **Description** |
| `https://docs.cloud.google.com/dotnet/docs/reference/Google.Cloud.BigQuery.Storage.V1/latest/Google.Cloud.BigQuery.Storage.V1.ReadSessionhttps://docs.cloud.google.com/dotnet/docs/reference/Google.Cloud.BigQuery.Storage.V1/latest/Google.Cloud.BigQuery.Storage.V1.ReadSession.Typeshttps://docs.cloud.google.com/dotnet/docs/reference/Google.Cloud.BigQuery.Storage.V1/latest/Google.Cloud.BigQuery.Storage.V1.ReadSession.Types.TableReadOptions` |   |

### ReadSessionName

    public ReadSessionName ReadSessionName { get; set; }

[ReadSessionName](https://docs.cloud.google.com/dotnet/docs/reference/Google.Cloud.BigQuery.Storage.V1/latest/Google.Cloud.BigQuery.Storage.V1.ReadSessionName)-typed view over the [Name](https://docs.cloud.google.com/dotnet/docs/reference/Google.Cloud.BigQuery.Storage.V1/latest/Google.Cloud.BigQuery.Storage.V1.ReadSession#Google_Cloud_BigQuery_Storage_V1_ReadSession_Name) resource name property.

| **Property Value** ||
|---|---|
| **Type** | **Description** |
| `https://docs.cloud.google.com/dotnet/docs/reference/Google.Cloud.BigQuery.Storage.V1/latest/Google.Cloud.BigQuery.Storage.V1.ReadSessionName` |   |

### SchemaCase

    public ReadSession.SchemaOneofCase SchemaCase { get; }

| **Property Value** ||
|---|---|
| **Type** | **Description** |
| `https://docs.cloud.google.com/dotnet/docs/reference/Google.Cloud.BigQuery.Storage.V1/latest/Google.Cloud.BigQuery.Storage.V1.ReadSessionhttps://docs.cloud.google.com/dotnet/docs/reference/Google.Cloud.BigQuery.Storage.V1/latest/Google.Cloud.BigQuery.Storage.V1.ReadSession.SchemaOneofCase` |   |

### Streams

    public RepeatedField<ReadStream> Streams { get; }

Output only. A list of streams created with the session.

At least one stream is created with the session. In the future, larger
request_stream_count values *may* result in this list being unpopulated,
in that case, the user will need to use a List method to get the streams
instead, which is not yet available.

| **Property Value** ||
|---|---|
| **Type** | **Description** |
| `https://cloud.google.com/dotnet/docs/reference/Google.Protobuf/latest/Google.Protobuf.Collections.RepeatedField-1.htmlhttps://docs.cloud.google.com/dotnet/docs/reference/Google.Cloud.BigQuery.Storage.V1/latest/Google.Cloud.BigQuery.Storage.V1.ReadStream` |   |

### Table

    public string Table { get; set; }

Immutable. Table that this ReadSession is reading from, in the form
`projects/{project_id}/datasets/{dataset_id}/tables/{table_id}`

| **Property Value** ||
|---|---|
| **Type** | **Description** |
| `https://learn.microsoft.com/dotnet/api/system.string` |   |

### TableAsTableName

    public TableName TableAsTableName { get; set; }

[TableName](https://docs.cloud.google.com/dotnet/docs/reference/Google.Cloud.BigQuery.Storage.V1/latest/Google.Cloud.BigQuery.Storage.V1.TableName)-typed view over the [Table](https://docs.cloud.google.com/dotnet/docs/reference/Google.Cloud.BigQuery.Storage.V1/latest/Google.Cloud.BigQuery.Storage.V1.ReadSession#Google_Cloud_BigQuery_Storage_V1_ReadSession_Table) resource name property.

| **Property Value** ||
|---|---|
| **Type** | **Description** |
| `https://docs.cloud.google.com/dotnet/docs/reference/Google.Cloud.BigQuery.Storage.V1/latest/Google.Cloud.BigQuery.Storage.V1.TableName` |   |

### TableModifiers

    public ReadSession.Types.TableModifiers TableModifiers { get; set; }

Optional. Any modifiers which are applied when reading from the specified
table.

| **Property Value** ||
|---|---|
| **Type** | **Description** |
| `https://docs.cloud.google.com/dotnet/docs/reference/Google.Cloud.BigQuery.Storage.V1/latest/Google.Cloud.BigQuery.Storage.V1.ReadSessionhttps://docs.cloud.google.com/dotnet/docs/reference/Google.Cloud.BigQuery.Storage.V1/latest/Google.Cloud.BigQuery.Storage.V1.ReadSession.Typeshttps://docs.cloud.google.com/dotnet/docs/reference/Google.Cloud.BigQuery.Storage.V1/latest/Google.Cloud.BigQuery.Storage.V1.ReadSession.Types.TableModifiers` |   |

### TraceId

    public string TraceId { get; set; }

Optional. ID set by client to annotate a session identity. This does not
need to be strictly unique, but instead the same ID should be used to group
logically connected sessions (e.g. All using the same ID for all sessions
needed to complete a Spark SQL query is reasonable).

Maximum length is 256 bytes.

| **Property Value** ||
|---|---|
| **Type** | **Description** |
| `https://learn.microsoft.com/dotnet/api/system.string` |   |