---

id: tableviews title: Work with TableView sidebar_label: “Work with TableView” description: Learn how to work with TableView in Pulsar.

import Tabs from '@theme/Tabs';
import TabItem from '@theme/TabItem';

After setting up your clients, you can explore more to start working with TableView.

Configure TableView

<Tabs groupId="lang-choice"
defaultValue="Java"
values={[{"label":"Java","value":"Java"},{"label":"C++","value":"C++"}]}>
<TabItem value="Java">

  The following is an example of how to configure a TableView.
  
  ```java
    TableView<String> tv = client.newTableViewBuilder(Schema.STRING)
    .topic("my-tableview")
    .create()
  ```

You can use the available parameters in the `loadConf` configuration or the API [`TableViewBuilder`](@pulsar:javadoc:client@/org/apache/pulsar/client/api/TableViewBuilder.html) to customize your TableView.

  | Name | Type| Required? |  <div>Description</div> | Default
  |---|---|---|---|---
  | `topic` | string | yes | The topic name of the TableView. | N/A
  | `autoUpdatePartitionInterval` | int | no | The interval to check for newly added partitions. | 60 (seconds)
  | `subscriptionName` | string | no | The subscription name of the TableView. | null

</TabItem>

<TabItem value="C++">


  This feature is supported in C++ client 3.2.0 or later versions.


  ```cpp
  ClientConfiguration clientConfiguration;
  clientConfiguration.setPartititionsUpdateInterval(100);
  Client client("pulsar://localhost:6650", clientConfiguration);
  TableViewConfiguration tableViewConfiguration{schemaInfo, "test-subscription-name"};
  TableView tableView;
  client.createTableView("my-tableview", tableViewConfiguration, tableView)
  ```

  You can use the following parameters to customize your TableView.

  | Name | Type| Required? |  <div>Description</div> | Default
  |---|---|---|---|---
  | `topic` | string | yes | The topic name of the TableView. | N/A
  | `schemaInfo` | struct | no | Declare the schema of the data that this TableView can accept. The schema is checked against the schema of the topic, and the TableView creation fails if it's incompatible. | N/A
  | `subscriptionName` | string | no | The subscription name of the TableView. | reader-\{random string\}
  | `partititionsUpdateInterval` | int | no | Topic partitions update interval in seconds. In the C++ client, `partititionsUpdateInterval` is global within the same client.  | 60


</TabItem>

</Tabs>

:::note Tombstone (null-value) messages

TableView treats a message with a null payload as a tombstone - the key is removed from the map.

• forEach(action) iterates over the current map snapshot only, so it does not surface keys that have been tombstoned.
• forEachAndListen(action) first runs forEach over the current non-tombstoned entries, then registers the action as a live listener. Every subsequent update - including tombstones - is delivered to the listener as action.accept(key, null). If you need to react to deletions (for example, to clean up downstream state), check for value == null in your listener.

:::

Register listeners

You can register listeners for both existing messages on a topic and new messages coming into the topic by using forEachAndListen, and specify to perform operations for all existing messages by using forEach.

The following is an example of how to register listeners with TableView.

<Tabs groupId="lang-choice"
defaultValue="Java"
values={[{"label":"Java","value":"Java"},{"label":"C++","value":"C++"}]}>

<TabItem value="Java">

  ```java
  // Register listeners for all existing and incoming messages
  tv.forEachAndListen((key, value) -> /*operations on all existing and incoming messages*/)

  // Register actions for all existing messages
  tv.forEach((key, value) -> /*operations on all existing messages*/)
  ```

</TabItem>


<TabItem value="C++">

    ```cpp
    // Register listeners for all existing and incoming messages
    tableView.forEach([](const std::string& key, const std::string& value) {});

    // Register actions for all existing messages
    tableView.forEachAndListen([](const std::string& key, const std::string& value) {});
    ```

</TabItem>

</Tabs>