# getPersistentSegmentInfo()

A MilvusClient interface. This method gets the information of persisted segments from data node, including row count, persistence state (growing or flushed), and more.

```Java
R<GetPersistentSegmentInfoResponse> getPersistentSegmentInfo(GetPersistentSegmentInfoParam requestParam);
```

## GetPersistentSegmentInfoParam

Use the `GetPersistentSegmentInfoParam.Builder` to construct a `GetPersistentSegmentInfoParam` object.

```Java
import io.milvus.param.GetPersistentSegmentInfoParam;
GetPersistentSegmentInfoParam.Builder builder = GetPersistentSegmentInfoParam.newBuilder();
```

Methods of `GetPersistentSegmentInfoParam.Builder`:

| Method                                      | Description                                                  | Parameters                                    |
| ------------------------------------------- | ------------------------------------------------------------ | --------------------------------------------- |
| `withCollectionName(String collectionName)` | Sets the collection name. The collection name cannot be empty or null. | `collectionName`: The name of the collection. |
| `build()`                                   | Constructs a `GetPersistentSegmentInfoParam` object.         | N/A                                           |

The `GetPersistentSegmentInfoParam.Builder.build()` can throw the following exceptions:

- `ParamException`: error if the parameter is invalid.

## Returns

This method catches all the exceptions and returns an `R<GetPersistentSegmentInfoResponse>` object.

- If the API fails on the server side, it returns the error code and message from the server.

- If the API fails by RPC exception, it returns `R.Status.Unknow` and the error message of the exception.

- If the API succeeds, it returns a valid `GetPersistentSegmentInfoResponse` held by the R template. The `GetPersistentSegmentInfoResponse` object contains a list of `PersistentSegmentInfo`, and you can use `getState()` in `PersistentSegmentInfo` to get the state of the segment.

## SegmentState

```Java
package io.milvus.grpc;
public enum SegmentState
```

| Type         | Code | Description                                  |
| ---------------- | -------- | ------------------------------------------------ |
| SegmentStateNone | 0        | For internal usage.                              |
| NotExist         | 1        | For internal usage.                              |
| Growing          | 2        | A growing segment in query node.                 |
| Sealed           | 3        | The segment is sealed and waiting to be flushed. |
| Flushed          | 4        | The segment has been flushed to storage.         |
| Flushing         | 5        | The server is flushing this segment.             |
| Dropped          | 6        | The segment has been marked as deleted.          |
| Importing        | 7        | Reserved for bulkload interface.                 |

## Example

```Java
import io.milvus.param.*;
import io.milvus.grpc.GetPersistentSegmentInfoResponse;
import io.milvus.grpc.PersistentSegmentInfo;

GetPersistentSegmentInfoParam param = GetPersistentSegmentInfoParam.newBuilder()
        .withCollectionName(collectionName)
        .build();
R<GetPersistentSegmentInfoResponse> response = client.getPersistentSegmentInfo(param);
if (response.getStatus() != R.Status.Success.getCode()) {
    System.out.println(response.getMessage());
}

GetPersistentSegmentInfoResponse segmentInfo = response.getData();
for (int i = 0; i < segmentInfo.getInfosCount(); i++) {
    PersistentSegmentInfo info = segmentInfo.getInfos(i);
    System.out.println("Segment ID: " + info.getSegmentID() + ", state: " + info.getState() + ", rows: " + info.getNumRows());
}
```