# InvalidateMask(ulong)

> Invalidate all properties stored from multiple documents that match a document key mask.

## Definition

* **Type:** Method
* **Namespace:** [UnityEditor.Search](/engine/6000.6/script-reference/unityeditor/search.md)
* **Assembly:** UnityEditor

```csharp
public void InvalidateMask(ulong documentKeyMask)
```

### Parameters

**** (\[ulong]\(https\://learn.microsoft.com/dotnet/api/system.uint64)): A document key mask.

### Remarks

This operation is slower than the simpler [PropertyDatabase.Invalidate](/engine/6000.6/script-reference/unityeditor/search/propertydatabase/invalidate.md) since we cannot rely on a binary search to find all keys that match the mask.

```csharp
// Store properties of multiple documents.
for (ulong i = 0; i < 10; ++i)
{
    for (var j = 0; j < 10; ++j)
        propertyDatabase.Store(i, PropertyDatabase.CreatePropertyHash($"prop{j}"), $"value{j}");
}
// Invalidate all documents that match any set bits of the mask.
ulong invalidatedDocumentMask = 2;
propertyDatabase.InvalidateMask(invalidatedDocumentMask);

// The invalidated documents can no longer be retrieved.
for (ulong i = 0; i < 10; ++i)
{
    if ((i & invalidatedDocumentMask) == 0)
        continue;
    if (propertyDatabase.TryLoad(i, out IEnumerable<object> invalidatedDocumentValues))
        Assert.Fail("TryLoad should have failed to retrieve the invalidated document values.");
}
```

Additional Resources: [PropertyDatabase.CreateDocumentKey](/engine/6000.6/script-reference/unityeditor/search/propertydatabase/createdocumentkey.md).