带有_store.enabled的ElasticSearch索引大小最终变小

Question

我正在测试多个索引，每个索引包含大约16k个文档。在一个索引中，我明确禁用了_source。我预计索引大小会比它的兄弟姐妹小，但实际上它实际上略有增加。

自：GET source_true,source_false/_stats/docs,store

"indices": {
"source_true": {
  "primaries": {
    "docs": {
      "count": 16079,
      "deleted": 0
    },
    "store": {
      "size_in_bytes": 948662734,
      "throttle_time_in_millis": 0
    }
  },
  "total": {
    "docs": {
      "count": 16079,
      "deleted": 0
    },
    "store": {
      "size_in_bytes": 948662734,
      "throttle_time_in_millis": 0
    }
  }
},
"source_false": {
  "primaries": {
    "docs": {
      "count": 16000,
      "deleted": 0
    },
    "store": {
      "size_in_bytes": 1039145361,
      "throttle_time_in_millis": 0
    }
  },
  "total": {
    "docs": {
      "count": 16000,
      "deleted": 0
    },
    "store": {
      "size_in_bytes": 1039145361,
      "throttle_time_in_millis": 0
    }
  }
}

这是预期的吗？我仔细检查过我没有改变映射中的任何其他内容。我还应该在哪里寻找线索？