关于elasticsearch:elasticsearch-实现聚合后两个字段相除相加相减相乘运算

有个需要，在 sql 中的计算形式是：

sum(cost) / 100 / sum(view_count) * 1000

统计出均匀千次展示均价，老本按分存储。

在 es 中须要聚合 cost 和 view_count 之后再运算。折腾了半天，记录下：

"aggs" => [
    'total_cost_count' => [
        'sum' => ['field' => 'cost']
    ],
    'total_view_count' => [
        'sum' => ['field' => 'view_count']
    ],
    '(total_cost / total_view)' => [
        'bucket_script' => [
            'buckets_path' => [
                'cost' => 'total_cost_count',
                'view_count' => 'total_view_count',
            ],
            'script' => [
                'source' => "params.cost / params.unit / params.view_count * params.days",
                'params' => [
                    'unit' => 100,
                    'days' => 1000,
                ]
            ]
        ]
    ]
],

调试过程中报错信息：

• Only sibling pipeline aggregations are allowed at the top level

  • 在顶层只容许兄弟管道聚合。也就是聚合运算只能在同一个桶内。

参考文档：https://www.elastic.co/guide/en/elasticsearch/painless/7.13/painless-bucket-script-agg-context.html