使用索引在 n1ql 和 couchbase 中提高性能

performance improve in n1ql,couchbase using index

我有以下查询

explain SELECT * FROM (select ROUND(sum(ARRAY_SUM(DailyCampaignUsage.`statistics`[*].clicksCost)),2) total_revenue,
ROUND(sum(CASE WHEN  DailyCampaignUsage.day between '2016-05-01' and '2016-05-23' THEN ARRAY_SUM(DailyCampaignUsage.`statistics`[*].clicksCost) ELSE 0 END),2) period_revenue,
ROUND(sum(CASe WHEN  DailyCampaignUsage.day between '2016-04-01' and '2016-04-23' THEN ARRAY_SUM(DailyCampaignUsage.`statistics`[*].clicksCost) ELSE 0 END),2) period_prev_revenue 
from Inheritx DailyCampaignUsage  use index(dailyCampaignUsage_type_day_clicksCost)
JOIN Inheritx Campaign ON KEYS ('Campaign|'||TOSTRING(DailyCampaignUsage.campaignId)) 
JOIN Inheritx Users on keys('User|'|| TOSTRING(Campaign.`user`)) 
WHERE DailyCampaignUsage._type='DailyCampaignUsage' and CASE WHEN FALSE THEN Users.`user` in FALSE ELSE TRUE END ) AS __viewdef__    ORDER BY `created` DESC

我的索引低于

CREATE INDEX dailyCampaignUsage_type_day_clicksCost  ON Inheritx 
(_type,day,`statistics`[*].clicksCost) WHERE _type='DailyCampaignUsage'

我在查询中使用了它。

我的解释计划失败了。

{
    "plan": {
      "#operator": "Sequence",
      "~children": [
        {
          "#operator": "Sequence",
          "~children": [
            {
              "#operator": "Sequence",
              "~children": [
                {
                  "#operator": "IndexScan",
                  "index": "dailyCampaignUsage_type_day_clicksCost",
                  "index_id": "37387d27d560354b",
                  "keyspace": "Inheritx",
                  "namespace": "default",
                  "spans": [
                    {
                      "Range": {
                        "High": [
                          "successor(\"DailyCampaignUsage\")"
                        ],
                        "Inclusion": 1,
                        "Low": [
                          "\"DailyCampaignUsage\""
                        ]
                      }
                    }
                  ],
                  "using": "gsi"
                },
                {
                  "#operator": "Parallel",
                  "~child": {
                    "#operator": "Sequence",
                    "~children": [
                      {
                        "#operator": "Fetch",
                        "as": "DailyCampaignUsage",
                        "keyspace": "Inheritx",
                        "namespace": "default"
                      },
                      {
                        "#operator": "Join",
                        "as": "Campaign",
                        "keyspace": "Inheritx",
                        "namespace": "default",
                        "on_keys": "(\"Campaign|\" || to_string((`DailyCampaignUsage`.`campaignId`)))"
                      },
                      {
                        "#operator": "Join",
                        "as": "Users",
                        "keyspace": "Inheritx",
                        "namespace": "default",
                        "on_keys": "(\"User|\" || to_string((`Campaign`.`user`)))"
                      },
                      {
                        "#operator": "Filter",
                        "condition": "(((`DailyCampaignUsage`.`_type`) = \"DailyCampaignUsage\") and case when false then ((`Users`.`user`) in false) else true end)"
                      },
                      {
                        "#operator": "InitialGroup",
                        "aggregates": [
                          "sum(array_sum((array_star((`DailyCampaignUsage`.`statistics`)).`clicksCost`)))",
                          "sum(case when ((`DailyCampaignUsage`.`day`) between \"2016-04-01\" and \"2016-04-23\") then array_sum((array_star((`DailyCampaignUsage`.`statistics`)).`clicksCost`)) else 0 end)",
                          "sum(case when ((`DailyCampaignUsage`.`day`) between \"2016-05-01\" and \"2016-05-23\") then array_sum((array_star((`DailyCampaignUsage`.`statistics`)).`clicksCost`)) else 0 end)"
                        ],
                        "group_keys": []
                      }
                    ]
                  }
                },
                {
                  "#operator": "IntermediateGroup",
                  "aggregates": [
                    "sum(array_sum((array_star((`DailyCampaignUsage`.`statistics`)).`clicksCost`)))",
                    "sum(case when ((`DailyCampaignUsage`.`day`) between \"2016-04-01\" and \"2016-04-23\") then array_sum((array_star((`DailyCampaignUsage`.`statistics`)).`clicksCost`)) else 0 end)",
                    "sum(case when ((`DailyCampaignUsage`.`day`) between \"2016-05-01\" and \"2016-05-23\") then array_sum((array_star((`DailyCampaignUsage`.`statistics`)).`clicksCost`)) else 0 end)"
                  ],
                  "group_keys": []
                },
                {
                  "#operator": "FinalGroup",
                  "aggregates": [
                    "sum(array_sum((array_star((`DailyCampaignUsage`.`statistics`)).`clicksCost`)))",
                    "sum(case when ((`DailyCampaignUsage`.`day`) between \"2016-04-01\" and \"2016-04-23\") then array_sum((array_star((`DailyCampaignUsage`.`statistics`)).`clicksCost`)) else 0 end)",
                    "sum(case when ((`DailyCampaignUsage`.`day`) between \"2016-05-01\" and \"2016-05-23\") then array_sum((array_star((`DailyCampaignUsage`.`statistics`)).`clicksCost`)) else 0 end)"
                  ],
                  "group_keys": []
                },
                {
                  "#operator": "Parallel",
                  "~child": {
                    "#operator": "Sequence",
                    "~children": [
                      {
                        "#operator": "InitialProject",
                        "result_terms": [
                          {
                            "as": "total_revenue",
                            "expr": "round(sum(array_sum((array_star((`DailyCampaignUsage`.`statistics`)).`clicksCost`))), 2)"
                          },
                          {
                            "as": "period_revenue",
                            "expr": "round(sum(case when ((`DailyCampaignUsage`.`day`) between \"2016-05-01\" and \"2016-05-23\") then array_sum((array_star((`DailyCampaignUsage`.`statistics`)).`clicksCost`)) else 0 end), 2)"
                          },
                          {
                            "as": "period_prev_revenue",
                            "expr": "round(sum(case when ((`DailyCampaignUsage`.`day`) between \"2016-04-01\" and \"2016-04-23\") then array_sum((array_star((`DailyCampaignUsage`.`statistics`)).`clicksCost`)) else 0 end), 2)"
                          }
                        ]
                      },
                      {
                        "#operator": "FinalProject"
                      }
                    ]
                  }
                }
              ]
            },
            {
              "#operator": "Alias",
              "as": "__viewdef__"
            },
            {
              "#operator": "Parallel",
              "~child": {
                "#operator": "Sequence",
                "~children": [
                  {
                    "#operator": "InitialProject",
                    "result_terms": [
                      {
                        "expr": "self",
                        "star": true
                      }
                    ]
                  }
                ]
              }
            }
          ]
        },
        {
          "#operator": "Order",
          "sort_terms": [
            {
              "desc": true,
              "expr": "(`__viewdef__`.`created`)"
            }
          ]
        },
        {
          "#operator": "FinalProject"
        }
      ]
    },
    "text": "SELECT * FROM (select ROUND(sum(ARRAY_SUM(DailyCampaignUsage.`statistics`[*].clicksCost)),2) total_revenue,\nROUND(sum(CASE WHEN  DailyCampaignUsage.day between '2016-05-01' and '2016-05-23' THEN ARRAY_SUM(DailyCampaignUsage.`statistics`[*].clicksCost) ELSE 0 END),2) period_revenue,\nROUND(sum(CASe WHEN  DailyCampaignUsage.day between '2016-04-01' and '2016-04-23' THEN ARRAY_SUM(DailyCampaignUsage.`statistics`[*].clicksCost) ELSE 0 END),2) period_prev_revenue \nfrom Inheritx DailyCampaignUsage  use index(dailyCampaignUsage_type_day_clicksCost)\nJOIN Inheritx Campaign ON KEYS ('Campaign|'||TOSTRING(DailyCampaignUsage.campaignId)) \nJOIN Inheritx Users on keys('User|'|| TOSTRING(Campaign.`user`)) \nWHERE DailyCampaignUsage._type='DailyCampaignUsage' and CASE WHEN FALSE THEN Users.`user` in FALSE ELSE TRUE END ) AS __viewdef__    ORDER BY `created` DESC"
  }

即使使用索引我也无法减少它的执行。这是 13s 我怎样才能做到 300 到 500 毫秒 ? 我的 json 如下所示 我有 50k+ json

DailyCampaignUsage|006657c0-c696-11e6-b6f2-7f0166ec7527{
      "_id": "006657c0-c696-11e6-b6f2-7f0166ec7527",
      "_type": "DailyCampaignUsage",
      "campaignId": 249,
      "day": "2015-11-19T00:00:00Z",
      "statistics": [
        {},
        {},
        {},
        {},
        {},
        {},
        {},
        {},
        {},
        {},
        {},
        {},
        {},
        {},
        {},
        {},
        {},
        {},
        {},
        {},
        {},
        {},
        {},
        {
          "clicks": 1741,
          "clicksCost": 48.748
        }
      ]
    }

1) 你能不能先尝试优化内部查询。通过在索引定义中包含 where/projections/join-on-keys 中使用的第一个键空间的所有字段,使其使用覆盖索引。参见 https://developer.couchbase.com/documentation/server/4.5/indexes/covering-indexes.html。文档中的最后一个示例适用于您。类似于:

CREATE INDEX dailyCampaignUsage_type_day_clicksCost  ON Inheritx 
(_type,day, campaignId, `statistics`[*].clicksCost) WHERE _type='DailyCampaignUsage'

2) 您可以尝试内存优化索引 (MOI) 来极大地提高性能。这需要企业版。参见 https://developer.couchbase.com/documentation/server/4.5/architecture/global-secondary-indexes.html#story-h2-2

3) 外部查询仅在 'created' 上进行排序,而内部查询并未预测。如果它在第一个键空间中,则将其包含在索引中。

4) 同时在 Users.user 上使用 CASE 检查 WHERE 条件。它总是评估为真。不确定您是否需要第三次加入。

嗯, -普拉萨德