Couchbase count query is so slow

SQL++
13

It looks like you don’t have index could you paste the index definition.
The Plan should look like below.

CREATE INDEX ix2 ON default(`_class`,`appId`, dp.language) WHERE IFMISSING(deleted,false) = false;
SELECT COUNT(1) AS cnt FROM default 
WHERE IFMISSING(deleted,false) = false AND
_class = "com. myexample.appconnect.device.data.model.DeviceEntity" AND 
appId = "whitelabel" AND dp.language = "tr";
{
  "plan": {
    "#operator": "Sequence",
    "~children": [
      {
        "#operator": "IndexScan3",
        "covers": [
          "cover ((`default`.`_class`))",
          "cover ((`default`.`appId`))",
          "cover (((`default`.`dp`).`language`))",
          "cover ((meta(`default`).`id`))",
          "cover (count(1))"
        ],
        "filter_covers": {
          "cover (ifmissing((`default`.`deleted`), false))": false
        },
        "index": "ix2",
        "index_group_aggs": {
          "aggregates": [
            {
              "aggregate": "COUNT",
              "expr": "1",
              "id": 4,
              "keypos": -1
            }
          ]
        },
        "index_id": "1252bfe73be75581",
        "index_projection": {
          "entry_keys": [
            4
          ]
        },
        "keyspace": "default",
        "namespace": "default",
        "spans": [
          {
            "exact": true,
            "range": [
              {
                "high": "\"com. myexample.appconnect.device.data.model.DeviceEntity\"",
                "inclusion": 3,
                "low": "\"com. myexample.appconnect.device.data.model.DeviceEntity\""
              },
              {
                "high": "\"whitelabel\"",
                "inclusion": 3,
                "low": "\"whitelabel\""
              },
              {
                "high": "\"tr\"",
                "inclusion": 3,
                "low": "\"tr\""
              }
            ]
          }
        ],
        "using": "gsi"
      },
      {
        "#operator": "Parallel",
        "~child": {
          "#operator": "Sequence",
          "~children": [
            {
              "#operator": "InitialProject",
              "result_terms": [
                {
                  "as": "cnt",
                  "expr": "cover (count(1))"
                }
              ]
            },
            {
              "#operator": "FinalProject"
            }
          ]
        }
      }
    ]
  },
  "text": "SELECT COUNT(1) AS cnt FROM default \nWHERE IFMISSING(deleted,false) = false AND\n_class = \"com. myexample.appconnect.device.data.model.DeviceEntity\" AND \nappId = \"whitelabel\" AND dp.language = \"tr\";"
}