Apache Pinot

Hi Team,

can some one help me on some configuration in UPSERT.
`APPEND`  and `UNION`  strategies. how to configure it?

<@U024ET8HGUQ> can you please help me on this?

These are partial upsert strategies. If for a given column you choose `APPEND`, the value from the new record being ingested will be appended to the last column's value. `UNION` will merge the incoming value with existing and only retain the unique set amongst them.
Both strategies are only applicable for multi-value columns

i am trying to configure it but getting a error

``` "upsertConfig": {
        "mode": "PARTIAL",
        "defaultPartialUpsertStrategy": "OVERWRITE",
        "partialUpsertStrategies":{
            "uuid":"APPEND"
        }
    },```

```{
    "code": 400,
    "error": "APPEND merger cannot be applied to single-value column: uuid"
}'```

Like I said, APPEND strategy is only applicable to multivalue columns. Your uuid field is a single value string column in the schema correct?

Could you describe what is it that you're trying to achieve?

we are not trying to achieve here but we are tying to explore features so we are just implementing it but getting above error

```{
  "schemaName": "tab",
  "dimensionFieldSpecs": [
    {
      "name": "key",
      "dataType": "INT"
    },
    {
      "name": "uuid",
      "dataType": "STRING"
    }
  ],
  "metricFieldSpecs": [
    {
      "name": "count",
      "dataType": "INT"
    }
  ],
  "dateTimeFieldSpecs": [
    {
      "name": "ts",
      "dataType": "TIMESTAMP",
      "format": "1:MILLISECONDS:EPOCH",
      "granularity": "1:MILLISECONDS"
    }
  ],
  "primaryKeyColumns": [
    "key"
  ]
}```


I meant to say while ingesting data, if a new row with the same PK is seen, what do you wish the uuid should be updated to? new value / old value / some combination of new and old value?

we want to create new column as fullname from firstname and last name

don't think I fully understand it.. Is firstName and lastName columns in your schema too?

its not there in schema, i just want to know how to configure append and union in tablE?

To generate fullName you'll need an ingestionConfig...
```"ingestionConfig": {
    "transformConfigs": [{
      "columnName": "fullName",
      "transformFunction": "Groovy({firstName+' '+lastName}, firstName, lastName)"
    }]
}```
<https://docs.pinot.apache.org/developers/advanced/ingestion-level-transformations>