Using Pre-Aggregation with calculated measures of types: string/time

[omrish10]

Problem

I have some calculated measures that either aggregate string values to an array using array_agg or finding a max timestamp using `MAX(time_column).

When trying to use pre-aggregations on those measures, I noticed that the pre-agg table is created correctly, however, the select clause is using the SUM function on those fields (string/timestamp).

Below are the Cube Schema, and both queries Im getting from cubejs,cubestore.

Was wandering if thats even possible, Thank you!

Related Cube.js schema

cube(`Cube`, {
  sql: `SELECT * FROM dummy`,
  preAggregations: {
    main: {
      dimensions: [CUBE.name],
      measures: [CUBE.idsWithThatName]
    }
  },
  measures: {
    idsWithThatName: {
      type: `string`,
      sql: `array_agg(${CUBE.id})`
    }
  },
  dimensions: {
     name: {
       sql: `name`,
       type: `string`
     },
    id: {
      sql: `id`,
      type: `string`
    }
  }
})

Related Cube.js generated SQL Regular query, without pre-aggregation: SELECT name, array_agg(id) FROM dummy group by 1; Pre-Aggregation Query:
SELECT `cube__name` `cube__name`, sum(`cube__ids_with_that_name`) `cube__ids_with_that_name` FROM local_cubejs_pre_agg.pre_agg_table_with_uniq_id AS `pre_agg_table` GROUP BY 1 ORDER BY 2 DESC LIMIT 20000

[paveltiunov]

@omrish10 I can confirm that it's currently not supported, but we're open to contributions here. Replacing aggregation to MAX should do the job.

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