{
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          {
            "expanded_query": "/* select#1 */ select count(distinct `tt`.`a`) AS `count(distinct a)` from `tt`"
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          {
            "considered_execution_plans": [
              {
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                    {
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                  ]
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                "condition_filtering_pct": 100,
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            ]
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          {
            "attaching_conditions_to_tables": {
              "original_condition": null,
              "attached_conditions_computation": [
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              "attached_conditions_summary": [
                {
                  "table": "`tt`",
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              ]
            }
          },
          {
            "refine_plan": [
              {
                "table": "`tt`"
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    },
    {
      "join_execution": {
        "select#": 1,
        "steps": [
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      }
    }
  ]
}