-- Note: All variables that look like <VARIABLE_NAME> need to be changed to user's preferences

-- Pipelines to migrate from non-partitioned to daily partitioned tables
-- This example illustrates partitioning only the past three days; try to modify it to partition dates between any date range!

DEFINE ({
  "connection": "<YOUR_CONNECTION>",
  "mode": "bigquery-v2",
  "pipelineRenderer": "MUSTACHE",
  "bigquery-v2": {
    "JobConfigurationQuery": {
      "allowLargeResults": false,
      "createDisposition": "CREATE_IF_NEEDED",
      "flattenResults": true,
      "maximumBillingTier": 1,
      "useLegacySql": false,
      "useQueryCache": true,
      "writeDisposition": "WRITE_TRUNCATE"
    },
    "QueryRequest": {
      "maxResults": 1000,
      "timeoutMs": 1000000,
      "useLegacySql": false,
      "useQueryCache": true
    },
    "JobConfigurationExtract": {
      "compression": "NONE",
      "destinationFormat": "CSV",
      "fieldDelimiter": ",",
      "printHeader": false
    }
  }
});


CREATE PIPELINE <YOUR_USERNAME>.migrating_to_partitioned_step_001_create_pivot AS (

  DROP TABLE {{{dataset_id}}}.{{{table_prefix}}}_partitions;

  CREATE TABLE {{{dataset_id}}}.{{{table_prefix}}}_partitions AS (
      SELECT
        {{#date_list}}
        ARRAY_CONCAT_AGG(CASE WHEN d = 'day{{{yyyymmdd}}}' THEN r END) AS day_{{{yyyymmdd}}},
        {{/date_list}}
        line
      FROM (
        SELECT d, r, ROW_NUMBER() OVER(PARTITION BY d) AS line
        FROM (
          SELECT
            stn, CONCAT('day', year, mo, da) AS d, ARRAY_AGG(t) AS r
          FROM `bigquery-public-data.noaa_gsod.gsod2017` AS t
          GROUP BY stn, d
        )
      )
      GROUP BY line
  )
  ;

);


RUN PIPELINE <YOUR_USERNAME>.migrating_to_partitioned_step_001_create_pivot (

  SELECT
    '<YOUR_DATASET_ID>' as dataset_id,
    'tmp_mtp_001' as table_prefix,
    CONCAT(
      '[',
        STRING_AGG(
          CONCAT('{"yyyymmdd":"',FORMAT_DATE('%Y%m%d',partition_date),'"}')
        ),
      ']'
    ) as date_list
  FROM (
    SELECT
      DATE_ADD(DATE(CURRENT_DATETIME()), INTERVAL -n DAY) as partition_date
    FROM (
      SELECT [1,2,3] as n
    ),
    UNNEST(n) AS n
  )

);


CREATE PIPELINE <YOUR_USERNAME>.migrating_to_partitioned_step_002_unnest AS (

  CREATE TABLE {{{dataset_id}}}.{{{table_prefix}}}_{{{day_partition_date}}} AS (
    SELECT r.*
    FROM {{{dataset_id}}}.{{{table_prefix}}}_partitions, UNNEST({{{day_partition_date}}}) as r
  );

);


RUN PIPELINE <YOUR_USERNAME>.migrating_to_partitioned_step_002_unnest (

  SELECT
    '<YOUR_USERNAME>' as dataset_id,
    'tmp_mtp_001' as table_prefix,
    CONCAT('day_',FORMAT_DATE('%Y%m%d',partition_date)) as day_partition_date
  FROM (
    SELECT
      DATE_ADD(DATE(CURRENT_DATETIME()), INTERVAL -n DAY) as partition_date
    FROM (
      SELECT [1,2,3] as n
    ),
    UNNEST(n) AS n
  )

);