Fix Timeseries/recent endpoint speed

[rohaan-rma]

Proposed query update that changes a single Timeseries/Recent request from 30 seconds down to half a second on our SWT db export.

WITH base_ids AS (
    SELECT DISTINCT
        ( ts_code ),
        cwms_ts_id
    FROM
        av_cwms_ts_id2
    WHERE
        cwms_ts_id IN ( 'HAMM.Stage-Alt.Inst.15Minutes.0.Decodes-Raw', 'HAMM.Stage.Inst.15Minutes.0.Decodes-Raw' )
), av_tsv_limited AS (
    SELECT
        *
    FROM
        at_tsv_2023
    WHERE
        date_time BETWEEN DATE '2024-06-24' AND DATE '2024-07-22'
        AND ts_code IN (
            SELECT
                ts_code
            FROM
                base_ids
        )
    UNION ALL
    SELECT
        *
    FROM
        at_tsv_2024
    WHERE
        date_time BETWEEN DATE '2024-06-24' AND DATE '2024-07-22'
        AND ts_code IN (
            SELECT
                ts_code
            FROM
                base_ids
        )
), max_values AS (
    SELECT
        b.cwms_ts_id,
        t.ts_code,
        t.date_time,
        t.value,
        t.version_date,
        t.data_entry_date,
        t.quality_code,
        ex.earliest_entry_time       start_date,
        ex.latest_entry_time         end_date,
        MAX(t.date_time)
        OVER(PARTITION BY t.ts_code) AS max_date_time
    FROM
             av_tsv_limited t
        JOIN base_ids      b ON b.ts_code = t.ts_code
        JOIN at_ts_extents ex ON ex.ts_code = t.ts_code
                                 AND ex.version_time = t.version_date
)
SELECT
    max_values.cwms_ts_id,
    max_values.date_time,
    max_values.version_date,
    max_values.data_entry_date,
    max_values.quality_code,
    max_values.start_date,
    max_values.end_date,
    cwms_util.get_default_units(
        cwms_ts.get_base_parameter_id(max_values.ts_code),
        'EN'
    )                    AS def_units,
    max_values.date_time AS max_date_time,
    cwms_util.convert_units(max_values.value,
                            cwms_util.get_default_units(
                      cwms_ts.get_base_parameter_id(max_values.ts_code),
                      'SI'
                  ),
                            cwms_util.get_default_units(
                      cwms_ts.get_base_parameter_id(max_values.ts_code),
                      'EN'
                  ))                   AS value_at_max_date
FROM
    max_values
WHERE
    max_values.date_time = max_values.max_date_time;

[MikeNeilson]

Looks reasonable. Definitely need to chew on it a bit. Fairly complex query, though I doubt unnecessarily so.

[MikeNeilson]

These should be AT_TSV_PREV_YEAR and AT_TSV_CURRENT_YEAR and calculated at usage. Otherwise we'll have to remember to update them constantly.

[rohaan-rma]

Yup you're correct. I just had those as place holders for now.