Redshift: Use QUALIFY statement instead of prep-CTEs to enhance performance

macros/tables/redshift/eff_sat_v0.sql

@@ -49,23 +49,13 @@ source_data AS (
     In all incremental cases, the current status for each hashkey is selected from the existing Effectivity Satellite.
 #}
 {%- if is_incremental() %}
-current_status_prep AS (
-
-    SELECT
-        {{ tracked_hashkey }},
-        {{ is_active_alias}},
-        ROW_NUMBER() OVER (PARTITION BY {{ tracked_hashkey }} ORDER BY {{ src_ldts }} DESC) as rn
-    FROM {{ this }}
-
-),
-
 current_status AS (
 
     SELECT
         {{ tracked_hashkey }},
         {{ is_active_alias }}
-    FROM current_status_prep
-    WHERE rn = 1 
+    FROM {{ this }} redshift_requires_an_alias_if_the_qualify_is_directly_after_the_from
+    QUALIFY ROW_NUMBER() OVER(PARTITION BY {{ tracked_hashkey }} ORDER BY {{ src_ldts }} DESC) = 1  
 
 ),
 {% endif %}
@@ -136,32 +126,19 @@ current_status AS (
 
     {#
         The rows are deduplicated on the is_active_alias, to only include status changes. 
-        Additionally, a ROW_NUMBER() is calculated in incremental runs, to use it in the next step for comparison against the current status.
     #}
-    deduplicated_incoming_prep AS (
-
-        SELECT
-            is_active.{{ tracked_hashkey }},
-            is_active.{{ src_ldts }},
-            is_active.{{ is_active_alias }},
-            LAG(is_active.{{ is_active_alias }}) OVER (PARTITION BY {{ tracked_hashkey }} ORDER BY {{ src_ldts }}) as lag_is_active
-
-        FROM is_active
-
-    ),
-
     deduplicated_incoming AS (
 
         SELECT
-            deduplicated_incoming_prep.{{ tracked_hashkey }},
-            deduplicated_incoming_prep.{{ src_ldts }},
-            deduplicated_incoming_prep.{{ is_active_alias }}
-
-        FROM
-            deduplicated_incoming_prep
-        WHERE
-            deduplicated_incoming_prep.{{ is_active_alias }} != deduplicated_incoming_prep.lag_is_active
-            OR deduplicated_incoming_prep.lag_is_active IS NULL
+            ia.{{ tracked_hashkey }},
+            ia.{{ src_ldts }},
+            ia.{{ is_active_alias }}
+        FROM is_active ia
+        QUALIFY 
+            CASE 
+                WHEN ia.{{ is_active_alias }} = LAG(ia.{{ is_active_alias }}) OVER (PARTITION BY {{ tracked_hashkey }} ORDER BY {{ src_ldts }}) THEN FALSE
+                ELSE TRUE
+            END
 
     ),
 

macros/tables/redshift/hub.sql

@@ -207,21 +207,17 @@ source_new_union AS (
 
 {%- endif %}
 
-earliest_hk_over_all_sources_prep AS (
-    SELECT
-        lcte.*,
-        ROW_NUMBER() OVER (PARTITION BY {{ hashkey }} ORDER BY {{ src_ldts
-        }}) as rn
-    FROM {{ ns.last_cte }} AS lcte),
-
 earliest_hk_over_all_sources AS (
 
     {#- Deduplicate the unionized records again to only insert the earliest one. #}
     SELECT
         lcte.*
-    FROM earliest_hk_over_all_sources_prep AS lcte
-        WHERE rn = 1
-    {%- set ns.last_cte = 'earliest_hk_over_all_sources' -%}),
+    FROM {{ ns.last_cte }} AS lcte
+    QUALIFY ROW_NUMBER() OVER (PARTITION BY {{ hashkey }} ORDER BY {{ src_ldts }}) = 1
+
+    {%- set ns.last_cte = 'earliest_hk_over_all_sources' -%}
+
+),
 
 records_to_insert AS (
     {#- Select everything from the previous CTE, if incremental filter for hashkeys that are not already in the hub. #}

macros/tables/redshift/link.sql

@@ -210,21 +210,17 @@ source_new_union AS (
 
 {%- endif %}
 
-earliest_hk_over_all_sources_prep AS (
-    SELECT
-        lcte.*,
-        ROW_NUMBER() OVER (PARTITION BY {{ link_hashkey }} ORDER BY {{ src_ldts
-        }}) as rn
-    FROM {{ ns.last_cte }} AS lcte),
-
 earliest_hk_over_all_sources AS (
 
     {#- Deduplicate the unionized records again to only insert the earliest one. #}
     SELECT
         lcte.*
-    FROM earliest_hk_over_all_sources_prep AS lcte
-        WHERE rn = 1
-    {%- set ns.last_cte = 'earliest_hk_over_all_sources' -%}),
+    FROM {{ ns.last_cte }} AS lcte
+    QUALIFY ROW_NUMBER() OVER (PARTITION BY {{ link_hashkey }} ORDER BY {{ src_ldts }}) = 1
+
+    {%- set ns.last_cte = 'earliest_hk_over_all_sources' -%}
+
+),
 
 records_to_insert AS (
     {# Select everything from the previous CTE, if incremental filter for hashkeys that are not already in the link. #}

macros/tables/redshift/ma_sat_v0.sql

@@ -41,44 +41,29 @@ source_data AS (
 
 {# Get the latest record for each parent hashkey in existing sat, if incremental. #}
 {%- if is_incremental() %}
-latest_entries_in_sat_prep AS (
-
-    SELECT
-        {{ parent_hashkey }},
-        {{ ns.hdiff_alias }},
-        ROW_NUMBER() OVER(PARTITION BY {{ parent_hashkey|lower }} ORDER BY {{ src_ldts }} DESC) as rn
-    FROM 
-        {{ this }}
-),
-
 latest_entries_in_sat AS (
 
     SELECT
         {{ parent_hashkey }},
         {{ ns.hdiff_alias }}
     FROM 
-        latest_entries_in_sat_prep
-    WHERE rn = 1  
+        {{ this }} redshift_requires_an_alias_if_the_qualify_is_directly_after_the_from
+    QUALIFY ROW_NUMBER() OVER(PARTITION BY {{ parent_hashkey }} ORDER BY {{ src_ldts }} DESC) = 1  
 ),
 {%- endif %}
 
 {# Get a list of all distinct hashdiffs that exist for each parent_hashkey. #}
- lag_source_data AS (
-  SELECT 
-    {{ parent_hashkey }},
-    {{ src_ldts }},
-    {{ ns.hdiff_alias }},
-    LAG({{ ns.hdiff_alias }}) OVER (PARTITION BY {{ parent_hashkey }} ORDER BY {{ src_ldts }}) as prev_ns_hdiff_alias
-  FROM source_data
-),
-
 deduped_row_hashdiff AS (
+
   SELECT 
     {{ parent_hashkey }},
     {{ src_ldts }},
     {{ ns.hdiff_alias }}
-  FROM lag_source_data
-  WHERE {{ ns.hdiff_alias }} != prev_ns_hdiff_alias OR prev_ns_hdiff_alias IS NULL
+  FROM source_data redshift_requires_an_alias_if_the_qualify_is_directly_after_the_from
+  QUALIFY CASE
+            WHEN {{ ns.hdiff_alias }} = LAG({{ ns.hdiff_alias }}) OVER (PARTITION BY {{ parent_hashkey }} ORDER BY {{ src_ldts }}) THEN FALSE
+            ELSE TRUE
+          END
 ),
 
 {# Dedupe the source data regarding non-delta groups. #}

macros/tables/redshift/nh_link.sql

@@ -226,21 +226,17 @@ source_new_union AS (
 
 {%- if not source_is_single_batch %}
 
-earliest_hk_over_all_sources_prep AS (
-    SELECT
-        lcte.*,
-        ROW_NUMBER() OVER (PARTITION BY {{ link_hashkey }} ORDER BY {{ src_ldts
-        }}) as rn
-    FROM {{ ns.last_cte }} AS lcte),
-
 earliest_hk_over_all_sources AS (
 
-    {#- Deduplicate the unionized records again to only insert the earliest one. #}
+{#- Deduplicate the unionized records again to only insert the earliest one. #}
     SELECT
         lcte.*
-    FROM earliest_hk_over_all_sources_prep AS lcte
-        WHERE rn = 1
-    {%- set ns.last_cte = 'earliest_hk_over_all_sources' -%}),
+    FROM {{ ns.last_cte }} AS lcte
+    QUALIFY ROW_NUMBER() OVER (PARTITION BY {{ link_hashkey }} ORDER BY {{ src_ldts }}) = 1
+
+    {%- set ns.last_cte = 'earliest_hk_over_all_sources' -%}
+
+),
 
 {%- endif %}
 

macros/tables/redshift/ref_sat_v0.sql

@@ -46,18 +46,6 @@ source_data AS (
 
 {# Get the latest record for each parent ref key combination in existing sat, if incremental. #}
 {%- if is_incremental() %}
-latest_entries_in_sat_prep AS (
-
-    SELECT
-        {% for ref_key in parent_ref_keys %}
-        {{ref_key}},
-        {% endfor %}
-        {{ ns.hdiff_alias }},
-        ROW_NUMBER() OVER(PARTITION BY {%- for ref_key in parent_ref_keys %} {{ref_key|lower}} {%- if not loop.last %}, {% endif %}{% endfor %} ORDER BY {{ src_ldts }} DESC) as rn
-    FROM 
-        {{ this }}
-),
-
 latest_entries_in_sat AS (
 
     SELECT
@@ -66,16 +54,16 @@ latest_entries_in_sat AS (
         {% endfor %}
         {{ ns.hdiff_alias }}
     FROM 
-        latest_entries_in_sat_prep
-    WHERE rn = 1  
+        {{ this }} redshift_requires_an_alias_if_the_qualify_is_directly_after_the_from
+    QUALIFY ROW_NUMBER() OVER(PARTITION BY {%- for ref_key in parent_ref_keys %} {{ref_key}} {%- if not loop.last %}, {% endif %}{% endfor %} ORDER BY {{ src_ldts }} DESC) = 1  
 ),
 {%- endif %}
 
 {#
     Deduplicate source by comparing each hashdiff to the hashdiff of the previous record, for each parent ref key combination.
     Additionally adding a row number based on that order, if incremental.
 #}
-deduplicated_numbered_source_prep AS (
+deduplicated_numbered_source AS (
 
     SELECT
     {% for ref_key in parent_ref_keys %}
@@ -86,24 +74,12 @@ deduplicated_numbered_source_prep AS (
     {% if is_incremental() -%}
     , ROW_NUMBER() OVER(PARTITION BY {%- for ref_key in parent_ref_keys %} {{ref_key}} {%- if not loop.last %}, {% endif %}{% endfor %} ORDER BY {{ src_ldts }}) as rn
     {%- endif %}
-    , LAG({{ ns.hdiff_alias }}) OVER(PARTITION BY {%- for ref_key in parent_ref_keys %} {{ref_key|lower}} {%- if not loop.last %}, {% endif %}{% endfor %} ORDER BY {{ src_ldts }}) as prev_hashdiff
-    FROM source_data
-),
-
-deduplicated_numbered_source AS (
-
-    SELECT
-    {% for ref_key in parent_ref_keys %}
-    {{ref_key}},
-    {% endfor %}
-    {{ ns.hdiff_alias }},
-    {{ datavault4dbt.print_list(source_cols) }}
-    FROM deduplicated_numbered_source_prep
-    WHERE 1=1
-        AND {{ ns.hdiff_alias }} <> prev_hashdiff OR prev_hashdiff IS NULL
-        {% if is_incremental() -%}
-        AND rn = 1
-        {%- endif %}
+    FROM source_data redshift_requires_an_alias_if_the_qualify_is_directly_after_the_from
+    QUALIFY
+        CASE
+            WHEN {{ ns.hdiff_alias }} = LAG({{ ns.hdiff_alias }}) OVER(PARTITION BY {%- for ref_key in parent_ref_keys %} {{ref_key}} {%- if not loop.last %}, {% endif %}{% endfor %} ORDER BY {{ src_ldts }}) THEN FALSE
+            ELSE TRUE
+        END
 ),
 
 {#
@@ -128,7 +104,7 @@ records_to_insert AS (
             AND {{ datavault4dbt.multikey(ref_key, prefix=['latest_entries_in_sat', 'deduplicated_numbered_source'], condition='=') }}
             {% endfor %}
             AND {{ datavault4dbt.multikey(ns.hdiff_alias, prefix=['latest_entries_in_sat', 'deduplicated_numbered_source'], condition='=') }}
-            )
+            AND deduplicated_numbered_source.rn = 1)
     {%- endif %}
 
     )

macros/tables/redshift/sat_v0.sql

@@ -42,32 +42,22 @@ source_data AS (
 
 {# Get the latest record for each parent hashkey in existing sat, if incremental. #}
 {%- if is_incremental() %}
-latest_entries_in_sat_prep AS (
-
-    SELECT
-        {{ parent_hashkey }},
-        {{ ns.hdiff_alias }},
-        ROW_NUMBER() OVER(PARTITION BY {{ parent_hashkey|lower }} ORDER BY {{ src_ldts }} DESC) as rn
-    FROM 
-        {{ this }}
-),
-
 latest_entries_in_sat AS (
 
     SELECT
         {{ parent_hashkey }},
         {{ ns.hdiff_alias }}
     FROM 
-        latest_entries_in_sat_prep
-    WHERE rn = 1  
+        {{ this }} redshift_requires_an_alias_if_the_qualify_is_directly_after_the_from
+    QUALIFY ROW_NUMBER() OVER(PARTITION BY {{ parent_hashkey }} ORDER BY {{ src_ldts }} DESC) = 1  
 ),
 {%- endif %}
 
 {#
     Deduplicate source by comparing each hashdiff to the hashdiff of the previous record, for each hashkey.
     Additionally adding a row number based on that order, if incremental.
 #}
-deduplicated_numbered_source_prep AS (
+deduplicated_numbered_source AS (
 
     SELECT
     {{ parent_hashkey }},
@@ -76,23 +66,12 @@ deduplicated_numbered_source_prep AS (
     {% if is_incremental() -%}
     , ROW_NUMBER() OVER(PARTITION BY {{ parent_hashkey }} ORDER BY {{ src_ldts }}) as rn
     {%- endif %}
-    , LAG({{ ns.hdiff_alias }}) OVER(PARTITION BY {{ parent_hashkey|lower }} ORDER BY {{ src_ldts }}) as prev_hashdiff
-    FROM source_data
-
-),
-
-deduplicated_numbered_source AS (
-
-    SELECT
-    {{ parent_hashkey }},
-    {{ ns.hdiff_alias }},
-    {{ datavault4dbt.print_list(source_cols) }}
-    FROM deduplicated_numbered_source_prep
-    WHERE 1=1
-        AND {{ ns.hdiff_alias }} <> prev_hashdiff OR prev_hashdiff IS NULL
-        {% if is_incremental() -%}
-        AND rn = 1
-        {%- endif %}
+    FROM source_data redshift_requires_an_alias_if_the_qualify_is_directly_after_the_from
+    QUALIFY
+        CASE
+            WHEN {{ ns.hdiff_alias }} = LAG({{ ns.hdiff_alias }}) OVER(PARTITION BY {{ parent_hashkey }} ORDER BY {{ src_ldts }}) THEN FALSE
+            ELSE TRUE
+        END
 ),
 
 {#
@@ -111,7 +90,8 @@ records_to_insert AS (
         SELECT 1
         FROM latest_entries_in_sat
         WHERE {{ datavault4dbt.multikey(parent_hashkey, prefix=['latest_entries_in_sat', 'deduplicated_numbered_source'], condition='=') }}
-            AND {{ datavault4dbt.multikey(ns.hdiff_alias, prefix=['latest_entries_in_sat', 'deduplicated_numbered_source'], condition='=') }})
+            AND {{ datavault4dbt.multikey(ns.hdiff_alias, prefix=['latest_entries_in_sat', 'deduplicated_numbered_source'], condition='=') }}
+            AND deduplicated_numbered_source.rn = 1)
     {%- endif %}
 
     )