fix: add Dremio-specific edr_dateadd and improve edr_cast_as_timestamp

macros/utils/cross_db_utils/dateadd.sql

@@ -1,7 +1,86 @@
 {% macro edr_dateadd(datepart, interval, from_date_or_timestamp) %}
+    {{
+        return(
+            adapter.dispatch("edr_dateadd", "elementary")(
+                datepart, interval, from_date_or_timestamp
+            )
+        )
+    }}
+{% endmacro %}
+
+{% macro default__edr_dateadd(datepart, interval, from_date_or_timestamp) %}
     {% set macro = dbt.dateadd or dbt_utils.dateadd %}
     {% if not macro %}
         {{ exceptions.raise_compiler_error("Did not find a `dateadd` macro.") }}
     {% endif %}
     {{ return(macro(datepart, interval, from_date_or_timestamp)) }}
 {% endmacro %}
+
+{#
+  Override dbt-dremio's dateadd macro which has two bugs:
+  1. Calls interval.replace() on the interval parameter, failing when interval is an integer
+  2. Wraps result in "select TIMESTAMPADD(...)" which creates a scalar subquery when
+     embedded in larger SQL expressions, causing $SCALAR_QUERY errors in Dremio
+
+  This override outputs just TIMESTAMPADD(...) as an expression (no "select" prefix).
+#}
+{% macro dremio__edr_dateadd(datepart, interval, from_date_or_timestamp) %}
+    {% set datepart = datepart | lower %}
+    {% if datepart == "year" %}
+        timestampadd(
+            year,
+            cast({{ interval }} as int),
+            cast({{ from_date_or_timestamp }} as timestamp)
+        )
+    {% elif datepart == "quarter" %}
+        timestampadd(
+            quarter,
+            cast({{ interval }} as int),
+            cast({{ from_date_or_timestamp }} as timestamp)
+        )
+    {% elif datepart == "month" %}
+        timestampadd(
+            month,
+            cast({{ interval }} as int),
+            cast({{ from_date_or_timestamp }} as timestamp)
+        )
+    {% elif datepart == "week" %}
+        timestampadd(
+            week,
+            cast({{ interval }} as int),
+            cast({{ from_date_or_timestamp }} as timestamp)
+        )
+    {% elif datepart == "hour" %}
+        timestampadd(
+            hour,
+            cast({{ interval }} as int),
+            cast({{ from_date_or_timestamp }} as timestamp)
+        )
+    {% elif datepart == "minute" %}
+        timestampadd(
+            minute,
+            cast({{ interval }} as int),
+            cast({{ from_date_or_timestamp }} as timestamp)
+        )
+    {% elif datepart == "second" %}
+        timestampadd(
+            second,
+            cast({{ interval }} as int),
+            cast({{ from_date_or_timestamp }} as timestamp)
+        )
+    {% elif datepart == "day" %}
+        timestampadd(
+            day,
+            cast({{ interval }} as int),
+            cast({{ from_date_or_timestamp }} as timestamp)
+        )
+    {% else %}
+        {{
+            exceptions.raise_compiler_error(
+                "dremio__edr_dateadd: unrecognized datepart '"
+                ~ datepart
+                ~ "'. Supported: year, quarter, month, week, day, hour, minute, second."
+            )
+        }}
+    {% endif %}
+{% endmacro %}

macros/utils/data_types/cast_column.sql

@@ -42,10 +42,29 @@
 {%- endmacro -%}
 -- fmt: on
 
+{#
+  Dremio's Gandiva (Arrow execution engine) cannot parse ISO 8601 timestamps:
+  1. The 'T' date-time separator is not recognized (needs space)
+  2. Sub-millisecond precision causes overflow
+  3. The 'Z' UTC timezone suffix is rejected as an unknown zone
+  This normalizes '2024-01-15T12:30:00.123456Z' to '2024-01-15 12:30:00.123'.
+  Three separate REGEXP_REPLACE calls are needed because each has a different
+  replacement pattern (space, truncation, removal) that can't be combined into one.
+#}
 {%- macro dremio__edr_cast_as_timestamp(timestamp_field) -%}
     cast(
         regexp_replace(
-            {{ timestamp_field }}, '(\.\d{3})\d+', '$1'
+            regexp_replace(
+                regexp_replace(
+                    cast({{ timestamp_field }} as {{ elementary.edr_type_string() }}),
+                    '(\d)T(\d)',
+                    '$1 $2'
+                ),
+                '(\.\d{3})\d+',
+                '$1'
+            ),
+            'Z$',
+            ''
         ) as {{ elementary.edr_type_timestamp() }}
     )
 {%- endmacro -%}