diff --git a/README.md b/README.md
index 0cd16ee..3607f51 100644
--- a/README.md
+++ b/README.md
@@ -82,11 +82,15 @@ vars:
 
 ### Database support
 
+Core:
 * Redshift
 * Snowflake
 * BigQuery
 * Postgres
 
+Plugins:
+* Spark (via [`spark_utils`](https://github.com/fishtown-analytics/spark-utils))
+
 ### Contributions ###
 
 Additional contributions to this package are very welcome! Please create issues
diff --git a/dbt_project.yml b/dbt_project.yml
index a47493c..bf4839b 100644
--- a/dbt_project.yml
+++ b/dbt_project.yml
@@ -1,7 +1,7 @@
 #settings specifically for this models directory
 #config other dbt settings within ~/.dbt/profiles.yml
 name: 'snowplow'
-version: '0.10.0'
+version: '0.12.0'
 config-version: 2
 
 source-paths: ["models"]
@@ -12,7 +12,7 @@ analysis-paths: ["analysis"]
 data-paths: ["data"]
 macro-paths: ["macros"]
 
-require-dbt-version: ">=0.17.0"
+require-dbt-version: ">=0.18.0"
 
 vars:
   #'snowplow:events': TABLE OR {{ REF() }}
diff --git a/macros/adapters/_get_snowplow_namespaces.sql b/macros/adapters/_get_snowplow_namespaces.sql
new file mode 100644
index 0000000..ca7486d
--- /dev/null
+++ b/macros/adapters/_get_snowplow_namespaces.sql
@@ -0,0 +1,4 @@
+{% macro _get_snowplow_namespaces() %}
+  {% set override_namespaces = var('snowplow_dispatch_list', []) %}
+  {% do return(override_namespaces + ['snowplow']) %}
+{% endmacro %}
diff --git a/macros/adapters/convert_timezone.sql b/macros/adapters/convert_timezone.sql
index 051eb5d..3d9da85 100644
--- a/macros/adapters/convert_timezone.sql
+++ b/macros/adapters/convert_timezone.sql
@@ -1,5 +1,6 @@
 {%- macro convert_timezone(in_tz, out_tz, in_timestamp) -%}
-    {{ adapter_macro('convert_timezone', in_tz, out_tz, in_timestamp) }}
+    {{ adapter.dispatch('convert_timezone', packages = snowplow._get_snowplow_namespaces())
+        (in_tz, out_tz, in_timestamp) }}
 {%- endmacro -%}
 
 {% macro default__convert_timezone(in_tz, out_tz, in_timestamp) %}
diff --git a/macros/adapters/get_start_ts.sql b/macros/adapters/get_start_ts.sql
index b510d7d..887b2cf 100644
--- a/macros/adapters/get_start_ts.sql
+++ b/macros/adapters/get_start_ts.sql
@@ -29,7 +29,7 @@
 
 
 {%- macro get_start_ts(relation, field = 'collector_tstamp') -%}
-    {{ adapter_macro('get_start_ts', relation, field) }}
+    {{ adapter.dispatch('get_start_ts', packages = snowplow._get_snowplow_namespaces())(relation, field) }}
 {%- endmacro -%}
 
 
diff --git a/macros/adapters/is_adapter.sql b/macros/adapters/is_adapter.sql
index 35ae903..ec7e100 100644
--- a/macros/adapters/is_adapter.sql
+++ b/macros/adapters/is_adapter.sql
@@ -1,35 +1,19 @@
-{% macro set_default_adapters() %}
-
-    {% set default_adapters = ['postgres', 'redshift', 'snowflake'] %}
+{% macro is_adapter(adapter_type='default') %}
     
-    {% do return(default_adapters) %}
+    {{ return(adapter.dispatch('is_adapter', packages = snowplow._get_snowplow_namespaces()) (adapter_type)) }}
 
 {% endmacro %}
 
-{% macro is_adapter(adapter='default') %}
+{% macro default__is_adapter(adapter_type='default') %}
 
-{#-
-    This logic means that if you add your own macro named `set_default_adapters`
-    to your project, that will be used, giving you the flexibility of overriding
-    which target types use the default implementation of Snowplow models.
--#}
+    {% set result = (adapter_type == 'default') %}
+    {{return(result)}}
 
-    {% if context.get(ref.config.project_name, {}).get('set_default_adapters')  %}
-        {% set default_adapters=context[ref.config.project_name].set_default_adapters() %}
-    {% else %}
-        {% set default_adapters=snowplow.set_default_adapters() %}
-    {% endif %}
+{% endmacro %}
 
-    {% if adapter == 'default' %}
-        {% set adapters = default_adapters %}
-    {% elif adapter is string %}
-        {% set adapters = [adapter] %}
-    {% else %}
-        {% set adapters = adapter %}
-    {% endif %}
-    
-    {% set result = (target.type in adapters) %}
-    
-    {{return(result)}}
+{% macro bigquery__is_adapter(adapter_type='default') %}
 
+    {% set result = (adapter_type == 'bigquery') %}
+    {{return(result)}}
+    
 {% endmacro %}
diff --git a/macros/adapters/timestamp_ntz.sql b/macros/adapters/timestamp_ntz.sql
index c5d264f..381ea63 100644
--- a/macros/adapters/timestamp_ntz.sql
+++ b/macros/adapters/timestamp_ntz.sql
@@ -1,5 +1,5 @@
 {% macro timestamp_ntz(field) %}
-  {{ adapter_macro('snowplow.timestamp_ntz', field) }}
+  {{ adapter.dispatch('timestamp_ntz', packages = snowplow._get_snowplow_namespaces()) (field) }}
 {% endmacro %}
 
 {% macro default__timestamp_ntz(field) %}
diff --git a/macros/snowplow_macros.yml b/macros/snowplow_macros.yml
index b94c3f0..2526f10 100644
--- a/macros/snowplow_macros.yml
+++ b/macros/snowplow_macros.yml
@@ -74,21 +74,15 @@ macros:
           Differs depending on the adapter:    
             - name of the timestamp/date column to get max value, with default value of `collector_tstamp`    
             - not needed on Bigquery, which always uses the model's configured partition field
-
-  - name: set_default_adapters
-    description: >
-      Which adapters should use the `default` implementation of Snowplow package 
-      models? By default, includes Postgres, Redshift, and Snowflake.
-      Override by creating a macro named `set_default_adapters` in your
-      own project.
       
   - name: is_adapter
     description: >
-      Determine whether a model should be enabled depending on the `target.type` 
-      of the current run. Returns `true` or `false`. All `default` models run on Postgres, Redshift,
-      and Snowflake. All `bigquery` models run on BigQuery.
+      Determine whether a model should be enabled depending on adapter being run.
+      Returns `true` or `false`. In practice, this macro runs the 'default' implementation
+      of Snowplow models unless an adapter-level override points to a different
+      model set (e.g. BigQuery).
     arguments:
-      - name: adapter
+      - name: adapter_type
         type: string
         description: "*default* or *bigquery*"
       
diff --git a/models/page_views/default/snowplow_page_views.sql b/models/page_views/default/snowplow_page_views.sql
index c36cbd9..f0e47a2 100644
--- a/models/page_views/default/snowplow_page_views.sql
+++ b/models/page_views/default/snowplow_page_views.sql
@@ -220,17 +220,17 @@ prep as (
             d.os_patch as os_build_version,
             d.device_family as device,
         {% else %}
-            null::text as browser,
+            cast(null as {{ dbt_utils.type_string() }}) as browser,
             a.br_family as browser_name,
             a.br_name as browser_major_version,
             a.br_version as browser_minor_version,
-            null::text as browser_build_version,
+            cast(null as {{ dbt_utils.type_string() }}) as browser_build_version,
             a.os_family as os,
             a.os_name as os_name,
-            null::text as os_major_version,
-            null::text as os_minor_version,
-            null::text as os_build_version,
-            null::text as device,
+            cast(null as {{ dbt_utils.type_string() }}) as os_major_version,
+            cast(null as {{ dbt_utils.type_string() }}) as os_minor_version,
+            cast(null as {{ dbt_utils.type_string() }}) as os_build_version,
+            cast(null as {{ dbt_utils.type_string() }}) as device,
         {% endif %}
 
         c.br_viewwidth as browser_window_width,
@@ -256,18 +256,18 @@ prep as (
             e.onload_time_in_ms,
             e.total_time_in_ms,
         {% else %}
-            null::bigint as redirect_time_in_ms,
-            null::bigint as unload_time_in_ms,
-            null::bigint as app_cache_time_in_ms,
-            null::bigint as dns_time_in_ms,
-            null::bigint as tcp_time_in_ms,
-            null::bigint as request_time_in_ms,
-            null::bigint as response_time_in_ms,
-            null::bigint as processing_time_in_ms,
-            null::bigint as dom_loading_to_interactive_time_in_ms,
-            null::bigint as dom_interactive_to_complete_time_in_ms,
-            null::bigint as onload_time_in_ms,
-            null::bigint as total_time_in_ms,
+            cast(null as bigint) as redirect_time_in_ms,
+            cast(null as bigint) as unload_time_in_ms,
+            cast(null as bigint) as app_cache_time_in_ms,
+            cast(null as bigint) as dns_time_in_ms,
+            cast(null as bigint) as tcp_time_in_ms,
+            cast(null as bigint) as request_time_in_ms,
+            cast(null as bigint) as response_time_in_ms,
+            cast(null as bigint) as processing_time_in_ms,
+            cast(null as bigint) as dom_loading_to_interactive_time_in_ms,
+            cast(null as bigint) as dom_interactive_to_complete_time_in_ms,
+            cast(null as bigint) as onload_time_in_ms,
+            cast(null as bigint) as total_time_in_ms,
         {% endif %}
 
         -- device
diff --git a/models/page_views/default/snowplow_web_events_scroll_depth.sql b/models/page_views/default/snowplow_web_events_scroll_depth.sql
index 75dd825..7a57c50 100644
--- a/models/page_views/default/snowplow_web_events_scroll_depth.sql
+++ b/models/page_views/default/snowplow_web_events_scroll_depth.sql
@@ -78,10 +78,10 @@ relative as (
         vmin,
         vmax,
 
-        round(100*(greatest(hmin, 0)/doc_width::float)) as relative_hmin,
-        round(100*(least(hmax + br_viewwidth, doc_width)/doc_width::float)) as relative_hmax,
-        round(100*(greatest(vmin, 0)/doc_height::float)) as relative_vmin,
-        round(100*(least(vmax + br_viewheight, doc_height)/doc_height::float)) as relative_vmax
+        round(100*(greatest(hmin, 0)/cast(doc_width as float))) as relative_hmin,
+        round(100*(least(hmax + br_viewwidth, doc_width)/cast(doc_width as float))) as relative_hmax,
+        round(100*(greatest(vmin, 0)/cast(doc_height as float))) as relative_vmin,
+        round(100*(least(vmax + br_viewheight, doc_height)/cast(doc_height as float))) as relative_vmax
 
     from prep
 
diff --git a/packages.yml b/packages.yml
index ecb7073..2246ac8 100644
--- a/packages.yml
+++ b/packages.yml
@@ -1,3 +1,3 @@
 packages:
   - package: fishtown-analytics/dbt_utils
-    version: [">=0.4.0", "<0.6.0"]
+    version: [">=0.6.0", "<0.7.0"]