diff --git a/integration_tests/data/expected/snowplow_sessions_expected.csv b/integration_tests/data/expected/snowplow_sessions_expected.csv
index 1afa351..db86958 100644
--- a/integration_tests/data/expected/snowplow_sessions_expected.csv
+++ b/integration_tests/data/expected/snowplow_sessions_expected.csv
@@ -1,6 +1,6 @@
 user_custom_id,inferred_user_id,user_snowplow_domain_id,user_snowplow_crossdomain_id,app_id,first_page_url,marketing_medium,marketing_source,marketing_term,marketing_campaign,marketing_content,referer_url,session_start,session_end,session_id,time_engaged_in_s,session_index
 NULL,user_id_2,domain_userid_2,network_userid_2,vandelay,vandelay.com/,social,facebook,abc,campaign_1,def,facebook.com/,2018-01-01 7:00:00,2018-01-01 7:00:02,user_2_session_1,30,1
 NULL,user_id_3,domain_userid_3,network_userid_3,vandelay,vandelay.com/,NULL,NULL,NULL,NULL,NULL,google.com/,2018-01-01 7:00:00,2018-01-01 7:00:00,user_3_session_1,0,1
-user_id_1,user_id_1,domain_userid_1,network_userid_1,vandelay,vandelay.com/,NULL,NULL,NULL,NULL,NULL,NULL,2018-01-01 7:00:00,2018-01-01 7:00:01,user_1_session_1,30,1
+user_id_1,user_id_1,domain_userid_1,network_userid_1,vandelay,vandelay.com/,NULL,NULL,NULL,NULL,NULL,NULL,2018-01-01 7:00:00,2018-01-01 7:00:05,user_1_session_1,30,1
 NULL,domain_userid_4,domain_userid_4,network_userid_4,vandelay,vandelay.com/,NULL,NULL,NULL,NULL,NULL,NULL,2018-01-01 7:00:30,2018-01-01 7:00:30,user_4_session_1,0,1
 user_id_3,user_id_3,domain_userid_3,network_userid_3,vandelay,vandelay.com/,medium,source,term,campaign,content,google.com/,2018-01-01 7:00:40,2018-01-01 7:00:40,user_3_session_2,0,2
diff --git a/macros/adapters/bigquery/identification/snowplow_id_map.sql b/macros/adapters/bigquery/identification/snowplow_id_map.sql
index 5b2f524..0e79e21 100644
--- a/macros/adapters/bigquery/identification/snowplow_id_map.sql
+++ b/macros/adapters/bigquery/identification/snowplow_id_map.sql
@@ -9,7 +9,6 @@
     config(
         materialized='incremental',
         partition_by='DATE(max_tstamp)',
-        sql_where='TRUE',
         unique_key="domain_userid"
     )
 }}
diff --git a/macros/adapters/bigquery/pageviews/snowplow_page_views.sql b/macros/adapters/bigquery/pageviews/snowplow_page_views.sql
index 653d381..93386c5 100644
--- a/macros/adapters/bigquery/pageviews/snowplow_page_views.sql
+++ b/macros/adapters/bigquery/pageviews/snowplow_page_views.sql
@@ -5,7 +5,6 @@
     config(
         materialized='incremental',
         partition_by='DATE(page_view_start)',
-        sql_where='TRUE',
         unique_key="page_view_id"
     )
 }}
diff --git a/macros/adapters/bigquery/sessions/snowplow_sessions_tmp.sql b/macros/adapters/bigquery/sessions/snowplow_sessions_tmp.sql
index 7ce635d..0f5eb21 100644
--- a/macros/adapters/bigquery/sessions/snowplow_sessions_tmp.sql
+++ b/macros/adapters/bigquery/sessions/snowplow_sessions_tmp.sql
@@ -5,7 +5,6 @@
     config(
         materialized='incremental',
         partition_by='DATE(session_start)',
-        sql_where='TRUE',
         unique_key="session_id"
     )
 }}
diff --git a/macros/adapters/default/identification/snowplow_id_map.sql b/macros/adapters/default/identification/snowplow_id_map.sql
index a0422ae..6824d13 100644
--- a/macros/adapters/default/identification/snowplow_id_map.sql
+++ b/macros/adapters/default/identification/snowplow_id_map.sql
@@ -17,7 +17,6 @@
         materialized='incremental',
         sort='domain_userid',
         dist='domain_userid',
-        sql_where='TRUE',
         unique_key='domain_userid'
     )
 }}
@@ -33,7 +32,7 @@ new_events as (
     select *
     from all_events
 
-    {% if adapter.already_exists(this.schema, this.name) and not flags.FULL_REFRESH %}
+    {% if is_incremental() %}
     where collector_tstamp > (
         select coalesce(max(max_tstamp), '0001-01-01') from {{ this }}
     )
diff --git a/macros/adapters/default/page_views/snowplow_page_views.sql b/macros/adapters/default/page_views/snowplow_page_views.sql
index 38b8601..87d2450 100644
--- a/macros/adapters/default/page_views/snowplow_page_views.sql
+++ b/macros/adapters/default/page_views/snowplow_page_views.sql
@@ -13,7 +13,6 @@
         materialized='incremental',
         sort='max_tstamp',
         dist='user_snowplow_domain_id',
-        sql_where='TRUE',
         unique_key='page_view_id'
     )
 }}
@@ -28,13 +27,12 @@
 with all_events as (
 
     select * from {{ ref('snowplow_web_events') }}
-
 ),
 
-web_events as (
+filtered_events as (
 
     select * from all_events
-    {% if adapter.already_exists(this.schema, this.name) and not flags.FULL_REFRESH %}
+    {% if is_incremental() %}
     where collector_tstamp > (
         select coalesce(max(max_tstamp), '0001-01-01') from {{ this }}
     )
@@ -42,6 +40,22 @@ web_events as (
 
 ),
 
+-- we need to grab all events for any session that has appeared
+-- in order to correctly process the session index below
+relevant_sessions as (
+
+    select distinct domain_sessionid
+    from filtered_events
+),
+
+web_events as (
+
+    select all_events.*
+    from all_events
+    join relevant_sessions using (domain_sessionid)
+
+),
+
 internal_session_mapping as (
 
     select * from {{ ref('snowplow_web_events_internal_fixed') }}
diff --git a/macros/adapters/default/page_views/snowplow_web_events.sql b/macros/adapters/default/page_views/snowplow_web_events.sql
index aec851a..8f466db 100644
--- a/macros/adapters/default/page_views/snowplow_web_events.sql
+++ b/macros/adapters/default/page_views/snowplow_web_events.sql
@@ -17,7 +17,6 @@
         materialized='incremental',
         sort='page_view_id',
         dist='page_view_id',
-        sql_where='TRUE',
         unique_key='page_view_id'
     )
 }}
@@ -32,7 +31,7 @@ with all_events as (
 events as (
 
     select * from all_events
-    {% if adapter.already_exists(this.schema, this.name) and not flags.FULL_REFRESH %}
+    {% if is_incremental() %}
     where collector_tstamp > (
         select coalesce(max(collector_tstamp), '0001-01-01') from {{ this }}
     )
diff --git a/macros/adapters/default/page_views/snowplow_web_events_scroll_depth.sql b/macros/adapters/default/page_views/snowplow_web_events_scroll_depth.sql
index 895e699..b6293e7 100644
--- a/macros/adapters/default/page_views/snowplow_web_events_scroll_depth.sql
+++ b/macros/adapters/default/page_views/snowplow_web_events_scroll_depth.sql
@@ -13,14 +13,10 @@
         materialized='incremental',
         sort='page_view_id',
         dist='page_view_id',
-        sql_where='TRUE',
         unique_key='page_view_id'
     )
 }}
 
-{# cache this because we need it below too #}
-{% set this_exists = adapter.already_exists(this.schema, this.name) and not flags.FULL_REFRESH%}
-
 with all_events as (
 
     select * from {{ ref('snowplow_base_events') }}
@@ -30,7 +26,7 @@ with all_events as (
 events as (
 
     select * from all_events
-    {% if this_exists %}
+    {% if is_incremental() %}
     where collector_tstamp > (
         select coalesce(max(max_tstamp), '0001-01-01') from {{ this }}
     )
@@ -101,7 +97,7 @@ relative as (
 
 ),
 
-{% if this_exists %}
+{% if is_incremental() %}
 
 relevant_existing as (
 
diff --git a/macros/adapters/default/page_views/snowplow_web_events_time.sql b/macros/adapters/default/page_views/snowplow_web_events_time.sql
index 631e6e6..6ef5941 100644
--- a/macros/adapters/default/page_views/snowplow_web_events_time.sql
+++ b/macros/adapters/default/page_views/snowplow_web_events_time.sql
@@ -13,13 +13,10 @@
         materialized='incremental',
         sort='page_view_id',
         dist='page_view_id',
-        sql_where='TRUE',
         unique_key='page_view_id'
     )
 }}
 
-{# cache this because we need it below too #}
-{% set this_exists = adapter.already_exists(this.schema, this.name) and not flags.FULL_REFRESH%}
 
 with all_events as (
 
@@ -30,7 +27,7 @@ with all_events as (
 events as (
 
     select * from all_events
-    {% if this_exists %}
+    {% if is_incremental() %}
     where collector_tstamp > (
         select coalesce(max(max_tstamp), '0001-01-01') from {{ this }}
     )
@@ -67,7 +64,7 @@ prep as (
 ),
 
 
-{% if this_exists %}
+{% if is_incremental() %}
 
 relevant_existing as (
 
diff --git a/macros/adapters/default/sessions/snowplow_sessions_tmp.sql b/macros/adapters/default/sessions/snowplow_sessions_tmp.sql
index c12a442..52eb57d 100644
--- a/macros/adapters/default/sessions/snowplow_sessions_tmp.sql
+++ b/macros/adapters/default/sessions/snowplow_sessions_tmp.sql
@@ -13,17 +13,39 @@
         materialized='incremental',
         sort='session_start',
         dist='user_snowplow_domain_id',
-        sql_where='session_start > (select max(session_start) from {{ this }})',
         unique_key='session_id'
     )
 }}
 
-with web_page_views as (
+with all_web_page_views as (
 
     select * from {{ ref('snowplow_page_views') }}
 
 ),
 
+relevant_sessions as (
+
+    select distinct session_id
+    from all_web_page_views
+
+    {% if is_incremental() %}
+        where page_view_start > (select max(session_start) from {{ this }})
+    {% endif %}
+
+),
+
+-- only select sessions that had page views in this time frame
+-- this strategy helps us grab _all_ of the page views for these
+-- sessions, including the ones that occurred before the
+-- max(session_start) in the table
+web_page_views as (
+
+    select all_web_page_views.*
+    from all_web_page_views
+    join relevant_sessions using (session_id)
+
+),
+
 prep AS (
 
     select
@@ -49,7 +71,6 @@ prep AS (
     from web_page_views
 
     group by 1
-    order by 1
 
 ),
 
diff --git a/models/identification/snowplow_id_map.sql b/models/identification/snowplow_id_map.sql
index 5c1dac5..de10f86 100644
--- a/models/identification/snowplow_id_map.sql
+++ b/models/identification/snowplow_id_map.sql
@@ -4,7 +4,6 @@
         materialized='incremental',
         sort='domain_userid',
         dist='domain_userid',
-        sql_where='TRUE',
         unique_key='domain_userid'
     )
 }}