rework incremental models to use a temp table

this should speed up query times and also provide a more
correct implementation.

See: #138

dbt/templates.py

@@ -9,32 +9,32 @@ class BaseCreateTemplate(object):
     # but you cannot explicitly set them in the CREATE TABLE ... LIKE statement.
     # via http://docs.aws.amazon.com/redshift/latest/dg/r_CREATE_TABLE_NEW.html
     incremental_template = """
-create temporary table "{identifier}__dbt_incremental_tmp" {dist_qualifier} {sort_qualifier} as (
+create temporary table "{identifier}__dbt_incremental_empty_tmp" {dist_qualifier} {sort_qualifier} as (
     select * from (
         {query}
     ) as tmp limit 0
 );
 
-create table if not exists "{schema}"."{identifier}" (like "{identifier}__dbt_incremental_tmp");
+create table if not exists "{schema}"."{identifier}" (like "{identifier}__dbt_incremental_empty_tmp");
 
-{incremental_delete_statement}
-
-insert into "{schema}"."{identifier}" (
+create temporary table "{identifier}__dbt_incremental_tmp" as (
     with dbt_incr_sbq as (
         {query}
     )
     select * from dbt_incr_sbq
     where ({sql_where}) or ({sql_where}) is null
 );
+
+{incremental_delete_statement}
+
+insert into "{schema}"."{identifier}" (
+    select * from "{identifier}__dbt_incremental_tmp"
+);
     """
 
     incremental_delete_template = """
 delete from "{schema}"."{identifier}" where  ({unique_key}) in (
-    with dbt_delete_sbq as (
-        {query}
-    )
-    select ({unique_key}) from dbt_delete_sbq
-    where ({sql_where}) or ({sql_where}) is null
+    select ({unique_key}) from "{identifier}__dbt_incremental_tmp"
 );
 """
 
@@ -105,33 +105,35 @@ class DryCreateTemplate(object):
 
 
     incremental_template = """
-create temporary table "{identifier}__dbt_incremental_tmp" {dist_qualifier} {sort_qualifier} as (
+create temporary table "{identifier}__dbt_incremental_empty_tmp" {dist_qualifier} {sort_qualifier} as (
     select * from (
         {query}
     ) as tmp limit 0
 );
 
-create table if not exists "{schema}"."{identifier}" (like "{identifier}__dbt_incremental_tmp");
 
-{incremental_delete_statement}
+create table if not exists "{schema}"."{identifier}" (like "{identifier}__dbt_incremental_empty_tmp");
 
-insert into "{schema}"."{identifier}" (
+create temporary table "{identifier}__dbt_incremental_tmp" as (
     with dbt_incr_sbq as (
         {query}
     )
     select * from dbt_incr_sbq
     where ({sql_where}) or ({sql_where}) is null
     limit 0
 );
+
+
+{incremental_delete_statement}
+
+insert into "{schema}"."{identifier}" (
+    select * from "{identifier}__dbt_incremental_tmp"
+);
     """
 
     incremental_delete_template = """
 delete from "{schema}"."{identifier}" where  ({unique_key}) in (
-    with dbt_delete_sbq as (
-        {query}
-    )
-    select ({unique_key}) from dbt_delete_sbq
-    where ({sql_where}) or ({sql_where}) is null
+    select ({unique_key}) from "{identifier}__dbt_incremental_tmp"
 );
 """