Update README for 0.1.0 release

README.md

@@ -6,7 +6,8 @@
 ```bash
 # iterate through all source nodes, run drop + create + refresh (if partitioned)
 dbt run-operation stage_external_sources
-# maybe someday: dbt source create-external ?
+
+# maybe someday: dbt source stage-external
 ```
 
 The macros assume that you have already created an external stage (Snowflake)
@@ -23,10 +24,10 @@ source:
 
         # NEW: "external" property of source node
         external:
-          location: # S3 file path or stage (Snowflake)
-          file_format: # Hive or Snowflake
-          row_format: # Hive
-          tbl_properties: # Hive
+          location: # S3 file path or Snowflake stage
+          file_format: # Hive specification or Snowflake named format / specification
+          row_format: # Hive specification
+          tbl_properties: # Hive specification
 
           # Specify a list of file-path partitions.
 
@@ -37,43 +38,47 @@ source:
               expression: to_date(substr(metadata$filename, 8, 10), 'YYYY/MM/DD')
 
           # ------ REDSHIFT -------
-          partitions:            
+          partitions:
             - name: appId
               data_type: varchar(255)
-              vals:     # array of values
+              vals:     # list of values
                 - dev
                 - prod
-              # macro to convert partition value to file path specification
-              # takes keyword arguments 'name' + 'value'
-              path_macro: test_external_sources_redshift.year_month_day
+              # macro to convert partition value to file path specification.
+              path_macro: dbt_external_tables.key_value
+              # this "helper" macro is defined in the package, but you can use
+              # custom macro that takes keyword arguments 'name' + 'value'
+              # and returns the path as a string
 
+            # if multiple partitions, order matters for compiling S3 path
             - name: collector_date
               data_type: date
-              vals:     # macro w/ args to generate array of values
-                macro: dbt.dates_in_range   
+              vals:     # macro w/ keyword args to generate list of values
+                macro: dbt.dates_in_range
                 args:
                   start_date_str: '2019-08-01'
                   end_date_str: '{{modules.datetime.date.today().strftime("%Y-%m-%d")}}'
                   in_fmt: "%Y-%m-%d"
                   out_fmt: "%Y-%m-%d"
-               path_macro: test_external_sources_redshift.year_month_day
+               path_macro: dbt_external_tables.year_month_day
 
 
-        # Specify ALL column names + datatypes
+        # Specify ALL column names + datatypes.
+        # Column order matters for CSVs. Other file formats require column
+        # names to exactly match.
         columns:
           - name: app_id
             data_type: varchar(255)
             description: "Application ID"
+          - name: platform
+            data_type: varchar(255)
+            description: "Platform"
         ...
 ```
 
-See `sample_sources` for full, valid YML config that establishes Snowplow events
+See [`sample_sources`](sample_sources) for full valid YML config that establishes Snowplow events
 as a dbt source and stage-ready external table in Snowflake and Spectrum.
 
-### Current dependencies
-
-* dbt@0.15.0 in [`dev/louisa-may-alcott`](https://github.com/fishtown-analytics/dbt/tree/dev/louisa-may-alcott)
-
 ### Supported databases
 
 * Redshift (Spectrum)