added a missing dependency; added support for redshift queries to return 0 rows

examples/redshift_basic_query.py

@@ -9,7 +9,10 @@ red   = m.redshift("s3://haystac-te-athena/",
                    workgroup = "phase1-trial2")
 
 query = red.query("""select agent, st_astext(geom), timestamp from
-                  public.baseline_v1 where agent = 44 limit 200""")
+                  public.baseline_v1 where agent = 4 limit 200""")
+
+import IPython
+IPython.embed()
 
 data  = query.results()
 

minerva/redshift.py

@@ -137,18 +137,18 @@ drop table temp_data;
         status = self.finish()
 
         if status == "FINISHED":
-            # Track the runtime
-            self.runtime = self.info_cache['UpdatedAt'] - self.info_cache['CreatedAt']
+            if self.info_cache['ResultRows'] != 0:
+                # Because we're using `UNLOAD`, we get a manifest of the files
+                # that make up our data.
+                manif = self.out + "manifest"
+                tmp   = self.handler.s3.download(manif)
+                with open(tmp, "r") as f:
+                    js = json.load(f)
 
-            # Because we're using `UNLOAD`, we get a manifest of the files
-            # that make up our data.
-            manif = self.out + "manifest"
-            tmp   = self.handler.s3.download(manif)
-            with open(tmp, "r") as f:
-                js = json.load(f)
-
-            # Filter empty strings
-            self.files = [e['url'].strip() for e in js['entries'] if e['url'].strip()]
+                # Filter empty strings
+                self.files = [e['url'].strip() for e in js['entries'] if e['url'].strip()]
+            else: # no results returned, so no manifest file was created
+                self.files = []
 
             return self.files
         else:

pyproject.toml

@@ -23,4 +23,5 @@ joblib = "^1.1.0"
 fabric = "^3.0.0"
 s3fs = "2023.6.0"
 mako = ">1.2.0"
-dask[distributed] = ">2023.11.0"
+dask = ">2023.11.0"
+distributed = ">2023.11.0"