chore(cubestore): Upgrade DF: Use lowercase names for UDAF registry

rust/cubestore/cubestore/src/queryplanner/mod.rs

@@ -502,18 +502,18 @@ impl ContextProvider for MetaStoreSchemaProvider {
         return Some(scalar_udf_by_kind(kind));
     }
 
-    fn get_aggregate_meta(&self, name: &str) -> Option<Arc<AggregateUDF>> {
+    fn get_aggregate_meta(&self, name_param: &str) -> Option<Arc<AggregateUDF>> {
         // HyperLogLog.
         // TODO: case-insensitive names.
+        /*
         let (_kind, name) = match name {
             "merge" | "MERGE" => (CubeAggregateUDFKind::MergeHll, "MERGE"),
             _ => return None,
         };
+        */
+        let name = name_param.to_ascii_lowercase();
 
-        let aggregate_udf_by_registry = self.session_state.aggregate_functions().get(name);
-
-        // TODO upgrade DF: Remove this assertion (and/or remove the kind lookup above).
-        assert!(aggregate_udf_by_registry.is_some(), "MERGE is not registered in SessionState");
+        let aggregate_udf_by_registry: Option<&Arc<AggregateUDF>> = self.session_state.aggregate_functions().get(&name);
 
         aggregate_udf_by_registry.map(|arc| arc.clone())
     }

rust/cubestore/cubestore/src/queryplanner/udfs.rs

@@ -78,6 +78,10 @@ pub fn scalar_kind_by_name(n: &str) -> Option<CubeScalarUDFKind> {
     if n == "DATE_BIN" {
         return Some(CubeScalarUDFKind::DateBin);
     }
+    // TODO upgrade DF: Remove this (once we are no longer in flux about naming casing of UDFs and UDAFs).
+    if ["CARDINALITY", /* "COALESCE", "NOW", */ "UNIX_TIMESTAMP", "DATE_ADD", "DATE_SUB", "DATE_BIN"].contains(&(&n.to_ascii_uppercase() as &str)) {
+        panic!("scalar_kind_by_name failing on '{}' due to uppercase/lowercase mixup", n);
+    }
     return None;
 }
 
@@ -109,7 +113,7 @@ pub fn aggregate_udf_by_kind(k: CubeAggregateUDFKind) -> AggregateUDF {
 
 /// Note that only full match counts. Pass capitalized names.
 pub fn aggregate_kind_by_name(n: &str) -> Option<CubeAggregateUDFKind> {
-    if n == "MERGE" {
+    if n == "merge" {
         return Some(CubeAggregateUDFKind::MergeHll);
     }
     return None;
@@ -642,7 +646,7 @@ impl HllMergeUDF {
 impl AggregateUDFImpl for HllMergeUDF {
 
     fn name(&self) -> &str {
-        return "MERGE";
+        return "merge";
     }
 
     fn as_any(&self) -> &dyn Any {