wip: remove uncessary with qualifier method

some docs

more docs

datafusion/common/src/dfschema.rs

@@ -915,11 +915,6 @@ impl DFField {
         self.field = f.into();
         self
     }
-
-    pub fn with_qualifier(mut self, qualifier: impl Into<OwnedTableReference>) -> Self {
-        self.qualifier = Some(qualifier.into());
-        self
-    }
 }
 
 impl From<FieldRef> for DFField {

datafusion/core/src/datasource/cte.rs → datafusion/core/src/datasource/cte_worktable.rs

@@ -35,14 +35,19 @@ use datafusion_common::DataFusionError;
 use crate::datasource::{TableProvider, TableType};
 use crate::execution::context::SessionState;
 
-/// TODO: add docs
+/// The temporary working table where the previous iteration of a recursive query is stored
+/// Naming is based on PostgreSQL's implementation.
+/// See here for more details: www.postgresql.org/docs/11/queries-with.html#id-1.5.6.12.5.4
 pub struct CteWorkTable {
     name: String,
+    /// This schema must be shared across both the static and recursive terms of a recursive query
     table_schema: SchemaRef,
 }
 
 impl CteWorkTable {
-    /// TODO: add doc
+    /// construct a new CteWorkTable with the given name and schema
+    /// This schema must match the schema of the recursive term of the query
+    /// Since the scan method will contain an physical plan that assumes this schema
     pub fn new(name: &str, table_schema: SchemaRef) -> Self {
         Self {
             name: name.to_owned(),

datafusion/core/src/datasource/mod.rs

@@ -20,7 +20,7 @@
 //! [`ListingTable`]: crate::datasource::listing::ListingTable
 
 pub mod avro_to_arrow;
-pub mod cte;
+pub mod cte_worktable;
 pub mod default_table_source;
 pub mod empty;
 pub mod file_format;

datafusion/core/src/execution/context/mod.rs

@@ -26,7 +26,7 @@ mod parquet;
 use crate::{
     catalog::{CatalogList, MemoryCatalogList},
     datasource::{
-        cte::CteWorkTable,
+        cte_worktable::CteWorkTable,
         function::{TableFunction, TableFunctionImpl},
         listing::{ListingOptions, ListingTable},
         provider::TableProviderFactory,
@@ -1900,6 +1900,9 @@ impl<'a> ContextProvider for SessionContextProvider<'a> {
         Ok(provider_as_source(provider))
     }
 
+    /// Create a new CTE work table for a recursive CTE logical plan
+    /// This table will be used in conjunction with a Worktable physical plan
+    /// to read and write each iteration of a recursive CTE
     fn create_cte_work_table(
         &self,
         name: &str,