fix: Remove db_name field from DeletePayload

Doesn't seem to be used anywhere.

generated_types/protos/influxdata/iox/delete/v1/service.proto

@@ -35,8 +35,9 @@ message DeleteResponse {
 
 // A delete payload
 message DeletePayload {
-  // The name of the database
-  string db_name = 1;
+  // Was the name of the database / namespace.
+  reserved "db_name";
+  reserved 1;
 
   // The catalog ID for this database / namespace.
   int64 database_id = 4;

influxdb_iox_client/src/client/delete.rs

@@ -52,7 +52,6 @@ pub mod generated_types {
 /// };
 /// client
 ///     .delete(
-///         "my_db",
 ///         42,
 ///         "my_table",
 ///         pred,
@@ -77,18 +76,15 @@ impl Client {
     /// Delete data from a table on a specified predicate
     pub async fn delete(
         &mut self,
-        db_name: impl Into<String> + Send,
         database_id: i64,
         table_name: impl Into<String> + Send,
         predicate: Predicate,
     ) -> Result<(), Error> {
-        let db_name = db_name.into();
         let table_name = table_name.into();
 
         self.inner
             .delete(DeleteRequest {
                 payload: Some(DeletePayload {
-                    db_name,
                     database_id,
                     table_name,
                     predicate: Some(predicate),

write_buffer/src/codec.rs

@@ -207,7 +207,7 @@ pub fn decode(
 
 /// Encodes a [`DmlOperation`] as a protobuf [`WriteBufferPayload`]
 pub fn encode_operation(
-    db_name: &str,
+    _db_name: &str,
     operation: &DmlOperation,
     buf: &mut Vec<u8>,
 ) -> Result<(), WriteBufferError> {
@@ -218,7 +218,6 @@ pub fn encode_operation(
             Payload::Write(batch)
         }
         DmlOperation::Delete(delete) => Payload::Delete(DeletePayload {
-            db_name: db_name.to_string(),
             database_id: delete.namespace_id().get(),
             table_name: delete
                 .table_name()