Method reset_runtime_variable

datafusion/core/src/execution/context/mod.rs:1221–1261

(&self, variable: &str)

    }

    fn reset_runtime_variable(&self, variable: &str) -> Result<()> {
        let key = variable.strip_prefix("datafusion.runtime.").unwrap();

        let mut state = self.state.write();

        let mut builder = RuntimeEnvBuilder::from_runtime_env(state.runtime_env());
        match key {
            "memory_limit" => {
                builder.memory_pool = None;
            }
            "max_temp_directory_size" => {
                builder =
                    builder.with_max_temp_directory_size(DEFAULT_MAX_TEMP_DIRECTORY_SIZE);
            }
            "temp_directory" => {
                builder.disk_manager_builder = Some(DiskManagerBuilder::default());
            }
            "metadata_cache_limit" => {
                builder = builder.with_metadata_cache_limit(DEFAULT_METADATA_CACHE_LIMIT);
            }
            "list_files_cache_limit" => {
                builder = builder
                    .with_object_list_cache_limit(DEFAULT_LIST_FILES_CACHE_MEMORY_LIMIT);
            }
            "list_files_cache_ttl" => {
                builder =
                    builder.with_object_list_cache_ttl(DEFAULT_LIST_FILES_CACHE_TTL);
            }
            "file_statistics_cache_limit" => {
                builder = builder.with_file_statistics_cache_limit(
                    DEFAULT_FILE_STATISTICS_MEMORY_LIMIT,
                );
            }
            _ => return plan_err!("Unknown runtime configuration: {variable}"),
        };
        *state = SessionStateBuilder::from(state.clone())
            .with_runtime_env(Arc::new(builder.build()?))
            .build();

        Ok(())
    }

    /// Parse memory limit from string to number of bytes
    /// Supports formats like '1.5G', '100M', '512K'