add refresh append overlap doc; address some inaccurate doc issue (#284)

* add refresh append overlap doc; address some inaccurate doc issue

* Update spiceaidocs/docs/reference/spicepod/datasets.md

Co-authored-by: Aurash Behbahani <aurashb@gmail.com>

* Update spiceaidocs/docs/reference/spicepod/datasets.md

Co-authored-by: Aurash Behbahani <aurashb@gmail.com>

* doc change

---------

Co-authored-by: Aurash Behbahani <aurashb@gmail.com>

Author: y-f-u

spiceaidocs/docs/reference/spicepod/datasets.md

@@ -145,11 +145,11 @@ Optional. The mode of acceleration. The following values are supported:
 Optional. How to refresh the dataset. The following values are supported:
 
 - `full` - Refresh the entire dataset.
-- `append` - Append new data to the dataset.
+- `append` - Append new data to the dataset. When `time_column` is specified, new records are fetched from the latest timestamp in the accelerated data at the `acceleration.refresh_check_interval`.
 
 ## `acceleration.refresh_check_interval`
 
-Optional. How often data should be refreshed. Only supported for `full` refresh_mode datasets. For `append` datasets, the refresh check interval not used.
+Optional. How often data should be refreshed. For `append` datasets without a specific `time_column`, this config is not used.
 
 See [Duration](../duration/index.md)
 
@@ -173,6 +173,16 @@ For example, `refresh_data_window: 24h` will include only records with a timesta
 
 See [Duration](../duration/index.md)
 
+## `acceleration.refresh_append_overlap`
+
+Optional. A duration to specify how far back to include records based on the most recent timestamp found in the accelerated data. Requires `time_column` to also be configured. Only supported for `append` refresh mode datasets.
+
+This setting can help mitigate missing data issues caused by late arriving data.
+
+Example: If the latest timestamp in the accelerated data table is `2020-01-01T02:00:00Z`, setting `refresh_append_overlap: 1h` will include records starting from `2020-01-01T01:00:00Z`.
+
+See [Duration](../duration/index.md)
+
 ## `acceleration.params`
 
 Optional. Parameters to pass to the acceleration engine. The parameters are specific to the acceleration engine used.

spiceaidocs/docs/reference/spicepod/index.md

@@ -43,7 +43,11 @@ secrets:
   store: env
 ```
 
-## `runtime` 
+## `runtime`
+
+### `num_of_parallel_loading_at_start_up`
+
+This configuration setting determines the maximum number of datasets that can be loaded in parallel during startup. This parallel loading capability accelerates Spice's startup process when multiple datasets are configured.
 
 ### `results_cache`