diff --git a/identify-slow-queries.md b/identify-slow-queries.md
index e170a2dd6de51..d877d8cbe9583 100644
--- a/identify-slow-queries.md
+++ b/identify-slow-queries.md
@@ -168,6 +168,11 @@ Fields related to Resource Control:
 * `Request_unit_write`: the total write RUs consumed by the statement.
 * `Time_queued_by_rc`: the total time that the statement waits for available resources.
 
+Fields related to storage engines:
+
+- `Storage_from_kv`: Whether this statement read data from TiKV.
+- `Storage_from_mpp`: Whether this statement read data from TiFlash.
+
 ## Related system variables
 
 * [`tidb_slow_log_threshold`](/system-variables.md#tidb_slow_log_threshold): Sets the threshold for the slow log. The SQL statement whose execution time exceeds this threshold is recorded in the slow log. The default value is 300 (ms).
diff --git a/statement-summary-tables.md b/statement-summary-tables.md
index 2ff39bc4e7962..5b382b0ff8439 100644
--- a/statement-summary-tables.md
+++ b/statement-summary-tables.md
@@ -467,6 +467,11 @@ Fields related to network traffic:
 - `SUM_UNPACKED_BYTES_SENT_TIFLASH_CROSS_ZONE`: bytes sent from SQL statements to TiFlash across availability zones, including bytes sent between TiFlash nodes across availability zones.
 - `SUM_UNPACKED_BYTES_RECEIVED_TIFLASH_CROSS_ZONE`: bytes received by SQL statements from TiFlash across availability zones, including bytes received between TiFlash nodes across availability zones.
 
+Fields related to storage engines:
+
+- `STORAGE_KV`: Indicates whether the previous execution of SQL statements of this category read data from TiKV.
+- `STORAGE_MPP`: Indicates whether the previous execution of SQL statements of this category read data from TiFlash.
+
 ### `statements_summary_evicted` fields description
 
 - `BEGIN_TIME`: Records the starting time.