feat(cubesql): Support SQL pushdown for LAG/LEAD functions (#10407)

Author: MazterQyou

packages/cubejs-schema-compiler/src/adapter/BaseQuery.js

@@ -4262,6 +4262,8 @@ export class BaseQuery {
         FLOOR: 'FLOOR({{ args_concat }})',
         CEIL: 'CEIL({{ args_concat }})',
         TRUNC: 'TRUNC({{ args_concat }})',
+        LAG: 'LAG({{ args_concat }})',
+        LEAD: 'LEAD({{ args_concat }})',
 
         // There is a difference in behaviour of these function processing in different DBs and DWHs.
         // The SQL standard requires greatest and least to return null in case one argument is null.

rust/cubesql/cubesql/src/compile/mod.rs

@@ -18377,4 +18377,40 @@ LIMIT {{ limit }}{% endif %}"#.to_string(),
 
         Ok(())
     }
+
+    #[tokio::test]
+    async fn test_lag_lead_fn_sql_push_down() {
+        if !Rewriter::sql_push_down_enabled() {
+            return;
+        }
+        init_testing_logger();
+
+        let query_plan = convert_select_to_query_plan(
+            r#"
+            SELECT
+                order_date,
+                customer_gender,
+                LAG(customer_gender, 1) OVER (ORDER BY order_date) AS lag,
+                LEAD(customer_gender, 1) OVER (ORDER BY order_date) AS lead
+            FROM KibanaSampleDataEcommerce
+            WHERE LOWER(customer_gender) = 'test'
+            GROUP BY 1, 2
+            "#
+            .to_string(),
+            DatabaseProtocol::PostgreSQL,
+        )
+        .await;
+
+        let logical_plan = query_plan.as_logical_plan();
+        let sql = logical_plan.find_cube_scan_wrapped_sql().wrapped_sql.sql;
+        assert!(sql.contains("LAG("));
+        assert!(sql.contains("LEAD("));
+        assert!(sql.contains(" OVER (ORDER BY "));
+
+        let physical_plan = query_plan.as_physical_plan().await.unwrap();
+        println!(
+            "Physical plan: {}",
+            displayable(physical_plan.as_ref()).indent()
+        );
+    }
 }

rust/cubesql/cubesql/src/compile/test/mod.rs

@@ -632,6 +632,8 @@ pub fn sql_generator(
                     ("functions/FLOOR".to_string(), "FLOOR({{ args_concat }})".to_string()),
                     ("functions/CEIL".to_string(), "CEIL({{ args_concat }})".to_string()),
                     ("functions/TRUNC".to_string(), "TRUNC({{ args_concat }})".to_string()),
+                    ("functions/LAG".to_string(), "LAG({{ args_concat }})".to_string()),
+                    ("functions/LEAD".to_string(), "LEAD({{ args_concat }})".to_string()),
                     ("functions/LEAST".to_string(), "LEAST({{ args_concat }})".to_string()),
                     ("functions/DATEDIFF".to_string(), "DATEDIFF({{ date_part }}, {{ args[1] }}, {{ args[2] }})".to_string()),
                     ("functions/CURRENTDATE".to_string(), "CURRENT_DATE({{ args_concat }})".to_string()),