review fixes

Author: akuzm

tsl/src/nodes/vector_agg/exec.c

@@ -43,14 +43,14 @@
  */
 typedef struct ExprCacheEntry
 {
-	Expr *key;
+	Expr const *key;
 	CompressedColumnValues result; /* DT_Invalid means not yet computed */
 	uint32 status;				   /* required by simplehash */
 } ExprCacheEntry;
 
 #define SH_PREFIX expr_cache
 #define SH_ELEMENT_TYPE ExprCacheEntry
-#define SH_KEY_TYPE Expr *
+#define SH_KEY_TYPE Expr const *
 #define SH_KEY key
 #define SH_HASH_KEY(tb, key) murmurhash64((uint64) (key))
 #define SH_EQUAL(tb, a, b) ((a) == (b))
@@ -674,7 +674,9 @@ vector_slot_evaluate_expression(DecompressContext *dcontext, TupleTableSlot *slo
 		 * broader result is safe to cache, because it has the correct values
 		 * for all rows of a narrower result.
 		 */
-		cache_entry = expr_cache_lookup(expr_cache, (Expr *) argument);
+		cache_entry = expr_cache_lookup(expr_cache, argument);
+
+		Assert(!contain_volatile_functions((Node *) argument));
 	}
 
 	if (cache_entry != NULL && cache_entry->result.decompression_type != DT_Invalid)

tsl/test/expected/vector_agg_expr.out

@@ -2120,6 +2120,25 @@ select sum(abs(v - 500)), count(abs(v - 500)) from aggexpr where abs(v) > 3 AND
 -------+-------
  14820 |    30
 
+-- CASE statement with cached parts
+select sum(case when i > 0 then abs(v)::int2 else length(x)::int4 end)
+from aggexpr
+where abs(v) < 10 and length(x) < 10
+;
+ sum 
+-----
+ 120
+
+-- CASE statement that is itself cached
+select sum(x) from (
+    select (case when i > 0 then abs(v)::int2 else length(x)::int4 end) as x
+    from aggexpr) t
+where x > 0
+;
+   sum   
+---------
+ 3321885
+
 reset timescaledb.debug_require_vector_agg;
 reset timescaledb.enable_vectorized_aggregation;
 -- Some CASE statements are vectorized.

tsl/test/sql/vector_agg_expr.sql

@@ -225,6 +225,19 @@ select sum((b = (i > 0))::int), count(b = (i > 0)) from aggexpr;
 -- Multiple qual evaluation with caching.
 select sum(abs(v - 500)), count(abs(v - 500)) from aggexpr where abs(v) > 3 AND abs(v) < 9;
 
+-- CASE statement with cached parts
+select sum(case when i > 0 then abs(v)::int2 else length(x)::int4 end)
+from aggexpr
+where abs(v) < 10 and length(x) < 10
+;
+
+-- CASE statement that is itself cached
+select sum(x) from (
+    select (case when i > 0 then abs(v)::int2 else length(x)::int4 end) as x
+    from aggexpr) t
+where x > 0
+;
+
 reset timescaledb.debug_require_vector_agg;
 reset timescaledb.enable_vectorized_aggregation;