Refactor expression handling for compressed UPDATE/DELETE

src/CMakeLists.txt

@@ -20,6 +20,7 @@ set(SOURCES
     event_trigger.c
     extension.c
     extension_constants.c
+    expression_utils.c
     gapfill.c
     guc.c
     histogram.c

src/expression_utils.c

@@ -0,0 +1,107 @@
+/*
+ * This file and its contents are licensed under the Apache License 2.0.
+ * Please see the included NOTICE for copyright information and
+ * LICENSE-APACHE for a copy of the license.
+ */
+
+#include <postgres.h>
+#include <catalog/pg_type.h>
+#include <nodes/primnodes.h>
+#include <utils/lsyscache.h>
+
+#include "expression_utils.h"
+#include "export.h"
+
+/*
+ * This function is meant to extract the expression components to be used in a ScanKey.
+ *
+ * It will work on the following expression types:
+ * - Var OP Expr
+ *
+ * Var OP Var is not supported as that will not work with scankeys.
+ *
+ */
+bool TSDLLEXPORT
+ts_extract_expr_args(Expr *expr, Var **var, Expr **arg_value, Oid *opno, Oid *opcode)
+{
+	List *args;
+	Oid expr_opno, expr_opcode;
+
+	switch (nodeTag(expr))
+	{
+		case T_OpExpr:
+		{
+			OpExpr *opexpr = castNode(OpExpr, expr);
+			args = opexpr->args;
+			expr_opno = opexpr->opno;
+			expr_opcode = opexpr->opfuncid;
+
+			if (opexpr->opresulttype != BOOLOID)
+				return false;
+
+			break;
+		}
+		case T_ScalarArrayOpExpr:
+		{
+			ScalarArrayOpExpr *sa_opexpr = castNode(ScalarArrayOpExpr, expr);
+			args = sa_opexpr->args;
+			expr_opno = sa_opexpr->opno;
+			expr_opcode = sa_opexpr->opfuncid;
+			break;
+		}
+		default:
+			return false;
+	}
+
+	if (list_length(args) != 2)
+		return false;
+
+	Expr *leftop = linitial(args);
+	Expr *rightop = lsecond(args);
+
+	if (IsA(leftop, RelabelType))
+		leftop = castNode(RelabelType, leftop)->arg;
+	if (IsA(rightop, RelabelType))
+		rightop = castNode(RelabelType, rightop)->arg;
+
+	if (IsA(leftop, Var) && !IsA(rightop, Var))
+	{
+		/* ignore system columns */
+		if (castNode(Var, leftop)->varattno <= 0)
+			return false;
+
+		*var = castNode(Var, leftop);
+
+		*arg_value = rightop;
+		*opno = expr_opno;
+		if (opcode)
+			*opcode = expr_opcode;
+		return true;
+	}
+	else if (IsA(rightop, Var) && !IsA(leftop, Var))
+	{
+		/* ignore system columns */
+		if (castNode(Var, rightop)->varattno <= 0)
+			return false;
+
+		*var = castNode(Var, rightop);
+		*arg_value = leftop;
+		expr_opno = get_commutator(expr_opno);
+		if (!OidIsValid(expr_opno))
+			return false;
+
+		if (opcode)
+		{
+			expr_opcode = get_opcode(expr_opno);
+			if (!OidIsValid(expr_opcode))
+				return false;
+			*opcode = expr_opcode;
+		}
+
+		*opno = expr_opno;
+
+		return true;
+	}
+
+	return false;
+}

src/expression_utils.h

@@ -0,0 +1,14 @@
+/*
+ * This file and its contents are licensed under the Apache License 2.0.
+ * Please see the included NOTICE for copyright information and
+ * LICENSE-APACHE for a copy of the license.
+ */
+
+#include <postgres.h>
+#include <nodes/primnodes.h>
+#include <utils/lsyscache.h>
+
+#include "export.h"
+
+bool TSDLLEXPORT ts_extract_expr_args(Expr *expr, Var **var, Expr **arg_value, Oid *opno,
+									  Oid *opcode);

tsl/src/compression/compression.c

@@ -53,6 +53,7 @@
 #include "debug_point.h"
 #include "deltadelta.h"
 #include "dictionary.h"
+#include "expression_utils.h"
 #include "gorilla.h"
 #include "guc.h"
 #include "nodes/chunk_dispatch/chunk_insert_state.h"
@@ -2538,8 +2539,8 @@ find_matching_index(Relation comp_chunk_rel, List **index_filters, List **heap_f
  * be used to build scan keys later.
  */
 static void
-fill_predicate_context(Chunk *ch, CompressionSettings *settings, List *predicates,
-					   List **heap_filters, List **index_filters, List **is_null)
+process_predicates(Chunk *ch, CompressionSettings *settings, List *predicates, List **heap_filters,
+				   List **index_filters, List **is_null)
 {
 	ListCell *lc;
 	foreach (lc, predicates)
@@ -2548,44 +2549,26 @@ fill_predicate_context(Chunk *ch, CompressionSettings *settings, List *predicate
 
 		Var *var;
 		char *column_name;
+
 		switch (nodeTag(node))
 		{
 			case T_OpExpr:
 			{
-				OpExpr *opexpr = (OpExpr *) node;
-				Oid opno = opexpr->opno;
-				RegProcedure opcode = opexpr->opfuncid;
+				OpExpr *opexpr = castNode(OpExpr, node);
+				Oid opno;
+				RegProcedure opcode;
 				Oid collation = opexpr->inputcollid;
-				Expr *leftop, *rightop;
+				Expr *expr;
 				Const *arg_value;
 
-				leftop = linitial(opexpr->args);
-				rightop = lsecond(opexpr->args);
-
-				if (IsA(leftop, RelabelType))
-					leftop = ((RelabelType *) leftop)->arg;
-				if (IsA(rightop, RelabelType))
-					rightop = ((RelabelType *) rightop)->arg;
-
-				if (IsA(leftop, Var) && IsA(rightop, Const))
-				{
-					var = (Var *) leftop;
-					arg_value = (Const *) rightop;
-				}
-				else if (IsA(rightop, Var) && IsA(leftop, Const))
-				{
-					var = (Var *) rightop;
-					arg_value = (Const *) leftop;
-					opno = get_commutator(opno);
-					if (!OidIsValid(opno))
-						continue;
-					opcode = get_opcode(opno);
-					if (!OidIsValid(opcode))
-						continue;
-				}
-				else
+				if (!ts_extract_expr_args(&opexpr->xpr, &var, &expr, &opno, &opcode))
 					continue;
 
+				if (!IsA(expr, Const))
+					continue;
+
+				arg_value = castNode(Const, expr);
+
 				/* ignore system-defined attributes */
 				if (var->varattno <= 0)
 					continue;
@@ -3124,7 +3107,7 @@ decompress_batches_for_update_delete(HypertableModifyState *ht_state, Chunk *chu
 	comp_chunk = ts_chunk_get_by_id(chunk->fd.compressed_chunk_id, true);
 	CompressionSettings *settings = ts_compression_settings_get(comp_chunk->table_id);
 
-	fill_predicate_context(chunk, settings, predicates, &heap_filters, &index_filters, &is_null);
+	process_predicates(chunk, settings, predicates, &heap_filters, &index_filters, &is_null);
 
 	chunk_rel = table_open(chunk->table_id, RowExclusiveLock);
 	comp_chunk_rel = table_open(comp_chunk->table_id, RowExclusiveLock);