[columnar] PostgreSQL 16 compatibility

columnar/configure

@@ -2802,7 +2802,7 @@ if test -z "$version_num"; then
   as_fn_error $? "Could not detect PostgreSQL version from pg_config." "$LINENO" 5
 fi
 
-if test "$version_num" != '13' -a "$version_num" != '14' -a "$version_num" != '15'; then
+if test "$version_num" != '13' -a "$version_num" != '14' -a "$version_num" != '15' -a "$version_num" != '16'; then
    as_fn_error $? "Citus is not compatible with the detected PostgreSQL version ${version_num}." "$LINENO" 5
 else
    { printf "%s\n" "$as_me:${as_lineno-$LINENO}: building against PostgreSQL $version_num" >&5

columnar/configure.in

@@ -74,7 +74,7 @@ if test -z "$version_num"; then
   AC_MSG_ERROR([Could not detect PostgreSQL version from pg_config.])
 fi
 
-if test "$version_num" != '13' -a "$version_num" != '14' -a "$version_num" != '15'; then
+if test "$version_num" != '13' -a "$version_num" != '14' -a "$version_num" != '15' -a "$version_num" != '16'; then
    AC_MSG_ERROR([Citus is not compatible with the detected PostgreSQL version ${version_num}.])
 else
    AC_MSG_NOTICE([building against PostgreSQL $version_num])

columnar/src/backend/columnar/columnar.c

@@ -47,7 +47,7 @@ bool columnar_enable_parallel_execution = true;
 int columnar_min_parallel_processes = 8;
 bool columnar_enable_vectorization = true;
 bool columnar_enable_dml = true;
-bool columnar_enable_page_cache = true;
+bool columnar_enable_page_cache = false;
 int columnar_page_cache_size = 200U;
 
 static const struct config_enum_entry columnar_compression_options[] =
@@ -132,7 +132,7 @@ columnar_guc_init()
 							 &columnar_enable_parallel_execution,
 							 true,
 							 PGC_USERSET,
-							 GUC_NO_SHOW_ALL,
+							 GUC_NO_SHOW_ALL | GUC_NOT_IN_SAMPLE,
 							 NULL, 
 							 NULL, 
 							 NULL);
@@ -156,7 +156,7 @@ columnar_guc_init()
 							 &columnar_enable_vectorization,
 							 true,
 							 PGC_USERSET,
-							 GUC_NO_SHOW_ALL,
+							 GUC_NO_SHOW_ALL | GUC_NOT_IN_SAMPLE,
 							 NULL, 
 							 NULL, 
 							 NULL);
@@ -167,7 +167,7 @@ columnar_guc_init()
 							&columnar_enable_dml,
 							true,
 							PGC_USERSET,
-							GUC_NO_SHOW_ALL,
+							GUC_NO_SHOW_ALL | GUC_NOT_IN_SAMPLE,
 							NULL, 
 							NULL, 
 							NULL);

columnar/src/backend/columnar/columnar_compression.c

@@ -14,6 +14,8 @@
 #include "postgres.h"
 
 #include "citus_version.h"
+#include "pg_version_compat.h"
+
 #include "common/pg_lzcompress.h"
 #include "lib/stringinfo.h"
 
@@ -27,6 +29,9 @@
 #include <zstd.h>
 #endif
 
+#if PG_VERSION_NUM >= PG_VERSION_16
+#include "varatt.h"
+#endif
 /*
  *	The information at the start of the compressed data. This decription is taken
  *	from pg_lzcompress in pre-9.5 version of PostgreSQL.

columnar/src/backend/columnar/columnar_customscan.c

@@ -14,6 +14,7 @@
  */
 
 #include "citus_version.h"
+#include "pg_version_compat.h"
 
 #include "postgres.h"
 
@@ -39,8 +40,13 @@
 #include "optimizer/plancat.h"
 #include "optimizer/planner.h"
 #include "optimizer/restrictinfo.h"
+#if PG_VERSION_NUM >= PG_VERSION_16
+#include "parser/parse_relation.h"
+#include "parser/parsetree.h"
+#endif
 #include "storage/smgr.h"
 #include "utils/builtins.h"
+#include "utils/guc.h"
 #include "utils/lsyscache.h"
 #include "utils/relcache.h"
 #include "utils/ruleutils.h"
@@ -56,6 +62,10 @@
 #include "columnar/vectorization/columnar_vector_execution.h"
 #include "columnar/vectorization/columnar_vector_types.h"
 
+#ifndef Abs
+#define Abs(x)			((x) >= 0 ? (x) : -(x))
+#endif
+
 /*
  * ColumnarScanState represents the state for a columnar scan. It's a
  * CustomScanState with additional fields specific to columnar scans.
@@ -188,7 +198,7 @@ static planner_hook_type PreviousPlannerHook = NULL;
 
 static bool EnableColumnarCustomScan = true;
 static bool EnableColumnarQualPushdown = true;
-static double ColumnarQualPushdownCorrelationThreshold = 0.9;
+static double ColumnarQualPushdownCorrelationThreshold = 0.4;
 static int ColumnarMaxCustomScanPaths = 64;
 static int ColumnarPlannerDebugLevel = DEBUG3;
 
@@ -267,7 +277,7 @@ columnar_customscan_init()
 		&EnableColumnarCustomScan,
 		true,
 		PGC_USERSET,
-		GUC_NO_SHOW_ALL,
+		GUC_NO_SHOW_ALL | GUC_NOT_IN_SAMPLE,
 		NULL, NULL, NULL);
 	DefineCustomBoolVariable(
 		"columnar.enable_qual_pushdown",
@@ -277,7 +287,7 @@ columnar_customscan_init()
 		&EnableColumnarQualPushdown,
 		true,
 		PGC_USERSET,
-		GUC_NO_SHOW_ALL,
+		GUC_NO_SHOW_ALL | GUC_NOT_IN_SAMPLE,
 		NULL, NULL, NULL);
 	DefineCustomRealVariable(
 		"columnar.qual_pushdown_correlation_threshold",
@@ -291,7 +301,7 @@ columnar_customscan_init()
 		0.0,
 		1.0,
 		PGC_USERSET,
-		GUC_NO_SHOW_ALL,
+		GUC_NO_SHOW_ALL |GUC_NOT_IN_SAMPLE,
 		NULL, NULL, NULL);
 	DefineCustomIntVariable(
 		"columnar.max_custom_scan_paths",
@@ -303,7 +313,7 @@ columnar_customscan_init()
 		1,
 		1024,
 		PGC_USERSET,
-		GUC_NO_SHOW_ALL,
+		GUC_NO_SHOW_ALL | GUC_NOT_IN_SAMPLE,
 		NULL, NULL, NULL);
 	DefineCustomEnumVariable(
 		"columnar.planner_debug_level",
@@ -1454,6 +1464,66 @@ ContainsExecParams(Node *node, void *notUsed)
 	return expression_tree_walker(node, ContainsExecParams, NULL);
 }
 
+#if PG_VERSION_NUM >= PG_VERSION_16
+
+/*
+ * fixup_inherited_columns
+ *
+ * Exact function Copied from PG16 as it's static.
+ *
+ * When user is querying on a table with children, it implicitly accesses
+ * child tables also. So, we also need to check security label of child
+ * tables and columns, but there is no guarantee attribute numbers are
+ * same between the parent and children.
+ * It returns a bitmapset which contains attribute number of the child
+ * table based on the given bitmapset of the parent.
+ */
+static Bitmapset *
+fixup_inherited_columns(Oid parentId, Oid childId, Bitmapset *columns)
+{
+	Bitmapset *result = NULL;
+
+	/*
+	 * obviously, no need to do anything here
+	 */
+	if (parentId == childId)
+	{
+		return columns;
+	}
+
+	int index = -1;
+	while ((index = bms_next_member(columns, index)) >= 0)
+	{
+		/* bit numbers are offset by FirstLowInvalidHeapAttributeNumber */
+		AttrNumber attno = index + FirstLowInvalidHeapAttributeNumber;
+
+		/*
+		 * whole-row-reference shall be fixed-up later
+		 */
+		if (attno == InvalidAttrNumber)
+		{
+			result = bms_add_member(result, index);
+			continue;
+		}
+
+		char *attname = get_attname(parentId, attno, false);
+		attno = get_attnum(childId, attname);
+		if (attno == InvalidAttrNumber)
+		{
+			elog(ERROR, "cache lookup failed for attribute %s of relation %u",
+				 attname, childId);
+		}
+
+		result = bms_add_member(result,
+								attno - FirstLowInvalidHeapAttributeNumber);
+
+		pfree(attname);
+	}
+
+	return result;
+}
+#endif
+
 
 /*
  * Create and add a path with the given parameterization paramRelids.
@@ -1536,7 +1606,42 @@ AddColumnarScanPath(PlannerInfo *root, RelOptInfo *rel, RangeTblEntry *rte,
 		cpath->custom_private = list_make2(NIL, NIL);
 	}
 
-	int numberOfColumnsRead = bms_num_members(rte->selectedCols);
+	int numberOfColumnsRead = 0;
+#if PG_VERSION_NUM >= PG_VERSION_16
+	if (rte->perminfoindex > 0)
+	{
+		/*
+		 * If perminfoindex > 0, that means that this relation's permission info
+		 * is directly found in the list of rteperminfos of the Query(root->parse)
+		 * So, all we have to do here is retrieve that info.
+		 */
+		RTEPermissionInfo *perminfo = getRTEPermissionInfo(root->parse->rteperminfos,
+														   rte);
+		numberOfColumnsRead = bms_num_members(perminfo->selectedCols);
+	}
+	else
+	{
+		/*
+		 * If perminfoindex = 0, that means we are skipping the check for permission info
+		 * for this relation, which means that it's either a partition or an inheritance child.
+		 * In these cases, we need to access the permission info of the top parent of this relation.
+		 * After thorough checking, we found that the index of the top parent pointing to the correct
+		 * range table entry in Query's range tables (root->parse->rtable) is found under
+		 * RelOptInfo rel->top_parent->relid.
+		 * For reference, check expand_partitioned_rtentry and expand_inherited_rtentry PG functions
+		 */
+		Assert(rel->top_parent);
+		RangeTblEntry *parent_rte = rt_fetch(rel->top_parent->relid, root->parse->rtable);
+		RTEPermissionInfo *perminfo = getRTEPermissionInfo(root->parse->rteperminfos,
+														   parent_rte);
+		numberOfColumnsRead = bms_num_members(fixup_inherited_columns(perminfo->relid,
+																	  rte->relid,
+																	  perminfo->
+																	  selectedCols));
+	}
+#else
+	numberOfColumnsRead = bms_num_members(rte->selectedCols);
+#endif
 	int numberOfClausesPushed = list_length(allClauses);
 
 	/* Queries that contain only aggregate with STAR doesn't have any
@@ -1631,7 +1736,7 @@ static Cost
 ColumnarPerStripeScanCost(RelOptInfo *rel, Oid relationId, int numberOfColumnsRead)
 {
 	Relation relation = RelationIdGetRelation(relationId);
-	List *stripeList = StripesForRelfilenode(relation->rd_node, ForwardScanDirection);
+	List *stripeList = StripesForRelfilenode(RelationPhysicalIdentifier_compat(relation), ForwardScanDirection);
 	RelationClose(relation);
 
 	uint32 maxColumnCount = 0;
@@ -1683,7 +1788,7 @@ static uint64
 ColumnarTableStripeCount(Oid relationId)
 {
 	Relation relation = RelationIdGetRelation(relationId);
-	List *stripeList = StripesForRelfilenode(relation->rd_node, ForwardScanDirection);
+	List *stripeList = StripesForRelfilenode(RelationPhysicalIdentifier_compat(relation), ForwardScanDirection);
 	int stripeCount = list_length(stripeList);
 	RelationClose(relation);
 
@@ -1966,7 +2071,11 @@ ColumnarScan_BeginCustomScan(CustomScanState *cscanstate, EState *estate, int ef
 	 */
 	columnarScanState->snapshot = estate->es_snapshot;
 	columnarScanState->snapshotRegisteredByUs = false;
+#if PG_VERSION_NUM >= PG_VERSION_16
+	Oid relationOid = cscanstate->ss.ss_currentRelation->rd_locator.relNumber;
+#else
 	Oid relationOid = cscanstate->ss.ss_currentRelation->rd_node.relNode;
+#endif
 
 	if(!IsInParallelMode())
 	{