From be2bec0b61e5a943df0f32cfd52ace9ef4dafa6c Mon Sep 17 00:00:00 2001
From: naisila <nicypp@gmail.com>
Date: Tue, 9 Jul 2024 17:19:21 +0200
Subject: [PATCH] attstattarget is nullable, define pg compatible functions for
 it

Relevant PG commit:
4f622503d6de975ac87448aea5cea7de4bc140d5
https://github.com/postgres/postgres/commit/4f622503d6de975ac87448aea5cea7de4bc140d5
---
 src/backend/distributed/commands/statistics.c |  5 ++--
 .../distributed/deparser/citus_ruleutils.c    |  9 ++++++--
 src/include/pg_version_compat.h               | 23 +++++++++++++++++++
 3 files changed, 33 insertions(+), 4 deletions(-)

diff --git a/src/backend/distributed/commands/statistics.c b/src/backend/distributed/commands/statistics.c
index 45d79afe4..223e8f612 100644
--- a/src/backend/distributed/commands/statistics.c
+++ b/src/backend/distributed/commands/statistics.c
@@ -651,14 +651,15 @@ GetAlterIndexStatisticsCommands(Oid indexOid)
 		}
 
 		Form_pg_attribute targetAttr = (Form_pg_attribute) GETSTRUCT(attTuple);
-		if (targetAttr->attstattarget != DEFAULT_STATISTICS_TARGET)
+		int32 targetAttstattarget = getAttstattarget_compat(attTuple);
+		if (targetAttstattarget != DEFAULT_STATISTICS_TARGET)
 		{
 			char *indexNameWithSchema = generate_qualified_relation_name(indexOid);
 
 			char *command =
 				GenerateAlterIndexColumnSetStatsCommand(indexNameWithSchema,
 														targetAttr->attnum,
-														targetAttr->attstattarget);
+														targetAttstattarget);
 
 			alterIndexStatisticsCommandList =
 				lappend(alterIndexStatisticsCommandList,
diff --git a/src/backend/distributed/deparser/citus_ruleutils.c b/src/backend/distributed/deparser/citus_ruleutils.c
index 3b387799b..87868238c 100644
--- a/src/backend/distributed/deparser/citus_ruleutils.c
+++ b/src/backend/distributed/deparser/citus_ruleutils.c
@@ -738,7 +738,12 @@ pg_get_tablecolumnoptionsdef_string(Oid tableRelationId)
 			 * If the user changed the column's statistics target, create
 			 * alter statement and add statement to a list for later processing.
 			 */
-			if (attributeForm->attstattarget >= 0)
+			HeapTuple tp = SearchSysCache2(ATTNUM,
+										   ObjectIdGetDatum(tableRelationId),
+										   Int16GetDatum(attributeForm->attnum));
+			int32 targetAttstattarget = getAttstattarget_compat(tp);
+			ReleaseSysCache(tp);
+			if (targetAttstattarget >= 0)
 			{
 				StringInfoData statement = { NULL, 0, 0, 0 };
 				initStringInfo(&statement);
@@ -746,7 +751,7 @@ pg_get_tablecolumnoptionsdef_string(Oid tableRelationId)
 				appendStringInfo(&statement, "ALTER COLUMN %s ",
 								 quote_identifier(attributeName));
 				appendStringInfo(&statement, "SET STATISTICS %d",
-								 attributeForm->attstattarget);
+								 targetAttstattarget);
 
 				columnOptionList = lappend(columnOptionList, statement.data);
 			}
diff --git a/src/include/pg_version_compat.h b/src/include/pg_version_compat.h
index 1407eccef..919c1f7bc 100644
--- a/src/include/pg_version_compat.h
+++ b/src/include/pg_version_compat.h
@@ -70,6 +70,29 @@ RangeVarCallbackOwnsTable(const RangeVar *relation,
 }
 
 
+#include "catalog/pg_attribute.h"
+#include "utils/syscache.h"
+
+static inline int32
+getAttstattarget_compat(HeapTuple attTuple)
+{
+	bool isnull;
+	Datum dat = SysCacheGetAttr(ATTNUM, attTuple,
+								Anum_pg_attribute_attstattarget, &isnull);
+	return (isnull ? -1 : DatumGetInt16(dat));
+}
+
+
+#else
+
+#include "access/htup_details.h"
+static inline int32
+getAttstattarget_compat(HeapTuple attTuple)
+{
+	return ((Form_pg_attribute) GETSTRUCT(attTuple))->attstattarget;
+}
+
+
 #endif
 
 #if PG_VERSION_NUM >= PG_VERSION_16