From d6c667946c4009be5a3c73029a2b75555467a957 Mon Sep 17 00:00:00 2001
From: Marco Slot <marco.slot@gmail.com>
Date: Sat, 29 Jun 2019 22:38:29 +0200
Subject: [PATCH] Fix citus_executor_name mapping by reimplementing it in C

---
 .../distributed/citus--8.2-3--8.2-4.sql       |  8 +++
 src/backend/distributed/citus.control         |  2 +-
 .../distributed/executor/query_stats.c        | 62 +++++++++++++++++++
 src/test/regress/expected/multi_extension.out |  6 ++
 src/test/regress/sql/multi_extension.sql      |  6 ++
 5 files changed, 83 insertions(+), 1 deletion(-)
 create mode 100644 src/backend/distributed/citus--8.2-3--8.2-4.sql

diff --git a/src/backend/distributed/citus--8.2-3--8.2-4.sql b/src/backend/distributed/citus--8.2-3--8.2-4.sql
new file mode 100644
index 000000000..424da426e
--- /dev/null
+++ b/src/backend/distributed/citus--8.2-3--8.2-4.sql
@@ -0,0 +1,8 @@
+/* citus--8.2-3--8.2-4 */
+
+CREATE OR REPLACE FUNCTION pg_catalog.citus_executor_name(executor_type int)
+RETURNS text
+LANGUAGE C STRICT
+AS 'MODULE_PATHNAME', $$citus_executor_name$$;
+COMMENT ON FUNCTION pg_catalog.citus_executor_name(int)
+IS 'return the name of the external based for the value in citus_stat_statements() output';
diff --git a/src/backend/distributed/citus.control b/src/backend/distributed/citus.control
index 8570537f0..4ca54d902 100644
--- a/src/backend/distributed/citus.control
+++ b/src/backend/distributed/citus.control
@@ -1,6 +1,6 @@
 # Citus extension
 comment = 'Citus distributed database'
-default_version = '8.2-3'
+default_version = '8.2-4'
 module_pathname = '$libdir/citus'
 relocatable = false
 schema = pg_catalog
diff --git a/src/backend/distributed/executor/query_stats.c b/src/backend/distributed/executor/query_stats.c
index 6b3cfd041..160ce1599 100644
--- a/src/backend/distributed/executor/query_stats.c
+++ b/src/backend/distributed/executor/query_stats.c
@@ -12,9 +12,14 @@
 #include "fmgr.h"
 
 #include "distributed/query_stats.h"
+#include "utils/builtins.h"
 
 PG_FUNCTION_INFO_V1(citus_stat_statements_reset);
 PG_FUNCTION_INFO_V1(citus_query_stats);
+PG_FUNCTION_INFO_V1(citus_executor_name);
+
+
+static char * CitusExecutorName(MultiExecutorType executorType);
 
 
 /* placeholder for InitializeCitusQueryStats */
@@ -58,3 +63,60 @@ citus_query_stats(PG_FUNCTION_ARGS)
 						   "Citus Enterprise")));
 	PG_RETURN_VOID();
 }
+
+
+/*
+ * citus_executor_name is a UDF that returns the name of the executor
+ * given the internal enum value.
+ */
+Datum
+citus_executor_name(PG_FUNCTION_ARGS)
+{
+	MultiExecutorType executorType = PG_GETARG_UINT32(0);
+
+	char *executorName = CitusExecutorName(executorType);
+
+	PG_RETURN_TEXT_P(cstring_to_text(executorName));
+}
+
+
+/*
+ * CitusExecutorName returns the name of the executor given the internal
+ * enum value.
+ */
+static char *
+CitusExecutorName(MultiExecutorType executorType)
+{
+	switch (executorType)
+	{
+		case MULTI_EXECUTOR_ADAPTIVE:
+		{
+			return "adaptive";
+		}
+
+		case MULTI_EXECUTOR_REAL_TIME:
+		{
+			return "real-time";
+		}
+
+		case MULTI_EXECUTOR_TASK_TRACKER:
+		{
+			return "task-tracker";
+		}
+
+		case MULTI_EXECUTOR_ROUTER:
+		{
+			return "router";
+		}
+
+		case MULTI_EXECUTOR_COORDINATOR_INSERT_SELECT:
+		{
+			return "insert-select";
+		}
+
+		default:
+		{
+			return "unknown";
+		}
+	}
+}
diff --git a/src/test/regress/expected/multi_extension.out b/src/test/regress/expected/multi_extension.out
index d9c0f4ddf..41c9de872 100644
--- a/src/test/regress/expected/multi_extension.out
+++ b/src/test/regress/expected/multi_extension.out
@@ -155,6 +155,12 @@ ALTER EXTENSION citus UPDATE TO '8.0-9';
 ALTER EXTENSION citus UPDATE TO '8.0-10';
 ALTER EXTENSION citus UPDATE TO '8.0-11';
 ALTER EXTENSION citus UPDATE TO '8.0-12';
+ALTER EXTENSION citus UPDATE TO '8.0-13';
+ALTER EXTENSION citus UPDATE TO '8.1-1';
+ALTER EXTENSION citus UPDATE TO '8.2-1';
+ALTER EXTENSION citus UPDATE TO '8.2-2';
+ALTER EXTENSION citus UPDATE TO '8.2-3';
+ALTER EXTENSION citus UPDATE TO '8.2-4';
 -- show running version
 SHOW citus.version;
  citus.version 
diff --git a/src/test/regress/sql/multi_extension.sql b/src/test/regress/sql/multi_extension.sql
index 19a852472..ba5f55e50 100644
--- a/src/test/regress/sql/multi_extension.sql
+++ b/src/test/regress/sql/multi_extension.sql
@@ -155,6 +155,12 @@ ALTER EXTENSION citus UPDATE TO '8.0-9';
 ALTER EXTENSION citus UPDATE TO '8.0-10';
 ALTER EXTENSION citus UPDATE TO '8.0-11';
 ALTER EXTENSION citus UPDATE TO '8.0-12';
+ALTER EXTENSION citus UPDATE TO '8.0-13';
+ALTER EXTENSION citus UPDATE TO '8.1-1';
+ALTER EXTENSION citus UPDATE TO '8.2-1';
+ALTER EXTENSION citus UPDATE TO '8.2-2';
+ALTER EXTENSION citus UPDATE TO '8.2-3';
+ALTER EXTENSION citus UPDATE TO '8.2-4';
 
 -- show running version
 SHOW citus.version;