Add enable_version_checks GUC and address feedback

Makefile

@@ -20,7 +20,7 @@ install-extension: extension
 install-headers: extension
 	$(MKDIR_P) '$(DESTDIR)$(includedir_server)/distributed/'
 # generated headers are located in the build directory
-	$(INSTALL_DATA) $(citus_abs_srcdir)/src/include/citus_config.h '$(DESTDIR)$(includedir_server)/'
+	$(INSTALL_DATA) $(citus_abs_srcdir)/src/include/citus_version.h '$(DESTDIR)$(includedir_server)/'
 # the rest in the source tree
 	$(INSTALL_DATA) $(citus_abs_srcdir)/src/include/distributed/*.h '$(DESTDIR)$(includedir_server)/distributed/'
 clean-extension:

src/backend/distributed/executor/multi_utility.c

@@ -83,7 +83,6 @@
 
 bool EnableDDLPropagation = true; /* ddl propagation is enabled */
 
-
 /*
  * This struct defines the state for the callback for drop statements.
  * It is copied as it is from commands/tablecmds.c in Postgres source.
@@ -173,6 +172,7 @@ multi_ProcessUtility(Node *parsetree,
 	int savedSecurityContext = 0;
 	List *ddlJobs = NIL;
 	bool extensionStatement = false;
+	bool checkExtensionVersion = false;
 
 	if (IsA(parsetree, TransactionStmt))
 	{
@@ -193,7 +193,7 @@ multi_ProcessUtility(Node *parsetree,
 		CreateExtensionStmt *createExtensionStmt = (CreateExtensionStmt *) parsetree;
 		if (strcmp(createExtensionStmt->extname, "citus") == 0)
 		{
-			ErrorIfUnstableCreateOrAlterExtensionStmt(parsetree);
+			checkExtensionVersion = true;
 		}
 
 		extensionStatement = true;
@@ -204,7 +204,7 @@ multi_ProcessUtility(Node *parsetree,
 		AlterExtensionStmt *alterExtensionStmt = (AlterExtensionStmt *) parsetree;
 		if (strcmp(alterExtensionStmt->extname, "citus") == 0)
 		{
-			ErrorIfUnstableCreateOrAlterExtensionStmt(parsetree);
+			checkExtensionVersion = true;
 		}
 
 		extensionStatement = true;
@@ -220,18 +220,23 @@ multi_ProcessUtility(Node *parsetree,
 		}
 	}
 
-	if (extensionStatement)
+	if (extensionStatement || IsA(parsetree, VariableSetStmt))
 	{
 		/*
 		 * In CitusHasBeenLoaded check below, we compare binary Citus version,
 		 * extension version and available version. If they are different, we
-		 * force user to execute ALTER EXTENSION citus UPDATE. Therefore, if
+		 * force user to execute ALTER EXTENSION citus UPDATE. Therefore, we
-		 * user executes ALTER EXTENSION or DROP EXTENSION query we should drop
+		 * drop to standard_ProcessUtility earlier for some commands which are
-		 * to the standart utility before CitusHasBeenLoaded check.
+		 * safe and necessary to user even in version mismatch situation.
 		 */
 		standard_ProcessUtility(parsetree, queryString, context,
 								params, dest, completionTag);
 
+		if (EnableVersionChecks && checkExtensionVersion)
+		{
+			ErrorIfUnstableCreateOrAlterExtensionStmt(parsetree);
+		}
+
 		return;
 	}
 
@@ -1310,7 +1315,7 @@ DeparseVacuumColumnNames(List *columnNameList)
  * ErrorIfUnstableCreateOrAlterExtensionStmt compares CITUS_EXTENSIONVERSION
  * and version given CREATE/ALTER EXTENSION statement will create/update to. If
  * they are not same in major or minor version numbers, this function errors
- * out. It ignores the catalog version.
+ * out. It ignores the schema version.
  */
 static void
 ErrorIfUnstableCreateOrAlterExtensionStmt(Node *parsetree)
@@ -1342,7 +1347,7 @@ ErrorIfUnstableCreateOrAlterExtensionStmt(Node *parsetree)
 		{
 			char *newVersion = strVal(defElement->arg);
 
-			if (!CompareVersions(newVersion, CITUS_EXTENSIONVERSION))
+			if (!MajorVersionsCompatible(newVersion, CITUS_EXTENSIONVERSION))
 			{
 				ereport(ERROR, (errmsg("requested version is not compatible with "
 									   "loaded Citus binaries.")));
@@ -1354,11 +1359,11 @@ ErrorIfUnstableCreateOrAlterExtensionStmt(Node *parsetree)
 
 	/*
 	 * new_version is not specified in ALTER EXTENSION statement, PostgreSQL will use
-	 * default_version from citus.control file. We will flush availableMajorVersion to
+	 * default_version from citus.control file. We will flush availableExtensionVersion
-	 * re-check the available version from citus.control file.
+	 * to re-check the available version from citus.control file.
 	 */
-	availableMajorVersion = NULL;
+	availableExtensionVersion = NULL;
-	ErrorIfNewMajorVersionAvailable();
+	ErrorIfAvailableVersionMismatch();
 }
 
 

src/backend/distributed/shared_library_init.c

@@ -49,7 +49,7 @@
 /* marks shared object as one loadable by the postgres version compiled against */
 PG_MODULE_MAGIC;
 
-static char *CitusVersion;
+static char *CitusVersion = CITUS_VERSION;
 
 void _PG_init(void);
 
@@ -623,6 +623,16 @@ RegisterCitusConfigVariables(void)
 		0,
 		NULL, NULL, NULL);
 
+	DefineCustomBoolVariable(
+		"citus.enable_version_checks",
+		gettext_noop("Enables version checks in CREATE/ALTER extension queries"),
+		NULL,
+		&EnableVersionChecks,
+		true,
+		PGC_USERSET,
+		GUC_NO_SHOW_ALL,
+		NULL, NULL, NULL);
+
 	/* warn about config items in the citus namespace that are not registered above */
 	EmitWarningsOnPlaceholders("citus");
 }

src/backend/distributed/utils/metadata_cache.c

@@ -100,8 +100,10 @@ static Oid distTransactionRelationId = InvalidOid;
 static Oid distTransactionGroupIndexId = InvalidOid;
 static Oid extraDataContainerFuncId = InvalidOid;
 
-/* Citus installed extension version */
+/* Citus extension version variables */
-char *availableMajorVersion = NULL;
+bool EnableVersionChecks = true; /* version checks are enabled */
+
+char *availableExtensionVersion = NULL;
 static char *installedExtensionVersion = NULL;
 
 /* Hash table for informations about each partition */
@@ -139,8 +141,8 @@ static bool HasUniformHashDistribution(ShardInterval **shardIntervalArray,
 									   int shardIntervalArrayLength);
 static bool HasUninitializedShardInterval(ShardInterval **sortedShardIntervalArray,
 										  int shardCount);
-static void ErrorIfExtensionUpdateNeeded(void);
+static void ErrorIfInstalledVersionMismatch(void);
-static char * AvailableMajorVersion(void);
+static char * AvailableExtensionVersion(void);
 static char * InstalledExtensionVersion(void);
 static void InitializeDistTableCache(void);
 static void InitializeWorkerNodeCache(void);
@@ -984,8 +986,8 @@ CitusHasBeenLoaded(void)
 
 	if (extensionLoaded)
 	{
-		ErrorIfNewMajorVersionAvailable();
+		ErrorIfAvailableVersionMismatch();
-		ErrorIfExtensionUpdateNeeded();
+		ErrorIfInstalledVersionMismatch();
 	}
 
 	return extensionLoaded;
@@ -993,16 +995,23 @@ CitusHasBeenLoaded(void)
 
 
 /*
- * ErrorIfNewMajorVersionAvailable compares CITUS_EXTENSIONVERSION and currently
+ * ErrorIfAvailableExtensionVersionMismatch compares CITUS_EXTENSIONVERSION and
- * available version from citus.control file. If they are not same in major or
+ * currently available version from citus.control file. If they are not same in
- * minor version numbers, this function errors out. It ignores the schema version.
+ * major or minor version numbers, this function errors out. It ignores the schema
+ * version.
  */
 void
-ErrorIfNewMajorVersionAvailable(void)
+ErrorIfAvailableVersionMismatch(void)
 {
-	char *availableVersion = AvailableMajorVersion();
+	char *availableVersion = NULL;
 
-	if (!CompareVersions(availableVersion, CITUS_EXTENSIONVERSION))
+	if (!EnableVersionChecks)
+	{
+		return;
+	}
+
+	availableVersion = AvailableExtensionVersion();
+	if (!MajorVersionsCompatible(availableVersion, CITUS_EXTENSIONVERSION))
 	{
 		ereport(ERROR, (errmsg("server restart is needed because, loaded Citus binaries "
 							   "does not match the available extension version")));
@@ -1011,16 +1020,23 @@ ErrorIfNewMajorVersionAvailable(void)
 
 
 /*
- * ErrorIfExtensionUpdateNeeded compares CITUS_EXTENSIONVERSION and currently and
+ * ErrorIfInstalledVersionMismatch compares CITUS_EXTENSIONVERSION and currently
- * catalog version from pg_extemsion catalog table. If they are not same in major or
+ * and catalog version from pg_extemsion catalog table. If they are not same in
- * minor version numbers, this function errors out. It ignores the schema version.
+ * major or minor version numbers, this function errors out. It ignores the schema
+ * version.
  */
 static void
-ErrorIfExtensionUpdateNeeded(void)
+ErrorIfInstalledVersionMismatch(void)
 {
-	char *installedVersion = InstalledExtensionVersion();
+	char *installedVersion = NULL;
 
-	if (!CompareVersions(installedVersion, CITUS_EXTENSIONVERSION))
+	if (!EnableVersionChecks)
+	{
+		return;
+	}
+
+	installedVersion = InstalledExtensionVersion();
+	if (!MajorVersionsCompatible(installedVersion, CITUS_EXTENSIONVERSION))
 	{
 		ereport(ERROR, (errmsg("\"ALTER EXTENSION citus UPDATE;\" is needed, because "
 							   "loaded Citus binaries does not match the installed "
@@ -1030,36 +1046,55 @@ ErrorIfExtensionUpdateNeeded(void)
 
 
 /*
- * CompareVersions compares given two versions. If they are same in major and
+ * MajorVersionsCompatible compares given two versions. If they are same in major
- * minor version numbers, this function returns true. It ignores the schema version.
+ * and minor version numbers, this function returns true. It ignores the schema
+ * version.
  */
 bool
-CompareVersions(char *leftVersion, char *rightVersion)
+MajorVersionsCompatible(char *leftVersion, char *rightVersion)
 {
 	const char schemaVersionSeparator = '-';
-	char *seperatorPosition = strchr(leftVersion, schemaVersionSeparator);
-	int comparisionLimit = 0;
 
-	if (seperatorPosition != NULL)
+	char *leftSeperatorPosition = strchr(leftVersion, schemaVersionSeparator);
+	char *rightSeperatorPosition = strchr(rightVersion, schemaVersionSeparator);
+	int leftComparisionLimit = 0;
+	int rightComparisionLimit = 0;
+
+	if (leftSeperatorPosition != NULL)
 	{
-		comparisionLimit = seperatorPosition - leftVersion;
+		leftComparisionLimit = leftSeperatorPosition - leftVersion;
 	}
 	else
 	{
-		comparisionLimit = strlen(leftVersion);
+		leftComparisionLimit = strlen(leftVersion);
 	}
 
-	return strncmp(leftVersion, rightVersion, comparisionLimit) == 0;
+	if (rightSeperatorPosition != NULL)
+	{
+		rightComparisionLimit = rightSeperatorPosition - rightVersion;
+	}
+	else
+	{
+		rightComparisionLimit = strlen(leftVersion);
+	}
+
+	/* we can error out early if hypens are not in the same position */
+	if (leftComparisionLimit != rightComparisionLimit)
+	{
+		return false;
+	}
+
+	return strncmp(leftVersion, rightVersion, leftComparisionLimit) == 0;
 }
 
 
 /*
- * AvailableMajorVersion returns the Citus version from citus.control file. It also
+ * AvailableExtensionVersion returns the Citus version from citus.control file. It also
  * saves the result, thus consecutive calls to CitusExtensionAvailableVersion will
  * not read the citus.control file again.
  */
 static char *
-AvailableMajorVersion(void)
+AvailableExtensionVersion(void)
 {
 	ReturnSetInfo *extensionsResultSet = NULL;
 	TupleTableSlot *tupleTableSlot = NULL;
@@ -1073,9 +1108,9 @@ AvailableMajorVersion(void)
 	bool doCopy = false;
 
 	/* if we cached the result before, return it*/
-	if (availableMajorVersion != NULL)
+	if (availableExtensionVersion != NULL)
 	{
-		return availableMajorVersion;
+		return availableExtensionVersion;
 	}
 
 	estate = CreateExecutorState();
@@ -1107,7 +1142,7 @@ AvailableMajorVersion(void)
 		if (strcmp(extensionName, "citus") == 0)
 		{
 			MemoryContext oldMemoryContext = NULL;
-			Datum citusVersionDatum = slot_getattr(tupleTableSlot, 2, &isNull);
+			Datum availableVersion = slot_getattr(tupleTableSlot, 2, &isNull);
 
 			/* we will cache the result of citus version to prevent catalog access */
 			if (CacheMemoryContext == NULL)
@@ -1116,14 +1151,14 @@ AvailableMajorVersion(void)
 			}
 			oldMemoryContext = MemoryContextSwitchTo(CacheMemoryContext);
 
-			availableMajorVersion = text_to_cstring(DatumGetTextPP(citusVersionDatum));
+			availableExtensionVersion = text_to_cstring(DatumGetTextPP(availableVersion));
 
 			MemoryContextSwitchTo(oldMemoryContext);
 
 			ExecClearTuple(tupleTableSlot);
 			ExecDropSingleTupleTableSlot(tupleTableSlot);
 
-			return availableMajorVersion;
+			return availableExtensionVersion;
 		}
 
 		ExecClearTuple(tupleTableSlot);
@@ -1177,8 +1212,8 @@ InstalledExtensionVersion(void)
 		TupleDesc tupleDescriptor = RelationGetDescr(relation);
 		bool isNull = false;
 
-		Datum extensionVersionDatum = heap_getattr(extensionTuple, extensionIndex,
+		Datum installedVersion = heap_getattr(extensionTuple, extensionIndex,
-												   tupleDescriptor, &isNull);
+											  tupleDescriptor, &isNull);
 
 		if (isNull)
 		{
@@ -1194,8 +1229,7 @@ InstalledExtensionVersion(void)
 
 		oldMemoryContext = MemoryContextSwitchTo(CacheMemoryContext);
 
-		installedExtensionVersion = text_to_cstring(DatumGetTextPP(
+		installedExtensionVersion = text_to_cstring(DatumGetTextPP(installedVersion));
-														extensionVersionDatum));
 
 		MemoryContextSwitchTo(oldMemoryContext);
 	}

src/include/distributed/metadata_cache.h

@@ -17,7 +17,8 @@
 #include "distributed/worker_manager.h"
 #include "utils/hsearch.h"
 
-extern char *availableMajorVersion;
+extern bool EnableVersionChecks;
+extern char *availableExtensionVersion;
 
 /*
  * Representation of a table's metadata that is frequently used for
@@ -69,8 +70,8 @@ extern void CitusInvalidateRelcacheByRelid(Oid relationId);
 extern void CitusInvalidateRelcacheByShardId(int64 shardId);
 
 extern bool CitusHasBeenLoaded(void);
-void ErrorIfNewMajorVersionAvailable(void);
+void ErrorIfAvailableVersionMismatch(void);
-bool CompareVersions(char *leftVersion, char *rightVersion);
+bool MajorVersionsCompatible(char *leftVersion, char *rightVersion);
 
 /* access WorkerNodeHash */
 extern HTAB * GetWorkerNodeHash(void);

src/include/distributed/multi_utility.h

@@ -13,6 +13,7 @@
 #include "tcop/utility.h"
 
 extern bool EnableDDLPropagation;
+extern bool EnableVersionChecks;
 
 /*
  * A DDLJob encapsulates the remote tasks and commands needed to process all or

src/test/regress/expected/multi_extension.out

@@ -24,11 +24,59 @@ WHERE pgd.refclassid = 'pg_extension'::regclass AND
 -- DROP EXTENSION pre-created by the regression suite
 DROP EXTENSION citus;
 \c
--- Create extension in oldest version, this is expected to fail
+SET citus.enable_version_checks TO 'false';
+-- Create extension in oldest version
 CREATE EXTENSION citus VERSION '5.0';
-ERROR:  requested version is not compatible with loaded Citus binaries.
+ALTER EXTENSION citus UPDATE TO '5.0-1';
--- Create extension in newest major version, test every upgrade step
+ALTER EXTENSION citus UPDATE TO '5.0-2';
-CREATE EXTENSION citus VERSION '6.2-1';
+ALTER EXTENSION citus UPDATE TO '5.1-1';
+ALTER EXTENSION citus UPDATE TO '5.1-2';
+ALTER EXTENSION citus UPDATE TO '5.1-3';
+ALTER EXTENSION citus UPDATE TO '5.1-4';
+ALTER EXTENSION citus UPDATE TO '5.1-5';
+ALTER EXTENSION citus UPDATE TO '5.1-6';
+ALTER EXTENSION citus UPDATE TO '5.1-7';
+ALTER EXTENSION citus UPDATE TO '5.1-8';
+ALTER EXTENSION citus UPDATE TO '5.2-1';
+ALTER EXTENSION citus UPDATE TO '5.2-2';
+ALTER EXTENSION citus UPDATE TO '5.2-3';
+ALTER EXTENSION citus UPDATE TO '5.2-4';
+ALTER EXTENSION citus UPDATE TO '6.0-1';
+ALTER EXTENSION citus UPDATE TO '6.0-2';
+ALTER EXTENSION citus UPDATE TO '6.0-3';
+ALTER EXTENSION citus UPDATE TO '6.0-4';
+ALTER EXTENSION citus UPDATE TO '6.0-5';
+ALTER EXTENSION citus UPDATE TO '6.0-6';
+ALTER EXTENSION citus UPDATE TO '6.0-7';
+ALTER EXTENSION citus UPDATE TO '6.0-8';
+ALTER EXTENSION citus UPDATE TO '6.0-9';
+ALTER EXTENSION citus UPDATE TO '6.0-10';
+ALTER EXTENSION citus UPDATE TO '6.0-11';
+ALTER EXTENSION citus UPDATE TO '6.0-12';
+ALTER EXTENSION citus UPDATE TO '6.0-13';
+ALTER EXTENSION citus UPDATE TO '6.0-14';
+ALTER EXTENSION citus UPDATE TO '6.0-15';
+ALTER EXTENSION citus UPDATE TO '6.0-16';
+ALTER EXTENSION citus UPDATE TO '6.0-17';
+ALTER EXTENSION citus UPDATE TO '6.0-18';
+ALTER EXTENSION citus UPDATE TO '6.1-1';
+ALTER EXTENSION citus UPDATE TO '6.1-2';
+ALTER EXTENSION citus UPDATE TO '6.1-3';
+ALTER EXTENSION citus UPDATE TO '6.1-4';
+ALTER EXTENSION citus UPDATE TO '6.1-5';
+ALTER EXTENSION citus UPDATE TO '6.1-6';
+ALTER EXTENSION citus UPDATE TO '6.1-7';
+ALTER EXTENSION citus UPDATE TO '6.1-8';
+ALTER EXTENSION citus UPDATE TO '6.1-9';
+ALTER EXTENSION citus UPDATE TO '6.1-10';
+ALTER EXTENSION citus UPDATE TO '6.1-11';
+ALTER EXTENSION citus UPDATE TO '6.1-12';
+ALTER EXTENSION citus UPDATE TO '6.1-13';
+ALTER EXTENSION citus UPDATE TO '6.1-14';
+ALTER EXTENSION citus UPDATE TO '6.1-15';
+ALTER EXTENSION citus UPDATE TO '6.1-16';
+ALTER EXTENSION citus UPDATE TO '6.1-17';
+ALTER EXTENSION citus UPDATE TO '6.2-1';
 ALTER EXTENSION citus UPDATE TO '6.2-2';
 -- show running version
 SHOW citus.version;
@@ -51,7 +99,11 @@ WHERE pgd.refclassid = 'pg_extension'::regclass AND
      0
 (1 row)
 
--- drop extension an re-create in newest version
+-- see incompatible version errors out
 DROP EXTENSION citus;
 \c
+CREATE EXTENSION citus VERSION '5.0';
+ERROR:  requested version is not compatible with loaded Citus binaries.
+-- re-create in newest version
+\c
 CREATE EXTENSION citus;

src/test/regress/sql/multi_extension.sql

@@ -24,11 +24,60 @@ WHERE pgd.refclassid = 'pg_extension'::regclass AND
 DROP EXTENSION citus;
 \c
 
--- Create extension in oldest version, this is expected to fail
+SET citus.enable_version_checks TO 'false';
-CREATE EXTENSION citus VERSION '5.0';
 
--- Create extension in newest major version, test every upgrade step
+-- Create extension in oldest version
-CREATE EXTENSION citus VERSION '6.2-1';
+CREATE EXTENSION citus VERSION '5.0';
+ALTER EXTENSION citus UPDATE TO '5.0-1';
+ALTER EXTENSION citus UPDATE TO '5.0-2';
+ALTER EXTENSION citus UPDATE TO '5.1-1';
+ALTER EXTENSION citus UPDATE TO '5.1-2';
+ALTER EXTENSION citus UPDATE TO '5.1-3';
+ALTER EXTENSION citus UPDATE TO '5.1-4';
+ALTER EXTENSION citus UPDATE TO '5.1-5';
+ALTER EXTENSION citus UPDATE TO '5.1-6';
+ALTER EXTENSION citus UPDATE TO '5.1-7';
+ALTER EXTENSION citus UPDATE TO '5.1-8';
+ALTER EXTENSION citus UPDATE TO '5.2-1';
+ALTER EXTENSION citus UPDATE TO '5.2-2';
+ALTER EXTENSION citus UPDATE TO '5.2-3';
+ALTER EXTENSION citus UPDATE TO '5.2-4';
+ALTER EXTENSION citus UPDATE TO '6.0-1';
+ALTER EXTENSION citus UPDATE TO '6.0-2';
+ALTER EXTENSION citus UPDATE TO '6.0-3';
+ALTER EXTENSION citus UPDATE TO '6.0-4';
+ALTER EXTENSION citus UPDATE TO '6.0-5';
+ALTER EXTENSION citus UPDATE TO '6.0-6';
+ALTER EXTENSION citus UPDATE TO '6.0-7';
+ALTER EXTENSION citus UPDATE TO '6.0-8';
+ALTER EXTENSION citus UPDATE TO '6.0-9';
+ALTER EXTENSION citus UPDATE TO '6.0-10';
+ALTER EXTENSION citus UPDATE TO '6.0-11';
+ALTER EXTENSION citus UPDATE TO '6.0-12';
+ALTER EXTENSION citus UPDATE TO '6.0-13';
+ALTER EXTENSION citus UPDATE TO '6.0-14';
+ALTER EXTENSION citus UPDATE TO '6.0-15';
+ALTER EXTENSION citus UPDATE TO '6.0-16';
+ALTER EXTENSION citus UPDATE TO '6.0-17';
+ALTER EXTENSION citus UPDATE TO '6.0-18';
+ALTER EXTENSION citus UPDATE TO '6.1-1';
+ALTER EXTENSION citus UPDATE TO '6.1-2';
+ALTER EXTENSION citus UPDATE TO '6.1-3';
+ALTER EXTENSION citus UPDATE TO '6.1-4';
+ALTER EXTENSION citus UPDATE TO '6.1-5';
+ALTER EXTENSION citus UPDATE TO '6.1-6';
+ALTER EXTENSION citus UPDATE TO '6.1-7';
+ALTER EXTENSION citus UPDATE TO '6.1-8';
+ALTER EXTENSION citus UPDATE TO '6.1-9';
+ALTER EXTENSION citus UPDATE TO '6.1-10';
+ALTER EXTENSION citus UPDATE TO '6.1-11';
+ALTER EXTENSION citus UPDATE TO '6.1-12';
+ALTER EXTENSION citus UPDATE TO '6.1-13';
+ALTER EXTENSION citus UPDATE TO '6.1-14';
+ALTER EXTENSION citus UPDATE TO '6.1-15';
+ALTER EXTENSION citus UPDATE TO '6.1-16';
+ALTER EXTENSION citus UPDATE TO '6.1-17';
+ALTER EXTENSION citus UPDATE TO '6.2-1';
 ALTER EXTENSION citus UPDATE TO '6.2-2';
 
 -- show running version
@@ -44,7 +93,11 @@ WHERE pgd.refclassid = 'pg_extension'::regclass AND
 	  pge.extname    = 'citus' AND
 	  pgio.schema    NOT IN ('pg_catalog', 'citus');
 
--- drop extension an re-create in newest version
+-- see incompatible version errors out
 DROP EXTENSION citus;
 \c
+CREATE EXTENSION citus VERSION '5.0';
+
+-- re-create in newest version
+\c
 CREATE EXTENSION citus;