SERVER-54597: Allow users to specify non-default collation on TS

4 files changed, 36 insertions, 15 deletions

diff --git a/src/mongo/db/commands/run_aggregate.cpp b/src/mongo/db/commands/run_aggregate.cpp
index 81d0b66e25a..23099af5e82 100644
--- a/src/mongo/db/commands/run_aggregate.cpp
+++ b/src/mongo/db/commands/run_aggregate.cpp
@@ -312,7 +312,7 @@ StatusWith<StringMap<ExpressionContext::ResolvedNamespace>> resolveInvolvedNames
         // If 'ns' refers to a view namespace, then we resolve its definition.
         auto resolveViewDefinition = [&](const NamespaceString& ns,
                                          std::shared_ptr<const ViewCatalog> vcp) -> Status {
-            auto resolvedView = vcp->resolveView(opCtx, ns);
+            auto resolvedView = vcp->resolveView(opCtx, ns, boost::none);
             if (!resolvedView.isOK()) {
                 return resolvedView.getStatus().withContext(
                     str::stream() << "Failed to resolve view '" << involvedNs.ns());
@@ -417,7 +417,7 @@ Status collatorCompatibleWithPipeline(OperationContext* opCtx,
         }
         if (!CollatorInterface::collatorsMatch(view->defaultCollator(), collator)) {
             return {ErrorCodes::OptionNotSupportedOnView,
-                    str::stream() << "Cannot override default collation of view "
+                    str::stream() << "Cannot override a view's default collation"
                                   << potentialViewNs.ns()};
         }
     }
@@ -681,16 +681,23 @@ Status runAggregate(OperationContext* opCtx,
             if (!request.getCollation().get_value_or(BSONObj()).isEmpty()) {
                 invariant(collatorToUse);  // Should already be resolved at this point.
                 if (!CollatorInterface::collatorsMatch(ctx->getView()->defaultCollator(),
-                                                       collatorToUse->get())) {
+                                                       collatorToUse->get()) &&
+                    !ctx->getView()->timeseries()) {
+
                     return {ErrorCodes::OptionNotSupportedOnView,
                             "Cannot override a view's default collation"};
                 }
             }
 
-
+            // Queries on timeseries views may specify non-default collation whereas queries
+            // on all other types of views must match the default collator (the collation use
+            // to originally create that collections). Thus in the case of operations on TS
+            // views, we use the request's collation.
+            auto timeSeriesCollator =
+                ctx->getView()->timeseries() ? request.getCollation() : boost::none;
             auto resolvedView = uassertStatusOK(DatabaseHolder::get(opCtx)
                                                     ->getViewCatalog(opCtx, nss.db())
-                                                    ->resolveView(opCtx, nss));
+                                                    ->resolveView(opCtx, nss, timeSeriesCollator));
 
             // With the view & collation resolved, we can relinquish locks.
             ctx.reset();
diff --git a/src/mongo/db/views/view_catalog.cpp b/src/mongo/db/views/view_catalog.cpp
index e84d0c0fa69..84e0f7b46a8 100644
--- a/src/mongo/db/views/view_catalog.cpp
+++ b/src/mongo/db/views/view_catalog.cpp
@@ -714,8 +714,10 @@ std::shared_ptr<const ViewDefinition> ViewCatalog::lookupWithoutValidatingDurabl
     return _lookup(opCtx, ns, ViewCatalogLookupBehavior::kAllowInvalidDurableViews);
 }
 
-StatusWith<ResolvedView> ViewCatalog::resolveView(OperationContext* opCtx,
-                                                  const NamespaceString& nss) const {
+StatusWith<ResolvedView> ViewCatalog::resolveView(
+    OperationContext* opCtx,
+    const NamespaceString& nss,
+    boost::optional<BSONObj> timeSeriesCollator) const {
     _requireValidCatalog();
 
     // Keep looping until the resolution completes. If the catalog is invalidated during the
@@ -765,8 +767,13 @@ StatusWith<ResolvedView> ViewCatalog::resolveView(OperationContext* opCtx,
             resolvedNss = &view->viewOn();
             dependencyChain.push_back(*resolvedNss);
             if (!collation) {
-                collation = view->defaultCollator() ? view->defaultCollator()->getSpec().toBSON()
-                                                    : CollationSpec::kSimpleSpec;
+                if (timeSeriesCollator) {
+                    collation = *timeSeriesCollator;
+                } else {
+                    collation = view->defaultCollator()
+                        ? view->defaultCollator()->getSpec().toBSON()
+                        : CollationSpec::kSimpleSpec;
+                }
             }
 
             // Prepend the underlying view's pipeline to the current working pipeline.
diff --git a/src/mongo/db/views/view_catalog.h b/src/mongo/db/views/view_catalog.h
index 0903fb46cb3..b118c532c4c 100644
--- a/src/mongo/db/views/view_catalog.h
+++ b/src/mongo/db/views/view_catalog.h
@@ -136,8 +136,15 @@ public:
      * Resolve the views on 'nss', transforming the pipeline appropriately. This function returns a
      * fully-resolved view definition containing the backing namespace, the resolved pipeline and
      * the collation to use for the operation.
-     */
-    StatusWith<ResolvedView> resolveView(OperationContext* opCtx, const NamespaceString& nss) const;
+     *
+     * With SERVER-54597, we allow queries on timeseries collections *only* to specify non-default
+     * collations. So in the case of queries on timeseries collections, we create a ResolvedView
+     * with the request's collation (timeSeriesCollator) rather than the collection's default
+     * collator.
+     */
+    StatusWith<ResolvedView> resolveView(OperationContext* opCtx,
+                                         const NamespaceString& nss,
+                                         boost::optional<BSONObj> timeseriesCollator) const;
 
     /**
      * Usage statistics about this view catalog.
diff --git a/src/mongo/db/views/view_catalog_test.cpp b/src/mongo/db/views/view_catalog_test.cpp
index 8dedba3d753..f468f5feac9 100644
--- a/src/mongo/db/views/view_catalog_test.cpp
+++ b/src/mongo/db/views/view_catalog_test.cpp
@@ -673,7 +673,7 @@ TEST_F(ViewCatalogFixture, ResolveViewCorrectPipeline) {
     ASSERT_OK(createView(operationContext(), view3, view2, pipeline3.arr(), emptyCollation));
 
     Lock::DBLock dbLock(operationContext(), "db", MODE_IX);
-    auto resolvedView = getViewCatalog()->resolveView(operationContext(), view3);
+    auto resolvedView = getViewCatalog()->resolveView(operationContext(), view3, boost::none);
     ASSERT(resolvedView.isOK());
 
     std::vector<BSONObj> expected = {BSON("$match" << BSON("foo" << 1)),
@@ -693,8 +693,8 @@ TEST_F(ViewCatalogFixture, ResolveViewOnCollectionNamespace) {
     const NamespaceString collectionNamespace("db.coll");
 
     Lock::DBLock dbLock(operationContext(), "db", MODE_IS);
-    auto resolvedView =
-        uassertStatusOK(getViewCatalog()->resolveView(operationContext(), collectionNamespace));
+    auto resolvedView = uassertStatusOK(
+        getViewCatalog()->resolveView(operationContext(), collectionNamespace, boost::none));
 
     ASSERT_EQ(resolvedView.getNamespace(), collectionNamespace);
     ASSERT_EQ(resolvedView.getPipeline().size(), 0U);
@@ -717,7 +717,7 @@ TEST_F(ViewCatalogFixture, ResolveViewCorrectlyExtractsDefaultCollation) {
     ASSERT_OK(createView(operationContext(), view2, view1, pipeline2.arr(), collation));
 
     Lock::DBLock dbLock(operationContext(), "db", MODE_IS);
-    auto resolvedView = getViewCatalog()->resolveView(operationContext(), view2);
+    auto resolvedView = getViewCatalog()->resolveView(operationContext(), view2, boost::none);
     ASSERT(resolvedView.isOK());
 
     ASSERT_EQ(resolvedView.getValue().getNamespace(), viewOn);