SERVER-22078 Remove term list limits for text index in FCV 4.2

1 files changed, 24 insertions, 13 deletions

diff --git a/src/mongo/db/fts/fts_index_format.cpp b/src/mongo/db/fts/fts_index_format.cpp
index 770930e90c1..2b0477a5d31 100644
--- a/src/mongo/db/fts/fts_index_format.cpp
+++ b/src/mongo/db/fts/fts_index_format.cpp
@@ -36,6 +36,7 @@
 #include "mongo/db/bson/dotted_path_support.h"
 #include "mongo/db/fts/fts_index_format.h"
 #include "mongo/db/fts/fts_spec.h"
+#include "mongo/db/server_options.h"
 #include "mongo/util/hex.h"
 #include "mongo/util/md5.hpp"
 #include "mongo/util/mongoutils/str.h"
@@ -160,12 +161,17 @@ void FTSIndexFormat::getKeys(const FTSSpec& spec, const BSONObj& obj, BSONObjSet
     // create index keys from raw scores
     // only 1 per string
 
-    uassert(16732,
-            mongoutils::str::stream() << "too many unique keys for a single document to"
-                                      << " have a text index, max is "
-                                      << term_freqs.size()
-                                      << obj["_id"],
-            term_freqs.size() <= 400000);
+    // TODO SERVER-36440: Completely remove this limit in 4.3.
+    if (serverGlobalParams.featureCompatibility.isVersionInitialized() &&
+        serverGlobalParams.featureCompatibility.getVersion() ==
+            ServerGlobalParams::FeatureCompatibility::Version::kFullyDowngradedTo40) {
+        uassert(16732,
+                mongoutils::str::stream() << "too many unique keys for a single document to"
+                                          << " have a text index, max is "
+                                          << term_freqs.size()
+                                          << obj["_id"],
+                term_freqs.size() <= 400000);
+    }
 
     long long keyBSONSize = 0;
     const int MaxKeyBSONSizeMB = 4;
@@ -194,13 +200,18 @@ void FTSIndexFormat::getKeys(const FTSSpec& spec, const BSONObj& obj, BSONObjSet
         keys->insert(res);
         keyBSONSize += res.objsize();
 
-        uassert(16733,
-                mongoutils::str::stream()
-                    << "trying to index text where term list is too big, max is "
-                    << MaxKeyBSONSizeMB
-                    << "mb "
-                    << obj["_id"],
-                keyBSONSize <= (MaxKeyBSONSizeMB * 1024 * 1024));
+        // TODO SERVER-36440: Completely remove this limit in 4.3.
+        if (serverGlobalParams.featureCompatibility.isVersionInitialized() &&
+            serverGlobalParams.featureCompatibility.getVersion() ==
+                ServerGlobalParams::FeatureCompatibility::Version::kFullyDowngradedTo40) {
+            uassert(16733,
+                    mongoutils::str::stream()
+                        << "trying to index text where term list is too big, max is "
+                        << MaxKeyBSONSizeMB
+                        << "mb "
+                        << obj["_id"],
+                    keyBSONSize <= (MaxKeyBSONSizeMB * 1024 * 1024));
+        }
     }
 }