From 1ff99c9bbbf7b26a8dc3c0c34f0a13a6bf439da7 Mon Sep 17 00:00:00 2001
From: mpoeter <manuel@manuel-poeter.at>
Date: Fri, 10 Sep 2021 11:15:37 +0200
Subject: [PATCH 1/2] Fix: truncate must not trigger intermediate commits in
 streaming trx.

---
 arangod/RocksDBEngine/RocksDBCollection.cpp | 11 ++++++-----
 1 file changed, 6 insertions(+), 5 deletions(-)

diff --git a/arangod/RocksDBEngine/RocksDBCollection.cpp b/arangod/RocksDBEngine/RocksDBCollection.cpp
index 1765765f0f3c..3182cc6ad55c 100644
--- a/arangod/RocksDBEngine/RocksDBCollection.cpp
+++ b/arangod/RocksDBEngine/RocksDBCollection.cpp
@@ -790,12 +790,16 @@ Result RocksDBCollection::truncate(transaction::Methods& trx, OperationOptions&
 
   // avoid OOM error for truncate by committing earlier
   uint64_t const prvICC = state->options().intermediateCommitCount;
-  state->options().intermediateCommitCount = std::min<uint64_t>(prvICC, 10000);
+  if (!state->hasHint(transaction::Hints::Hint::GLOBAL_MANAGED)) {
+    state->options().intermediateCommitCount = std::min<uint64_t>(prvICC, 10000);
+  }
 
   // push our current transaction on the stack
   state->beginQuery(true);
-  auto stateGuard = scopeGuard([state]() noexcept {
+  auto stateGuard = scopeGuard([state, prvICC]() noexcept {
     state->endQuery(true);
+    // reset to previous value after truncate is finished
+    state->options().intermediateCommitCount = prvICC;
   });
 
   uint64_t found = 0;
@@ -844,9 +848,6 @@ Result RocksDBCollection::truncate(transaction::Methods& trx, OperationOptions&
     trackWaitForSync(&trx, options);
   }
 
-  // reset to previous value after truncate is finished
-  state->options().intermediateCommitCount = prvICC;
-
 #ifdef ARANGODB_ENABLE_MAINTAINER_MODE
   if (state->numCommits() == 0) {
     // check IN TRANSACTION if documents have been deleted

From 7e8a12f17fc2dffbbee490064b64288bb1fd7d56 Mon Sep 17 00:00:00 2001
From: jsteemann <jsteemann@users.noreply.github.com>
Date: Fri, 10 Sep 2021 19:02:19 +0200
Subject: [PATCH 2/2] add CHANGELOG entry

---
 CHANGELOG | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/CHANGELOG b/CHANGELOG
index e4d4dc7014cb..e3fa10a81a57 100644
--- a/CHANGELOG
+++ b/CHANGELOG
@@ -1,6 +1,10 @@
 devel
 -----
 
+* Truncate must not trigger intermediate commits while in a streaming
+  transaction, because that would be against the assumption that
+  streaming transactions never do intermediate commits.
+
 * Added ArangoSearch condition optimization: STARTS_WITH is merged 
   with LEVENSHTEIN_MATCH if used in the same AND node and field name and prefix
   matches.