From 58b42fc373bfd6e17ed017122f9e03cb125575aa Mon Sep 17 00:00:00 2001
From: Anton Alkin <anton.alkin@cern.ch>
Date: Mon, 1 Jun 2026 11:34:39 +0200
Subject: [PATCH] DPL Analysis: reserve binary views to avoid arrow
 preallocating extra buffers

---
 Framework/CCDBSupport/src/AnalysisCCDBHelpers.cxx | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/Framework/CCDBSupport/src/AnalysisCCDBHelpers.cxx b/Framework/CCDBSupport/src/AnalysisCCDBHelpers.cxx
index 21fdae4a57760..483d26007d853 100644
--- a/Framework/CCDBSupport/src/AnalysisCCDBHelpers.cxx
+++ b/Framework/CCDBSupport/src/AnalysisCCDBHelpers.cxx
@@ -148,6 +148,12 @@ AlgorithmSpec AnalysisCCDBHelpers::fetchFromCCDB(ConfigContext const& /*ctx*/)
           builders.emplace_back(std::make_shared<arrow::BinaryViewBuilder>());
         }
 
+        auto reserveSize = timestampColumn->length();
+        arrow::Status status;
+        for (auto i = 0U; i < builders.size(); ++i) {
+          status &= builders[i]->Reserve(reserveSize);
+        }
+
         for (auto ci = 0; ci < timestampColumn->num_chunks(); ++ci) {
           std::shared_ptr<arrow::Array> chunk = timestampColumn->chunk(ci);
           auto const* timestamps = chunk->data()->GetValuesSafe<size_t>(1);