Resolve "cta-statistics-update can fail for catalogues in postgres"

ReleaseNotes.md

@@ -12,6 +12,7 @@
 - cta/CTA#251 - Increase free drive STALE threshold to 4 hours
 - cta/CTA#218 - Do not retry during repack requests
 ### Bug Fixes
+- cta/CTA#181 - cta-statistics-update can fail for catalogues in postgres
 - cta/CTA#234 - Replace stoi with toUint64 in standalone cli tool
 - cta/CTA#238 - Compilation fails when using cta::common::Configuration::getConfEntInt(...)
 ### Continuous Integration

statistics/DatabaseStatisticsService.cpp

@@ -16,6 +16,7 @@
  */
 
 #include <string>
+#include <vector>
 
 #include "DatabaseStatisticsService.hpp"
 
@@ -92,10 +93,16 @@ void DatabaseStatisticsService::updateStatisticsPerTape() {
   try {
     auto selectStmt = m_conn.createStmt(selectVids);
     auto rset = selectStmt.executeQuery();
+    // Make a list of all dirty vids. The memory required for the list is
+    // expected to be acceptable.
+    std::vector<std::string> dirtyVids;
     while (rset.next()) {
+      dirtyVids.push_back(rset.columnString("VID"));
+    }
+    for (const auto & vid : dirtyVids) {
       // For all DIRTY tapes, update its statistics
       auto updateStmt = m_conn.createStmt(updateSql);
-      updateStmt.bindString(":VID", rset.columnString("VID"));
+      updateStmt.bindString(":VID", vid);
       updateStmt.executeNonQuery();
       m_nbUpdatedTapes += updateStmt.getNbAffectedRows();
     }