Resolve "postgres frequently logging warning "there is no transaction in progress""

ReleaseNotes.md

@@ -13,6 +13,7 @@
 - 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#189 - Avoid postgres logging frequent warnings about no transaction in progress
 - cta/CTA#234 - Replace stoi with toUint64 in standalone cli tool
 - cta/CTA#238 - Compilation fails when using cta::common::Configuration::getConfEntInt(...)
 ### Continuous Integration

rdbms/wrapper/PostgresConn.cpp

@@ -105,6 +105,14 @@ void PostgresConn::commit()
     throw exception::Exception(std::string(__FUNCTION__) + " can not execute sql, another query is in progress");
   }
 
+  if (PQTRANS_IDLE == PQtransactionStatus(m_pgsqlConn)) {
+    // Commit is always called when returning a conneciton to the pool.
+    // Postgres logs a warning if we commit without a transaction. To avoid
+    // this a check is made, using client side server status tracking information:
+    // if we're not in a transaction return, otherwise attempt the commit.
+    return;
+  }
+
   Postgres::Result res(PQexec(m_pgsqlConn, "COMMIT"));
   throwDBIfNotStatus(res.get(), PGRES_COMMAND_OK, std::string(__FUNCTION__) + " problem committing the DB transaction");
 }