From a62fe3c88506b84f3c3b78987fa593b6022a2abc Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Sylvain=20Veyri=C3=A9?= <sylvain@quansic.com>
Date: Thu, 25 Mar 2021 10:19:02 +0100
Subject: [PATCH] [BEAM-12044] JdbcIO read: always force autocommit to false

---
 .../src/main/java/org/apache/beam/sdk/io/jdbc/JdbcIO.java     | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/sdks/java/io/jdbc/src/main/java/org/apache/beam/sdk/io/jdbc/JdbcIO.java b/sdks/java/io/jdbc/src/main/java/org/apache/beam/sdk/io/jdbc/JdbcIO.java
index 93b0d393f3a0..d220679dab62 100644
--- a/sdks/java/io/jdbc/src/main/java/org/apache/beam/sdk/io/jdbc/JdbcIO.java
+++ b/sdks/java/io/jdbc/src/main/java/org/apache/beam/sdk/io/jdbc/JdbcIO.java
@@ -903,6 +903,10 @@ public void processElement(ProcessContext context) throws Exception {
       if (connection == null) {
         connection = dataSource.getConnection();
       }
+      // PostgreSQL requires autocommit to be disabled to enable cursor streaming
+      // see https://jdbc.postgresql.org/documentation/head/query.html#query-with-cursor
+      LOG.info("Autocommit has been disabled");
+      connection.setAutoCommit(false);
       try (PreparedStatement statement =
           connection.prepareStatement(
               query.get(), ResultSet.TYPE_FORWARD_ONLY, ResultSet.CONCUR_READ_ONLY)) {