From a2e32b69fbb9e0934377653054ea5ac599535fd8 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

---
 .../jdbc/src/main/java/org/apache/beam/sdk/io/jdbc/JdbcIO.java | 3 +++
 1 file changed, 3 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..1bf6904a8ef1 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 +903,9 @@ 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
+      connection.setAutoCommit(false);
       try (PreparedStatement statement =
           connection.prepareStatement(
               query.get(), ResultSet.TYPE_FORWARD_ONLY, ResultSet.CONCUR_READ_ONLY)) {