Message-ID: <gh-pgjdbc-pgjdbc-3892@github.com>
From: "CTH57 (@CTH57)" <noreply+CTH57@github.com>
To: "pgjdbc/pgjdbc" <noreply+pgjdbc-pgjdbc@github.com>
Date: Mon, 08 Dec 2025 10:20:52 +0000
Subject: [pgjdbc/pgjdbc] issue #3892: org.postgresql.xa.PGXAConnection.prepare(Xid) should return XA_RDONLY
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X-GitHub-Issue: 3892
X-GitHub-Repo: pgjdbc/pgjdbc
X-GitHub-State: closed
X-GitHub-Type: issue
X-GitHub-Url: https://github.com/pgjdbc/pgjdbc/issues/3892
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**Describe the issue**
This issue is a possible misalignment of pgjdbc from the XA specification.
PGXAConnection.prepare(Xid) should return XA_RDONLY when the connection is read-only.
Instead, PGXAConnection.prepare(Xid) tries to execute an update on the connection, which inevitably fails.

**Driver Version?** 
42.7.8

**Java Version?**
21.0.6

**OS Version?**


**PostgreSQL Version?**
17.4

**To Reproduce**
Create a XATransaction with at least one readonly connection

**Expected behaviour**
No exception when commit the transaction

**Logs**
```