Updating to org.postgresql:postgresql 42.7.0 trips: Missing entry `default_transaction_isolation` in `pg_catalog.pg_settings`

[amotl]

CrateDB version

Nightly

CrateDB setup information

Standard Docker "services" setup on CI/GHA.

Problem description

When upgrading org.postgresql:postgresql from 42.6.0 to 42.7.0 on behalf of a Dependabot patch, a QA-style test code yields an error.

Unable to determine a value for DefaultTransactionIsolation due to missing entry in pg_catalog.pg_settings WHERE name=default_transaction_isolation.

-- https://github.com/crate/cratedb-examples/actions/runs/7000332105/job/19040823665?pr=162#step:8:1829

References

• https://github.com/crate/crate-qa/pull/288
• https://github.com/crate/cratedb-examples/pull/162
• https://github.com/crate/cratedb-examples/pull/191

Steps to Reproduce

git clone https://github.com/crate/cratedb-examples --branch=dependabot/maven/by-language/java-qa/org.postgresql-postgresql-42.7.0
cd cratedb-examples/by-language/java-qa
mvn test

Actual Result

The test suite breaks.

Expected Result

The test suite succeeds.

[mfussenegger]

Can you share a short java snippet that leads to the error?

Just updated the driver in the test suite here, and everything seems to work: https://github.com/crate/crate/pull/15116

[amotl]

Hi Mathias,

thank you for looking into this.

Can you share a short java snippet that leads to the error?

Sure. It seems to be this code snippet at crate-qa::stock_jdbc::JdbcMetaDataTest.java#L192-L197. Below, you will also find references where it trips on behalf of a corresponding crate-qa test run.

With kind regards, Andreas.

Code Snippet

@Test
public void test_getDefaultTransactionIsolation() throws Exception {
    try (var conn = DriverManager.getConnection(URL)) {
        assertThat(conn.getMetaData().getDefaultTransactionIsolation(), is(Connection.TRANSACTION_READ_COMMITTED));
    }
}

References

• https://github.com/crate/crate-qa/pull/288
• https://jenkins.crate.io/blue/organizations/jenkins/CrateDB%2Fqa%2Fcrate_qa_on_pr/detail/crate_qa_on_pr/299/pipeline/41#step-286-log-178

[mfussenegger]

Closing this for now. Given that CrateDB has no transactions none of the regular transaction isolation levels are a 100% match. Failing on the method is therefore not entirely wrong.

We can revisit this if a more concrete use case pops up