t8y2/dbx · error · SQLException

Failed to restore the original JDBC schema context

Error message

Failed to restore the original JDBC schema context

What it means

JdbcSchemaSwitcher.apply throws SQLException when asked to switch back to the original (null/blank schema) JDBC schema context and restore(conn, true) fails to reinstate the saved catalog/schema. It signals the connection's original schema context could not be re-established, leaving the connection on the wrong schema.

Source

Thrown at agents/common/src/main/java/com/dbx/agent/JdbcSchemaSwitcher.java:31

    private static final Map<Connection, ResetState> RESET_STATE_BY_CONNECTION =
        Collections.synchronizedMap(new WeakHashMap<>());

    private JdbcSchemaSwitcher() {
    }

    static void apply(Connection conn, String schema, Function<String, String> setSchemaSql) throws Exception {
        apply(conn, schema, setSchemaSql, () -> "");
    }

    static void apply(
        Connection conn,
        String schema,
        Function<String, String> setSchemaSql,
        Supplier<String> resetSchemaSql
    ) throws Exception {
        if (schema == null || schema.trim().isEmpty()) {
            if (!restore(conn, true)) {
                throw new SQLException("Failed to restore the original JDBC schema context");
            }
            return;
        }

        ResetState resetState = resetState(conn);
        SchemaSqlResult schemaSqlResult = applySchemaSql(conn, () -> setSchemaSql.apply(schema));
        Exception schemaSqlError = schemaSqlResult.error;
        if (schemaSqlError == null) {
            resetState.mode = ResetMode.SQL;
            rememberResetSql(resetState, resetSchemaSql);
            return;
        }

        try {
            conn.setSchema(schema);
            resetState.mode = ResetMode.SCHEMA;
            return;
        } catch (SQLException | UnsupportedOperationException | AbstractMethodError ignored) {

View on GitHub (pinned to c0390bff16)

Solutions

Verify the connection is still open and valid before calling apply(null, ...) to restore
Ensure an original schema context was recorded by a prior successful switch (or capture conn.getSchema()/getCatalog() yourself before switching)
Check the resetSchemaSql supplier returns driver-correct SQL for your database
Catch the SQLException, close/reconnect, and re-run the intended schema switch

Example fix

// before
switcher.apply(conn, null, setSql, resetSql);
// after
if (conn.isValid(2)) {
    switcher.apply(conn, null, setSql, resetSql);
} else {
    conn = reconnect(); // restore on a fresh connection
}

Defensive patterns

Strategy: try-catch

Validate before calling

if (conn == null || conn.isClosed()) throw new IllegalStateException("Cannot restore schema on a closed connection");

Type guard

boolean restorable(Connection c) { try { return c != null && !c.isClosed(); } catch (SQLException e) { return false; } }

Try / catch

try {
    switcher.apply(conn, null, setSql, resetSql);
} catch (SQLException e) {
    // restore failed: reconnect and re-apply intended schema
    conn = reconnect();
    switcher.apply(conn, targetSchema, setSql, resetSql);
}

Prevention

Capture conn.getSchema()/getCatalog() before any schema switch
Validate the connection before restore attempts
Ensure resetSchemaSql matches the target database dialect
Restore schema context in a finally block and verify afterwards

When it happens

Trigger: Calling apply with a null/empty schema (meaning 'reset to original') while the connection has no recorded original state, or the reset statements fail (e.g. resetSchemaSql supplier returns SQL the driver rejects, connection already broken).

Common situations: Tooling that switches schemas per query then restores; connections where the original schema was never captured because switch happened before restore support; DB2/Postgres drivers rejecting the RESET SEARCH_PATH style statement; connection dropped mid-operation.

Related errors

AI-assisted analysis of t8y2/dbx@c0390bff16 (2026-09-05). Data as JSON: /api/errors/096130180a090d17. Report an issue: GitHub.