apache/shardingsphere · error · UnsupportedSQLOperationException

Unsupported SQL operation: Unsupported describe type: %s.

Error message

Unsupported SQL operation: Unsupported describe type: %s.

What it means

Error "Unsupported SQL operation: Unsupported describe type: %s." thrown in apache/shardingsphere.

Source

Thrown at proxy/frontend/dialect/postgresql/src/main/java/org/apache/shardingsphere/proxy/frontend/postgresql/command/query/extended/describe/PostgreSQLComDescribeExecutor.java:95

    private static final String ANONYMOUS_COLUMN_NAME = "?column?";
    
    private final PortalContext portalContext;
    
    private final PostgreSQLComDescribePacket packet;
    
    private final ConnectionSession connectionSession;
    
    private final ColumnTypeOIDResolver columnTypeOIDResolver;
    
    @Override
    public Collection<DatabasePacket> execute() throws SQLException {
        switch (packet.getType()) {
            case 'S':
                return describePreparedStatement();
            case 'P':
                return Collections.singleton(portalContext.get(packet.getName()).describe());
            default:
                throw new UnsupportedSQLOperationException("Unsupported describe type: " + packet.getType());
        }
    }
    
    private List<DatabasePacket> describePreparedStatement() throws SQLException {
        List<DatabasePacket> result = new ArrayList<>(2);
        PostgreSQLServerPreparedStatement preparedStatement = connectionSession.getServerPreparedStatementRegistry().getPreparedStatement(packet.getName());
        if (preparedStatement.getParameterTypes().stream().anyMatch(each -> PostgreSQLBinaryColumnType.UNSPECIFIED == each) || !preparedStatement.describeRows().isPresent()) {
            tryDescribePreparedStatement(preparedStatement);
        }
        result.add(preparedStatement.describeParameters());
        preparedStatement.describeRows().ifPresent(result::add);
        return result;
    }
    
    private void tryDescribePreparedStatement(final PostgreSQLServerPreparedStatement preparedStatement) throws SQLException {
        if (preparedStatement.getSqlStatementContext().getSqlStatement() instanceof InsertStatement) {
            describeInsertStatementByDatabaseMetaData(preparedStatement);
        } else {

View on GitHub (pinned to e952770a21)

Solutions

1. Describe only prepared statements ('S') or portals ('P').
2. Check the type byte of the Describe message the client sends.
3. Update the client driver if it emits an invalid Describe type.

When it happens

Trigger: PostgreSQLComDescribeExecutor receives a Describe message with an unsupported type indicator.

Common situations: Malformed extended-protocol Describe packets from buggy clients or middleboxes.

AI-assisted analysis of apache/shardingsphere@e952770a21 (2026-08-14). Data as JSON: /api/errors/d7bf43fe869c5989. Report an issue: GitHub.