pentaho/pentaho-kettle · error · KettleDatabaseException

Unable to retrieve metadata from resultset

Error message

Unable to retrieve metadata from resultset

What it means

Thrown in Database.getRow(ResultSet, boolean) when rs.getMetaData() throws SQLException while lazily initializing the cached rowMeta. The library caches row metadata on first getRow call; failure to fetch it blocks all subsequent row reads.

Solutions

1. Check the connection is valid (isValid/ping) before executing and reading
2. Inspect the chained SQLException cause for the driver's reason
3. Re-execute the query to obtain a fresh result set
4. Upgrade the JDBC driver if getMetaData() fails on valid result sets

Example fix

// before
Object[] row = db.getRow(rs, false);
// after
if (!rs.isClosed() && conn.isValid(5)) {
  Object[] row = db.getRow(rs, false);
} else {
  rs = stmt.executeQuery(sql); // re-acquire
}

if (rs.isClosed() || !conn.isValid(5)) {
  rs = stmt.executeQuery(sql); // re-acquire before reading
}

null

try {
  row = db.getRow(rs, false);
} catch (KettleDatabaseException e) {
  if (e.getMessage().contains("Unable to retrieve metadata")) {
    rs = stmt.executeQuery(sql); // retry with fresh result set
  } else { throw e; }
}

When it happens

Trigger: First call to Database.getRow(rs, lazyConversion) on a result set whose metadata cannot be retrieved — result set closed, connection dropped, or driver error on getMetaData().

Common situations: Long-running reads where the connection timed out before the first getRow; result set closed by another thread; driver bugs after executing large or complex queries.

Understand the failure class

Background: Database query failed: Internal Server Error 500s wrapping SQL, Prisma, and connection failures — what to check first — this error's family across 16 libraries.

Related errors

• MySQLDatabaseMeta.Exception.LegacyColumnNameNoRSMetaDataException
• MySQLDatabaseMeta.Exception.LegacyColumnNameException
• No result set metadata available to retrieve row metadata!
• Cannot fetch driver metadata for
• Couldn't close query: resultset or prepared statements

AI-assisted analysis of pentaho/pentaho-kettle@f3058517a1 (2026-09-13). Data as JSON: /api/errors/f2e4f499d21e7178. Report an issue: GitHub.

Appendix: source

Thrown at core/src/main/java/org/pentaho/di/core/database/Database.java:2996

   */
  public Object[] getRow( ResultSet rs ) throws KettleDatabaseException {
    return getRow( rs, false );
  }

  /**
   * Get a row from the resultset.
   *
   * @param rs             The resultset to get the row from
   * @param lazyConversion set to true if strings need to have lazy conversion enabled
   * @return one row or null if no row was found on the resultset or if an error occurred.
   */
  public Object[] getRow( ResultSet rs, boolean lazyConversion ) throws KettleDatabaseException {
    if ( rowMeta == null ) {
      ResultSetMetaData rsmd = null;
      try {
        rsmd = rs.getMetaData();
      } catch ( SQLException e ) {
        throw new KettleDatabaseException( "Unable to retrieve metadata from resultset", e );
      }

      rowMeta = getRowInfo( rsmd, false, lazyConversion );
    }

    return getRow( rs, null, rowMeta );
  }

  /**
   * Get a row from the resultset.
   *
   * @param rs The resultset to get the row from
   * @return one row or null if no row was found on the resultset or if an error occurred.
   */
  public Object[] getRow( ResultSet rs, ResultSetMetaData dummy, RowMetaInterface rowInfo )
    throws KettleDatabaseException {
    long startTime = System.currentTimeMillis();

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