Class SetStmt

fe/src/main/java/org/apache/impala/analysis/SetStmt.java:28–85

Representation of a SET query options statement.

 * Representation of a SET query options statement.
 */
public class SetStmt extends StatementBase {
  private final String key_;
  private final String value_;
  private final TQueryOptionType queryOptionType_;

  // This key is deprecated in Impala 2.0; COMPRESSION_CODEC_KEY replaces this
  private static final String DEPRECATED_PARQUET_CODEC_KEY = "PARQUET_COMPRESSION_CODEC";
  private static final String COMPRESSION_CODEC_KEY = "COMPRESSION_CODEC";

  // maps the given key name to a key defined in the thrift file
  private static String resolveThriftKey(String key) {
    if (key.toLowerCase().equals(DEPRECATED_PARQUET_CODEC_KEY.toLowerCase())) {
      return COMPRESSION_CODEC_KEY;
    }
    return key;
  }

  public SetStmt(String key, String value, TQueryOptionType queryOptionType) {
    Preconditions.checkArgument((key == null) == (value == null));
    Preconditions.checkArgument(key == null || !key.isEmpty());
    Preconditions.checkArgument(
        queryOptionType != TQueryOptionType.SET_ALL || (key == null && value == null));
    key_ = key;
    value_ = value;
    queryOptionType_ = queryOptionType;
  }

  @Override
  public String toSql(ToSqlOptions options) {
    if (queryOptionType_ == TQueryOptionType.UNSET_ALL) {
      return "UNSET ALL";
    }
    if (key_ == null) {
      if (queryOptionType_ == TQueryOptionType.SET_ALL) return "SET ALL";
      return "SET";
    }
    Preconditions.checkNotNull(value_);
    return "SET " + ToSqlUtils.getIdentSql(key_) + "='" + value_ + "'";
  }

  @Override
  public void analyze(Analyzer analyzer) {
    // Query option key is validated by the backend.
  }

  public TSetQueryOptionRequest toThrift() {
    TSetQueryOptionRequest request = new TSetQueryOptionRequest();
    if (key_ != null) {
      request.setKey(resolveThriftKey(key_));
      request.setValue(value_);
    }
    request.setQuery_option_type(queryOptionType_);
    return request;
  }

  @Override
  public boolean requiresHmsMetadata() { return false; }
}