18.1. Teradata Additions

The following are additions that Teradata has added on top Facebook’s 0.148 release of Presto

Bug Fixes

  • Fix issue “Hive table is corrupt. It is declared as being bucketed, but the files do not match the bucketing declaration. The number of files in the directory (1) does not match the declared.” by fixing support for Hive bucketed tables. See option hive.multi-file-bucketing.enabled in the Presto Hive connector documentation.
  • Fix issue “low must be less than or equal to high” that can occur with ORC and Character data.

Prepared Statements

Add support for Prepared statements and parameters via sql syntax.

  • PREPARE
  • DEALLOCATE PREPARE
  • EXECUTE
  • DESCRIBE INPUT
  • DESCRIBE OUTPUT

Data Types

Add FLOAT support to the Hive connector Add Char support to Hive connector Additional Varchar(x) function implementations Additional Decimal functions implementations

Documentation

Additional Kerberos Grant/Revoke Presto-Admin Presto YARN Integration Presto Ambari Integration TINYINT, SMALLINT, INTEGER

Performance Improvements

Window Functions

Windows Functions with identical specifications merged to share work

Regular Expressions

Add support for running regular expression functions using the more efficent re2j-td library by setting the session variable regex_library to RE2J. The memory footprint can be adjusted by setting re2j_dfa_states_limit. Additionally, the number of times the re2j library falls back from its DFA algorithm to the NFA algorithm (due to hitting the states limit) before immediately starting with the NFA algorithm can be set with the re2j_dfa_retries session variable.

18.2. Discontinue to support

Implicit casts from Varchar(x) to date types are no longer supported.