Presto 0.215 Documentation

11.31. Release 0.185

11.31. Release 0.185

General Changes

  • Fix incorrect column names in QueryCompletedEvent.
  • Fix excessive CPU usage in coordinator for queries that have large string literals containing non-ASCII characters.
  • Fix potential infinite loop during query optimization when constant expressions fail during evaluation.
  • Fix incorrect ordering when the same field appears multiple times with different ordering specifications in a window function ORDER BY clause. For example: OVER (ORDER BY x ASC, x DESC).
  • Do not allow dropping or renaming hidden columns.
  • When preparing to drop a column, ignore hidden columns when checking if the table only has one column.
  • Improve performance of joins where the condition is a range over a function. For example: a JOIN b ON b.x < f(a.x) AND b.x > g(a.x)
  • Improve performance of certain window functions (e.g., LAG) with similar specifications.
  • Extend substr() function to work on VARBINARY in addition to CHAR and VARCHAR.
  • Add cast from JSON to ROW.
  • Allow usage of TRY within lambda expressions.

Hive Changes

  • Improve ORC reader efficiency by only reading small ORC streams when accessed in the query.
  • Improve RCFile IO efficiency by increasing the buffer size from 1 to 8 MB.
  • Fix native memory leak for optimized RCFile writer.
  • Fix potential native memory leak for optimized ORC writer.

Memory Connector Changes

  • Add support for views.