Release 0.194#

General Changes#

  • Fix planning performance regression that can affect queries over Hive tables with many partitions.

  • Fix deadlock in memory management logic introduced in the previous release.

  • Add word_stem() function.

  • Restrict n (number of result elements) to 10,000 or less for min(col, n), max(col, n), min_by(col1, col2, n), and max_by(col1, col2, n).

  • Improve error message when a session property references an invalid catalog.

  • Reduce memory usage of histogram() aggregation function.

  • Improve coordinator CPU efficiency when discovering splits.

  • Include minimum and maximum values for columns in SHOW STATS.

Web UI Changes#

  • Fix previously empty peak memory display in the query details page.

CLI Changes#

  • Fix regression in CLI that makes it always print “query aborted by user” when the result is displayed with a pager, even if the query completes successfully.

  • Return a non-zero exit status when an error occurs.

  • Add --client-info option for specifying client info.

  • Add --ignore-errors option to continue processing in batch mode when an error occurs.

JDBC Driver Changes#

  • Allow configuring connection network timeout with setNetworkTimeout().

  • Allow setting client tags via the ClientTags client info property.

  • Expose update type via getUpdateType() on PrestoStatement.

Hive Changes#

  • Consistently fail queries that attempt to read partitions that are offline. Previously, the query can have one of the following outcomes: fail as expected, skip those partitions and finish successfully, or hang indefinitely.

  • Allow setting username used to access Hive metastore via the hive.metastore.username config property.

  • Add hive_storage_format and respect_table_format session properties, corresponding to the hive.storage-format and hive.respect-table-format config properties.

  • Reduce ORC file reader memory consumption by allocating buffers lazily. Buffers are only allocated for columns that are actually accessed.

Cassandra Changes#

  • Fix failure when querying information_schema.columns when there is no equality predicate on table_name.