Release 0.194#
General#
- 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#
- Fix previously empty peak memory display in the query details page. 
CLI#
- 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-infooption for specifying client info.
- Add - --ignore-errorsoption to continue processing in batch mode when an error occurs.
JDBC driver#
- Allow configuring connection network timeout with - setNetworkTimeout().
- Allow setting client tags via the - ClientTagsclient info property.
- Expose update type via - getUpdateType()on- PrestoStatement.
Hive#
- 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.usernameconfig property.
- Add - hive_storage_formatand- respect_table_formatsession properties, corresponding to the- hive.storage-formatand- hive.respect-table-formatconfig properties.
- Reduce ORC file reader memory consumption by allocating buffers lazily. Buffers are only allocated for columns that are actually accessed. 
Cassandra#
- Fix failure when querying - information_schema.columnswhen there is no equality predicate on- table_name.