DISTINCT argument qualifier for aggregation functions is now
fully supported. For example:
SELECT country, count(DISTINCT city), count(DISTINCT age) FROM users GROUP BY country
approx_distinct() should be used in preference to this
whenever an approximate answer is allowable as it is substantially
faster and does not have any limits on the number of distinct items it
COUNT(DISTINCT ...) must transfer every item over the
network and keep each distinct item in memory.
hive-hadoop2 connector to read Hive data from Hadoop 2.x.
See Deploying Presto for details.
All Hive connectors support reading data from Amazon S3. This requires two additional catalog properties for the Hive connector to specify your AWS Access Key ID and Secret Access Key:
Allow specifying catalog and schema in the JDBC Driver URL.
Implement more functionality in the JDBC driver.
Allow certain custom
InputFormats to work by propagating Hive serialization properties to the
Many execution engine performance improvements.
Fix optimizer performance regression.