presto-docs/src/main/sphinx/release/release-0.70.rst
.. warning::
This release contained a packaging error that resulted in an
unusable server tarball. Do not use this release.
We have added support for creating views within Presto. Views are defined using Presto syntax but are stored (as blobs) by connectors. Currently, views are supported by the Raptor and Hive connectors. For the Hive connector, views are stored within the Hive metastore as Hive views, but they cannot be queried by Hive, nor can Hive views be queried by Presto.
See :doc:/sql/create-view and :doc:/sql/drop-view
for details and examples.
The synthetic DUAL table is no longer supported. As an alternative, please
write your queries without a FROM clause or use the VALUES syntax.
There is a new project, :doc:/admin/verifier, which can be used to
verify a set of queries against two different clusters.
Connectors can now add hidden columns to a table. Hidden columns are not
displayed in DESCRIBE or information_schema, and are not
considered for SELECT *. As an example, we have added a hidden
row_number column to the tpch connector.
Presto contains an extensive test suite to verify the correctness. This test
suite has been extracted into the presto-test module for use during
connector development. For an example, see TestRaptorDistributedQueries.
We have added two new machine learning functions, which can be used
by advanced users familiar with LIBSVM. The functions are
learn_libsvm_classifier and learn_libsvm_regressor. Both take a
parameters string which has the form key=value,key=value
New comparison functions: :func:!greatest and :func:!least
New window functions: :func:!first_value, :func:!last_value, and :func:!nth_value
We have added a config option to disable falling back to the interpreter when
expressions fail to be compiled to bytecode. To set this option, add
compiler.interpreter-enabled=false to etc/config.properties.
This will force certain queries to fail rather than running slowly.
DATE values are now implicitly coerced to TIMESTAMP and TIMESTAMP WITH TIME ZONE
by setting the hour/minute/seconds to 0 with respect to the session timezone.
Minor performance optimization when planning queries over tables with tens of thousands of partitions or more.
Fixed a bug when planning ORDER BY ... LIMIT queries which could result in
duplicate and un-ordered results under rare conditions.
Reduce the size of stats collected from tasks, which dramatically reduces garbage generation and improves coordinator stability.
Fix compiler cache for expressions.
Fix processing of empty or commented out statements in the CLI.
There are two new configuration options for the Hive connector,
hive.max-initial-split-size, which configures the size of the
initial splits, and hive.max-initial-splits, which configures
the number of initial splits. This can be useful for speeding up small
queries, which would otherwise have low parallelism.
The Hive connector will now consider all tables with a non-empty value
for the table property presto_offline to be offline. The value of the
property will be used in the error message.
We have added support for for DROP TABLE in the hive connector.
By default, this feature is not enabled. To enable it, set
hive.allow-drop-table=true in your Hive catalog properties file.
Ignore subdirectories when generating splits (this now matches the non-recursive behavior of Hive).
Fix handling of maps with null keys.