Closed martint closed 6 years ago
zip
from 4 to 5.array_agg
to avoid excessive object overhead. It also fixes excessive native memory usage with G1 garbage collection.
General
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* Improve performance of dynamic writer scaling.
SPI
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* Add performance statistics to plan in ``QueryCompletedEvent``.
* Remove ``Page.getBlocks()``. This call was rarely used and is performs an expensive copy. Instead use ``Page.getBlock(channel)`` or the new helper ``Page.appendColumn()``.
* Improve validation ``MapBlock``, ``RowBlock`` and ``ArrayBlock`` during construction.
General
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* Allow omission of step parameter in ``DATE`` variant of :func:`sequence` function
when the desired step is 1/-1 day.
General
* Optimize empty table scan to empty `VALUES`.
JMX Connector
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* Add wildcard character * which allows to query several MBeans data with single query.
VARCHAR
or VARBINARY
into files.General
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* Parse decimal literals (e.g. ``42.0``) as ``DECIMAL``. Previously they were parsed as ``DOUBLE``.
* Fix ``current_date`` failure when session time zone had a "gap" at 1970-01-01 00:00:00, e.g. ``America/Bahia_Banderas``.
* Support ``ESCAPE`` for ``LIKE`` predicate in ``SHOW SCHEMAS`` and ``SHOW TABLES`` queries.
* Enable simplification and pushdown of operators on ``DECIMAL``s.
However I think current_date
and fixing DECIMAL
operators are so small a thing that they don't deserve release note's space. @martint ?
The current_date change makes sense to document. What's the "simplification and pushdown of operators" for DECIMAL?
Resource Groups Changes
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* Query Queues have been removed. Resource Groups are always enabled. The
config property ``experimental.resource-groups-enabled`` has been removed.
CLI Changes
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* The ``--enable-authentication`` option has been removed. Kerberos authentication
is automatically enabled when ``--krb5-remote-service-name`` is specified.
* Kerberos authentication now requires HTTPS.
Hive Changes
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* Add support for using `AWS Glue <https://aws.amazon.com/glue/>`_ as the metastore.
Enable it by setting the ``hive.metastore`` config property to ``glue``.
What's the "simplification and pushdown of operators" for DECIMAL?
@martint certain operations on decimal were registered as nondeterministic (https://github.com/prestodb/presto/commit/7713581f712f0ae3e50a3de7715f2f4f4f06cb51 + https://github.com/prestodb/presto/commit/250aa04e4906ffa8560a9ea0d7a735bf27c43c00).
I observed this prevented them from being simplified by ExpressionOptimizer
(https://github.com/prestodb/presto/blob/aad321268dcee7228748652ff276d479124e8aba/presto-main/src/main/java/com/facebook/presto/sql/relational/optimizer/ExpressionOptimizer.java#L173), but i thought we consider determinism in other places too.
However, this bullet may be actually wrong, since https://github.com/prestodb/presto/blob/aad321268dcee7228748652ff276d479124e8aba/presto-main/src/main/java/com/facebook/presto/sql/planner/ExpressionInterpreter.java#L771 and https://github.com/prestodb/presto/blob/aad321268dcee7228748652ff276d479124e8aba/presto-main/src/main/java/com/facebook/presto/sql/planner/ExpressionInterpreter.java#L1120 do not check determinism and DeterminismEvaluator
checks determinism of function calls only. If indeed so, the bullet should be removed. ExpressionOptimizer
misbehavior was actually a regression after Construct proper literal for DECIMAL in LiteralInterpreter.toExpression
commit, which is also part of this release.
General
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* Add configuration property ``task.max-local-exchange-buffer-size`` for setting local exchange buffer size
* Improve parallelism of queries with empty grouping set
Dain Sundstrom
David Phillips
Grzegorz Kokosiński
Haozhun Jin
James Sun
Jiexi Lin
Karol Sobczak
Maria Basmanova
Martin Traverso
Nezih Yigitbasi
Piotr Findeisen
else
Raghav Sethi
Rebecca Schlussel
Wenlei Xie
sr
Łukasz Osipiuk