IMPALA-15278: Fix incorrect cardinality with OFFSET OFFSET is used to skip a number of rows before returning results. When calculating cardinality of a node that has OFFSET, the cardinality should substract this number before applying the LIMIT. MERGING-EXCHANGE currently does the reverse which could results in 0 cardinality when OFFSET >= LIMIT. SortNode currently ignores the offset. This fixes both issue by adding an overload of capCardinalityAtLimit() that has a parameter for offset. It's used in ExchangeNode and SortNode. Tests - Added FE test - Ran PlannerTest, TpcdsCpuCostPlannerTest and TpcdsTupleCachePlannerTest locally. Change-Id: I3b628beabc5c7ec6c4fdda9dff6aaf7a4acae538 Reviewed-on: http://gerrit.cloudera.org:8080/24718 Reviewed-by: Impala Public Jenkins <impala-public-jenkins@cloudera.com> Tested-by: Impala Public Jenkins <impala-public-jenkins@cloudera.com>
Lightning-fast, distributed SQL queries for petabytes of data stored in open data and table formats.
Impala is a modern, massively-distributed, massively-parallel, C++ query engine that lets you analyze, transform and combine data from a variety of data sources:
The fastest way to try out Impala is a quickstart Docker container. You can try out running queries and processing data sets in Impala on a single machine without installing dependencies. It can automatically load test data sets into Apache Kudu and Apache Parquet formats and you can start playing around with Apache Impala SQL within minutes.
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Impala only supports Linux at the moment. Impala supports x86_64 and arm64 (as of Impala 4.4). Impala Requirements contains more detailed information on the minimum CPU requirements.
Impala runs on Linux systems only. The supported distros are
Other systems, e.g. SLES15/16, may also be supported but are not tested by the community.
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