f6e6899a8b
## What changes were proposed in this pull request? Provide a continuous processing implementation of coalesce(1), as well as allowing aggregates on top of it. The changes in ContinuousQueuedDataReader and such are to use split.index (the ID of the partition within the RDD currently being compute()d) rather than context.partitionId() (the partition ID of the scheduled task within the Spark job - that is, the post coalesce writer). In the absence of a narrow dependency, these values were previously always the same, so there was no need to distinguish. ## How was this patch tested? new unit test Author: Jose Torres <torres.joseph.f+github@gmail.com> Closes #21560 from jose-torres/coalesce. |
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| .. | ||
| catalyst | ||
| core | ||
| hive | ||
| hive-thriftserver | ||
| create-docs.sh | ||
| gen-sql-markdown.py | ||
| mkdocs.yml | ||
| README.md | ||
Spark SQL
This module provides support for executing relational queries expressed in either SQL or the DataFrame/Dataset API.
Spark SQL is broken up into four subprojects:
- Catalyst (sql/catalyst) - An implementation-agnostic framework for manipulating trees of relational operators and expressions.
- Execution (sql/core) - A query planner / execution engine for translating Catalyst's logical query plans into Spark RDDs. This component also includes a new public interface, SQLContext, that allows users to execute SQL or LINQ statements against existing RDDs and Parquet files.
- Hive Support (sql/hive) - Includes an extension of SQLContext called HiveContext that allows users to write queries using a subset of HiveQL and access data from a Hive Metastore using Hive SerDes. There are also wrappers that allow users to run queries that include Hive UDFs, UDAFs, and UDTFs.
- HiveServer and CLI support (sql/hive-thriftserver) - Includes support for the SQL CLI (bin/spark-sql) and a HiveServer2 (for JDBC/ODBC) compatible server.
Running sql/create-docs.sh generates SQL documentation for built-in functions under sql/site.