52e5cc46bc
### What changes were proposed in this pull request? This patch proposes to provide a new option to specify time-to-live (TTL) for output file entries in FileStreamSink. TTL is defined via current timestamp - the last modified time for the file. This patch will filter out outdated output files in metadata while compacting batches (other batches don't have functionality to clean entries), which helps metadata to not grow linearly, as well as filtered out files will be "eventually" no longer seen in reader queries which leverage File(Stream)Source. ### Why are the changes needed? The metadata log greatly helps to easily achieve exactly-once but given the output path is open to arbitrary readers, there's no way to compact the metadata log, which ends up growing the metadata file as query runs for long time, especially for compacted batch. Lots of end users have been reporting the issue: see comments in [SPARK-24295](https://issues.apache.org/jira/browse/SPARK-24295) and [SPARK-29995](https://issues.apache.org/jira/browse/SPARK-29995), and [SPARK-30462](https://issues.apache.org/jira/browse/SPARK-30462). (There're some reports from end users which include their workarounds: SPARK-24295) ### Does this PR introduce any user-facing change? No, as the configuration is new and by default it is not applied. ### How was this patch tested? New UT. Closes #28363 from HeartSaVioR/SPARK-27188-v2. Lead-authored-by: Jungtaek Lim (HeartSaVioR) <kabhwan.opensource@gmail.com> Co-authored-by: Jungtaek Lim (HeartSaVioR) <kabhwan@gmail.com> Signed-off-by: Jungtaek Lim (HeartSaVioR) <kabhwan.opensource@gmail.com> |
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| .. | ||
| catalyst | ||
| core | ||
| hive | ||
| hive-thriftserver | ||
| create-docs.sh | ||
| gen-sql-api-docs.py | ||
| gen-sql-config-docs.py | ||
| gen-sql-functions-docs.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 extensions that allow 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, and SQL configuration documentation that gets included as part of configuration.md in the main docs directory.