bef5828e12
### What changes were proposed in this pull request? Skip timestamps rebasing after a global threshold when there is no difference between Julian and Gregorian calendars. This allows to avoid checking hash maps of switch points, and fixes perf regressions in `toJavaTimestamp()` and `fromJavaTimestamp()`. ### Why are the changes needed? The changes fix perf regressions of conversions to/from external type `java.sql.Timestamp`. Before (see the PR's results https://github.com/apache/spark/pull/28440): ``` ================================================================================================ Conversion from/to external types ================================================================================================ OpenJDK 64-Bit Server VM 1.8.0_252-8u252-b09-1~18.04-b09 on Linux 4.15.0-1063-aws Intel(R) Xeon(R) CPU E5-2670 v2 2.50GHz To/from Java's date-time: Best Time(ms) Avg Time(ms) Stdev(ms) Rate(M/s) Per Row(ns) Relative ------------------------------------------------------------------------------------------------------------------------ From java.sql.Timestamp 376 388 10 13.3 75.2 1.1X Collect java.sql.Timestamp 1878 1937 64 2.7 375.6 0.2X ``` After: ``` ================================================================================================ Conversion from/to external types ================================================================================================ OpenJDK 64-Bit Server VM 1.8.0_252-8u252-b09-1~18.04-b09 on Linux 4.15.0-1063-aws Intel(R) Xeon(R) CPU E5-2670 v2 2.50GHz To/from Java's date-time: Best Time(ms) Avg Time(ms) Stdev(ms) Rate(M/s) Per Row(ns) Relative ------------------------------------------------------------------------------------------------------------------------ From java.sql.Timestamp 249 264 24 20.1 49.8 1.7X Collect java.sql.Timestamp 1503 1523 24 3.3 300.5 0.3X ``` Perf improvements in average of: 1. From java.sql.Timestamp is ~ 34% 2. To java.sql.Timestamps is ~16% ### Does this PR introduce _any_ user-facing change? No ### How was this patch tested? By existing test suites `DateTimeUtilsSuite` and `RebaseDateTimeSuite`. Closes #28441 from MaxGekk/opt-rebase-common-threshold. Authored-by: Max Gekk <max.gekk@gmail.com> Signed-off-by: Wenchen Fan <wenchen@databricks.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.