a1dbcd13a3
### What changes were proposed in this pull request? In the PR, I propose to add new benchmark `DateTimeRebaseBenchmark` which should measure the performance of rebasing of dates/timestamps from/to to the hybrid calendar (Julian+Gregorian) to/from Proleptic Gregorian calendar: 1. In write, it saves separately dates and timestamps before and after 1582 year w/ and w/o rebasing. 2. In read, it loads previously saved parquet files by vectorized reader and by regular reader. Here is the summary of benchmarking: - Saving timestamps is **~6 times slower** - Loading timestamps w/ vectorized **off** is **~4 times slower** - Loading timestamps w/ vectorized **on** is **~10 times slower** ### Why are the changes needed? To know the impact of date-time rebasing introduced by #27915, #27953, #27807. ### Does this PR introduce any user-facing change? No ### How was this patch tested? Run the `DateTimeRebaseBenchmark` benchmark using Amazon EC2: | Item | Description | | ---- | ----| | Region | us-west-2 (Oregon) | | Instance | r3.xlarge | | AMI | ubuntu/images/hvm-ssd/ubuntu-bionic-18.04-amd64-server-20190722.1 (ami-06f2f779464715dc5) | | Java | OpenJDK8/11 | Closes #28057 from MaxGekk/rebase-bechmark. Lead-authored-by: Maxim Gekk <max.gekk@gmail.com> Co-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 | ||
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.