3e9821edfd
### What changes were proposed in this pull request? The mainstream database support `[ IGNORE NULLS | RESPECT NULLS ]` for `LEAD`/`LAG`/`NTH_VALUE`/`FIRST_VALUE`/`LAST_VALUE`. But the current implement of `LEAD`/`LAG` don't support this syntax. **Oracle** https://docs.oracle.com/en/database/oracle/oracle-database/19/sqlrf/LEAD.html#GUID-0A0481F1-E98F-4535-A739-FCCA8D1B5B77 **Presto** https://prestodb.io/docs/current/functions/window.html **Redshift** https://docs.aws.amazon.com/redshift/latest/dg/r_WF_LEAD.html **DB2** https://www.ibm.com/support/knowledgecenter/SSGU8G_14.1.0/com.ibm.sqls.doc/ids_sqs_1513.htm **Teradata** https://docs.teradata.com/r/756LNiPSFdY~4JcCCcR5Cw/GjCT6l7trjkIEjt~7Dhx4w **Snowflake** https://docs.snowflake.com/en/sql-reference/functions/lead.html https://docs.snowflake.com/en/sql-reference/functions/lag.html ### Why are the changes needed? Support `[ IGNORE NULLS | RESPECT NULLS ]` for `LEAD`/`LAG` is very useful. ### Does this PR introduce _any_ user-facing change? 'Yes'. ### How was this patch tested? Jenkins test. Closes #30387 from beliefer/SPARK-33443. Lead-authored-by: gengjiaan <gengjiaan@360.cn> Co-authored-by: beliefer <beliefer@163.com> Co-authored-by: Jiaan Geng <beliefer@163.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.