de73a54269
## What changes were proposed in this pull request? This updates CTE substitution to avoid needing to run all resolution rules on each substituted expression. Running resolution rules was previously used to avoid infinite recursion. In the updated rule, CTE plans are substituted as sub-queries from right to left. Using this scope-based order, it is not necessary to replace multiple CTEs at the same time using `resolveOperatorsDown`. Instead, `resolveOperatorsUp` is used to replace each CTE individually. By resolving using `resolveOperatorsUp`, this no longer needs to run all analyzer rules on each substituted expression. Previously, this was done to apply `ResolveRelations`, which would throw an `AnalysisException` for all unresolved relations so that unresolved relations that may cause recursive substitutions were not left in the plan. Because this is no longer needed, `ResolveRelations` no longer needs to throw `AnalysisException` and resolution can be done in multiple rules. ## How was this patch tested? Existing tests in `SQLQueryTestSuite`, `cte.sql`. Closes #24763 from rdblue/SPARK-27909-fix-cte-substitution. Authored-by: Ryan Blue <blue@apache.org> Signed-off-by: gatorsmile <gatorsmile@gmail.com> |
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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.