spark-instrumented-optimizer/sql
Yuming Wang ab6bb8fc1c [SPARK-28075][SQL] Enhance TRIM function
## What changes were proposed in this pull request?

The `TRIM` function accept these patterns:
```sql
TRIM(str)
TRIM(trimStr, str)
TRIM(BOTH trimStr FROM str)
TRIM(LEADING trimStr FROM str)
TRIM(TRAILING trimStr FROM str)
```
This pr add support other three patterns:
```sql
TRIM(BOTH FROM str)
TRIM(LEADING FROM str)
TRIM(TRAILING FROM str)
```

PostgreSQL, Vertica, MySQL, Teradata, Oracle and DB2 support these patterns. Hive, Presto and SQL Server does not support this feature.

**PostgreSQL**:
```sql
postgres=# select substr(version(), 0, 16), trim(BOTH from '    SparkSQL   '), trim(LEADING FROM '    SparkSQL   '), trim(TRAILING FROM '    SparkSQL   ');
     substr      |  btrim   |    ltrim    |    rtrim
-----------------+----------+-------------+--------------
 PostgreSQL 11.3 | SparkSQL | SparkSQL    |     SparkSQL
(1 row)
```
**Vertica**:
```
dbadmin=> select version(), trim(BOTH from '    SparkSQL   '), trim(LEADING FROM '    SparkSQL   '), trim(TRAILING FROM '    SparkSQL   ');
              version               |  btrim   |    ltrim    |    rtrim
------------------------------------+----------+-------------+--------------
 Vertica Analytic Database v9.1.1-0 | SparkSQL | SparkSQL    |     SparkSQL
(1 row)
```
**MySQL**:
```
mysql> select version(), trim(BOTH from '    SparkSQL   '), trim(LEADING FROM '    SparkSQL   '), trim(TRAILING FROM '    SparkSQL   ');
+-----------+-----------------------------------+--------------------------------------+---------------------------------------+
| version() | trim(BOTH from '    SparkSQL   ') | trim(LEADING FROM '    SparkSQL   ') | trim(TRAILING FROM '    SparkSQL   ') |
+-----------+-----------------------------------+--------------------------------------+---------------------------------------+
| 5.7.26    | SparkSQL                          | SparkSQL                             |     SparkSQL                          |
+-----------+-----------------------------------+--------------------------------------+---------------------------------------+
1 row in set (0.01 sec)
```
**Teradata**:
![image](https://user-images.githubusercontent.com/5399861/59587081-070bcd00-9117-11e9-8534-df547860b585.png)
**Oracle**:
![image](https://user-images.githubusercontent.com/5399861/59587003-cf048a00-9116-11e9-839e-90da9e5183e0.png)
**DB2**:
![image](https://user-images.githubusercontent.com/5399861/59587801-af6e6100-9118-11e9-80be-ee1f6bbbeceb.png)

## How was this patch tested?

unit tests

Closes #24891 from wangyum/SPARK-28075.

Authored-by: Yuming Wang <yumwang@ebay.com>
Signed-off-by: Wenchen Fan <wenchen@databricks.com>
2019-06-18 12:26:10 +08:00
..
catalyst [SPARK-28075][SQL] Enhance TRIM function 2019-06-18 12:26:10 +08:00
core [SPARK-28052][SQL] Make ArrayExists follow the three-valued boolean logic. 2019-06-15 10:48:06 -07:00
hive [SPARK-27418][SQL] Migrate Parquet to File Data Source V2 2019-06-15 20:52:50 +09:00
hive-thriftserver [SPARK-27899][SQL] Make HiveMetastoreClient.getTableObjectsByName available in ExternalCatalog/SessionCatalog API 2019-06-11 15:32:59 +08:00
create-docs.sh [MINOR][DOCS] Minor doc fixes related with doc build and uses script dir in SQL doc gen script 2017-08-26 13:56:24 +09:00
gen-sql-markdown.py [SPARK-27328][SQL] Add 'deprecated' in ExpressionDescription for extended usage and SQL doc 2019-04-09 13:49:42 +08:00
mkdocs.yml [SPARK-21485][SQL][DOCS] Spark SQL documentation generation for built-in functions 2017-07-26 09:38:51 -07:00
README.md [MINOR][DOC] Fix some typos and grammar issues 2018-04-06 13:37:08 +08:00

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.