[SPARK-16463] Support `truncate` option in Overwrite mode for JDBC DataFrameWriter

• Type: Improvement
• Status: Resolved
• Priority: Minor
• Resolution: Fixed
• Fix Version/s: 2.1.0
• Component/s: SQL
• Assignee: Dongjoon Hyun
• Reporter: Dongjoon Hyun
• Created: 09/Jul/16 19:33
• Updated: 09/Jun/17 16:39
• Resolved: 24/Jul/16 08:25

Description

This issue adds a boolean option, `truncate`, for SaveMode.Overwrite of JDBC DataFrameWriter. If this option is `true`, it use `TRUNCATE TABLE` instead of `DROP TABLE`.

• Without CREATE/DROP privilege, we can save dataframe to database. Sometime these are not allowed for security.
• It will keep the existing table information, so users can add and keep some additional CONSTRAINTs for the table.
• Sometime, TRUNCATE is faster than the combination of DROP/CREATE.

This issue is different from SPARK-16410 which aims to use `TRUNCATE` only for JDBC sources.

Issue Links

• is duplicated by: SPARK-16410 DataFrameWriter's jdbc method drops table in overwrite mode
• relates to: SPARK-21036 Truncate action and writes should be in one transaction.
• links to: [Github] Pull Request #14086 (dongjoon-hyun)