[HIVE-6013] Supporting Quoted Identifiers in Column Names

• Type: Improvement
• Status: Reopened
• Priority: Major
• Resolution: Unresolved
• Fix Version/s: 0.13.0
• Component/s: Query Processor
• Hadoop Flags: Incompatible change

Release Note

The default behavior for quoted identifiers has been changed. Now at the language level any Column Name that is specified within back-ticks(`) is treated literally. This is inline with standard sql behavior for quoted identifiers. Within back-tick strings use double back-ticks to escape.

To revert to old behavior(that of interpreting back-ticked names as regular expressions) use the new parameter: hive.support.quoted.identifiers; set to the value 'none'.

• Assignee: Harish Butani
• Reporter: Harish Butani
• Created: 12/Dec/13 00:04
• Updated: 08/Apr/21 03:10

Description

Hive's current behavior on Quoted Identifiers is different from the normal interpretation. Quoted Identifier (using backticks) has a special interpretation for Select expressions(as Regular Expressions). Have documented current behavior and proposed a solution in attached doc.

Summary of solution is:

• Introduce 'standard' quoted identifiers for columns only.
• At the langauage level this is turned on by a flag.
• At the metadata level we relax the constraint on column names.

Issue Links

• is related to: HIVE-2949 bug with describe and reserved keyword
• is related to: HIVE-6187 Add test to verify that DESCRIBE TABLE works with quoted table names
• is related to: HIVE-6305 test use of quoted identifiers in user/role names
• relates to: HIVE-7097 The Support for REGEX Column Broken in HIVE 0.13