[IMPALA-889] Add trim() function matching ANSI SQL definition

• Type: New Feature
• Status: Open
• Priority: Minor
• Resolution: Unresolved
• Affects Version/s: Impala 1.2.4
• Component/s: Backend
• Labels: ansi-sql built-in-function ramp-up
• Target Version: Product Backlog
• Assignee: Adam Tamas
• Reporter: Jonathan Seidman
• Created: 17/Mar/14 22:02
• Updated: 24/Mar/20 08:25

Description

Add support for an ISO-SQL compliant trim() function, i.e. trim([leading | trailing | both] [characters] from string). Lack of this impacts users of BI tools migrating existing SQL from other systems.

Reference: https://my.vertica.com/docs/8.1.x/HTML/index.htm#Authoring/SQLReferenceManual/Functions/String/TRIM.htm

Part of the ANSI definition

<trim function> ::=
  TRIM <left paren> <trim operands> <right paren>
<trim operands> ::=
  [ [ <trim specification> ] [ <trim character> ] FROM ] <trim source>
<trim source> ::=
  <character value expression>
<trim specification> ::=
    LEADING
  | TRAILING
  | BOTH

Issue Links

• Blocked: IMPALA-6059 Enhance ltrim() and rtrim() functions to trim any set of characters

Sub-Tasks

• Impala Doc: New TRIM function: Closed