[OAK-904] Query: support "union" and "union all"

• Type: New Feature
• Status: Closed
• Priority: Minor
• Resolution: Fixed
• Fix Version/s: 0.20
• Component/s: query
• Assignee: Thomas Mueller
• Reporter: Thomas Mueller
• Created: 16/Jul/13 13:57
• Updated: 01/Mar/16 08:53
• Resolved: 26/Mar/14 12:34

Description

The query engine currently doesn't use an index for conditions of the type "x=1 or y=1". As a first step to implement this feature, we should support "union". The next step is to automatically convert queries with this condition to a union; but even if this is not implemented, the user could convert the query himself (manually) to a union.

And for JSR-333, we anyway want to support union.

Issue Links

• is related to: OAK-1116 XPath queries: use indexes for queries with "or" conditions
• is related to: OAK-1336 Query: use "union" for complex XPath queries that use "or"
• relates to: OAK-1617 Automatically convert "or" queries to "union" for SQL-2