[ASTERIXDB-2438] Consider assigns when pushing limit with condition into data scan

• Type: Improvement
• Status: Resolved
• Priority: Minor
• Resolution: Fixed
• Component/s: COMP - Compiler
• Assignee: Dmitry Lychagin
• Reporter: Dmitry Lychagin
• Created: 08/Aug/18 00:15
• Updated: 08/Aug/18 17:01
• Resolved: 08/Aug/18 17:01

Description

Currently PushLimitIntoPrimarySearchRule stops at assign operators and therefore doesn't not push select condition into data-scan if there's an assign in between. We should fix this to allow such conditions be pushed into data scan.

Here are example queries:

Q1:

select substring(dblpid, 0, 21)
from DBLP1
where dblpid > "series"
limit 1;

Q2:

select value t.user.lang
from TweetMessages t
where t.user.friends_count between 0 and 150
limit 2