[ https://issues.apache.org/jira/browse/PHOENIX-5451?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel ]
chenglei reassigned PHOENIX-5451: --------------------------------- Attachment: PHOENIX-5451_v1-4.x-HBase-1.4.patch Assignee: chenglei > Column pruning for Subselect > ---------------------------- > > Key: PHOENIX-5451 > URL: https://issues.apache.org/jira/browse/PHOENIX-5451 > Project: Phoenix > Issue Type: Improvement > Affects Versions: 4.14.2 > Reporter: chenglei > Assignee: chenglei > Priority: Major > Fix For: 4.15.0, 5.1.0 > > Attachments: PHOENIX-5451_v1-4.x-HBase-1.4.patch > > > Phoenix has already could prune column for single flat table query, but for > subselect in subquery or join, column pruning is not implemented. > Consider following join sql : > {code:java} > select a.aid,b.bid from > (select aid,age from table1 where age >=11 and age<=33 order by age limit 3) > a inner join > (select bid,code from table2 order by code limit 1) b on a.aid=b.bid > {code} > for LHS, {{table1.age}} is not referenced by outer join, and for RHS, > {{table2.code}} is also not referenced by outer join, {{table1.age}} and > {{table2.code}} could both be pruned when execute query for LHS and RHS, but > now Phoenix does not prune them. > Another example is subquery sql: > {code:java} > SELECT t.eid id, t.bstr b FROM > (SELECT entity_id eid, a_string astr, b_string bstr FROM table WHERE a_byte > + 1 < 9 limit 2) t ORDER BY b,id > {code} > for inner subselect sql, {{a_string}} is never used by outer sql, so > {{a_string}} could be pruned when execute query for inner subselect, but now > Phoenix does not prune it. > Some existing test cases could be optimized by this patch. -- This message was sent by Atlassian Jira (v8.3.2#803003)