Maryann Xue created PHOENIX-1167:
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Summary: Support subqueries (derived tables)
Key: PHOENIX-1167
URL: https://issues.apache.org/jira/browse/PHOENIX-1167
Project: Phoenix
Issue Type: Bug
Affects Versions: 3.0.0, 4.0.0, 5.0.0
Reporter: Maryann Xue
Assignee: Maryann Xue
Fix For: 3.0.0, 4.0.0, 5.0.0
1. Semi/anti joins: including "IN / NOT IN" tests operating on non-correlated
sub-queries (PHOENIX-167).
We can evaluate the sub-queries as sets and execute the outer query the
same way as we now do IN clause.
2. Other non-correlated sub-queries: having a comparison operator with no
modifier or a comparison operator modified by ANY, SOME or ALL.
a) The sub-query can/must be evaluated as a single value. (Like "= / !="
with no modifiers; Or in cases like "> / < / >= / <=" "ANY/SOME/ALL", either
max() or min() can be applied to the sub-query).
b) In cases like "= / !=" "ANY / SOME / ALL", they are equivalent to
category 2 queries.
3. General correlated sub-queries (PHOENIX-945):
Need more sophisticated rewriting techniques to convert them into joins.
** if none of the dependence of inner query on the outer query is equi
condition, we are currently unable to handle them.
4. Nested sub-queries: having sub-queries in the FROM clause.
We are now able to handle most of them. Exceptions are PHOENIX-943,
PHOENIX-944.
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