Maryann Xue created PHOENIX-2957:
------------------------------------
Summary: WhereOptimizer to provide an estimate of key selectivity
for key filters containing bind variables
Key: PHOENIX-2957
URL: https://issues.apache.org/jira/browse/PHOENIX-2957
Project: Phoenix
Issue Type: Bug
Reporter: Maryann Xue
Priority: Minor
Calcite will not load values of bind parameters until execution. This will not
affect the runtime efficiency even if the bind parameter appears in primary key
related filters, since we support "dynamic filter" and thus can re-compile it
into a SkipScanFilter whenever possible. But it does affect cost calculation at
compile time in some way, so it's better for Phoenix to be able to provide an
estimate of key selectivity if bind parameters appear in key filters.
For example, t has a primary key of (k0, k1):
"select * from t where k0 = ?"
"select * from t where k0 = 'xxx' and k1 < ?"
Given some filter estimate constants, like 0.1 for "=", 0.5 for "<" or ">", we
can calculate an estimate of the entire filter selectivity using logic provided
by WhereOptimizer.
--
This message was sent by Atlassian JIRA
(v6.3.4#6332)
