opt: split a disjunction of equijoin predicates into a union of joins

[cockroach-teamcity]

Exalate commented:

cockroachdb/cockroach#74303 --- Release note (performance improvement): Performance of inner, semi or anti join between two tables with ORed equijoin predicates is improved by enabling the optimizer to select a join plan in which each equijoin predicate is evaluated by a separate join, with the results of the joins unioned or intersected together.

Jira Issue: DOC-3113

[exalate-issue-sync]

Ryan Kuo (taroface) commented:
Closing as this doesn’t require docs IMO.