The query used a subquery of this form:
SELECT ...
WHERE
EXISTS( SELECT ...
FROM JSON_TABLE(outer_ref, ..) as JT
WHERE trivial_correlation_cond)
EXISTS-to-IN conversion code was unable to see that the subquery will
still be correlated after the trivial_correlation is removed, which
eventually caused a crash due to inability to construct a query plan.
Fixed by making Item_subselect::walk() also walk arguments of Table
Functions.
(Also fixes MDEV-25254).
Re-work Name Resolution for the argument of JSON_TABLE(json_doc, ....)
function. The json_doc argument can refer to other tables, but it can
only refer to the tables that precede[*] the JSON_TABLE(...) call.
[*] - For queries with RIGHT JOINs, the "preceding" is determined after
the query is normalized by converting RIGHT JOIN into left one.
The implementation is as follows:
- Table function arguments use their own Name_resolution_context.
- The Name_resolution_context now has a bitmap of tables that should be
ignored when searching for a field.
- get_disallowed_table_deps() walks the TABLE_LIST::nested_join tree
and computes a bitmap of tables that do not "precede" the given
JSON_TABLE(...) invocation (according the above definition of
"preceding").
Field length can increase after the change_charset(), so need to
set field->ptr properly.
also sensitive parts of the test moved to json_not_embedded.test.
Fix for for the problem with
- Cross-outer-join dependency
- dead-end join prefix
- join order pruning
See the comments in the patch for detailed description
