The function spider_db_mbase::print_warnings() can potentially result
in a null pointer dereference.
Remove the null pointer dereference by cleaning up the function.
Some small changes to the original commit
422fb63a9b.
Co-Authored-By: Yuchen Pei <yuchen.pei@mariadb.com>
The conn_kind, which stands for "connection kind", is no longer useful
because the HandlerSocket support is deleted and Spider now has only
one connection kind, SPIDER_CONN_KIND_MYSQL. Remove conn_kind and
related code.
Signed-off-by: Yuchen Pei <yuchen.pei@mariadb.com>
Reviewed-by: Nayuta Yanagisawa <nayuta.yanagisawa@mariadb.com>
Spider converts HA_READ_KEY_EXACT to the equality (=) in the
function spider_db_append_key_where_internal() but the conversion
is not necessarily correct for tables with prefix indices.
We fix the bug by converting HA_READ_KEY_EXACT to 'LIKE "foo%"' when
a target key is a prefix key. The fix is partly inspired by FEDERATED.
See ha_federated::create_where_from_key() for more details.
Item_func_xor and Item_cond are both derived class of Item_bool_func.
Spider converts *Item_func_xor to *Item_cond and then calls the member
function argument_list(), which Item_func_xor does not implement.
The Spider mixes the comma join with other join types, and thus
ERROR 1054 occurs. This is well-known issue caused by the higher
precedence of JOIN over the comma (,).
We can fix the problem simply by using JOINs instead of commas.
Spider supports (or at least allows) INSERT DELAYED but the
documentation does not specify spider as a storage engine that supports
"INSERT DELAYED".
Also, although not mentioned in the documentation, "INSERT DELAYED" is
not intended to be executed inside a transaction, as can be seen from
the list of supported storage engines.
The current implementation allows executing a delayed insert on a
remote transactional table and this breaks the consistency ensured by
the transaction.
We too remove "internal_delayed", one of the Spider table parameters.
Documentation says,
> Whether to transmit existence of delay to remote servers when
> executing an INSERT DELAYED statement on local server.
This table parameter is only used for "INSERT DELAYED".
Reviewed by: Nayuta Yanagisawa
