The check on the SQL command type, in ha_spider::external_lock() is deleted
by e954d9de. This resulted in the wrong call of spider_internal_start_trx()
(and thus Ha_trx_info::register_ha()).
I reverted the check and refactored ha_spider::external_lock().
Configuring UDFs via plugin variables looks not a good idea.
The more variables Spider has, the more complex it becomes.
Further, I expect that only a few users use Spider UDFs.
Deprecate the following plugin variables regarding Spider UDFs:
* spider_udf_ds_bulk_insert_rows
* spider_udf_ds_table_loop_mode
* spider_udf_ds_use_real_table
* spider_udf_ct_bulk_insert_interval
* spider_udf_ct_bulk_insert_rows
spider_udf_table_lock_mutex_count and spider_udf_table_mon_mutex_count
are also for tweaking UDFs but they are already read-only. So,
there is no need to deprecate them.
Some Spider table options introduces an unnecessary complication to
Spider settings. For example, the default value of the plugin variable
spider_auto_increment_mode is -1 (use table value) and the default
table option value is 0 (normal mode). Thus, the virtual default value
of the variable is 0. This kind of indirection is confusing.
In order to delete such confusing table options in a future release,
we first change the default values of some Spider plugin variables
from -1 (use table value) to the corresponding default table values.
The default table values are defined in spider_set_connect_info_default().
At the same time, we also deprecate the option value -1 (use table value).
Deprecate the plugin variable spider_use_handler and the corresponding
table parameters "uhd" and "use_handler".
Passing a Handler statement to data nodes, without converting it to
SQL sometimes, might improve the performance, while this introduces
some complication to the implementation.
In the first place, only a few people use Handler statements and the
performance gain seems not to be very significant. Further, setting
spider_use_handler > 0 disables the GROUP BY handler. So, we decided
to deprecate the variable.
The commit e954d9de gave different lifetime to wide_share and
partition_handler_share. This introduced the possibility that
partition_handler_share could be accessed even after it was freed.
We stop sharing partitoiin_handler_share and make it belong to
a single wide_handler to fix the problem.
The Spider storage engine ignored the implicit grouping when
aggregation was converted to constant by the query optimizer.
As a result, the Spider SE returned rows more than expected.
To fix the problem, we notify the Spider SE of the existence of
the implicit grouping via Query::distinct.
The reason of the double lock was an extraneous ha_flush_logs().
Unlike the upstream it is unnecessary in Mariadb that exploits a binlog
checkpoint mechanism for not letting PURGE or RESET-MASTER to trouble
transaction recovery. That is in case should a trx
be prepared but its binlog file gone, the trx then is committed on disk too.
Those facts have been always verified by existing tests of
binlog.binlog_{checkpoint,xa_recover}.test.
A regression test for the bug is included though.
in case of a bulk insert the server sends all rows to the engine, and
then the engine replies that there was ER_DUP_ENTRY somewhere.
the exact number of the row that caused the error is unknown.
The server crashes due to passing NULL to spider_free().
In some cases, this == pt_handler_share_handlers[0] at the label
error_get_share in ha_spider::open().
In such cases, to nullify pt_handler_share_handlers[0]->wide_handler
is nothing but to nullify this->wide_handler. We should not do this
before freeing this->wide_handler.
Spider accesses a freed connection in ha_spider::end_bulk_insert()
and results in SIGSEGV.
The cause of the bug is that ha_spider::is_bulk_insert_exec_period()
wrongly returns TRUE when the bulk insertion has not yet started.
Spider decides whether it is during the bulk insertion or not by
the value of insert_pos, but the variable is not reset in a case,
and this result in the bug.
The server crashes if ALTER TABLE, which accesses physical data
placed at data nodes, is performed on a Spider table.
The cause of the bug is that spider_check_trx_and_get_conn() does
not allocate connections if sql_command == SQLCOM_ALTER_TABLE.
Some ALTER TABLE statements, like ALTER TABLE ... CHECK PARTITION,
access data nodes. So, we need to allocate a new connection before
performing ALTER TABLEs.
- Handle stored function conditions correctly, with the same logic as with UDFs.
- When running queries on Spider SE, by default, we do not push down WHERE conditions containing usage of UDFs/stored functions to remote data nodes, unless the user demands (by setting spider_use_pushdown_udf).
- Disable direct update/delete when a udf condition is skipped.
The server crashed when SPIDER_DIRECT_SQL UDF was called with
non-existing temporary table.
The bug has been introduced by 91ffdc8. The commit removed
the check, from THD::open_temporary_table(), which ensure that
the target temporary tables exist.
We can fix the bug by adding the check before the call of
THD::open_temporary_table().
JSON_REPLACE() function executed with an error on Spider SE.
This patch fixes the problem, and it also fixes the MDEV-24541.
The problem is that Item_func_json_insert::func_name() returns
the wrong function name "json_update".
The Spider SE reconstructs a query based on the return value
in some cases. Thus, if the return value is wrong, the Spider SE
may generate a wrong query.
