|
When the first SQL to use a SEQUENCE table is DDL, it is only discovered with TEST_SQL_DISCOVERY enabled.
TEST_SQL_DISCOVERY enabled:
MariaDB [test]> show engines;
|
+--------------------+---------+----------------------------------------------------------------+--------------+------+------------+
|
| MRG_MyISAM | YES | Collection of identical MyISAM tables | NO | NO | NO |
|
| CSV | YES | CSV storage engine | NO | NO | NO |
|
| MyISAM | YES | MyISAM storage engine | NO | NO | NO |
|
| BLACKHOLE | YES | /dev/null storage engine (anything you write to it disappears) | NO | NO | NO |
|
| Aria | YES | Crash-safe tables with MyISAM heritage | NO | NO | NO |
|
| MEMORY | YES | Hash based, stored in memory, useful for temporary tables | NO | NO | NO |
|
| ARCHIVE | YES | Archive storage engine | NO | NO | NO |
|
| TEST_SQL_DISCOVERY | YES | Minimal engine to test table discovery via sql statements | NO | NO | NO |
|
| InnoDB | DEFAULT | Supports transactions, row-level locking, and foreign keys | YES | YES | YES |
|
| PERFORMANCE_SCHEMA | YES | Performance Schema | NO | NO | NO |
|
| FEDERATED | YES | FederatedX pluggable storage engine | YES | NO | YES |
|
| SPHINX | YES | Sphinx storage engine | NO | NO | NO |
|
| CONNECT | YES | Direct access to external data, including many file formats | NO | NO | NO |
|
| SEQUENCE | YES | Generated tables filled with sequential values | YES | YES | YES |
|
+--------------------+---------+----------------------------------------------------------------+--------------+------+------------+
|
14 rows in set (0.00 sec)
|
|
MariaDB [test]> drop table seq_1_to_1;
|
Query OK, 0 rows affected (0.01 sec)
|
TEST_SQL_DISCOVERY disabled:
MariaDB [test]> show engines;
|
+--------------------+---------+----------------------------------------------------------------+--------------+------+------------+
|
| MRG_MyISAM | YES | Collection of identical MyISAM tables | NO | NO | NO |
|
| CSV | YES | CSV storage engine | NO | NO | NO |
|
| MyISAM | YES | MyISAM storage engine | NO | NO | NO |
|
| BLACKHOLE | YES | /dev/null storage engine (anything you write to it disappears) | NO | NO | NO |
|
| Aria | YES | Crash-safe tables with MyISAM heritage | NO | NO | NO |
|
| MEMORY | YES | Hash based, stored in memory, useful for temporary tables | NO | NO | NO |
|
| ARCHIVE | YES | Archive storage engine | NO | NO | NO |
|
| TEST_SQL_DISCOVERY | NO | Minimal engine to test table discovery via sql statements | NULL | NULL | NULL |
|
| InnoDB | DEFAULT | Supports transactions, row-level locking, and foreign keys | YES | YES | YES |
|
| PERFORMANCE_SCHEMA | YES | Performance Schema | NO | NO | NO |
|
| FEDERATED | YES | FederatedX pluggable storage engine | YES | NO | YES |
|
| SPHINX | YES | Sphinx storage engine | NO | NO | NO |
|
| CONNECT | YES | Direct access to external data, including many file formats | NO | NO | NO |
|
| SEQUENCE | YES | Generated tables filled with sequential values | YES | YES | YES |
|
+--------------------+---------+----------------------------------------------------------------+--------------+------+------------+
|
14 rows in set (0.00 sec)
|
|
MariaDB [test]> drop table seq_1_to_1;
|
ERROR 1051 (42S02): Unknown table 'seq_1_to_1'
|
SELECT and SHOW CREATE still work as expected:
MariaDB [test]> select * from seq_1_to_2;
|
+-----+
|
| seq |
|
+-----+
|
| 1 |
|
| 2 |
|
+-----+
|
2 rows in set (0.01 sec)
|
|
MariaDB [test]> show create table seq_1_to_3;
|
+------------+----------------------------------------------------------------------------------------------------------------------------------+
|
| Table | Create Table |
|
+------------+----------------------------------------------------------------------------------------------------------------------------------+
|
| seq_1_to_3 | CREATE TABLE `seq_1_to_3` (
|
`seq` bigint(20) unsigned NOT NULL,
|
PRIMARY KEY (`seq`)
|
) ENGINE=SEQUENCE DEFAULT CHARSET=latin1 |
|
+------------+----------------------------------------------------------------------------------------------------------------------------------+
|
1 row in set (0.00 sec)
|
I would actually expect DROP TABLE to cause ER_ILLEGAL_HA, but maybe it's impossible or undesirable for engine purposes; in any case the behavior on DDL is somewhat inconsistent now, but it's out of scope of this report. I will file something about it separately for the record, although it doesn't seem important.
|