[#MDEV-28831] Improve and unify error messages on ALTER TABLE ... RENAME to unknown db

CREATE TABLE t (c INT) ENGINE=InnoDB;

ALTER TABLE t RENAME a.t;

On MySQL 8.0 will give:

8.0.29-opt>ALTER TABLE t RENAME a.t;

ERROR 1049 (42000): Unknown database 'a'

This will be the same output, no matter what the engine or options (like partitioning) are.

On MariaDB 10.10 we see a variety of outputs:

CREATE TABLE t (c INT) ENGINE=InnoDB;

ALTER TABLE t RENAME a.t;

Leads to:

10.10.0 081a284712bb661349e2e3802077b12211cede3e (Optimized)
10.10.0-opt>ALTER TABLE t RENAME a.t;
ERROR 1025 (HY000): Error on rename of './test/t' to './a/t' (errno: 168 "Unknown (generic) error from engine")

And for MyISAM/Aria:

CREATE TABLE t (c INT) ENGINE=MyISAM;

ALTER TABLE t RENAME a.t;

Leads to:

10.10.0 081a284712bb661349e2e3802077b12211cede3e (Optimized)
10.10.0-opt>ALTER TABLE t RENAME a.t;
ERROR 7 (HY000): Error on rename of './test/t.MYI' to './a/t.MYI' (Errcode: 20 "Not a directory")

And

CREATE TABLE t (c INT) ENGINE=InnoDB;

ALTER TABLE t PARTITION BY LIST (c) (PARTITION p VALUES IN (1,2));

ALTER TABLE t RENAME a.t;

Leads to a similar message as the InnoDB testcase above, but we also see in the error log:

10.10.0 081a284712bb661349e2e3802077b12211cede3e (Optimized)
2022-06-14 13:57:04 4 [ERROR] InnoDB: Cannot rename file './test/t#P#p.ibd' to './a/t#P#p.ibd'

And for MEMORY and Spider (which both seem to correctly report the right error);

# INSTALL PLUGIN spider SONAME 'ha_spider.so';  # For Spider

CREATE TABLE t (c INT) ENGINE=MEMORY;  # or ENGINE=Spider for Spider

ALTER TABLE t RENAME a.t;

We see:

For RocksDB:

INSTALL SONAME 'ha_rocksdb.so';

CREATE TABLE t (c INT) ENGINE=rocksdb;

ALTER TABLE t RENAME a.t;

Leads to:

10.10.0 081a284712bb661349e2e3802077b12211cede3e (Optimized)
10.10.0-opt>ALTER TABLE t RENAME a.t;
ERROR 1025 (HY000): Error on rename of './test/t' to './a/t' (errno: -1 "Internal error < 0 (Not system error)")

Bug fix: change all various engine messages to a uniform:

ERROR 1049 (42000): Unknown database 'a'

[MDEV-28831] Improve and unify error messages on ALTER TABLE ... RENAME to unknown db Created: 2022-06-14 Updated: 2022-10-14 Resolved: 2022-10-14
Status:	Closed
Project:	MariaDB Server
Component/s:	Data Definition - Alter Table, Partitioning, Storage Engine - Aria, Storage Engine - InnoDB, Storage Engine - MyISAM, Storage Engine - RocksDB
Affects Version/s:	10.2, 10.3, 10.4, 10.5, 10.6, 10.7, 10.8, 10.9, 10.10
Fix Version/s:	N/A