The InnoDB internal tables SYS_TABLESPACES and SYS_DATAFILES as well as the
INFORMATION_SCHEMA views INNODB_SYS_TABLESPACES and INNODB_SYS_DATAFILES
were introduced in MySQL 5.6 for no good reason in
mysql/mysql-server/commit/e9255a22ef16d612a8076bc0b34002bc5a784627
when the InnoDB support for the DATA DIRECTORY attribute was introduced.
The file system should be the authoritative source of information on files.
Storing information about file system paths in the file system (symlinks,
or even the .isl files that were unfortunately chosen as the solution) is
sufficient. If information is additionally stored in some hidden tables
inside the InnoDB system tablespace, everything unnecessarily becomes
more complicated, because more copies of data mean more opportunity
for the copies to be out of sync, and because modifying the data in
the system tablespace in the desired way might not be possible at all
without modifying the InnoDB source code. So, the copy in the system
tablespace basically is a redundant, non-authoritative source of
information.
We will stop creating or accessing the system tables SYS_TABLESPACES
and SYS_DATAFILES.
We will also remove the view
INFORMATION_SCHEMA.INNODB_SYS_DATAFILES along with SYS_DATAFILES.
The view
INFORMATION_SCHEMA.INNODB_SYS_TABLESPACES will be repurposed
to directly reflect fil_system.space_list. The column
PAGE_SIZE, which would always contain the value of
the GLOBAL read-only variable innodb_page_size, is
removed. The column ZIP_PAGE_SIZE, which would actually
contain the physical page size of a page, is renamed to
PAGE_SIZE. Finally, a new column FILENAME is added, as a
replacement of SYS_DATAFILES.PATH.
This will also
address MDEV-21801 (files that were created before upgrading
to MySQL 5.6 or MariaDB 10.0 or later were never registered
in SYS_TABLESPACES or SYS_DATAFILES) and
MDEV-21801 (information about the system tablespace is not stored
in SYS_TABLESPACES or SYS_DATAFILES).
This allows one to run the test suite even if any of the following
options are changed:
- character-set-server
- collation-server
- join-cache-level
- log-basename
- max-allowed-packet
- optimizer-switch
- query-cache-size and query-cache-type
- skip-name-resolve
- table-definition-cache
- table-open-cache
- Some innodb options
etc
Changes:
- Don't print out the value of system variables as one can't depend on
them to being constants.
- Don't set global variables to 'default' as the default may not
be the same as the test was started with if there was an additional
option file. Instead save original value and reset it at end of test.
- Test that depends on the latin1 character set should include
default_charset.inc or set the character set to latin1
- Test that depends on the original optimizer switch, should include
default_optimizer_switch.inc
- Test that depends on the value of a specific system variable should
set it in the test (like optimizer_use_condition_selectivity)
- Split subselect3.test into subselect3.test and subselect3.inc to
make it easier to set and reset system variables.
- Added .opt files for test that required specfic options that could
be changed by external configuration files.
- Fixed result files in rockdsb & tokudb that had not been updated for
a while.
