In MariaDB, we have a confusing problem where:
* The transaction_isolation option can be set in a configuration file, but it cannot be set dynamically.
* The tx_isolation system variable can be set dynamically, but it cannot be set in a configuration file.
Therefore, we have two different names for the same thing in different contexts. This is needlessly confusing, and it complicates the documentation. The same thing applys for transaction_read_only.
MySQL 5.7 solved this problem by making them into system variables. https://dev.mysql.com/doc/relnotes/mysql/5.7/en/news-5-7-20.html
This commit takes a similar approach by adding new system variables and marking the original ones as deprecated. This commit also resolves some legacy problems related to SET STATEMENT and transaction_isolation.
Some GNU/Linux distributions ship a zlib that is modified to use
the s390x DFLTCC instruction. That modification would essentially
redefine compressBound(sourceLen) as (sourceLen * 16 + 2308) / 8 + 6.
Let us relax the tests for InnoDB ROW_FORMAT=COMPRESSED to cope with
such a weaker compression guarantee.
create_table_info_t::row_size_is_acceptable(): Remove a bogus debug-only
assertion that would fail to hold for the test innodb_zip.bug36169.
The function page_zip_empty_size() may indeed return 0.
Let us introduce the parameter innodb_read_only_compressed
that is ON by default, making any ROW_FORMAT=COMPRESSED tables
read-only.
I developed the ROW_FORMAT=COMPRESSED format based on
Heikki Tuuri's rough design between 2005 and 2008. It might
have been a good idea back then, but no proper benchmarks were
ever run to validate the design or the implementation.
The format has been more or less obsolete for years.
It limits innodb_page_size to 16384 bytes (the default),
and instant ALTER TABLE is not supported.
This is the first step towards deprecating and removing
write support for ROW_FORMAT=COMPRESSED tables.
In the test innodb.instant_alter,4k we would be flagging an error
for too large row size. That error was previously only being reported
if the table was being rebuilt. Thus, this merge is fixing a small
omission in MDEV-11369 (instant ADD COLUMN).
Move row size check to early CREATE/ALTER TABLE phase. Stop checking
on table open.
dict_index_add_to_cache(): remove parameter 'strict', stop checking row size
dict_index_t::record_size_info_t: this is a result of row size check operation
create_table_info_t::row_size_is_acceptable(): performs row size check.
Issues error or warning. Writes first overflow field to InnoDB log.
create_table_info_t::create_table(): add row size check
dict_index_t::record_size_info(): this is a refactored version
of dict_index_t::rec_potentially_too_big(). New version doesn't change global
state of a program but return all interesting info. And it's callers who
decide how to handle row size overflow.
dict_index_t::rec_potentially_too_big(): removed
The parameters innodb_file_format and innodb_large_prefix were overridden
in the Debian-distributed configuration files, because the default values
of these parameters between MariaDB 5.5 and MariaDB 10.2
did not make any sense.
To allow a more seamless upgrade from MariaDB 10.1 to later versions,
let InnoDB recognize the parameters innodb_file_format and
innodb_large_prefix and issue deprecation warnings for them if they
are specified. A deprecation period of only one major release
(one year between the MariaDB 10.2 and 10.3 releases) is insufficient
for these widely used parameters.
This MySQL 5.5 test innodb_zip.innodb_prefix_index_lifted
was renamed in MySQL 5.7. In
commit 2e814d4702
the test was inadvertently removed, instead of being renamed.
The absence of this test caused a regression in MariaDB 10.2:
MDEV-15257 Invalid CREATE INDEX fails to report error correctly
