On Windows systems, occurrences of ERROR_SHARING_VIOLATION due to
conflicting share modes between processes accessing the same file can
result in CreateFile failures.
mysys' my_open() already incorporates a workaround by implementing
wait/retry logic on Windows.
But this does not help if files are opened using shell redirection like
mysqltest traditionally did it, i.e via
--echo exec "some text" > output_file
In such cases, it is cmd.exe, that opens the output_file, and it
won't do any sharing-violation retries.
This commit addresses the issue by introducing a new built-in command,
'write_line', in mysqltest. This new command serves as a brief alternative
to 'write_file', with a single line output, that also resolves variables
like "exec" would.
Internally, this command will use my_open(), and therefore retry-on-error
logic.
Hopefully this will eliminate the very sporadic "can't open file because
it is used by another process" error on CI.
By design, InnoDB has always hung when permanently running out of
buffer pool, for example when several threads are waiting to allocate
a block, and all of the buffer pool is buffer-fixed by the active threads.
The hang that we are fixing here occurs when the buffer pool is only
temporarily running out and the situation could be rescued by writing out
some dirty pages or evicting some clean pages.
buf_LRU_get_free_block(): Simplify the way how we wait for
the buf_flush_page_cleaner thread. This fixes occasional hangs
of the test encryption.innochecksum that were introduced by
commit a55b951e60 (MDEV-26827).
To play it safe, we use a timed wait when waiting for the
buf_flush_page_cleaner() thread to perform its job. Should that
thread get stuck, we will invoke buf_pool.LRU_warn() in order to
display a message that pages could not be freed, and keep trying
to wake up the buf_flush_page_cleaner() thread.
The INFORMATION_SCHEMA.INNODB_METRICS counters
buffer_LRU_single_flush_failure_count and
buffer_LRU_get_free_waits will be removed.
The latter is represented by buffer_pool_wait_free.
Also removed will be the message
"InnoDB: Difficult to find free blocks in the buffer pool"
because in d34479dc66 we
introduced a more precise message
"InnoDB: Could not free any blocks in the buffer pool"
in the buf_flush_page_cleaner thread.
buf_pool_t::LRU_warn(): Issue the warning message that we could
not free any blocks in the buffer pool. This may also be invoked
by buf_LRU_get_free_block() if buf_flush_page_cleaner() appears
to be stuck.
buf_pool_t::n_flush_dec(): Remove.
buf_pool_t::n_flush_dec_holding_mutex(): Rename to n_flush_dec().
buf_flush_LRU_list_batch(): Increment the eviction counter for blocks
of temporary, discarded or dropped tablespaces.
buf_flush_LRU(): Make static, and remove the constant parameter
evict=false. The only caller will be the buf_flush_page_cleaner()
thread.
IORequest::is_LRU(): Remove. The only case of evicting pages on
write completion will be when we are writing out pages of the
temporary tablespace. Those pages are not in buf_pool.flush_list,
only in buf_pool.LRU.
buf_page_t::flush(): Remove the parameter evict.
buf_page_t::write_complete(): Change the parameter "bool temporary"
to "bool persistent" and add a parameter for an already read state().
Reviewed by: Debarun Banerjee
In any test that uses wait_all_purged.inc, ensure that InnoDB tables
will be created without persistent statistics.
This is a follow-up to commit cd04673a17
after a similar failure was observed in the innodb_zip.blob test.
dict_find_max_space_id(): Return SELECT MAX(SPACE) FROM SYS_TABLES.
dict_check_tablespaces_and_store_max_id(): In the normal case
(no encryption plugin has been loaded and the change buffer is empty),
invoke dict_find_max_space_id() and do not open any .ibd files.
If a std::set<uint32_t> has been specified, open the files whose
tablespace ID is mentioned. Else, open all data files that are identified
by SYS_TABLES records.
fil_ibd_open(): Remove a call to os_file_get_last_error() that can
report a misleading error, such as EINVAL inside my_realpath() that is
not an actual error. This could be invoked when a data file is found
but the FSP_SPACE_FLAGS are incorrect, such as is the case for
table test.td in
./mtr --mysqld=--innodb-buffer-pool-dump-at-shutdown=0 innodb.table_flags
buf_load(): If any tablespaces could not be found, invoke
dict_check_tablespaces_and_store_max_id() on the missing tablespaces.
dict_load_tablespace(): Try to load the tablespace unless it was found
to be futile. This fixes failures related to FTS_*.ibd files for
FULLTEXT INDEX.
btr_cur_t::search_leaf(): Prevent a crash when the tablespace
does not exist. This was caught by the test innodb_fts.fts_concurrent_insert
when the change to dict_load_tablespaces() was not present.
We modify a few tests to ensure that tables will not be loaded at startup.
For some fault injection tests this means that the corrupted tables
will not be loaded, because dict_load_tablespace() would perform stricter
checks than dict_check_tablespaces_and_store_max_id().
Tested by: Matthias Leich
Reviewed by: Thirunarayanan Balathandayuthapani
The motivation of introducing the parameter
innodb_purge_rseg_truncate_frequency in
mysql/mysql-server@28bbd66ea5 and
mysql/mysql-server@8fc2120fed
seems to have been to avoid stalls due to freeing undo log pages
or truncating undo log tablespaces. In MariaDB Server,
innodb_undo_log_truncate=ON should be a much lighter operation
than in MySQL, because it will not involve any log checkpoint.
Another source of performance stalls should be
trx_purge_truncate_rseg_history(), which is shrinking the history list
by freeing the undo log pages whose undo records have been purged.
To alleviate that, we will introduce a purge_truncation_task that will
offload this from the purge_coordinator_task. In that way, the next
innodb_purge_batch_size pages may be parsed and purged while the pages
from the previous batch are being freed and the history list being shrunk.
The processing of innodb_undo_log_truncate=ON will still remain the
responsibility of the purge_coordinator_task.
purge_coordinator_state::count: Remove. We will ignore
innodb_purge_rseg_truncate_frequency, and act as if it had been
set to 1 (the maximum shrinking frequency).
purge_coordinator_state::do_purge(): Invoke an asynchronous task
purge_truncation_callback() to free the undo log pages.
purge_sys_t::iterator::free_history(): Free those undo log pages
that have been processed. This used to be a part of
trx_purge_truncate_history().
purge_sys_t::clone_end_view(): Take a new value of purge_sys.head
as a parameter, so that it will be updated while holding exclusive
purge_sys.latch. This is needed for race-free access to the field
in purge_truncation_callback().
Reviewed by: Vladislav Lesin
Some s390x environments include
https://github.com/madler/zlib/pull/410
and a more pessimistic compressBound: (sourceLen * 16 + 2308) / 8 + 6.
Let us adjust the recently enabled tests accordingly.
The test innodb_zip.index_large_prefix_4k would not run unless it is
invoked as
./mtr --mysqld=--innodb-page-size=4k innodb_zip.index_large_prefix_4k
This test was originally developed to cover an option that was removed
in commit 0c92794db3. Starting with
MariaDB Server 10.2, which introduced innodb_default_row_format=dynamic,
the option innodb_large_prefix had become useless.
Let us remove some of the stale tests and adjust the outcome to the
expected behaviour.
btr_cur_need_opposite_intention(): Check also page_zip_available()
so that we will escalate to exclusive index latch when a non-leaf
page may have to be split further due to ROW_FORMAT=COMPRESSED page
overflow.
Tested by: Matthias Leich
The approach to handling corruption that was chosen by Oracle in
commit 177d8b0c12
is not really useful. Not only did it actually fail to prevent InnoDB
from crashing, but it is making things worse by blocking attempts to
rescue data from or rebuild a partially readable table.
We will try to prevent crashes in a different way: by propagating
errors up the call stack. We will never mark the clustered index
persistently corrupted, so that data recovery may be attempted by
reading from the table, or by rebuilding the table.
This should also fix MDEV-13680 (crash on btr_page_alloc() failure);
it was extensively tested with innodb_file_per_table=0 and a
non-autoextend system tablespace.
We should now avoid crashes in many cases, such as when a page
cannot be read or allocated, or an inconsistency is detected when
attempting to update multiple pages. We will not crash on double-free,
such as on the recovery of DDL in system tablespace in case something
was corrupted.
Crashes on corrupted data are still possible. The fault injection mechanism
that is introduced in the subsequent commit may help catch more of them.
buf_page_import_corrupt_failure: Remove the fault injection, and instead
corrupt some pages using Perl code in the tests.
btr_cur_pessimistic_insert(): Always reserve extents (except for the
change buffer), in order to prevent a subsequent allocation failure.
btr_pcur_open_at_rnd_pos(): Merged to the only caller ibuf_merge_pages().
btr_assert_not_corrupted(), btr_corruption_report(): Remove.
Similar checks are already part of btr_block_get().
FSEG_MAGIC_N_BYTES: Replaces FSEG_MAGIC_N_VALUE.
dict_hdr_get(), trx_rsegf_get_new(), trx_undo_page_get(),
trx_undo_page_get_s_latched(): Replaced with error-checking calls.
trx_rseg_t::get(mtr_t*): Replaces trx_rsegf_get().
trx_rseg_header_create(): Let the caller update the TRX_SYS page if needed.
trx_sys_create_sys_pages(): Merged with trx_sysf_create().
dict_check_tablespaces_and_store_max_id(): Do not access
DICT_HDR_MAX_SPACE_ID, because it was already recovered in dict_boot().
Merge dict_check_sys_tables() with this function.
dir_pathname(): Replaces os_file_make_new_pathname().
row_undo_ins_remove_sec(): Do not modify the undo page by adding
a terminating NUL byte to the record.
btr_decryption_failed(): Report decryption failures
dict_set_corrupted_by_space(), dict_set_encrypted_by_space(),
dict_set_corrupted_index_cache_only(): Remove.
dict_set_corrupted(): Remove the constant parameter dict_locked=false.
Never flag the clustered index corrupted in SYS_INDEXES, because
that would deny further access to the table. It might be possible to
repair the table by executing ALTER TABLE or OPTIMIZE TABLE, in case
no B-tree leaf page is corrupted.
dict_table_skip_corrupt_index(), dict_table_next_uncorrupted_index(),
row_purge_skip_uncommitted_virtual_index(): Remove, and refactor
the callers to read dict_index_t::type only once.
dict_table_is_corrupted(): Remove.
dict_index_t::is_btree(): Determine if the index is a valid B-tree.
BUF_GET_NO_LATCH, BUF_EVICT_IF_IN_POOL: Remove.
UNIV_BTR_DEBUG: Remove. Any inconsistency will no longer trigger
assertion failures, but error codes being returned.
buf_corrupt_page_release(): Replaced with a direct call to
buf_pool.corrupted_evict().
fil_invalid_page_access_msg(): Never crash on an invalid read;
let the caller of buf_page_get_gen() decide.
btr_pcur_t::restore_position(): Propagate failure status to the caller
by returning CORRUPTED.
opt_search_plan_for_table(): Simplify the code.
row_purge_del_mark(), row_purge_upd_exist_or_extern_func(),
row_undo_ins_remove_sec_rec(), row_undo_mod_upd_del_sec(),
row_undo_mod_del_mark_sec(): Avoid mem_heap_create()/mem_heap_free()
when no secondary indexes exist.
row_undo_mod_upd_exist_sec(): Simplify the code.
row_upd_clust_step(), dict_load_table_one(): Return DB_TABLE_CORRUPT
if the clustered index (and therefore the table) is corrupted, similar
to what we do in row_insert_for_mysql().
fut_get_ptr(): Replace with buf_page_get_gen() calls.
buf_page_get_gen(): Return nullptr and *err=DB_CORRUPTION
if the page is marked as freed. For other modes than
BUF_GET_POSSIBLY_FREED or BUF_PEEK_IF_IN_POOL this will
trigger a debug assertion failure. For BUF_GET_POSSIBLY_FREED,
we will return nullptr for freed pages, so that the callers
can be simplified. The purge of transaction history will be
a new user of BUF_GET_POSSIBLY_FREED, to avoid crashes on
corrupted data.
buf_page_get_low(): Never crash on a corrupted page, but simply
return nullptr.
fseg_page_is_allocated(): Replaces fseg_page_is_free().
fts_drop_common_tables(): Return an error if the transaction
was rolled back.
fil_space_t::set_corrupted(): Report a tablespace as corrupted if
it was not reported already.
fil_space_t::io(): Invoke fil_space_t::set_corrupted() to report
out-of-bounds page access or other errors.
Clean up mtr_t::page_lock()
buf_page_get_low(): Validate the page identifier (to check for
recently read corrupted pages) after acquiring the page latch.
buf_page_t::read_complete(): Flag uninitialized (all-zero) pages
with DB_FAIL. Return DB_PAGE_CORRUPTED on page number mismatch.
mtr_t::defer_drop_ahi(): Renamed from mtr_defer_drop_ahi().
recv_sys_t::free_corrupted_page(): Only set_corrupt_fs()
if any log records exist for the page. We do not mind if read-ahead
produces corrupted (or all-zero) pages that were not actually needed
during recovery.
recv_recover_page(): Return whether the operation succeeded.
recv_sys_t::recover_low(): Simplify the logic. Check for recovery error.
Thanks to Matthias Leich for testing this extensively and to the
authors of https://rr-project.org for making it easy to diagnose
and fix any failures that were found during the testing.
In commit 7a4fbb55b0 (MDEV-25105)
the innochecksum option --write (-w) was removed altogether.
It should have been made a Boolean option, so that old data files
may be converted to a format that is compatible with
innodb_checksum_algorithm=strict_crc32 by executing the following:
innochecksum -n -w ibdata* */*.ibd
It would be better to use an older-version innochecksum
for such a conversion, so that page checksums will be validated
before updating the checksum.
It never was possible for innochecksum to convert files to the
innodb_checksum_algorithm=full_crc32 format that is the default
for new InnoDB data files.
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.
The InnoDB DATA DIRECTORY attribute is not implemented via
symbolic links but something similar, *.isl files that contain
the names of data files.
InnoDB failed to ignore the DATA DIRECTORY attribute even though
the server was started with --skip-symbolic-links.
Native ALTER TABLE in InnoDB will retain the DATA DIRECTORY attribute
of the table, no matter if the table will be rebuilt or not.
Generic ALTER TABLE (with ALGORITHM=COPY) as well as TRUNCATE TABLE
will discard the DATA DIRECTORY attribute.
All tests have been run with and without the ./mtr option
--mysqld=--skip-symbolic-links
and some tests that use the InnoDB DATA DIRECTORY attribute
have been adjusted for this.
ALTER TABLE IMPORT doesn't properly handle instant alter metadata.
This patch makes IMPORT read, parse and apply instant alter metadata at the
very beginning of operation. So, cases when source table has some metadata
and destination table doesn't have it now works fine.
DISCARD already removes instant metadata so importing normal table into
instant table worked fine before this patch.
decrypt_decompress(): decrypts and decompresses page if needed
handle_instant_metadata(): this should be the first thing to read source
table. Basically, it applies instant metadata to a destination
dict_table_t object. This is the first thing to read FSP flags so
all possible checks of it were moved to this function.
PageConverter::update_index_page(): it doesn't now read instant metadata.
This logic were moved into handle_instant_metadata()
row_import::match_flags(): this is a first part row_import::match_schema().
As a separate function it's used by handle_instant_metadata().
fil_space_t::is_full_crc32_compressed(): added convenient function
ha_innobase::discard_or_import_tablespace(): do not reload table definition
to read instant metadata because handle_instant_metadata() does it better.
The reverted code was originally added in
4e7ee166a9
ANONYMOUS_VAR: this is a handy thing to use along with make_scope_exit()
full_crc32_import.test shows different results, because no
dict_table_close() and dict_table_open_on_id() happens.
Thus, SHOW CREATE TABLE shows a little bit older table definition.
This essentially reverts commit 4e89ec6692
and only disables InnoDB persistent statistics for tests where it is
desirable. By design, InnoDB persistent statistics will not be updated
except by ANALYZE TABLE or by STATS_AUTO_RECALC.
The internal transactions that update persistent InnoDB statistics
in background tasks (with innodb_stats_auto_recalc=ON) may cause
nondeterministic query plans or interfere with some tests that deal
with other InnoDB internals, such as the purge of transaction history.
InnoDB tablespace identifiers and page numbers are 32-bit numbers.
Let us use a 32-bit type for them in innochecksum.
The changes in commit 1918bdf32c
broke the build on 32-bit Windows.
Thanks to Vicențiu Ciorbaru for an initial version of this fixup.
This is a complete rewrite of DROP TABLE, also as part of other DDL,
such as ALTER TABLE, CREATE TABLE...SELECT, TRUNCATE TABLE.
The background DROP TABLE queue hack is removed.
If a transaction needs to drop and create a table by the same name
(like TRUNCATE TABLE does), it must first rename the table to an
internal #sql-ib name. No committed version of the data dictionary
will include any #sql-ib tables, because whenever a transaction
renames a table to a #sql-ib name, it will also drop that table.
Either the rename will be rolled back, or the drop will be committed.
Data files will be unlinked after the transaction has been committed
and a FILE_RENAME record has been durably written. The file will
actually be deleted when the detached file handle returned by
fil_delete_tablespace() will be closed, after the latches have been
released. It is possible that a purge of the delete of the SYS_INDEXES
record for the clustered index will execute fil_delete_tablespace()
concurrently with the DDL transaction. In that case, the thread that
arrives later will wait for the other thread to finish.
HTON_TRUNCATE_REQUIRES_EXCLUSIVE_USE: A new handler flag.
ha_innobase::truncate() now requires that all other references to
the table be released in advance. This was implemented by Monty.
ha_innobase::delete_table(): If CREATE TABLE..SELECT is detected,
we will "hijack" the current transaction, drop the table in
the current transaction and commit the current transaction.
This essentially fixes MDEV-21602. There is a FIXME comment about
making the check less failure-prone.
ha_innobase::truncate(), ha_innobase::delete_table():
Implement a fast path for temporary tables. We will no longer allow
temporary tables to use the adaptive hash index.
dict_table_t::mdl_name: The original table name for the purpose of
acquiring MDL in purge, to prevent a race condition between a
DDL transaction that is dropping a table, and purge processing
undo log records of DML that had executed before the DDL operation.
For #sql-backup- tables during ALTER TABLE...ALGORITHM=COPY, the
dict_table_t::mdl_name will differ from dict_table_t::name.
dict_table_t::parse_name(): Use mdl_name instead of name.
dict_table_rename_in_cache(): Update mdl_name.
For the internal FTS_ tables of FULLTEXT INDEX, purge would
acquire MDL on the FTS_ table name, but not on the main table,
and therefore it would be able to run concurrently with a
DDL transaction that is dropping the table. Previously, the
DROP TABLE queue hack prevented a race between purge and DDL.
For now, we introduce purge_sys.stop_FTS() to prevent purge from
opening any table, while a DDL transaction that may drop FTS_
tables is in progress. The function fts_lock_table(), which will
be invoked before the dictionary is locked, will wait for
purge to release any table handles.
trx_t::drop_table_statistics(): Drop statistics for the table.
This replaces dict_stats_drop_index(). We will drop or rename
persistent statistics atomically as part of DDL transactions.
On lock conflict for dropping statistics, we will fail instantly
with DB_LOCK_WAIT_TIMEOUT, because we will be holding the
exclusive data dictionary latch.
trx_t::commit_cleanup(): Separated from trx_t::commit_in_memory().
Relax an assertion around fts_commit() and allow DB_LOCK_WAIT_TIMEOUT
in addition to DB_DUPLICATE_KEY. The call to fts_commit() is
entirely misplaced here and may obviously break the consistency
of transactions that affect FULLTEXT INDEX. It needs to be fixed
separately.
dict_table_t::n_foreign_key_checks_running: Remove (MDEV-21175).
The counter was a work-around for missing meta-data locking (MDL)
on the SQL layer, and not really needed in MariaDB.
ER_TABLE_IN_FK_CHECK: Replaced with ER_UNUSED_28.
HA_ERR_TABLE_IN_FK_CHECK: Remove.
row_ins_check_foreign_constraints(): Do not acquire
dict_sys.latch either. The SQL-layer MDL will protect us.
This was reviewed by Thirunarayanan Balathandayuthapani
and tested by Matthias Leich.
Many InnoDB data dictionary cache operations require that the
table name be copied so that it will be NUL terminated.
(For example, SYS_TABLES.NAME is not guaranteed to be NUL-terminated.)
dict_table_t::is_garbage_name(): Check if a name belongs to
the background drop table queue.
dict_check_if_system_table_exists(): Remove.
dict_sys_t::load_sys_tables(): Load the non-hard-coded system tables
SYS_FOREIGN, SYS_FOREIGN_COLS, SYS_VIRTUAL on startup.
dict_sys_t::create_or_check_sys_tables(): Replaces
dict_create_or_check_foreign_constraint_tables() and
dict_create_or_check_sys_virtual().
dict_sys_t::load_table(): Replaces dict_table_get_low()
and dict_load_table().
dict_sys_t::find_table(): Renamed from get_table().
dict_sys_t::sys_tables_exist(): Check whether all the non-hard-coded
tables SYS_FOREIGN, SYS_FOREIGN_COLS, SYS_VIRTUAL exist.
trx_t::has_stats_table_lock(): Moved to dict0stats.cc.
Some error messages will now report table names in the internal
databasename/tablename format, instead of `databasename`.`tablename`.
A side effect of the MDEV-24589 bug fix is that if
FLUSH TABLE...FOR EXPORT is initiated before the history of an
earlier DROP INDEX operation has been purged, then the data file
will contain allocated pages that belonged to the dropped indexes.
These pages would never be freed after a subsequent IMPORT TABLESPACE.
We will work around this regression by making IMPORT TABLESPACE
tolerate pages that refer to an unknown index.
Historically, InnoDB supported a buggy page checksum algorithm that did not
compute a checksum over the full page. Later, well before MySQL 4.1
introduced .ibd files and the innodb_file_per_table option, the algorithm
was corrected and the first 4 bytes of each page were redefined to be
a checksum.
The original checksum was so slow that an option to disable page checksum
was introduced for benchmarketing purposes.
The Intel Nehalem microarchitecture introduced the SSE4.2 instruction set
extension, which includes instructions for faster computation of CRC-32C.
In MySQL 5.6 (and MariaDB 10.0), innodb_checksum_algorithm=crc32 was
implemented to make of that. As that option was changed to be the default
in MySQL 5.7, a bug was found on big-endian platforms and some work-around
code was added to weaken that checksum further. MariaDB disables that
work-around by default since MDEV-17958.
Later, SIMD-accelerated CRC-32C has been implemented in MariaDB for POWER
and ARM and also for IA-32/AMD64, making use of carry-less multiplication
where available.
Long story short, innodb_checksum_algorithm=crc32 is faster and more secure
than the pre-MySQL 5.6 checksum, called innodb_checksum_algorithm=innodb.
It should have removed any need to use innodb_checksum_algorithm=none.
The setting innodb_checksum_algorithm=crc32 is the default in
MySQL 5.7 and MariaDB Server 10.2, 10.3, 10.4. In MariaDB 10.5,
MDEV-19534 made innodb_checksum_algorithm=full_crc32 the default.
It is even faster and more secure.
The default settings in MariaDB do allow old data files to be read,
no matter if a worse checksum algorithm had been used.
(Unfortunately, before innodb_checksum_algorithm=full_crc32,
the data files did not identify which checksum algorithm is being used.)
The non-default settings innodb_checksum_algorithm=strict_crc32 or
innodb_checksum_algorithm=strict_full_crc32 would only allow CRC-32C
checksums. The incompatibility with old data files is why they are
not the default.
The newest server not to support innodb_checksum_algorithm=crc32
were MySQL 5.5 and MariaDB 5.5. Both have reached their end of life.
A valid reason for using innodb_checksum_algorithm=innodb could have
been the ability to downgrade. If it is really needed, data files
can be converted with an older version of the innochecksum utility.
Because there is no good reason to allow data files to be written
with insecure checksums, we will reject those option values:
innodb_checksum_algorithm=none
innodb_checksum_algorithm=innodb
innodb_checksum_algorithm=strict_none
innodb_checksum_algorithm=strict_innodb
Furthermore, the following innochecksum options will be removed,
because only strict crc32 will be supported:
innochecksum --strict-check=crc32
innochecksum -C crc32
innochecksum --write=crc32
innochecksum -w crc32
If a user wishes to convert a data file to use a different checksum
(so that it might be used with the no-longer-supported
MySQL 5.5 or MariaDB 5.5, which do not support IMPORT TABLESPACE
nor system tablespace format changes that were made in MariaDB 10.3),
then the innochecksum tool from MariaDB 10.2, 10.3, 10.4, 10.5 or
MySQL 5.7 can be used.
Reviewed by: Thirunarayanan Balathandayuthapani
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).
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.
The background DROP TABLE queue may be blocked for some more time
due to MDEV-16678. Let us apply similar adjustments as earlier:
commit 6af00b2cc6
commit 89633995e4
commit ccd87d34a4
Remove CREATE/DROP database.
Remove some unnecessary suppressions, replacements, and
SQL statements.
Populate tables via have_sequence.inc to avoid the creation of
explicit InnoDB record locks in INSERT...SELECT. This will remove
some gaps in AUTO_INCREMENT values.
btr_cur_upd_rec_in_place(): Invoke page_zip_rec_set_deleted()
for ROW_FORMAT=COMPRESSED pages, so that the change will be
written to the redo log.
This part of crash recovery was broken in
commit 08ba388713 (MDEV-12353).
