Fixed by:
- Make all quick_* variable allocated according to real number keys instead
of MAX_KEY
- Store all the quick* items in separated allocated structure (OPT_RANGE)
- Ensure we don't access any quick* variable without first checking
opt_range_keys.is_set(). Thanks to this, we don't need any
pre-initialization of quick* variables anymore.
Some renames was done to use the new structure:
table->quick_keys -> table->opt_range_keys
table->quick_rows[X] -> table->opt_range[X].rows
table->quick_key_parts[X] -> table->opt_range[X].key_parts
table->quick_costs[X] -> table->opt_range[X].cost
table->quick_index_only_costs[X] -> table->opt_range[X].index_only_cost
table->quick_n_ranges[X] -> table->opt_range[X].ranges
table->quick_condition_rows -> table->opt_range_condition_rows
This patch should both decrease memory needed for TABLE objects
(3528 -> 984 + keyinfo) and increase performance, thanks to less
initializations per query, and more localized memory, thanks to the
opt_range structure.
Starting from 10.3, the optimizer is able to detect that entire outer join
nests are constants (because of "Impossible ON") and remove them (see
mark_join_nest_as_const)
However, this was not properly accounted for in NESTED_JOIN structure
and the way check_interleaving_with_nj() uses its n_tables member to
check if the join prefix order is allowed.
(The result was that the optimizer could conclude that no join prefix is
allowed and fail an assertion)
reduce the amount of engine-specific code in the server,
particularly as it does not serve any purpose now.
may be needed for VP engine,
to be reconsidered in MDEV-7795
Previously multiple threads were allowed to load histograms concurrently.
There were no known problems caused by this. But given amount of data
races in this code, it'd happen sooner or later.
To avoid scalability bottleneck, histograms loading is protected by
per-TABLE_SHARE atomic variable.
Whenever histograms were loaded by preceding statement (hot-path), a
scalable load-acquire check is performed.
Whenever histograms have to be loaded anew, mutual exclusion for loaders
is established by atomic variable. If histograms are being loaded
concurrently, statement waits until load is completed.
- Table_statistics::total_hist_size moved to TABLE_STATISTICS_CB: only
meaningful within TABLE_SHARE (not used for collected stats).
- TABLE_STATISTICS_CB::histograms_can_be_read and
TABLE_STATISTICS_CB::histograms_are_read are replaced with a tri state
atomic variable.
- Simplified away alloc_histograms_for_table_share().
Note: there's still likely a data race if a thread attempts accessing
histograms data after it failed to load it (because of concurrent load).
It was there previously and goes out of the scope of this effort. One way
of fixing it could be reviving TABLE::histograms_are_read and adding
appropriate checks whenever it is needed.
Part of MDEV-19061 - table_share used for reading statistical tables is
not protected
Previously multiple threads were allowed to load statistics concurrently.
There were no known problems caused by this. But given amount of data
races in this code, it'd happen sooner or later.
To avoid scalability bottleneck, statistics loading is protected by
per-TABLE_SHARE atomic variable.
Whenever statistics were loaded by preceding statement (hot-path), a
scalable load-acquire check is performed.
Whenever statistics have to be loaded anew, mutual exclusion for loaders
is established by atomic variable. If statistics are being loaded
concurrently, statement waits until load is completed.
TABLE_STATISTICS_CB::stats_can_be_read and
TABLE_STATISTICS_CB::stats_is_read are replaced with a tri state atomic
variable.
Part of MDEV-19061 - table_share used for reading statistical tables is
not protected
MDEV-21398 Deadlock (server hang) or assertion failure in
Diagnostics_area::set_error_status upon ALTER under lock
This failure could only happen if one locked the same table
multiple times and then did an ALTER TABLE on the table.
Major change is to change all instances of
table->m_needs_reopen= true;
to
table->mark_table_for_reopen();
The main fix for the problem was to ensure that we mark all
instances of the table in the locked_table_list and when we
reopen the tables, we first close all tables before reopening
and locking them.
Other things:
- Don't call thd->locked_tables_list.reopen_tables if there
are no tables marked for reopen. (performance)
only MDL-prelock but do not open FK child tables for read-only (RESTRICT)
FK actions.
Tables still needs to be opened for CASCADE actions, see 9180e8666b
MDEV-22088 S3 partitioning support
All ALTER PARTITION commands should now work on S3 tables except
REBUILD PARTITION
TRUNCATE PARTITION
REORGANIZE PARTITION
In addition, PARTIONED S3 TABLES can also be replicated.
This is achived by storing the partition tables .frm and .par file on S3
for partitioned shared (S3) tables.
The discovery methods are enchanced by allowing engines that supports
discovery to also support of the partitioned tables .frm and .par file
Things in more detail
- The .frm and .par files of partitioned tables are stored in S3 and kept
in sync.
- Added hton callback create_partitioning_metadata to inform handler
that metadata for a partitoned file has changed
- Added back handler::discover_check_version() to be able to check if
a table's or a part table's definition has changed.
- Added handler::check_if_updates_are_ignored(). Needed for partitioning.
- Renamed rebind() -> rebind_psi(), as it was before.
- Changed CHF_xxx hadnler flags to an enum
- Changed some checks from using table->file->ht to use
table->file->partition_ht() to get discovery to work with partitioning.
- If TABLE_SHARE::init_from_binary_frm_image() fails, ensure that we
don't leave any .frm or .par files around.
- Fixed that writefrm() doesn't leave unusable .frm files around
- Appended extension to path for writefrm() to be able to reuse to function
for creating .par files.
- Added DBUG_PUSH("") to a a few functions that caused a lot of not
critical tracing.
- Print the rowid filters that are available for use with each table.
- Make print_best_access_for_table() print which filter it has picked.
- Make best_access_path() print the filter for considered ref accesses.
* The overlaps check is implemented on a handler level per row command.
It creates a separate cursor (actually, another handler instance) and
caches it inside the original handler, when ha_update_row or
ha_insert_row is issued. Cursor closes on unlocking the handler.
* Containing the same key in index means unique constraint violation
even in usual terms. So we fetch left and right neighbours and check
that they have same key prefix, excluding from the key only the period part.
If it doesnt match, then there's no such neighbour, and the check passes.
Otherwise, we check if this neighbour intersects with the considered key.
* The check does not introduce new error and fails with ER_DUPP_KEY error.
This might break REPLACE workflow and should be fixed separately
* rename to a generic name
* move remaning initializations from query exec to prepare time
* simplify/unify key handling in open_table_from_share and delayed
* remove dead code
* move tests where they belong
MDEV-21606 Improve update handler (long unique keys on blobs)
MDEV-21470 MyISAM and Aria start_bulk_insert doesn't work with long unique
MDEV-21606 Bug fix for previous version of this code
MDEV-21819 2 Assertion `inited == NONE || update_handler != this'
- Move update_handler from TABLE to handler
- Move out initialization of update handler from ha_write_row() to
prepare_for_insert()
- Fixed that INSERT DELAYED works with update handler
- Give an error if using long unique with an autoincrement column
- Added handler function to check if table has long unique hash indexes
- Disable write cache in MyISAM and Aria when using update_handler as
if cache is used, the row will not be inserted until end of statement
and update_handler would not find conflicting rows.
- Removed not used handler argument from
check_duplicate_long_entries_update()
- Syntax cleanups
- Indentation fixes
- Don't use single character indentifiers for arguments
Some .c and .cc files are compiled as part of Mariabackup.
Enabling -Wconversion for InnoDB would also enable it for
Mariabackup. The .h files are being included during
InnoDB or Mariabackup compilation.
Notably, GCC 5 (but not GCC 4 or 6 or later versions)
would report -Wconversion for x|=y when the type is
unsigned char. So, we will either write x=(uchar)(x|y)
or disable the -Wconversion warning for GCC 5.
bitmap_set_bit(), bitmap_flip_bit(), bitmap_clear_bit(), bitmap_is_set():
Always implement as inline functions.
When there are E empty partitions left, auto-create N new empty
partitions for SYSTEM_TIME partitioning rotated by INTERVAL/LIMIT and
marked by AUTO_INCREMENT keyword. Syntax change: AUTO_INCREMENT
keyword (or shorter AUTO may be used instead) after LIMIT/INTERVAL
clause.
CREATE OR REPLACE TABLE t (x INT) WITH SYSTEM VERSIONING
PARTITION BY SYSTEM_TIME LIMIT 100000 AUTO_INCREMENT;
CREATE OR REPLACE TABLE t (x INT) WITH SYSTEM VERSIONING
PARTITION BY SYSTEM_TIME INTERVAL 1 WEEK AUTO_INCREMENT;
The current revision implements hard-coded values of 1 for E and N. As
well as auto-creation threshold MinInterval = 1 hour, MinLimit = 1000.
The name for newly added partition will be first chosen as "pX", where
X is partition number and "p" is hard-coded name prefix. If this name
is already occupied, the X will be incremented until the resulting
name will be free to use.
ALTER TABLE ADD PARTITION is now always fast. If there some history
partition overflow occurs manual ALTER TABLE REBUILD PARTITION is
needed.
Wrong assertion condition. SYSTEM_TIME_ALL indicates that
vers_setup_conds() is done. In case FOR SYSTEM_TIME ALL is specified
in command the assertion passes but not checks anything.
Don't do skip_setup_conds() unless all errors are checked.
Fixes following errors:
ER_PERIOD_NOT_FOUND
ER_VERS_QUERY_IN_PARTITION
ER_VERS_ENGINE_UNSUPPORTED
ER_VERS_NOT_VERSIONED
Don't do skip_setup_conds() unless all errors are checked.
Fixes following errors:
ER_PERIOD_NOT_FOUND
ER_VERS_QUERY_IN_PARTITION
ER_VERS_ENGINE_UNSUPPORTED
ER_VERS_NOT_VERSIONED
When view is merged by DT_MERGE_FOR_INSERT it is then skipped from
processing and doesn't update WHERE clause with
vers_setup_conds(). Note that view itself cannot work in
vers_setup_conds() because it doesn't have row_start, row_end
fields. Thus it is required to descend down to material TABLE_LIST
through calls of mysql_derived_prepare() and run vers_setup_conds()
from there. Luckily, all views (views of views, views of views of
views, etc.) are linked in one list through next_global pointer, so we
can skip all views of views and get straight to non-view TABLE_LIST by
checking its merge_underlying_list property for zero value (it is
assigned by DT_MERGE_FOR_INSERT for merged derived tables).
We have to do that only for UPDATE and DELETE. Other DML commands
don't use WHERE clause.
MDEV-21146 Assertion `m_lock_type == 2' in handler::ha_drop_table upon LOAD DATA
LOAD DATA does not use WHERE and the above call of vers_setup_conds()
is not needed. unit->prepare() led to wrongly locked temporary table.
Turn read cache off for update and multi-update for versioned
table. no_cache is reinited on each TABLE open because it is
applicable for specific algorithms.
As a side fix vers_insert_history_row() honors vers_write setting.
Aria with row_format=fixed uses IO_CACHE of type READ_CACHE for
sequential read in update loop. When history row is inserted inside
this loop the cache misses it and fails with error.
TODO:
Currently maria_extra() does not support SEQ_READ_APPEND. Probably it
might be possible to use this type of cache.
