into a separate transaction_participant structure
handlerton inherits it, so handlerton itself doesn't change.
but entities that only need to participate in a transaction,
like binlog or online alter log, use a transaction_participant
and no longer need to pretend to be a full-blown but invisible
storage engine which doesn't support create table.
* preserve the graph in memory between statements
* keep it in a TABLE_SHARE, available for concurrent searches
* nodes are generally read-only, walking the graph doesn't change them
* distance to target is cached, calculated only once
* SIMD-optimized bloom filter detects visited nodes
* nodes are stored in an array, not List, to better utilize bloom filter
* auto-adjusting heuristic to estimate the number of visited nodes
(to configure the bloom filter)
* many threads can concurrently walk the graph. MEM_ROOT and Hash_set
are protected with a mutex, but walking doesn't need them
* up to 8 threads can concurrently load nodes into the cache,
nodes are partitioned into 8 mutexes (8 is chosen arbitrarily, might
need tuning)
* concurrent editing is not supported though
* this is fine for MyISAM, TL_WRITE protects the TABLE_SHARE and the
graph (note that TL_WRITE_CONCURRENT_INSERT is not allowed, because an
INSERT into the main table means multiple UPDATEs in the graph)
* InnoDB uses secondary transaction-level caches linked in a list in
in thd->ha_data via a fake handlerton
* on rollback the secondary cache is discarded, on commit nodes
from the secondary cache are invalidated in the shared cache
while it is exclusively locked
* on savepoint rollback both caches are flushed. this can be improved
in the future with a row visibility callback
* graph size is controlled by @@mhnsw_cache_size, the cache is flushed
when it reaches the threshold
MDEV-33407 Parser support for vector indexes
The syntax is
create table t1 (... vector index (v) ...);
limitation:
* v is a binary string and NOT NULL
* only one vector index per table
* temporary tables are not supported
MDEV-33404 Engine-independent indexes: subtable method
added support for so-called "high level indexes", they are not visible
to the storage engine, implemented on the sql level. For every such
an index in a table, say, t1, the server implicitly creates a second
table named, like, t1#i#05 (where "05" is the index number in t1).
This table has a fixed structure, no frm, not accessible directly,
doesn't go into the table cache, needs no MDLs.
MDEV-33406 basic optimizer support for k-NN searches
for a query like SELECT ... ORDER BY func() optimizer will use
item_func->part_of_sortkey() to decide what keys can be used
to resolve ORDER BY.
the information about index algorithm was stored in two
places inconsistently split between both.
BTREE index could have key->algorithm == HA_KEY_ALG_BTREE, if the user
explicitly specified USING BTREE or HA_KEY_ALG_UNDEF, if not.
RTREE index had key->algorithm == HA_KEY_ALG_RTREE
and always had key->flags & HA_SPATIAL
FULLTEXT index had key->algorithm == HA_KEY_ALG_FULLTEXT
and always had key->flags & HA_FULLTEXT
HASH index had key->algorithm == HA_KEY_ALG_HASH or HA_KEY_ALG_UNDEF
long unique index always had key->algorithm == HA_KEY_ALG_LONG_HASH
In this commit:
All indexes except BTREE and HASH always have key->algorithm
set, HA_SPATIAL and HA_FULLTEXT flags are not used anymore (except
for storage to keep frms backward compatible).
As a side effect ALTER TABLE now detects FULLTEXT index renames correctly
to explicit row_start/row_end columns
In case of adding both system fields of same type (length, unsigned
flag) as old implicit system fields do the rename of implicit system
fields to the ones specified in ALTER, remove SYSTEM_INVISIBLE flag in
that case. Correct PERIOD clause must be specified in ALTER as well.
MDEV-34904 Inplace alter for implicit to explicit versioning is broken
Whether ALTER goes inplace and how it goes inplace depends on
handler_flags which goes from alter_info->flags by this logic:
ha_alter_info->handler_flags|= (alter_info->flags & ~flags_to_remove);
ALTER_VERS_EXPLICIT was not in flags_to_remove and its value (1ULL <<
35) clashed with ALTER_ADD_NON_UNIQUE_NON_PRIM_INDEX.
ALTER_VERS_EXPLICIT must not affect inplace, it is SQL-only so we
remove it from handler_flags.
When a derived table which has distinct values and BLOB fields is
materialized, an index is created over all columns to ensure only
unique values are placed to the result.
This index is created in a special mode HA_UNIQUE_HASH to support BLOBs.
Later the optimizer may incorrectly choose this index to retrieve values
from the derived table, although such type of index cannot be used
for data retrieval.
This commit excludes HA_UNIQUE_HASH indexes from adding to
`JOIN::keyuse` array thus preventing their subsequent usage for
data retrieval
work consistently on replication
Row-based replication does not execute CREATE .. SELECT but instead
CREATE TABLE. CREATE .. SELECT creates implict system fields on
unusual place: in-between declared fields and select fields. That was
done because select_field_pos logic requires select fields go last in
create_list.
So, CREATE .. SELECT on master and CREATE TABLE on slave create system
fields on different positions and replication gets field mismatch.
To fix this we've changed CREATE .. SELECT to create implicit system
fields on usual place in the end and updated select_field_pos for
handling this case.
Fixed by checking handler_stats if it's active instead of
thd->variables.log_slow_verbosity & LOG_SLOW_VERBOSITY_ENGINE.
Reviewed-by: Sergei Petrunia <sergey@mariadb.com>
The method was declared to return an unsigned integer, but it is
really a boolean (and used as such by all callers).
A secondary change is the addition of "const" and "noexcept" to this
method.
In ha_mroonga.cpp, I also added "inline" to the two helper methods of
referenced_by_foreign_key(). This allows the compiler to flatten the
method.
crash recovery
Summary
=======
When doing server recovery, the active transactions will be rolled
back by InnoDB background rollback thread automatically. The
prepared transactions will be committed or rolled back accordingly
by binlog recovery. Binlog recovery is done in main thread before
the server can provide service to users. If there is a big
transaction to rollback, the server will not available for a long
time.
This patch provides a way to rollback the prepared transactions
asynchronously. Thus the rollback will not block server startup.
Design
======
- Handler::recover_rollback_by_xid()
This patch provides a new handler interface to rollback transactions
in recover phase. InnoDB just set the transaction's state to active.
Then the transaction will be rolled back by the background rollback
thread.
- Handler::signal_tc_log_recover_done()
This function is called after tc log is opened(typically binlog opened)
has done. When this function is called, all transactions will be rolled
back have been reverted to ACTIVE state. Thus it starts rollback thread
to rollback the transactions.
- Background rollback thread
With this patch, background rollback thread is defered to run until binlog
recovery is finished. It is started by innobase_tc_log_recovery_done().
This commit adds 3 new status variables to 'show all slaves status':
- Master_last_event_time ; timestamp of the last event read from the
master by the IO thread.
- Slave_last_event_time ; Master timestamp of the last event committed
on the slave.
- Master_Slave_time_diff: The difference of the above two timestamps.
All the above variables are NULL until the slave has started and the
slave has read one query event from the master that changes data.
- Added information_schema.slave_status, which allows us to remove:
- show_master_info(), show_master_info_get_fields(),
send_show_master_info_data(), show_all_master_info()
- class Sql_cmd_show_slave_status.
- Protocol::store(I_List<i_string_pair>* str_list) as it is not
used anymore.
- Changed old SHOW SLAVE STATUS and SHOW ALL SLAVES STATUS to
use the SELECT code path, as all other SHOW ... STATUS commands.
Other things:
- Xid_log_time is set to time of commit to allow slave that reads the
binary log to calculate Master_last_event_time and
Slave_last_event_time.
This is needed as there is not 'exec_time' for row events.
- Fixed that Load_log_event calculates exec_time identically to
Query_event.
- Updated RESET SLAVE to reset Master/Slave_last_event_time
- Updated SQL thread's update on first transaction read-in to
only update Slave_last_event_time on group events.
- Fixed possible (unlikely) bugs in sql_show.cc ...old_format() functions
if allocation of 'field' would fail.
Reviewed By:
Brandon Nesterenko <brandon.nesterenko@mariadb.com>
Kristian Nielsen <knielsen@knielsen-hq.org>
* A new table INFORMATION_SCHEMA.USERS is introduced.
* It stores auxiliary user data
* An unprivileged user can access their own data, and that is the main
difference with what mysql.global_priv provides
* The fields are currently: USER, PASSWORD_ERRORS, PASSWORD_EXPIRATION_TIME
* If password_errors is ignored for the user, PASSWORD_ERRORS is NULL
* PASSWORD_EXPIRATION_TIME is a timestamp with exact point in time, calculated
from password_last_changed and password_lifetime (i.e. days) stored for the user
Columns added to TABLE_STATISTICS
- ROWS_INSERTED, ROWS_DELETED, ROWS_UPDATED, KEY_READ_HITS and
KEY_READ_MISSES.
Columns added to CLIENT_STATISTICS and USER_STATISTICS:
- KEY_READ_HITS and KEY_READ_MISSES.
User visible changes (except new columns):
- CLIENT_STATISTICS and USER_STATISTICS has columns KEY_READ_HITS and
KEY_READ_MISSES added after column ROWS_UPDATED before SELECT_COMMANDS.
Other changes:
- Do not collect table statistics for system tables like index_stats
table_stats, performance_schema, information_schema etc as the user
has no control of these and the generate noice in the statistics.
- All row variables that are part of user_stats are moved to
'struct rows_stats' to make it easy to clear all of them at once.
- ha_read_key_misses added to STATUS_VAR
Notes:
- userstat.result has a change of numbers of rows for handler_read_key.
This is because use-stat-tables is now disabled for the test.
MDEV-32188 make TIMESTAMP use whole 32-bit unsigned range
- Added --update-history option to mariadb-dump to change 2038
row_end timestamp to 2106.
- Updated ALTER TABLE ... to convert old row_end timestamps to
2106 timestamp for tables created before MariaDB 11.4.0.
- Fixed bug in CHECK TABLE where we wrongly suggested to USE REPAIR
TABLE when ALTER TABLE...FORCE is needed.
- mariadb-check printed table names that where used with REPAIR TABLE but
did not print table names used with ALTER TABLE or with name repair.
Fixed by always printing a table that is fixed if --silent is not
used.
- Added TABLE::vers_fix_old_timestamp() that will change max-timestamp
for versioned tables when replication from a pre-11.4.0 server.
A few test cases changed. This is caused by:
- CHECK TABLE now prints 'Please do ALTER TABLE... instead of
'Please do REPAIR TABLE' when there is a problem with the information
in the .frm file (for example a very old frm file).
- mariadb-check now prints repaired table names.
- mariadb-check also now prints nicer error message in case ALTER TABLE
is needed to repair a table.
This task is to ensure we have a clear definition and rules of how to
repair or optimize a table.
The rules are:
- REPAIR should be used with tables that are crashed and are
unreadable (hardware issues with not readable blocks, blocks with
'unexpected data' etc)
- OPTIMIZE table should be used to optimize the storage layout for the
table (recover space for delete rows and optimize the index
structure.
- ALTER TABLE table_name FORCE should be used to rebuild the .frm file
(the table definition) and the table (with the original table row
format). If the table is from and older MariaDB/MySQL release with a
different storage format, it will convert the data to the new
format. ALTER TABLE ... FORCE is used as part of mariadb-upgrade
Here follows some more background:
The 3 ways to repair a table are:
1) ALTER TABLE table_name FORCE" (not other options).
As an alias we allow: "ALTER TABLE table_name ENGINE=original_engine"
2) "REPAIR TABLE" (without FORCE)
3) "OPTIMIZE TABLE"
All of the above commands will optimize row space usage (which means that
space will be needed to hold a temporary copy of the table) and
re-generate all indexes. They will also try to replicate the original
table definition as exact as possible.
For ALTER TABLE and "REPAIR TABLE without FORCE", the following will hold:
If the table is from an older MariaDB version and data conversion is
needed (for example for old type HASH columns, MySQL JSON type or new
TIMESTAMP format) "ALTER TABLE table_name FORCE, algorithm=COPY" will be
used.
The differences between the algorithms are
1) Will use the fastest algorithm the engine supports to do a full repair
of the table (except if data conversions are is needed).
2) Will use the storage engine internal REPAIR facility (MyISAM, Aria).
If the engine does not support REPAIR then
"ALTER TABLE FORCE, ALGORITHM=COPY" will be used.
If there was data incompatibilities (which means that FORCE was used)
then there will be a warning after REPAIR that ALTER TABLE FORCE is
still needed.
The reason for this is that REPAIR may be able to go around data
errors (wrong incompatible data, crashed or unreadable sectors) that
ALTER TABLE cannot do.
3) Will use the storage engine internal OPTIMIZE. If engine does not
support optimize, then "ALTER TABLE FORCE" is used.
The above will ensure that ALTER TABLE FORCE is able to
correct almost any errors in the row or index data. In case of
corrupted blocks then REPAIR possible followed by ALTER TABLE is needed.
This is important as mariadb-upgrade executes ALTER TABLE table_name
FORCE for any table that must be re-created.
Bugs fixed with InnoDB tables when using ALTER TABLE FORCE:
- No error for INNODB_DEFAULT_ROW_FORMAT=COMPACT even if row length
would be too wide. (Independent of innodb_strict_mode).
- Tables using symlinks will be symlinked after any of the above commands
(Independent of the setting of --symbolic-links)
If one specifies an algorithm together with ALTER TABLE FORCE, things
will work as before (except if data conversion is required as then
the COPY algorithm is enforced).
ALTER TABLE .. OPTIMIZE ALL PARTITIONS will work as before.
Other things:
- FORCE argument added to REPAIR to allow one to first run internal
repair to fix damaged blocks and then follow it with ALTER TABLE.
- REPAIR will not update frm_version if ha_check_for_upgrade() finds
that table is still incompatible with current version. In this case the
REPAIR will end with an error.
- REPAIR for storage engines that does not have native repair, like InnoDB,
is now using ALTER TABLE FORCE.
- REPAIR csv-table USE_FRM now works.
- It did not work before as CSV tables had extension list in wrong
order.
- Default error messages length for %M increased from 128 to 256 to not
cut information from REPAIR.
- Documented HA_ADMIN_XX variables related to repair.
- Added HA_ADMIN_NEEDS_DATA_CONVERSION to signal that we have to
do data conversions when converting the table (and thus ALTER TABLE
copy algorithm is needed).
- Fixed typo in error message (caused test changes).
on disable_indexes(HA_KEY_SWITCH_NONUNIQ_SAVE) the engine does
not know that the long unique is logically unique, because on the
engine level it is not. And the engine disables it,
Change the disable_indexes/enable_indexes API. Instead of the enum
mode, send a key_map of indexes that should be enabled. This way the
server will decide what is unique, not the engine.
