The non-persistent UPDATE_TIME for InnoDB tables was not being
updated consistently at transaction commit.
If a transaction is partly rolled back so that in the end it will
not modify a table that it intended to modify, the update_time will
be updated nevertheless. This will also happen when InnoDB fails
to write an undo log record for the intended modification.
If a transaction is committed internally in InnoDB, instead of
being committed from the SQL interface, then the trx_t::mod_tables
will not be applied to the update_time of the tables.
trx_t::mod_tables: Replace the std::set<dict_table_t*>
with std::map<dict_table_t*,undo_no_t>, so that the very first
modification within the transaction is identified.
trx_undo_report_row_operation(): Update mod_tables for every operation
after the undo log record was successfully written.
trx_rollback_to_savepoint_low(): After partial rollback, erase from
trx_t::mod_tables any tables for which all changes were rolled back.
trx_commit_in_memory(): Tighten some assertions and simplify conditions.
Invoke trx_update_mod_tables_timestamp() if persistent tables were
affected.
trx_commit_for_mysql(): Remove the call to
trx_update_mod_tables_timestamp(), as it is now invoked at the
lower level, in trx_commit_in_memory().
trx_rollback_finish(): Clear mod_tables before invoking trx_commit(),
because the trx_commit_in_memory() would otherwise wrongly process
mod_tables after a full ROLLBACK.
As they fail on TRT schema check:
innodb.log_file
innodb.table_flags
innodb.row_format_redundant
encryption.innodb_encrypt_log_corruption
encryption.innodb_first_page
Allow DROP TABLE `#mysql50##sql-...._.` to drop tables that were
being rebuilt by ALGORITHM=INPLACE
NOTE: If the server is killed after the table-rebuilding ALGORITHM=INPLACE
commits inside InnoDB but before the .frm file has been replaced, then
the recovery will involve something else than DROP TABLE.
NOTE: If the server is killed in a true inplace ALTER TABLE commits
inside InnoDB but before the .frm file has been replaced, then we
are really out of luck. To properly handle that situation, we would
need a transactional mysql.ddl_fixup table that directs recovery to
rename or remove files.
prepare_inplace_alter_table_dict(): Use the altered_table->s->table_name
for generating the new_table_name.
table_name_t::part_suffix: The start of the partition name suffix.
table_name_t::dbend(): Return the end of the schema name.
table_name_t::dblen(): Return the length of the schema name, in bytes.
table_name_t::basename(): Return the name without the schema name.
table_name_t::part(): Return the partition name, or NULL if none.
row_drop_table_for_mysql(): Assert for #sql, not #sql-ib.
Ideally, we would move some code from
ha_innobase::prepare_inplace_alter_table() to
ha_innobase::check_if_supported_inplace_alter(),
but the API does not really allow us to return errors; it can
only inform which forms of ALGORITHM and LOCK are allowed.
So, we have to duplicate some logic between the "check" and "prepare"
phases. We do the duplication by calling common functions.
instant_alter_column_possible(): Check if instant column operation
is possible. Invoked from both
ha_innobase::check_if_supported_inplace_alter() and
prepare_inplace_alter_table_dict().
ha_innobase::check_if_supported_inplace_alter(): Before refusing
certain operations if FULLTEXT INDEX exist, check if instant ALTER TABLE
is possible and return early if it is the case.
prepare_inplace_alter_table_dict(): Before checking the limitations
on FULLTEXT INDEX, check if instant ALTER TABLE is possible, and suppress
the checks if it is the case. If instant ADD COLUMN is used when the
table already contains FULLTEXT INDEX, do account for a
hidden FTS_DOC_ID_INDEX in a debug assertion.
When MariaDB 10.1.0 introduced table options for encryption and
compression, it unnecessarily changed
ha_innobase::check_if_supported_inplace_alter() so that ALGORITHM=COPY
is forced when these parameters differ.
A better solution is to move the check to innobase_need_rebuild().
In that way, the ALGORITHM=INPLACE interface (yes, the syntax is
very misleading) can be used for rebuilding the table much more
efficiently, with merge sort, with no undo logging, and allowing
concurrent DML operations.
row_upd_changes_field_size_or_external(): Always return TRUE
if an instantly added column is being updated such that the
column value is absent from the record.
Also, avoid some unnecessary computations.
New test cases
innodb-page-cleaners
Modified test cases
innodb_page_cleaners_basic
New function buf_flush_set_page_cleaner_thread_cnt
Increase or decrease the amount of page cleaner worker threads.
In case of increase this function creates based on current
abount and requested amount how many new threads should be
created. In case of decrease this function sets up the
requested amount of threads and uses is_requested event
to signal workers. Then we wait until all new treads
are started, old threads that should exit signal
is_finished or shutdown has marked that page cleaner
should finish.
buf_flush_page_cleaner_worker
Store current thread id and thread_no and then signal
event is_finished. If number of used page cleaner threads
decrease we shut down those threads that have thread_no
greater or equal than number of page configured page
cleaners - 1 (note that there will be always page cleaner
coordinator). Before exiting we signal is_finished.
New function innodb_page_cleaners_threads_update
Update function for innodb-page-cleaners system variable.
innobase_start_or_create_for_mysql
If more than one page cleaner threads is configured
we use new function buf_flush_set_page_cleaner_thread_cnt
to set up the requested threads (-1 coordinator).
InnoDB was writing unnecessary information to the
update undo log records. Most notably, if an indexed column is updated,
the old value of the column would be logged twice: first as part of
the update vector, and then another time because it is an indexed column.
Because the InnoDB undo log record must fit in a single page,
this would cause unnecessary failure of certain updates.
Even after this fix, InnoDB still seems to be unnecessarily logging
indexed column values for non-updated columns. It seems that non-updated
secondary index columns only need to be logged when a PRIMARY KEY
column is updated. To reduce risk, we are not fixing this remaining flaw
in GA versions.
trx_undo_page_report_modify(): Log updated indexed columns only once.
remove remnants of 10.0 bugfix, incorrectly merged into 10.2
Using col_names[i] was obviously, wrong, must've been col_names[ifield->col_no].
incorrect column name resulted in innodb having index unique_id2(id1),
while the server thought it's unique_id2(id4).
But col_names[ifield->col_no] is wrong too, because `table` has non-renamed
columns, so the correct column name is always dict_table_get_col_name(table, ifield->col_no)
When MySQL 5.6.10 introduced innodb_read_only mode, it skipped the
creation of the InnoDB buffer pool dump/restore subsystem in that mode.
Attempts to set the variable innodb_buf_pool_dump_now would have
no effect in innodb_read_only mode, but the corresponding condition
was forgotten in from the other two update functions.
MySQL 5.7.20 would fix the innodb_buffer_pool_load_now,
but not innodb_buffer_pool_load_abort. Let us fix both in MariaDB.
There are two bugs related to failed ADD INDEX and
the InnoDB table cache eviction.
dict_table_close(): Try dropping failed ADD INDEX when releasing
the last table handle, not when releasing the last-but-one.
dict_table_remove_from_cache_low(): Do not invoke
row_merge_drop_indexes() after freeing all index metadata.
Instead, directly invoke row_merge_drop_indexes_dict() to
remove the metadata from the persistent data dictionary
and to free the index pages.
Problem was that we could take page latches on different
order than wat is entitled with SX-lock. To follow the
latching order defined in WL#6326, acquire index->lock X-latch.
This entitles us to acquire page latches in any order for the index.
btr0btr.cc
Document latch rules before and after MariaDB 10.2.2
sync0rw.cc
Document latch compatibility rules better.
btr_defragment_merge_pages
Fix parameter value.
btr_defragment_thread
Acquire X-lock to dict_index_t::lock before restoring
cursor position and continuing defragmentation.
ha_innobase::optimize
Restore defragment feature.
Testing
Add GIS-index and FT-index to table being defragmented.
Defragmentation is not done to GIS-indexes and FT auxiliary
tables.
Reverted incorrect changes done on MDEV-7367 and MDEV-9469. Fixes properly
also related bugs:
MDEV-13668: InnoDB unnecessarily rebuilds table when renaming a column and adding index
MDEV-9469: 'Incorrect key file' on ALTER TABLE
MDEV-9548: Alter table (renaming and adding index) fails with "Incorrect key file for table"
MDEV-10535: ALTER TABLE causes standalone/wsrep cluster crash
MDEV-13640: ALTER TABLE CHANGE and ADD INDEX on auto_increment column fails with "Incorrect key file for table..."
Root cause for all these bugs is the fact that MariaDB .frm file
can contain virtual columns but InnoDB dictionary does not and
previous fixes were incorrect or unnecessarily forced table
rebuilt. In index creation key_part->fieldnr can be bigger than
number of columns in InnoDB data dictionary. We need to skip not
stored fields when calculating correct column number for InnoDB
data dictionary.
dict_table_get_col_name_for_mysql
Remove
innobase_match_index_columns
Revert incorrect change done on MDEV-7367
innobase_need_rebuild
Remove unnecessary rebuild force when column is renamed.
innobase_create_index_field_def
Calculate InnoDB column number correctly and remove
unnecessary column name set.
innobase_create_index_def, innobase_create_key_defs
Remove unneeded fields parameter. Revert unneeded memset.
prepare_inplace_alter_table_dict
Remove unneeded col_names parameter
index_field_t
Remove unneeded col_name member.
row_merge_create_index
Remove unneeded col_names parameter and resolution.
Effected tests:
innodb-alter-table : Add test case for MDEV-13668
innodb-alter : Remove MDEV-13668, MDEV-9469 FIXMEs
and restore original tests
innodb-wl5980-alter : Remove MDEV-13668, MDEV-9469 FIXMEs
and restore original tests
Mariabackup 10.2.7 would delete the redo log files after a successful
--prepare operation. If the user is manually copying the prepared files
instead of using the --copy-back option, it could happen that some old
redo log file would be preserved in the restored location. These old
redo log files could cause corruption of the restored data files when
the server is started up.
We prevent this scenario by creating a "poisoned" redo log file
ib_logfile0 at the end of the --prepare step. The poisoning consists
of simply truncating the file to an empty file. InnoDB will refuse
to start up on an empty redo log file.
copy_back(): Delete all redo log files in the target if the source
file ib_logfile0 is empty. (Previously we did this if the source
file is missing.)
SRV_OPERATION_RESTORE_EXPORT: A new variant of SRV_OPERATION_RESTORE
when the --export option is specified. In this mode, we will keep
deleting all redo log files, instead of truncating the first one.
delete_log_files(): Add a parameter for the first file to delete,
to be passed as 0 or 1.
innobase_start_or_create_for_mysql(): In mariabackup --prepare,
tolerate an empty ib_logfile0 file. Otherwise, require the first
redo log file to be longer than 4 blocks (2048 bytes). Unless
--export was specified, truncate the first log file at the
end of --prepare.
innodb.instant_alter: Demonstrate that instant ADD COLUMN
is not supported for ROW_FORMAT=COMPRESSED but is for
ROW_FORMAT=DYNAMIC. Test adding NOT NULL columns without
explict DEFAULT using both ALGORITHM=COPY and ALGORITHM=INPLACE
(so that implicit DEFAULT will be used).
For the two ALTER TABLE statements that are interrupted by killing the
server, manually remove the #sql*.frm files, because server startup
will not remove the files.
For InnoDB tables, adding, dropping and reordering columns has
required a rebuild of the table and all its indexes. Since MySQL 5.6
(and MariaDB 10.0) this has been supported online (LOCK=NONE), allowing
concurrent modification of the tables.
This work revises the InnoDB ROW_FORMAT=REDUNDANT, ROW_FORMAT=COMPACT
and ROW_FORMAT=DYNAMIC so that columns can be appended instantaneously,
with only minor changes performed to the table structure. The counter
innodb_instant_alter_column in INFORMATION_SCHEMA.GLOBAL_STATUS
is incremented whenever a table rebuild operation is converted into
an instant ADD COLUMN operation.
ROW_FORMAT=COMPRESSED tables will not support instant ADD COLUMN.
Some usability limitations will be addressed in subsequent work:
MDEV-13134 Introduce ALTER TABLE attributes ALGORITHM=NOCOPY
and ALGORITHM=INSTANT
MDEV-14016 Allow instant ADD COLUMN, ADD INDEX, LOCK=NONE
The format of the clustered index (PRIMARY KEY) is changed as follows:
(1) The FIL_PAGE_TYPE of the root page will be FIL_PAGE_TYPE_INSTANT,
and a new field PAGE_INSTANT will contain the original number of fields
in the clustered index ('core' fields).
If instant ADD COLUMN has not been used or the table becomes empty,
or the very first instant ADD COLUMN operation is rolled back,
the fields PAGE_INSTANT and FIL_PAGE_TYPE will be reset
to 0 and FIL_PAGE_INDEX.
(2) A special 'default row' record is inserted into the leftmost leaf,
between the page infimum and the first user record. This record is
distinguished by the REC_INFO_MIN_REC_FLAG, and it is otherwise in the
same format as records that contain values for the instantly added
columns. This 'default row' always has the same number of fields as
the clustered index according to the table definition. The values of
'core' fields are to be ignored. For other fields, the 'default row'
will contain the default values as they were during the ALTER TABLE
statement. (If the column default values are changed later, those
values will only be stored in the .frm file. The 'default row' will
contain the original evaluated values, which must be the same for
every row.) The 'default row' must be completely hidden from
higher-level access routines. Assertions have been added to ensure
that no 'default row' is ever present in the adaptive hash index
or in locked records. The 'default row' is never delete-marked.
(3) In clustered index leaf page records, the number of fields must
reside between the number of 'core' fields (dict_index_t::n_core_fields
introduced in this work) and dict_index_t::n_fields. If the number
of fields is less than dict_index_t::n_fields, the missing fields
are replaced with the column value of the 'default row'.
Note: The number of fields in the record may shrink if some of the
last instantly added columns are updated to the value that is
in the 'default row'. The function btr_cur_trim() implements this
'compression' on update and rollback; dtuple::trim() implements it
on insert.
(4) In ROW_FORMAT=COMPACT and ROW_FORMAT=DYNAMIC records, the new
status value REC_STATUS_COLUMNS_ADDED will indicate the presence of
a new record header that will encode n_fields-n_core_fields-1 in
1 or 2 bytes. (In ROW_FORMAT=REDUNDANT records, the record header
always explicitly encodes the number of fields.)
We introduce the undo log record type TRX_UNDO_INSERT_DEFAULT for
covering the insert of the 'default row' record when instant ADD COLUMN
is used for the first time. Subsequent instant ADD COLUMN can use
TRX_UNDO_UPD_EXIST_REC.
This is joint work with Vin Chen (陈福荣) from Tencent. The design
that was discussed in April 2017 would not have allowed import or
export of data files, because instead of the 'default row' it would
have introduced a data dictionary table. The test
rpl.rpl_alter_instant is exactly as contributed in pull request #408.
The test innodb.instant_alter is based on a contributed test.
The redo log record format changes for ROW_FORMAT=DYNAMIC and
ROW_FORMAT=COMPACT are as contributed. (With this change present,
crash recovery from MariaDB 10.3.1 will fail in spectacular ways!)
Also the semantics of higher-level redo log records that modify the
PAGE_INSTANT field is changed. The redo log format version identifier
was already changed to LOG_HEADER_FORMAT_CURRENT=103 in MariaDB 10.3.1.
Everything else has been rewritten by me. Thanks to Elena Stepanova,
the code has been tested extensively.
When rolling back an instant ADD COLUMN operation, we must empty the
PAGE_FREE list after deleting or shortening the 'default row' record,
by calling either btr_page_empty() or btr_page_reorganize(). We must
know the size of each entry in the PAGE_FREE list. If rollback left a
freed copy of the 'default row' in the PAGE_FREE list, we would be
unable to determine its size (if it is in ROW_FORMAT=COMPACT or
ROW_FORMAT=DYNAMIC) because it would contain more fields than the
rolled-back definition of the clustered index.
UNIV_SQL_DEFAULT: A new special constant that designates an instantly
added column that is not present in the clustered index record.
len_is_stored(): Check if a length is an actual length. There are
two magic length values: UNIV_SQL_DEFAULT, UNIV_SQL_NULL.
dict_col_t::def_val: The 'default row' value of the column. If the
column is not added instantly, def_val.len will be UNIV_SQL_DEFAULT.
dict_col_t: Add the accessors is_virtual(), is_nullable(), is_instant(),
instant_value().
dict_col_t::remove_instant(): Remove the 'instant ADD' status of
a column.
dict_col_t::name(const dict_table_t& table): Replaces
dict_table_get_col_name().
dict_index_t::n_core_fields: The original number of fields.
For secondary indexes and if instant ADD COLUMN has not been used,
this will be equal to dict_index_t::n_fields.
dict_index_t::n_core_null_bytes: Number of bytes needed to
represent the null flags; usually equal to UT_BITS_IN_BYTES(n_nullable).
dict_index_t::NO_CORE_NULL_BYTES: Magic value signalling that
n_core_null_bytes was not initialized yet from the clustered index
root page.
dict_index_t: Add the accessors is_instant(), is_clust(),
get_n_nullable(), instant_field_value().
dict_index_t::instant_add_field(): Adjust clustered index metadata
for instant ADD COLUMN.
dict_index_t::remove_instant(): Remove the 'instant ADD' status
of a clustered index when the table becomes empty, or the very first
instant ADD COLUMN operation is rolled back.
dict_table_t: Add the accessors is_instant(), is_temporary(),
supports_instant().
dict_table_t::instant_add_column(): Adjust metadata for
instant ADD COLUMN.
dict_table_t::rollback_instant(): Adjust metadata on the rollback
of instant ADD COLUMN.
prepare_inplace_alter_table_dict(): First create the ctx->new_table,
and only then decide if the table really needs to be rebuilt.
We must split the creation of table or index metadata from the
creation of the dictionary table records and the creation of
the data. In this way, we can transform a table-rebuilding operation
into an instant ADD COLUMN operation. Dictionary objects will only
be added to cache when table rebuilding or index creation is needed.
The ctx->instant_table will never be added to cache.
dict_table_t::add_to_cache(): Modified and renamed from
dict_table_add_to_cache(). Do not modify the table metadata.
Let the callers invoke dict_table_add_system_columns() and if needed,
set can_be_evicted.
dict_create_sys_tables_tuple(), dict_create_table_step(): Omit the
system columns (which will now exist in the dict_table_t object
already at this point).
dict_create_table_step(): Expect the callers to invoke
dict_table_add_system_columns().
pars_create_table(): Before creating the table creation execution
graph, invoke dict_table_add_system_columns().
row_create_table_for_mysql(): Expect all callers to invoke
dict_table_add_system_columns().
create_index_dict(): Replaces row_merge_create_index_graph().
innodb_update_n_cols(): Renamed from innobase_update_n_virtual().
Call my_error() if an error occurs.
btr_cur_instant_init(), btr_cur_instant_init_low(),
btr_cur_instant_root_init():
Load additional metadata from the clustered index and set
dict_index_t::n_core_null_bytes. This is invoked
when table metadata is first loaded into the data dictionary.
dict_boot(): Initialize n_core_null_bytes for the four hard-coded
dictionary tables.
dict_create_index_step(): Initialize n_core_null_bytes. This is
executed as part of CREATE TABLE.
dict_index_build_internal_clust(): Initialize n_core_null_bytes to
NO_CORE_NULL_BYTES if table->supports_instant().
row_create_index_for_mysql(): Initialize n_core_null_bytes for
CREATE TEMPORARY TABLE.
commit_cache_norebuild(): Call the code to rename or enlarge columns
in the cache only if instant ADD COLUMN is not being used.
(Instant ADD COLUMN would copy all column metadata from
instant_table to old_table, including the names and lengths.)
PAGE_INSTANT: A new 13-bit field for storing dict_index_t::n_core_fields.
This is repurposing the 16-bit field PAGE_DIRECTION, of which only the
least significant 3 bits were used. The original byte containing
PAGE_DIRECTION will be accessible via the new constant PAGE_DIRECTION_B.
page_get_instant(), page_set_instant(): Accessors for the PAGE_INSTANT.
page_ptr_get_direction(), page_get_direction(),
page_ptr_set_direction(): Accessors for PAGE_DIRECTION.
page_direction_reset(): Reset PAGE_DIRECTION, PAGE_N_DIRECTION.
page_direction_increment(): Increment PAGE_N_DIRECTION
and set PAGE_DIRECTION.
rec_get_offsets(): Use the 'leaf' parameter for non-debug purposes,
and assume that heap_no is always set.
Initialize all dict_index_t::n_fields for ROW_FORMAT=REDUNDANT records,
even if the record contains fewer fields.
rec_offs_make_valid(): Add the parameter 'leaf'.
rec_copy_prefix_to_dtuple(): Assert that the tuple is only built
on the core fields. Instant ADD COLUMN only applies to the
clustered index, and we should never build a search key that has
more than the PRIMARY KEY and possibly DB_TRX_ID,DB_ROLL_PTR.
All these columns are always present.
dict_index_build_data_tuple(): Remove assertions that would be
duplicated in rec_copy_prefix_to_dtuple().
rec_init_offsets(): Support ROW_FORMAT=REDUNDANT records whose
number of fields is between n_core_fields and n_fields.
cmp_rec_rec_with_match(): Implement the comparison between two
MIN_REC_FLAG records.
trx_t::in_rollback: Make the field available in non-debug builds.
trx_start_for_ddl_low(): Remove dangerous error-tolerance.
A dictionary transaction must be flagged as such before it has generated
any undo log records. This is because trx_undo_assign_undo() will mark
the transaction as a dictionary transaction in the undo log header
right before the very first undo log record is being written.
btr_index_rec_validate(): Account for instant ADD COLUMN
row_undo_ins_remove_clust_rec(): On the rollback of an insert into
SYS_COLUMNS, revert instant ADD COLUMN in the cache by removing the
last column from the table and the clustered index.
row_search_on_row_ref(), row_undo_mod_parse_undo_rec(), row_undo_mod(),
trx_undo_update_rec_get_update(): Handle the 'default row'
as a special case.
dtuple_t::trim(index): Omit a redundant suffix of an index tuple right
before insert or update. After instant ADD COLUMN, if the last fields
of a clustered index tuple match the 'default row', there is no
need to store them. While trimming the entry, we must hold a page latch,
so that the table cannot be emptied and the 'default row' be deleted.
btr_cur_optimistic_update(), btr_cur_pessimistic_update(),
row_upd_clust_rec_by_insert(), row_ins_clust_index_entry_low():
Invoke dtuple_t::trim() if needed.
row_ins_clust_index_entry(): Restore dtuple_t::n_fields after calling
row_ins_clust_index_entry_low().
rec_get_converted_size(), rec_get_converted_size_comp(): Allow the number
of fields to be between n_core_fields and n_fields. Do not support
infimum,supremum. They are never supposed to be stored in dtuple_t,
because page creation nowadays uses a lower-level method for initializing
them.
rec_convert_dtuple_to_rec_comp(): Assign the status bits based on the
number of fields.
btr_cur_trim(): In an update, trim the index entry as needed. For the
'default row', handle rollback specially. For user records, omit
fields that match the 'default row'.
btr_cur_optimistic_delete_func(), btr_cur_pessimistic_delete():
Skip locking and adaptive hash index for the 'default row'.
row_log_table_apply_convert_mrec(): Replace 'default row' values if needed.
In the temporary file that is applied by row_log_table_apply(),
we must identify whether the records contain the extra header for
instantly added columns. For now, we will allocate an additional byte
for this for ROW_T_INSERT and ROW_T_UPDATE records when the source table
has been subject to instant ADD COLUMN. The ROW_T_DELETE records are
fine, as they will be converted and will only contain 'core' columns
(PRIMARY KEY and some system columns) that are converted from dtuple_t.
rec_get_converted_size_temp(), rec_init_offsets_temp(),
rec_convert_dtuple_to_temp(): Add the parameter 'status'.
REC_INFO_DEFAULT_ROW = REC_INFO_MIN_REC_FLAG | REC_STATUS_COLUMNS_ADDED:
An info_bits constant for distinguishing the 'default row' record.
rec_comp_status_t: An enum of the status bit values.
rec_leaf_format: An enum that replaces the bool parameter of
rec_init_offsets_comp_ordinary().
fil_space_extend_must_retry(): If the table is being truncated,
do not call fil_flush_low(). The operation is covered by the
truncate log. File extension during TRUNCATE only occurs
if there are many indexes on the table. With smaller innodb_page_size,
the file extension occurs already with fewer indexes on the table.
