In the original InnoDB storage format (which was retroactively named
ROW_FORMAT=REDUNDANT in MySQL 5.0.3), the length of each index field
is stored explicitly. Thus, we can and from now on will allow arbitrary
extension of VARBINARY and VARCHAR columns when the table is in
ROW_FORMAT=REDUNDANT.
ha_innobase::open(): Advertise a new HA_EXTENDED_TYPES_CONVERSION
capability for ROW_FORMAT=REDUNDANT tables.
Field_varstring::is_equal(): If the HA_EXTENDED_TYPES_CONVERSION
capability is advertised for the table, return IS_EQUAL_PACK_LENGTH
for any length extension.
This task involves the implementation for the optimizer trace.
This feature produces a trace for any SELECT/UPDATE/DELETE/,
which contains information about decisions taken by the optimizer during
the optimization phase (choice of table access method, various costs,
transformations, etc). This feature would help to tell why some decisions were
taken by the optimizer and why some were rejected.
Trace is session-local, controlled by the @@optimizer_trace variable.
To enable optimizer trace we need to write:
set @@optimizer_trace variable= 'enabled=on';
To display the trace one can run:
SELECT trace FROM INFORMATION_SCHEMA.OPTIMIZER_TRACE;
This task also involves:
MDEV-18489: Limit the memory used by the optimizer trace
introduces a switch optimizer_trace_max_mem_size which limits
the memory used by the optimizer trace. This was implemented by
Sergei Petrunia.
MDEV-17631 select_handler for a full query pushdown
Interfaces + Proof of Concept for federatedx with test cases.
The interfaces have been developed for integration of ColumnStore engine.
ANALYZE and ANALYZE FORMAT=JSON structures are changed in the way that they
show additional information when rowid filter is used:
- r_selectivity_pct - the observed filter selectivity
- r_buffer_size - the size of the rowid filter container buffer
- r_filling_time_ms - how long it took to fill rowid filter container
New class Rowid_filter_tracker was added. This class is needed to collect data
about how rowid filter is executed.
This patch contains a full implementation of the optimization
that allows to use in-memory rowid / primary filters built for range
conditions over indexes. In many cases usage of such filters reduce
the number of disk seeks spent for fetching table rows.
In this implementation the choice of what possible filter to be applied
(if any) is made purely on cost-based considerations.
This implementation re-achitectured the partial implementation of
the feature pushed by Galina Shalygina in the commit
8d5a11122c.
Besides this patch contains a better implementation of the generic
handler function handler::multi_range_read_info_const() that
takes into account gaps between ranges when calculating the cost of
range index scans. It also contains some corrections of the
implementation of the handler function records_in_range() for MyISAM.
This patch supports the feature for InnoDB and MyISAM.
Analysis:
========
Increasing the length of the indexed varchar column is not an instant operation for
innodb.
Fix:
===
- Introduce the new handler flag 'Alter_inplace_info::ALTER_COLUMN_INDEX_LENGTH' to
indicate the index length differs due to change of column length changes.
- InnoDB makes the ALTER_COLUMN_INDEX_LENGTH flag as instant operation.
This is a port of Mysql fix.
commit 913071c0b16cc03e703308250d795bc381627e37
Author: Nisha Gopalakrishnan <nisha.gopalakrishnan@oracle.com>
Date: Wed May 30 14:54:46 2018 +0530
BUG#26848813: INDEXED COLUMN CAN'T BE CHANGED FROM VARCHAR(15)
TO VARCHAR(40) INSTANTANEOUSLY
Implement according to standard SQL specification 2008.
The check_constraints table is used for fetching metadata about
the constraints defined for tables in all databases.
There were some result files which failed after running mtr.
These files are updated with newly create record with mtr --record.
When using buffered sort in `UPDATE`, keyread is used. In this case,
`TABLE::update_virtual_field` should be aborted, but it actually isn't,
because it is called not with a top-level handler, but with the one that
is actually going to access the disk. Here the problemm is issued with
partitioning, so the solution is to recursively mark for keyread all the
underlying partition handlers.
* ha_partition: update keyread state for child partitions
Closes#800
Part of MDEV-5336 Implement LOCK FOR BACKUP
- Added new locks to MDL_BACKUP for all stages of backup locks and
a new MDL lock needed for backup stages.
- Renamed MDL_BACKUP_STMT to MDL_BACKUP_DDL
- flush_tables() takes a new parameter that decides what should be flushed.
- InnoDB, Aria (transactional tables with checksums), Blackhole, Federated
and Federatedx tables are marked to be safe for online backup. We are
using MDL_BACKUP_TRANS_DML instead of MDL_BACKUP_DML locks for these
which allows any DML's to proceed for these tables during the whole
backup process until BACKUP STAGE COMMIT which will block the final
commit.
We don't have many bits left, no need to add another InnoDB-specific flag.
Instead, we say that HA_REQUIRE_PRIMARY_KEY does not apply to SEQUENCE.
Meaning, if the engine declares HA_CAN_TABLES_WITHOUT_ROLLBACK (required
for SEQUENCE) it *must* support tables without a primary key.
Fixed by adding table flag HA_WANTS_PRIMARY_KEY, which is like
HA_REQUIRE_PRIMARY_KEY but tells SQL upper layer that the storage engine
internally can handle tables without primary keys (for example for
sequences or trough user variables)
When using buffered sort in `UPDATE`, keyread is used. In this case,
`TABLE::update_virtual_field` should be aborted, but it actually isn't,
because it is called not with a top-level handler, but with the one that
is actually going to access the disk. Here the problemm is issued with
partitioning, so the solution is to recursively mark for keyread all the
underlying partition handlers.
* ha_partition: update keyread state for child partitions
Closes#800
Implement according to standard SQL specification 2008.
The check_constraints table is used for fetching metadata about
the constraints defined for tables in all databases.
Make all system tables in mysql directory of type
engine=Aria
Privilege tables are using transactional=1
Statistical tables are using transactional=0, to allow them
to be quickly updated with low overhead.
Help tables are also using transactional=0 as these are only
updated at init time.
Other changes:
- Aria store engine is now a required engine
- Update comment for Aria tables to reflect their new usage
- Fixed that _ma_reset_trn_for_table() removes unlocked table
from transaction table list. This was needed to allow one
to lock and unlock system tables separately from other
tables, for example when reading a procedure from mysql.proc
- Don't give a warning when using transactional=1 for engines
that is using transactions. This is both logical and also
to avoid warnings/errors when doing an alter of a privilege
table to InnoDB.
- Don't abort on warnings from ALTER TABLE for changes that
would be accepted by CREATE TABLE.
- New created Aria transactional tables are marked as not movable
(as they include create_rename_lsn).
- bootstrap.test was changed to kill orignal server, as one
can't anymore have two servers started at same time on same
data directory and data files.
- Disable maria.small_blocksize as one can't anymore change
aria block size after system tables are created.
- Speed up creation of help tables by using lock tables.
- wsrep_sst_resync now also copies Aria redo logs.
The problem occurred because the Spider node was incorrectly handling
timestamp values sent to and received from the data nodes.
The problem has been corrected as follows:
- Added logic to set and maintain the UTC time zone on the data nodes.
To prevent timestamp ambiguity, it is necessary for the data nodes to use
a time zone such as UTC which does not have daylight savings time.
- Removed the spider_sync_time_zone configuration variable, which did not
solve the problem and which interfered with the solution.
- Added logic to convert to the UTC time zone all timestamp values sent to
and received from the data nodes. This is done for both unique and
non-unique timestamp columns. It is done for WHERE clauses, applying to
SELECT, UPDATE and DELETE statements, and for UPDATE columns.
- Disabled Spider's use of direct update when any of the columns to update is
a timestamp column. This is necessary to prevent false duplicate key value
errors.
- Added a new test spider.timestamp to thoroughly test Spider's handling of
timestamp values.
Author:
Jacob Mathew.
Reviewer:
Kentoku Shiba.
Merged:
Commit 97cc9d3 on branch bb-10.3-MDEV-16246
The problem occurred because the Spider node was incorrectly handling
timestamp values sent to and received from the data nodes.
The problem has been corrected as follows:
- Added logic to set and maintain the UTC time zone on the data nodes.
To prevent timestamp ambiguity, it is necessary for the data nodes to use
a time zone such as UTC which does not have daylight savings time.
- Removed the spider_sync_time_zone configuration variable, which did not
solve the problem and which interfered with the solution.
- Added logic to convert to the UTC time zone all timestamp values sent to
and received from the data nodes. This is done for both unique and
non-unique timestamp columns. It is done for WHERE clauses, applying to
SELECT, UPDATE and DELETE statements, and for UPDATE columns.
- Disabled Spider's use of direct update when any of the columns to update is
a timestamp column. This is necessary to prevent false duplicate key value
errors.
- Added a new test spider.timestamp to thoroughly test Spider's handling of
timestamp values.
Author:
Jacob Mathew.
Reviewer:
Kentoku Shiba.
Cherry-Picked:
Commit 97cc9d3 on branch bb-10.3-MDEV-16246
Observed and described
partitioned engine execution time difference
between master and slave was caused by excessive invocation
of base_engine::rnd_init which was done also for partitions
uninvolved into Rows-event operation.
The bug's slave slowdown therefore scales with the number of partitions.
Fixed with applying an upstream patch.
References:
----------
https://bugs.mysql.com/bug.php?id=73648
Bug#25687813 REPLICATION REGRESSION WITH RBR AND PARTITIONED TABLES
commit 2dbeebdb16 accidentally changed
ALTER_COLUMN_OPTION and ALTER_COLUMN_STORAGE_TYPE to be separate flags.
InnoDB and Mroonga are only checking for the latter;
the example storage engine is checking for the former only.
The impact of this bug should be incorrect operation of Mroonga when
the column options GROONGA_TYPE, FLAGS are changed.
InnoDB does not define any column options, only table options,
so the flag ALTER_COLUMN_OPTION should never have been set.
Also, remove the unused flag ALTER_DROP_HISTORICAL.
Introduced new alter algorithm type called NOCOPY & INSTANT for
inplace alter operation.
NOCOPY - Algorithm refuses any alter operation that would
rebuild the clustered index. It is a subset of INPLACE algorithm.
INSTANT - Algorithm allow any alter operation that would
modify only meta data. It is a subset of NOCOPY algorithm.
Introduce new variable called alter_algorithm. The values are
DEFAULT(0), COPY(1), INPLACE(2), NOCOPY(3), INSTANT(4)
Message to deprecate old_alter_table variable and make it alias
for alter_algorithm variable.
alter_algorithm variable for slave is always set to default.
