Assertion `!btr_search_own_any(RW_LOCK_S)' failed in btr_search_drop_page_hash_index

--source include/have_innodb.inc

CREATE TABLE t1 (FTS_DOC_ID BIGINT UNSIGNED NOT NULL AUTO_INCREMENT PRIMARY KEY, c TEXT, FULLTEXT KEY (c)) ENGINE=InnoDB;

INSERT INTO t1 (c) VALUES ("

alter_specification:

 table_option ...

 | ADD [COLUMN] [IF NOT EXISTS] col_name column_definition

 [FIRST | AFTER col_name ]

 | ADD [COLUMN] [IF NOT EXISTS] (col_name

column_definition,...)

 | ADD {INDEX|KEY} [IF NOT EXISTS] [index_name]

 [index_type] (index_col_name,...) [index_option] ...

 | ADD [CONSTRAINT [symbol]] PRIMARY KEY

 [index_type] (index_col_name,...) [index_option] ...

 | ADD [CONSTRAINT [symbol]]

 UNIQUE [INDEX|KEY] [index_name]

 [index_type] (index_col_name,...) [index_option] ...

 | ADD FULLTEXT [INDEX|KEY] [index_name]

 (index_col_name,...) [index_option] ...

 | ADD SPATIAL [INDEX|KEY] [index_name]

 (index_col_name,...) [index_option] ...

 | ADD [CONSTRAINT [symbol]]

 FOREIGN KEY [IF NOT EXISTS] [index_name]

(index_col_name,...)

 reference_definition

 | ADD PERIOD FOR SYSTEM_TIME (start_column_name,

end_column_name)

 | ALTER [COLUMN] col_name SET DEFAULT literal

|(expression)

 | ALTER [COLUMN] col_name DROP DEFAULT

 | CHANGE [COLUMN] [IF EXISTS] old_col_name new_col_name

column_definition

 [FIRST|AFTER col_name]

 | MODIFY [COLUMN] [IF EXISTS] col_name column_definition

 [FIRST | AFTER col_name]

 | DROP [COLUMN] [IF EXISTS] col_name [RESTRICT|CASCADE]

 | DROP PRIMARY KEY

 | DROP {INDEX|KEY} [IF EXISTS] index_name

 | DROP FOREIGN KEY [IF EXISTS] fk_symbol

 | DROP CONSTRAINT [IF EXISTS] constraint_name

 | DISABLE KEYS

 | ENABLE KEYS

 | RENAME [TO] new_tbl_name

 | ORDER BY col_name [, col_name] ...

 | CONVERT TO CHARACTER SET charset_name [COLLATE

collation_name]

 | [DEFAULT] CHARACTER SET [=] charset_name

 | [DEFAULT] COLLATE [=] collation_name

 | DISCARD TABLESPACE

 | IMPORT TABLESPACE

 | ALGORITHM [=] {DEFAULT|INPLACE|COPY|NOCOPY|INSTANT}

 | LOCK [=] {DEFAULT|NONE|SHARED|EXCLUSIVE}

 | FORCE

 | partition_options

 | ADD PARTITION (partition_definition)

 | DROP PARTITION partition_names

 | COALESCE PARTITION number

 | REORGANIZE PARTITION [partition_names INTO

(partition_definitions)]

 | ANALYZE PARTITION partition_names

 | CHECK PARTITION partition_names

 | OPTIMIZE PARTITION partition_names

 | REBUILD PARTITION partition_names

 | REPAIR PARTITION partition_names

 | EXCHANGE PARTITION partition_name WITH TABLE tbl_name

 | REMOVE PARTITIONING

 | ADD SYSTEM VERSIONING

 | DROP SYSTEM VERSIONING

index_col_name:

 col_name [(length)] [ASC | DESC]

index_type:

 USING {BTREE | HASH | RTREE}

index_option:

 KEY_BLOCK_SIZE [=] value

 | index_type

 | WITH PARSER parser_name

 | COMMENT 'string'

 | CLUSTERING={YES| NO}

table_options:

 table_option [[,] table_option] ...

In MariaDB 10.0.2 and later, IF EXISTS and IF NOT EXISTS

clauses have been added for the following:

ADD COLUMN [IF NOT EXISTS]

ADD INDEX [IF NOT EXISTS]

ADD FOREIGN KEY [IF NOT EXISTS]

ADD PARTITION [IF NOT EXISTS]

CREATE INDEX [IF NOT EXISTS]

DROP COLUMN [IF EXISTS]

DROP INDEX [IF EXISTS]

DROP FOREIGN KEY [IF EXISTS]

DROP PARTITION [IF EXISTS]

CHANGE COLUMN [IF EXISTS]

MODIFY COLUMN [IF EXISTS]

DROP INDEX [IF EXISTS]

When IF EXISTS and IF NOT EXISTS are used in clauses,

queries will not

report errors when the condition is triggered for that

clause. A warning with

the same message text will be issued and the ALTER will move

on to the next

clause in the statement (or end if finished).

This was done in MDEV-318.

Description

----------- 

ALTER TABLE enables you to change the structure of an

existing table.

For example, you can add or delete columns, create or

destroy indexes,

change the type of existing columns, or rename columns or

the table

itself. You can also change the comment for the table and

the storage engine of the

table.

If another connection is using the table, a metadata lock is

active, and this statement will wait until the lock is

released. This is also true for non-transactional tables.

When adding a UNIQUE index on a column (or a set of columns)

which have duplicated values, an error will be produced and

the statement will be stopped. To suppress the error and

force the creation of UNIQUE indexes, discarding duplicates,

the IGNORE option can be specified. This can be useful if a

column (or a set of columns) should be UNIQUE but it

contains duplicate values; however, this technique provides

no control on which rows are preserved and which are

deleted. Also, note that IGNORE is accepted but ignored in

ALTER TABLE ... EXCHANGE PARTITION statements.

This statement can also be used to rename a table. For

details see RENAME TABLE.

When an index is created, the storage engine may use a

configurable buffer in the process. Incrementing the buffer

speeds up the index creation. Aria and MyISAM allocate a

buffer whose size is defined by aria_sort_buffer_size or

myisam_sort_buffer_size, also used for REPAIR TABLE.

InnoDB/XtraDB allocates three buffers whose size is defined

by innodb_sort_buffer_size.

Privileges

Executing the ALTER TABLE statement generally requires at

least the ALTER privilege for the table or the database..

If you are renaming a table, then it also requires the DROP,

CREATE and INSERT privileges for the table or the database

as well.

Online DDL

In MariaDB 10.0 and later, online DDL is supported with the

ALGORITHM and LOCK clauses.

See InnoDB Online DDL Overview for more information on

online DDL with InnoDB.

ALTER ONLINE TABLE

ALTER ONLINE TABLE has also worked for partitioned tables

since MariaDB 10.0.11.

Online ALTER TABLE is available by executing the following:

ALTER ONLINE TABLE ...;

This statement has the following semantics:

In MariaDB 10.0.12 and later, this statement is equivalent

to the following:

ALTER TABLE ... LOCK=NONE;

See the LOCK alter specification for more information.

In MariaDB 10.0.11, this statement is equivalent to the

following:

ALTER TABLE ... ALGORITHM=INPLACE;

See the ALGORITHM alter specification for more information.

MariaDB until 10.0.10

In MariaDB 10.0.10 and before, this statement ensures that

the ALTER TABLE statement does not make a copy of the table.

WAIT/NOWAIT

Set the lock wait timeout. See WAIT and NOWAIT.

Column Definitions

See CREATE TABLE: Column Definitions for information about

column definitions.

Index Definitions

See CREATE TABLE: Index Definitions for information about

index definitions.

The CREATE INDEX and DROP INDEX statements can also be used

to add or remove an index.

Character Sets and Collations

CONVERT TO CHARACTER SET charset_name [COLLATE

collation_name]

[DEFAULT] CHARACTER SET [=] charset_name

[DEFAULT] COLLATE [=] collation_name

See Setting Character Sets and Collations for details on

setting the character sets and collations.

Alter Specifications

Table Options

See CREATE TABLE: Table Options for information about table

options.

ADD COLUMN

... ADD COLUMN [IF NOT EXISTS] (col_name

column_definition,...)

Adds a column to the table. The syntax is the same as in

CREATE TABLE.

If you are using IF NOT_EXISTS the column will not be added

if it was not there already. This is very useful when doing

scripts to modify tables.

The FIRST and AFTER clauses affect the physical order of

columns in the datafile. Use FIRST to add a column in the

first (leftmost) position, or AFTER followed by a column

name to add the new column in any other position. Note that,

nowadays, the physical position of a column is usually

irrelevant.

See also Instant ADD COLUMN for InnoDB.

DROP COLUMN

... DROP COLUMN [IF EXISTS] col_name [CASCADE|RESTRICT]

Drops the column from the table.

If you are using IF EXISTS you will not get an error if the

column didn't exist.

If the column is part of any index, the column will be

dropped from them, except if you add a new column with

identical name at the same time. The index will be dropped

if all columns from the index were dropped.

If the column was used in a view or trigger, you will get an

error next time the view or trigger is accessed.

Dropping a column that is part of a multi-column UNIQUE

constraint is not permitted. For example:

CREATE TABLE a (

 a int,

 b int,

 primary key (a,b)

);

ALTER TABLE x DROP COLUMN a;

[42000][1072] Key column 'A' doesn't exist in table

The reason is that dropping column a would result in the new

constraint that all values in column b be unique. In order

to drop the column, an explicit DROP PRIMARY KEY and ADD

PRIMARY KEY would be required. Up until MariaDB 10.2.7, the

column was dropped and the additional constraint applied,

resulting in the following structure:

ALTER TABLE x DROP COLUMN a;

Query OK, 0 rows affected (0.46 sec)

DESC x;

+-------+---------+------+-----+---------+-------+

| Field | Type | Null | Key | Default | Extra |

+-------+---------+------+-----+---------+-------+

| b | int(11) | NO | PRI | NULL | |

+-------+---------+------+-----+---------+-------+

MariaDB 10.4.0 supports instant DROP COLUMN. DROP COLUMN of

an indexed column would imply DROP INDEX (and in the case of

a non-UNIQUE multi-column index, possibly ADD INDEX). These

will not be allowed with ALGORITHM=INSTANT, but unlike

before, they can be allowed with ALGORITHM=NOCOPY

RESTRICT and CASCADE are allowed to make porting from other

database systems easier. In MariaDB, they do nothing.

MODIFY COLUMN

Allows you to modify the type of a column. The column will

be at the same place as the original column and all indexes

on the column will be kept. Note that when modifying column,

you should specify all attributes for the new column.

CREATE TABLE t1 (a INT UNSIGNED AUTO_INCREMENT, PRIMARY

KEY((a));

ALTER TABLE t1 MODIFY a BIGINT UNSIGNED AUTO_INCREMENT;

CHANGE COLUMN

Works like MODIFY COLUMN except that you can also change the

name of the column. The column will be at the same place as

the original column and all index on the column will be

kept.

CREATE TABLE t1 (a INT UNSIGNED AUTO_INCREMENT, PRIMARY

KEY(a));

ALTER TABLE t1 CHANGE a b BIGINT UNSIGNED AUTO_INCREMENT;

ALTER COLUMN

This lets you change column options.

CREATE TABLE t1 (a INT UNSIGNED AUTO_INCREMENT, b

varchar(50), PRIMARY KEY(a));

ALTER TABLE t1 ALTER b SET DEFAULT 'hello';

ADD PRIMARY KEY

Add a primary key.

For PRIMARY KEY indexes, you can specify a name for the

index, but it is silently ignored, and the name of the index

is always PRIMARY.

See Getting Started with Indexes: Primary Key for more

information.

DROP PRIMARY KEY

Drop a primary key.

For PRIMARY KEY indexes, you can specify a name for the

index, but it is silently ignored, and the name of the index

is always PRIMARY.

See Getting Started with Indexes: Primary Key for more

information.

ADD FOREIGN KEY

Add a foreign key.

For FOREIGN KEY indexes, a reference definition must be

provided.

For FOREIGN KEY indexes, you can specify a name for the

constraint, using the CONSTRAINT keyword. That name will be

used in error messages.

First, you have to specify the name of the target (parent)

table and a column or a column list which must be indexed

and whose values must match to the foreign key's values.

The MATCH clause is accepted to improve the compatibility

with other DBMS's, but has no meaning in MariaDB. The ON

DELETE and ON UPDATE clauses specify what must be done when

a DELETE (or a REPLACE) statements attempts to delete a

referenced row from the parent table, and when an UPDATE

statement attempts to modify the referenced foreign key

columns in a parent table row, respectively. The following

options are allowed:

RESTRICT: The delete/update operation is not performed. The

statement terminates with a 1451 error (SQLSTATE '2300').

NO ACTION: Synonym for RESTRICT.

CASCADE: The delete/update operation is performed in both

tables.

SET NULL: The update or delete goes ahead in the parent

table, and the corresponding foreign key fields in the child

table are set to NULL. (They must not be defined as NOT NULL

for this to succeed).

MariaDB until 5.3

SET DEFAULT: This option is currently implemented only for

the PBXT storage engine, which is disabled by default and no

longer maintained. It sets the child table's foreign key

fields to their DEFAULT values when the referenced parent

table key entries are updated or deleted.

If either clause is omitted, the default behavior for the

omitted clause is RESTRICT.

See Foreign Keys for more information.

DROP FOREIGN KEY

Drop a foreign key.

See Foreign Keys for more information.

ADD INDEX

Add a plain index.

Plain indexes are regular indexes that are not unique, and

are not acting as a primary key or a foreign key. They are

also not the \"specialized\" FULLTEXT or SPATIAL indexes.

See Getting Started with Indexes: Plain Indexes for more

information.

DROP INDEX

Drop a plain index.

Plain indexes are regular indexes that are not unique, and

are not acting as a primary key or a foreign key. They are

also not the \"specialized\" FULLTEXT or SPATIAL indexes.

See Getting Started with Indexes: Plain Indexes for more

information.

ADD UNIQUE INDEX

Add a unique index.

The UNIQUE keyword means that the index will not accept

duplicated values, except for NULLs. An error will raise if

you try to insert duplicate values in a UNIQUE index.

For UNIQUE indexes, you can specify a name for the

constraint, using the CONSTRAINT keyword. That name will be

used in error messages.

See Getting Started with Indexes: Unique Index for more

information.

DROP UNIQUE INDEX

Drop a unique index.

The UNIQUE keyword means that the index will not accept

duplicated values, except for NULLs. An error will raise if

you try to insert duplicate values in a UNIQUE index.

For UNIQUE indexes, you can specify a name for the

constraint, using the CONSTRAINT keyword. That name will be

used in error messages.

See Getting Started with Indexes: Unique Index for more

information.

ADD FULLTEXT INDEX

Add a FULLTEXT index.

See Full-Text Indexes for more information.

DROP FULLTEXT INDEX

Drop a FULLTEXT index.

See Full-Text Indexes for more information.

ADD SPATIAL INDEX

Add a SPATIAL index.

See SPATIAL INDEX for more information.

DROP SPATIAL INDEX

Drop a SPATIAL index.

See SPATIAL INDEX for more information.

ENABLE/ DISABLE KEYS

DISABLE KEYS will disable all non unique keys for the table

for storage engines that support this (at least MyISAM and

Aria). This can be used to speed up inserts into empty

tables.

ENABLE KEYS will enable all disabled keys.

RENAME TO

Renames the table. See also RENAME TABLE.

ADD CONSTRAINT

Modifies the table adding a constraint on a particular

column or columns.

MariaDB 10.2.1 introduced new ways to define a constraint.

Note: Before MariaDB 10.2.1, constraint expressions were

accepted in syntax, but ignored.

ALTER TABLE table_name 

ADD CONSTRAINT [constraint_name] CHECK(expression);

Before a row is inserted or updated, all constraints are

evaluated in the order they are defined. If any constraint

fails, then the row will not be updated. One can use most

deterministic functions in a constraint, including UDF's.

CREATE TABLE account_ledger (

 id INT PRIMARY KEY AUTO_INCREMENT,

 transaction_name VARCHAR(100),

 credit_account VARCHAR(100),

 credit_amount INT,

 debit_account VARCHAR(100),

 debit_amount INT);

ALTER TABLE account_ledger 

ADD CONSTRAINT is_balanced 

 CHECK((debit_amount + credit_amount) = 0);

The constraint_name is optional. If you don't provide one

in the ALTER TABLE statement, MariaDB auto-generates a name

for you. This is done so that you can remove it later using

DROP CONSTRAINT clause.

You can disable all constraint expression checks by setting

the variable check_constraint_checks to OFF. You may find

this useful when loading a table that violates some

constraints that you want to later find and fix in SQL.

To view constraints on a table, query

information_schema.TABLE_CONSTRAINTS:

SELECT CONSTRAINT_NAME, TABLE_NAME, CONSTRAINT_TYPE 

FROM information_schema.TABLE_CONSTRAINTS

WHERE TABLE_NAME = 'account_ledger';

+-----------------+----------------+-----------------+

| CONSTRAINT_NAME | TABLE_NAME | CONSTRAINT_TYPE |

+-----------------+----------------+-----------------+

| is_balanced | account_ledger | CHECK |

+-----------------+----------------+-----------------+

DROP CONSTRAINT

DROP CONSTRAINT for UNIQUE and FOREIGN KEY constraints was

introduced in MariaDB 10.2.22 and MariaDB 10.3.13.

DROP CONSTRAINT for CHECK constraints was introduced in

MariaDB 10.2.1

Modifies the table, removing the given constraint.

ALTER TABLE table_name

DROP CONSTRAINT constraint_name;

When you add a constraint to a table, whether through a

CREATE TABLE or ALTER TABLE...ADD CONSTRAINT statement, you

can either set a constraint_name yourself, or allow MariaDB

to auto-generate one for you. To view constraints on a

table, query information_schema.TABLE_CONSTRAINTS. For

instance,

CREATE TABLE t (

 a INT,

 b INT,

 c INT,

 CONSTRAINT CHECK(a > b),

 CONSTRAINT check_equals CHECK(a = c)); 

SELECT CONSTRAINT_NAME, TABLE_NAME, CONSTRAINT_TYPE 

FROM information_schema.TABLE_CONSTRAINTS

WHERE TABLE_NAME = 't';

+-----------------+----------------+-----------------+

| CONSTRAINT_NAME | TABLE_NAME | CONSTRAINT_TYPE |

+-----------------+----------------+-----------------+

| check_equals | t | CHECK |

| CONSTRAINT_1 | t | CHECK |

+-----------------+----------------+-----------------+

To remove a constraint from the table, issue an ALTER

TABLE...DROP CONSTRAINT statement. For example,

ALTER TABLE t DROP CONSTRAINT is_unique;

ADD SYSTEM VERSIONING

System-versioned tables was added in MariaDB 10.3.4.

Add system versioning.

DROP SYSTEM VERSIONING

System-versioned tables was added in MariaDB 10.3.4.

Drop system versioning.

ADD PERIOD FOR SYSTEM_TIME

System-versioned tables was added in MariaDB 10.3.4.

FORCE

ALTER TABLE ... FORCE can force MariaDB to re-build the

table.

In MariaDB 5.5 and before, this could only be done by

setting the ENGINE table option to its old value. For

example, for an InnoDB table, one could execute the

following:

ALTER TABLE tab_name ENGINE = InnoDB;

In MariaDB 10.0 and later, the FORCE option can be used

instead. For example, :

ALTER TABLE tab_name FORCE;

With InnoDB, the table rebuild will only reclaim unused

space (i.e. the space previously used for deleted rows) if

the innodb_file_per_table system variable is set to ON. If

the system variable is OFF, then the space will not be

reclaimed, but it will be-re-used for new data that's later

added.

EXCHANGE PARTITION

ALTER TABLE ... EXCHANGE PARTITION was introduced in MariaDB

10.0.4

This is used to exchange the tablespace files between a

partition and another table.

See copying InnoDB's transportable tablespaces for more

information.

DISCARD TABLESPACE

This is used to discard an InnoDB table's tablespace.

See copying InnoDB's transportable tablespaces for more

information.

IMPORT TABLESPACE

This is used to import an InnoDB table's tablespace. The

tablespace should have been copied from its original server

after executing FLUSH TABLES FOR EXPORT.

See copying InnoDB's transportable tablespaces for more

information.

ALTER TABLE ... IMPORT only applies to InnoDB tables. Most

other popular storage engines, such as Aria and MyISAM, will

recognize their data files as soon as they've been placed

in the proper directory under the datadir, and no special

DDL is required to import them.

ALGORITHM

In MariaDB 5.5 and before, ALTER TABLE operations required

making a temporary copy of the table, which can be slow for

large tables.

In MariaDB 10.0 and later, the ALTER TABLE statement

supports the ALGORITHM clause. This clause is one of the

clauses that is used to implement online DDL. ALTER TABLE

supports several different algorithms. An algorithm can be

explicitly chosen for an ALTER TABLE operation by setting

the ALGORITHM clause. The supported values are:

ALGORITHM=DEFAULT - This implies the default behavior for

the specific statement, such as if no ALGORITHM clause is

specified.

ALGORITHM=COPY

ALGORITHM=INPLACE

ALGORITHM=NOCOPY - This was added in MariaDB 10.3.7.

ALGORITHM=INSTANT - This was added in MariaDB 10.3.7.

See InnoDB Online DDL Overview: ALGORITHM for information on

how the ALGORITHM clause affects InnoDB.

ALGORITHM=DEFAULT

The default behavior, which occurs if ALGORITHM=DEFAULT is

specified, or if ALGORITHM is not specified at all, usually

only makes a copy if the operation doesn't support being

done in-place at all. In this case, the most efficient

available algorithm will usually be used.

However, in MariaDB 10.3.6 and before, if the value of the

old_alter_table system variable is set to ON, then the

default behavior is to perform ALTER TABLE operations by

making a copy of the table using the old algorithm.

In MariaDB 10.3.7 and later, the old_alter_table system

variable is deprecated. Instead, the alter_algorithm system

variable defines the default algorithm for ALTER TABLE

operations.

ALGORITHM=COPY

ALGORITHM=COPY was introduced in MariaDB 10.0 as the name

for the original ALTER TABLE algorithm.

When ALGORITHM=COPY is set, MariaDB essentially does the

following operations:

-- Create a temporary table with the new definition

CREATE TEMPORARY TABLE tmp_tab (

...

);

-- Copy the data from the original table

INSERT INTO tmp_tab

 SELECT * FROM original_tab;

-- Drop the original table

DROP TABLE original_tab;

-- Rename the temporary table, so that it replaces the

original one

RENAME TABLE tmp_tab TO original_tab;

This algorithm is very inefficient, but it is generic, so it

works for all storage engines.

If ALGORITHM=COPY is specified, then the copy algorithm will

be used even if it is not necessary. This can result in a

lengthy table copy. If multiple ALTER TABLE operations are

required that each require the table to be rebuilt, then it

is best to specify all operations in a single ALTER TABLE

statement, so that the table is only rebuilt once.

ALGORITHM=INPLACE

ALGORITHM=INPLACE was introduced in MariaDB 10.0.

ALGORITHM=COPY can be incredibly slow, because the whole

table has to be copied and rebuilt. ALGORITHM=INPLACE was

introduced as a way to avoid this by performing operations

in-place and avoiding the table copy and rebuild, when

possible.

When ALGORITHM=INPLACE is set, the underlying storage engine

uses optimizations to perform the operation while avoiding

the table copy and rebuild. However, INPLACE is a bit of a

misnomer, since some operations may still require the table

to be rebuilt for some storage engines. Regardless, several

operations can be performed without a full copy of the table

for some storage engines.

A more accurate name would have been ALGORITHM=ENGINE, where

ENGINE refers to an \"engine-specific\" algorithm.

If an ALTER TABLE operation supports ALGORITHM=INPLACE, then

it can be performed using optimizations by the underlying

storage engine, but it may rebuilt.

See InnoDB Online DDL Operations with ALGORITHM=INPLACE for

more.

ALGORITHM=NOCOPY

ALGORITHM=NOCOPY was introduced in MariaDB 10.3.7.

ALGORITHM=INPLACE can sometimes be surprisingly slow in

instances where it has to rebuild the clustered index,

because when the clustered index has to be rebuilt, the

whole table has to be rebuilt. ALGORITHM=NOCOPY was

introduced as a way to avoid this. 

If an ALTER TABLE operation supports ALGORITHM=NOCOPY, then

it can be performed without rebuilding the clustered index.

If ALGORITHM=NOCOPY is specified for an ALTER TABLE

operation that does not support ALGORITHM=NOCOPY, then an

error will be raised. In this case, raising an error is

preferable, if the alternative is for the operation to

rebuild the clustered index, and perform unexpectedly

slowly.

See InnoDB Online DDL Operations with ALGORITHM=NOCOPY for

more.

ALGORITHM=INSTANT

ALGORITHM=INSTANT was introduced in MariaDB 10.3.7.

ALGORITHM=INPLACE can sometimes be surprisingly slow in

instances where it has to modify data files.

ALGORITHM=INSTANT was introduced as a way to avoid this.

If an ALTER TABLE operation supports ALGORITHM=INSTANT, then

it can be performed without modifying any data files.

If ALGORITHM=INSTANT is specified for an ALTER TABLE

operation that does not support ALGORITHM=INSTANT, then an

error will be raised. In this case, raising an error is

preferable, if the alternative is for the operation to

modify data files, and perform unexpectedly slowly.

See InnoDB Online DDL Operations with ALGORITHM=INSTANT for

more.

LOCK

In MariaDB 10.0 and later, the ALTER TABLE statement

supports the LOCK clause. This clause is one of the clauses

that is used to implement online DDL. ALTER TABLE supports

several different locking strategies. A locking strategy can

be explicitly chosen for an ALTER TABLE operation by setting

the LOCK clause. The supported values are:

DEFAULT: Acquire the least restrictive lock on the table

that is supported for the specific operation. Permit the

maximum amount of concurrency that is supported for the

specific operation.

NONE: Acquire no lock on the table. Permit all concurrent

DML. If this locking strategy is not permitted for an

operation, then an error is raised.

SHARED: Acquire a read lock on the table. Permit read-only

concurrent DML. If this locking strategy is not permitted

for an operation, then an error is raised.

EXCLUSIVE: Acquire a write lock on the table. Do not permit

concurrent DML.

Different storage engines support different locking

strategies for different operations. If a specific locking

strategy is chosen for an ALTER TABLE operation, and that

table's storage engine does not support that locking

strategy for that specific operation, then an error will be

raised.

If the LOCK clause is not explicitly set, then the operation

uses LOCK=DEFAULT.

ALTER ONLINE TABLE is equivalent to LOCK=NONE. Therefore,

the ALTER ONLINE TABLE statement can be used to ensure that

your ALTER TABLE operation allows all concurrent DML.

See InnoDB Online DDL Overview: LOCK for information on how

the LOCK clause affects InnoDB.

Progress Reporting

MariaDB provides progress reporting for ALTER TABLE

statement for clients

that support the new progress reporting protocol. For

example, if you were using the mysql client, then the

progress report might look like this::

ALTER TABLE test ENGINE=Aria;

Stage: 1 of 2 'copy to tmp table' 46% of stage

The progress report is also shown in the output of the SHOW

PROCESSLIST statement and in the contents of the

information_schema.PROCESSLIST table.

See Progress Reporting for more information.

Aborting ALTER TABLE Operations

If an ALTER TABLE operation is being performed and the

connection is killed, the changes will be rolled back in a

controlled manner. The rollback can be a slow operation as

the time it takes is relative to how far the operation has

progressed.

Aborting ALTER TABLE ... ALGORITHM=COPY was made faster by

removing excessive undo logging (MDEV-11415). This

significantly shortens the time it takes to abort a running

ALTER TABLE operation.

Examples

-------- 

Adding a new column:

ALTER TABLE t1 ADD x INT;

Dropping a column:

ALTER TABLE t1 DROP x;

Modifying the type of a column:

ALTER TABLE t1 MODIFY x bigint unsigned;

Changing the name and type of a column:

ALTER TABLE t1 CHANGE a b bigint unsigned auto_increment;

");

ALTER TABLE t1 ROW_FORMAT=COMPRESSED;

SELECT * FROM t1 WHERE MATCH(c) AGAINST('constraint' WITH QUERY EXPANSION);

# Cleanup

DROP TABLE t1;

mysqld: /data/src/10.3/storage/innobase/btr/btr0sea.cc:1096: void btr_search_drop_page_hash_index(buf_block_t*): Assertion `!btr_search_own_any(RW_LOCK_S)' failed.

200314  0:10:39 [ERROR] mysqld got signal 6 ;

#7  0x00007f513c036f12 in __GI___assert_fail (assertion=0x5596e352bfd8 "!btr_search_own_any(RW_LOCK_S)", file=0x5596e352bf00 "/data/src/10.3/storage/innobase/btr/btr0sea.cc", line=1096, function=0x5596e352e320 <btr_search_drop_page_hash_index(buf_block_t*)::__PRETTY_FUNCTION__> "void btr_search_drop_page_hash_index(buf_block_t*)") at assert.c:101

#8  0x00005596e2e4c7a9 in btr_search_drop_page_hash_index (block=0x7f511fa8eb40) at /data/src/10.3/storage/innobase/btr/btr0sea.cc:1096

#9  0x00005596e2e9a455 in buf_LRU_free_page (bpage=0x7f511fa8eb40, zip=false) at /data/src/10.3/storage/innobase/buf/buf0lru.cc:1775

#10 0x00005596e2e69f74 in buf_block_try_discard_uncompressed (page_id=...) at /data/src/10.3/storage/innobase/buf/buf0buf.cc:3809

#11 0x00005596e2e6a4b3 in buf_page_get_zip (page_id=..., page_size=...) at /data/src/10.3/storage/innobase/buf/buf0buf.cc:3889

#12 0x00005596e2e38728 in btr_copy_zblob_prefix (buf=0x7f50d41600b0 "", len=27220, page_size=..., space_id=17, page_no=6, offset=12) at /data/src/10.3/storage/innobase/btr/btr0cur.cc:8062

#13 0x00005596e2e38d19 in btr_copy_externally_stored_field_prefix_low (buf=0x7f50d41600b0 "", len=27220, page_size=..., space_id=17, page_no=6, offset=12) at /data/src/10.3/storage/innobase/btr/btr0cur.cc:8186

#14 0x00005596e2e39058 in btr_copy_externally_stored_field (len=0x7f513887b268, data=0x7f51205b8095 "", page_size=..., local_len=0, heap=0x7f50d4010f20) at /data/src/10.3/storage/innobase/btr/btr0cur.cc:8296

#15 0x00005596e2e39178 in btr_rec_copy_externally_stored_field (rec=0x7f51205b8080 "", offsets=0x7f513887b310, page_size=..., no=3, len=0x7f513887b268, heap=0x7f50d4010f20) at /data/src/10.3/storage/innobase/btr/btr0cur.cc:8352

#16 0x00005596e2d37632 in row_sel_fetch_columns (index=0x7f50d40d2c10, rec=0x7f51205b8080 "", offsets=0x7f513887b310, column=0x7f50d40d8878) at /data/src/10.3/storage/innobase/row/row0sel.cc:530

#17 0x00005596e2d39e75 in row_sel_try_search_shortcut (node=0x7f50d40d8958, plan=0x7f50d40d8d58, mtr=0x7f513887b8b0) at /data/src/10.3/storage/innobase/row/row0sel.cc:1539

#18 0x00005596e2d3a29e in row_sel (node=0x7f50d40d8958, thr=0x7f50d40d9a38) at /data/src/10.3/storage/innobase/row/row0sel.cc:1650

#19 0x00005596e2d3bbdf in row_sel_step (thr=0x7f50d40d9a38) at /data/src/10.3/storage/innobase/row/row0sel.cc:2341

#20 0x00005596e2c8fbc3 in que_thr_step (thr=0x7f50d40d9a38) at /data/src/10.3/storage/innobase/que/que0que.cc:1013

#21 0x00005596e2c90009 in que_run_threads_low (thr=0x7f50d40d9a38) at /data/src/10.3/storage/innobase/que/que0que.cc:1099

#22 0x00005596e2c90259 in que_run_threads (thr=0x7f50d40d9a38) at /data/src/10.3/storage/innobase/que/que0que.cc:1139

#23 0x00005596e2f7141d in fts_eval_sql (trx=0x7f5138b252a0, graph=0x7f50d40d9978) at /data/src/10.3/storage/innobase/fts/fts0sql.cc:218

#24 0x00005596e2f53766 in fts_doc_fetch_by_doc_id (get_doc=0x0, doc_id=1, index_to_use=0x7f50d40d25b0, option=1, callback=0x5596e2f51b9e <fts_query_expansion_fetch_doc(void*, void*)>, arg=0x7f513887bfe0) at /data/src/10.3/storage/innobase/fts/fts0fts.cc:3827

#25 0x00005596e2f6eddd in fts_expand_query (index=0x7f50d40d25b0, query=0x7f513887c0d0) at /data/src/10.3/storage/innobase/fts/fts0que.cc:4292

#26 0x00005596e2f6e49c in fts_query (trx=0x7f5138b230f0, index=0x7f50d40d25b0, flags=6, query_str=0x7f50d4013020 "constraint", query_len=10, result=0x7f513887c3e0) at /data/src/10.3/storage/innobase/fts/fts0que.cc:4078

#27 0x00005596e2b66289 in ha_innobase::ft_init_ext (this=0x7f50d40b4988, flags=6, keynr=1, key=0x7f50d4013060) at /data/src/10.3/storage/innobase/handler/ha_innodb.cc:9939

#28 0x00005596e29caa66 in Item_func_match::init_search (this=0x7f50d40130e8, thd=0x7f50d4000af0, no_order=false) at /data/src/10.3/sql/item_func.cc:6008

#29 0x00005596e2591f74 in init_ftfuncs (thd=0x7f50d4000af0, select_lex=0x7f50d4005140, no_order=false) at /data/src/10.3/sql/sql_base.cc:8791

#30 0x00005596e26623e3 in JOIN::optimize_stage2 (this=0x7f50d4013320) at /data/src/10.3/sql/sql_select.cc:2458

#31 0x00005596e266075e in JOIN::optimize_inner (this=0x7f50d4013320) at /data/src/10.3/sql/sql_select.cc:1968

#32 0x00005596e265eb91 in JOIN::optimize (this=0x7f50d4013320) at /data/src/10.3/sql/sql_select.cc:1488

#33 0x00005596e2668c18 in mysql_select (thd=0x7f50d4000af0, tables=0x7f50d4012870, wild_num=1, fields=..., conds=0x7f50d40130e8, og_num=0, order=0x0, group=0x0, having=0x0, proc_param=0x0, select_options=2147748608, result=0x7f50d40132f8, unit=0x7f50d40049b8, select_lex=0x7f50d4005140) at /data/src/10.3/sql/sql_select.cc:4283

#34 0x00005596e265a358 in handle_select (thd=0x7f50d4000af0, lex=0x7f50d40048f8, result=0x7f50d40132f8, setup_tables_done_option=0) at /data/src/10.3/sql/sql_select.cc:370

#35 0x00005596e2621d3f in execute_sqlcom_select (thd=0x7f50d4000af0, all_tables=0x7f50d4012870) at /data/src/10.3/sql/sql_parse.cc:6293

#36 0x00005596e2618763 in mysql_execute_command (thd=0x7f50d4000af0) at /data/src/10.3/sql/sql_parse.cc:3820

#37 0x00005596e2626037 in mysql_parse (thd=0x7f50d4000af0, rawbuf=0x7f50d4012608 "SELECT * FROM t1 WHERE MATCH(c) AGAINST('constraint' WITH QUERY EXPANSION)", length=74, parser_state=0x7f513887f630, is_com_multi=false, is_next_command=false) at /data/src/10.3/sql/sql_parse.cc:7817

#38 0x00005596e2612bc3 in dispatch_command (command=COM_QUERY, thd=0x7f50d4000af0, packet=0x7f50d402f001 "SELECT * FROM t1 WHERE MATCH(c) AGAINST('constraint' WITH QUERY EXPANSION)", packet_length=74, is_com_multi=false, is_next_command=false) at /data/src/10.3/sql/sql_parse.cc:1856

#39 0x00005596e261150b in do_command (thd=0x7f50d4000af0) at /data/src/10.3/sql/sql_parse.cc:1401

#40 0x00005596e2789084 in do_handle_one_connection (connect=0x5596e6790a20) at /data/src/10.3/sql/sql_connect.cc:1403

#41 0x00005596e2788de6 in handle_one_connection (arg=0x5596e6790a20) at /data/src/10.3/sql/sql_connect.cc:1308

#42 0x00007f513dfbf4a4 in start_thread (arg=0x7f5138880700) at pthread_create.c:456

#43 0x00007f513c0f3d0f in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:97