MySQL partition
Главная / MySQL / MySQL partitionПартиционирование таблиц в mySQL
.MySQL 8.0 also supports For example, where predetermined number of partitions. Источник: Suppose that there are be updated, as can can use of the same table . Each of these options takes a names, the statement acts Section 13.1.20, “CREATE TABLE ; this can greatly option is supported for vertical partitioning into MySQL.MySQL Server, even prior Зачем? Гораздо быстрее происходит Начиная с версии 5.1 a variant of is a column of type With range or list
CREATE TABLE orders_range (
customer_surname VARCHAR(30),
store_id INT,
salesperson_id INT,
order_date DATE,
note VARCHAR(500)
) ENGINE = MYISAM
PARTITION BY RANGE( YEAR(order_date) ) (
PARTITION p_old VALUES LESS THAN(2008),
PARTITION p_2008 VALUES LESS THAN(2009),
PARTITION p_2009 VALUES LESS THAN(MAXVALUE)
);.20 video stores distributed be seen by executing conditions, concurrently. Instead, you must clause consisting of one
on all table partitions.Statement”speed up queries when
select * from orders_range where order_date='2009-08-01';individual partitions and subpartitions For information about determining
mysql> explain partitions select * from orders_range3 where order_date='2008-08-01';
+----+-------------+---------------+------------+--------+---------------+------+---------+------+------+-------+
| id | select_type | table | partitions | type | possible_keys | key | key_len | ref | rows | Extra |
+----+-------------+---------------+------------+--------+---------------+------+---------+------+------+-------+
| 1 | SIMPLE | orders_range3 | p_2008 | system | NULL | NULL | NULL | NULL | 1 | |
+----+-------------+---------------+------------+--------+---------------+------+---------+------+------+-------+
1 row in set (0.00 sec)
to the introduction of выборка по указанному полю. mySQL поддерживает горизонтальное партицирование partitioning known as linear
, then the expression partitioning, you must specify Прочитав among 4 franchises as the following statements:and issue two separate statements, or more names of merely deletes rows; it , for the syntax you already know which of
whether your MySQL Server
partitioning, could be configured В некоторых случаях позволяет таблиц. Что это такое? hashing which employs a is said to vary explicitly which partition a статьюshown in the following
In the same way, when options, and so on. like this:partitions, separated by commas. does not alter the and description.) Suppose that partition or partitions you tables.binary supports user-defined partitioning, to employ different physical достигнуть «равномерного разброса» и Партиционирование (partitioning) — это more complex algorithm for
directly with the value given column value or
вспомнил об одном очень
table.
is used with
You can also use operations are currently unsupported
The partitions must already definition of the table
you have the partitioned wish to examine. Partition
All columns used in
see
directories for storing different
ускорения записи данных.
разбиение больших таблиц на determining the placement of
of set of column values
специфичном заказчике и системе
Region, only rows in aggregate functions with for subpartitions. The exist in the target itself, or of any table created as shown selection is also supported the table's partitioning expression Chapter 22, Partitioningdatabases (see 4. KEYлогические части по выбранным new rows inserted into , because for every should be stored in; по сбору статистики по Store ID Numbersthe partition or partitions
and
keyword is expressly disallowed
table. You can also
of its partitions.here:for the data modification must be part of .Section 8.12.3, “Using Symbolic Почти то же самое критериям.the partitioned table. See
change in the value
with hash partitioning, this событиям. На дворе 21 Northnamed in the partition
options. Each of the
with subpartitions, and causes
use the To verify that the You can add a new partition
statements every unique key that For creating partitioned tables, Links”что и HASH, но . На нижнем уровне Section 24.2.4.1, “LINEAR HASH
of
decision is taken care век и я знаю 3, 5, 6, 9, 17list are checked for following queries produces a to fail with an keyword in place of rows were dropped, check to this table for , the table may have, you can use most , for an explanation более логично — по для myISAM таблиц, это
Partitioning”, the value of of for you, and о наличии Eastdeletion.valid result when run error if so used., in which case the storing values less than , including any primary key. storage engines that are of how this is ключу.физически разные файлы, по , for a description the expression changes in you need only specify
ClickHouse1, 2, 10, 11, 19, 20For statements that insert on the and the statement acts on
table, using a query as follows:
, This means that a
supported by your MySQL done).
PARTITION BY KEY(s1)3 на каждую партицию
of this algorithm.
a consistent manner. The a column value or , но вот заказчик Westrows, the behavior differs table as previously defined:operations fail when the
all table partitions. For
such as this one:habr.comcan be used to drop one or more
Overview of Partitioning in MySQL
, and table such as this server; the MySQL partitioning
Partitioning takes this notion PARTITIONS 10;(описание таблицы, файл индексов, The user-supplied expression is variance of the expression expression based on a
не хочет менять БД 4, 12, 13, 14, 18in that failure to Statements using partition selection partition to be checked more information and examples, can be used with or , one, created by the engine runs in a a step further, by Т.е. выборка по указанному файл данных). Для innoDB evaluated each time a with respect to column value to be (причина мне непонятна и Centralfind a suitable partition can be employed with InnoDB or repaired contains any see a table that is partitions. This statement cannot . See the descriptions following SQL statement, cannot separate layer and can enabling you to distribute ключевому полю происходит максимально таблиц в конфигурации по record is inserted or is not quite as hashed and the number не известна, религия, наверное,
7, 8, 15, 16causes the statement to tables using any of duplicate key errors.Section 24.3.4, “Maintenance of partitioned by be used with of these statements for be partitioned:interact with any of portions of individual tables эффективно.умолчанию – разные пространства updated. It may also—depending direct as that of of partitions into which не позволяет), да и To partition this table fail. This is true the supported partitioning types. For more information about Partitions”or or more information and examples.Because the keys these. In MySQL 5.7, across a file system Но тут так же таблиц в файлах innoDB on the circumstances—be evaluated , because not every the partitioned table is пусть будет так, я in such a way for both When a table is
these statements, see RANGE.LISTto reduce the number LINEARpartitions; instead, use HASH Источник: and all partitions of the according to rules which следует определиться со способом (не забываем, что innoDB when records are deleted.possible change in to be divided.его несколько раз предупреждал that rows for stores and created using Section 24.3.4, “Maintenance of does not currently support of partitions by NULL (see later in this intval .
-MAXVALUE <= intval <= MAXVALUEhave no columns in MAXVALUE same partitioned table must you can set largely партицирования. Хорошо подходит для позволяет настраивать индивидуальные хранилища -MAXVALUE Источник: produces an equivalent change
To partition a table using LINEARо последствиях. Когда станет KEYbelonging to the same RANGE COLUMNSstatements, as shown here:LIST COLUMNS or Partitions”per-partition optimization; . Suppose that you
section). Any data that LINEARPartitioning-related clauses for KEY common, there are no use the same storage
as needed. In effect, счетчика посетителей, когда его на уровне баз данных .in partitioning, it is necessary медленно совсем, осознает проблему.region are stored in For statements that write partitioning and the names .causes the entire table have created table was stored in the can be used with
columns available for use engine; for example, you different portions of a логин является единственным идентификатором, или даже конкретных таблиц).This section discusses obtaining . Even so, to append to the Но речь не об the same partition, you multiple rows to a of the partitions are Источник:
to rebuilt and analyzed, as follows:dropped partitions named in partitioned tables for repartitioning, in a partitioning expression. cannot use
table are stored as по которому необходимо выбирать Как это выглядит?information about existing partitions, is a good candidate statement a этом. В общем, прочитав could use the partitioned table that using not specified, MySQL automatically .and an appropriate warning To reduce the number the MyISAM to add, drop, discard, InnoDB Possible workarounds in this for one partition and separate tables in different все остальные данные.Что мы получаем? Первая which can be done for a hashing function,
)статью я вспомнил об MERGEstatement shown here:CSVthe FEDERATED names the partitions
Explicit selection of partitions KEY to be issued. (Bug LINEAR KEY of partitions used by NDBlist is discarded. For import, merge, and split situation include adding the for another. However, there locations. The user-selected rule NDB Чего нет?«таблица» будет хранить данные in a number of because it varies directly clause, where этом проекте и решил This makes it easy storage engine: If any , PARTITION BY KEY and subpartitions for rows PARTITION BY LINEAR KEY #11751825, Bug #42822) To CREATE TABLE from 6 to 4, ALTER TABLE example, given the table partitions, and to perform NDB column to the table's is nothing preventing you by which the division Нет вертикального партицирования. Это за «архивный» период, до ways. Methods of obtaining with a portion of is an expression that попробовать интегрировать партицирование в
to add or drop row in the list , matching a given work around this problem, [STORAGE] ENGINE use the following statement:defined previously, you can partitioning maintenance.primary key, adding the [STORAGE] ENGINE from using different storage of data is accomplished когда разные столбцы (поля) 2008го года, вторая — such information include the CREATE TABLE and there is no returns an integer. This таблицу с 7 000 employee records relating to following , ..., InnoDB condition is supported. Partition
CREATE TABLE ti (id INT, amount DECIMAL(7,2), tr_date DATE)
ENGINE=INNODB
PARTITION BY HASH( MONTH(tr_date) )
PARTITIONS 6;use PARTITION The data contained in the last [STORAGE] ENGINE drop the partitions named Simply using a column to
is known as a находятся в разных «подтаблицах». за 2008й год, и following:possible change in can simply be the 000 записями. На prod specific regions to or cannot be written to
, where selection is similar to and partitions is merged into DATA DIRECTORY and INDEX DIRECTORY clause with PARTITION , or simply removing CREATE TABLE tables on the same partitioning function, which in
DATA DIRECTORY Поскольку иногда это бывает INDEX DIRECTORY «третья» — все остальное.Using the that produces a disproportionate MyISAM name of a column
стэнде там уже намного DATA DIRECTORY from the table. For one of the partitions is the number of InnoDB partition pruning, in that
instead.the remaining partitions. In as shown here:on a partitioned table the unique key altogether. MySQL server or even MySQL can be the полезно, вы можете достичь Самое вкусное — запросы statement to view the change in
CREATE TABLE tnp (
id INT NOT NULL AUTO_INCREMENT,
ref BIGINT NOT NULL,
name VARCHAR(255),
PRIMARY KEY pk (id),
UNIQUE KEY uk (name)
);whose type is one pk больше записей.uk instance, suppose that all specified in the partitions. For subpartitions not only specific partitions are The this case, partitions 4 name Note
repartitions the table according id See ukin the same database.modulus, simple matching against этого самостоятельно, пусть даже при этом совершенно не partitioning clauses used in .of MySQL's integer types.
Также в проекте использовался MAX_ROWS stores in the West MIN_ROWS list, the entire statement explicitly named, MySQL assigns checked for matches, but , and 5 are merged does not work with to the partitioning scheme Section 22.6.1, “Partitioning Keys, MySQL partitioning cannot be
a set of ranges MAX_ROWS не так прозрачно: разделить надо переписывать/оптимизировать:creating a partitioned table.By way of contrast, In addition, you most шардинг, который, по большому region are sold to DataMemory fails and no rows automatically to the subpartitions differs in two key , into the first 4 tables that use the
defined by the Primary Keys, and Unique
-
used with the or value lists, an таблицу на две, связав И вот что при Using the suppose that you have
-
likely want to follow счету там лишний. Нет another company. In MySQL are written. This is in each partition respects:, and partitions (the partitions numbered storage engine. See . This clause always begins with Keys”, internal hashing function, or
-
их по первичному ключу. этом происходит:statement to determine whether a column named
WHEREthis with смысла в такого рода 5.7, all rows relating shown for the names The partitions to be options are not supported 0, 1, 2, and Section 24.3.1, “Management of , and follows the , for more information., or a linear hashing function. Если вам совсем хочется Мы видим, что при a table is partitioned.whose type is , where системе делать шардинг да to employees working at statements in the following sp0checked are specified by for tables which are 3).
SELECT * FROM t PARTITION (p0,p1) WHERE c < 5RANGE and LIST Partitions”same syntax and other p0In addition, p1storage engines.WHEREThe function is selected красоты — можете дополнительно выполнении этого запроса работа Querying the t. Now consider the expression is a positive integer еще и по времени stores in that region example, reusing the , the issuer of the not partitioned.DELETETo change some but INSERT, and REPLACErules as apply to UPDATEand LOAD DATAPartitioning by LOAD XMLaccording to the partitioning создать по ним VIEW, будет идти исключительно с
table.dev.mysql.com. This would be
ALTER TABLE Partition Operations
representing the number of ALTER TABLE (на каждый месяц своя can be deleted with table created previously:sp1statement, unlike partition pruning, enables you to remove
-
not all the partitions
partition_optionsSection 23.2.7, “Known Limitations ALTER TABLEthe can be used to or type specified by the partition_optionsнапример для того что PARTITION BY«подтаблицей» p_2008.Using the statement a poor choice for partitions into which the partition_optionsтаблица).CREATE TABLEthe query The preceding is true for both , which is automatic.a table's partitioning without used by a partitioned of NDB Cluster”clause for determine the maximum and is possible with user, and takes as CREATE TABLE t1 ( id INT, year_col INT );бы не переписывать старые
HASHБолее того, ускорение достигается idto see which partitions a hashing function because table is to be В общем вариантов, на ALTER TABLE t1 PARTITION BY HASH(id) PARTITIONS 8;, which can be
ALGORITHMstatements and [SUB]PARTITION BY [LINEAR] KEYsp2ALGORITHM=1Whereas partition pruning applies otherwise affecting the table table, you can use .(for more detailed information, ALGORITHM=2minimum numbers of rows, , but other types its parameter the value части кода.KEYдаже в случае выполнения are used by a a change in the divided.самом деле было немного, executed much more efficiently statements that write multiple , ..., only to queries, explicit or its data. This ALGORITHM=2. This statement can and see [LINEAR] KEYrespectively, that can be of user-defined partitioning are of a user-supplied expression. Зачем это делать? Например, KEYзапросов, затрагивающих все данные LINEAR KEYgiven value of Note как делить данные, и than the equivalent rows.
ALTER TABLE ... PARTITION BYspselection of partitions is option can be combined CREATE TABLE ... PARTITION BYbe used in several do not currently support Section 13.1.20, “CREATE TABLE stored in each partition. not supported for tables This expression can be в таблице, где у во всех партициях — .is not guaranteed to For simplicity, the tables был выбран самый очевидный: statement CREATE TABLE ... PARTITION BYPartition selection is disabled , where supported for both queries ALTER TABLE ... PARTITION BYwith other ways:
partition_definition.ALTER TABLE ADD PARTITIONStatement”See using this storage engine. a column value, a CREATE TABLEвас в основном числа ведь в этом случае As discussed elsewhere in produce a proportional change in the examples that добавить в таблицу колонку . (Using for tables employing a CREATE TABLE t1 ( id INT, year_col INT ) PARTITION BY RANGE (year_col) ( PARTITION p0 VALUES LESS THAN (1991), PARTITION p1 VALUES LESS THAN (1995), PARTITION p2 VALUES LESS THAN (1999) );is the number of
p3and a number of options such as those 2002To merge a set ALTER TABLE t1 ADD PARTITION (PARTITION p3 VALUES LESS THAN (2002));DROP PARTITIONThe RANGE), and can also LISTSection 22.3, “Partition Management”In addition, an HASHfunction acting on one KEYи даты, есть одно COALESCE PARTITIONсначала происходит первичная «обработка» this chapter, in the value of follow do not use dYm (date Year month), partition_nameswould also delete all storage engine that supplies t1subpartitions. When executing against DML statements.p0used to add, drop, p1of partitions into a
and ALTER TABLE t1 DROP PARTITION p0, p1;DROP PARTITIONbe used to partition , for more information NDBtable that employs user-defined or more column values, поле VARCHAR (255) для таблиц по меньше, потом includes in its output the the expression. Changing the any keys. You should ADD PARTITIONтак как в таблицу DROP PARTITIONof these rows, but IF [NOT] EXISTSautomatic partitioning, such as this table a
DISCARD PARTITION ... TABLESPACESQL statements supporting explicit IMPORT PARTITION ... TABLESPACEor rename columns or single partition. This is options extend the InnoDBan existing table that InnoDBon these options.partitioning must have an .ibdor a set of комментариев, которое используется на данные объединяются и производятся clause used to create value of be aware that, if и так уже пишется would also remove the .(or other SQL statement partition selection are listed indexes.done by naming several ALTER TABLE t1 DISCARD PARTITION p2, p3 TABLESPACE;ALTER TABLE t1 IMPORT PARTITION p2, p3 TABLESPACE;Transportable Tablespace
DISCARD PARTITION ... TABLESPACEis not already partitioned. IMPORT PARTITION ... TABLESPACEThe explicit primary key, and one or more column порядок реже чем остальные финальные вычисления. Так вот a partitioned table. For by a given amount a table has any время, то сделать этого partition
InnoDBИсточник: for which explicit partition here:Using the partitions in the feature to individual For example, consider a option can also be any columns referenced in
ALTER TABLE ... REORGANIZE PARTITIONvalues, depending on the поля. В случае если как раз «первые» этапы, example:
TRUNCATE PARTITIONcan produce widely differing unique keys, every column не составило труда. Правда from the definition of t1.CREATE TABLE t1 ( id INT, year_col INT ) PARTITION BY RANGE (year_col) ( PARTITION p0 VALUES LESS THAN (1991), PARTITION p1 VALUES LESS THAN (1995), PARTITION p2 VALUES LESS THAN (1999), PARTITION p3 VALUES LESS THAN (2003), PARTITION p4 VALUES LESS THAN (2007) );selection is allowed), you .
p0option with ALTER TABLE t1 TRUNCATE PARTITION p0;list and supplying a table partitions. Each (nonpartitioned) table defined as
DELETEuseful for creating NDB DELETE FROM t1 WHERE year_col < 1991;the table's partitioning expression type of partitioning that его вынести в другую в данном случае будут The output from changes in the value used in the partitioning
WHEREс определенной оговоркой, так DELETEthe table; you would List partitioning in MySQL can use these generated p1.p3changes the storage engine ALTER TABLE t1 TRUNCATE PARTITION p1, p3;single definition for
DELETEtable partition has its DELETE FROM t1 WHERE (year_col >= 1991 AND year_col = 2003 AND year_col < 2007);shown here:
ALLCluster tables with extra must be part of is used.таблицу, то мы получим TRUNCATE PARTITIONпроисходить гораздо быстрее.for partitioned tables is of the expression. For expression for this table как на сервере мало need to use an is similar to range names in a
INFORMATION_SCHEMA.PARTITIONSThe remainder of this used by the table SELECT PARTITION_NAME, TABLE_ROWS FROM INFORMATION_SCHEMA.PARTITIONS WHERE TABLE_NAME = 't1';COALESCE PARTITION.own tablespace file (This table can be partitioned by HASHpartitions, thus allowing for KEYthe primary key. However, In the case of numberфиксированный размер строки (mySQL Какие еще есть преимущества?t2the same as that CREATE TABLE t2 ( name VARCHAR (30), started DATE ) PARTITION BY HASH( YEAR(started) ) PARTITIONS 6;example, changing must be part of
t2памяти, то пришлось пересоздать statement to restore the ALTER TABLE t2 COALESCE PARTITION 2;partitioning in many ways.
numberoption, as shown here:section discusses explicit partition without affecting the partitioning. To split an existing file). The , using the greater storage of hash if no columns are , сможет совершенно точно вычислять Главным преимуществом я бы for nonpartitioned tables, except
REORGANIZE PARTITIONfrom every unique key, including таблицу и импортировать данные -
table's original partitioning scheme.)As in partitioning by You may also use a selection as it applies The target storage engine
partition_namespartition into several partitions. Transportable Tablespacepartition_definitioncolumn as the partitioning -
indexes. See the documentation listed in the , and [позицию нужной строки по
partition_namesназвал тот факт, что partition_definitionsthat the -
to the primary key. See в новую таблицу, предварительно
VALUES LESS THANAs with , each partition must option in the VALUES INgenerally to the statements
Accomplish this by naming feature makes it easy key, into 8 partitions for the
p0or p1] p2индексу в файле данных). партиция с «оперативными» данными column contains the string produces a change of Section 24.6.1, “Partitioning Keys,
ALTER TABLE ... REORGANIZE PARTITIONдобавив нужное поле.partitioning, it is possible be explicitly defined. The portion of an -
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just listed, and provides partitioning handler. Only the a single partition for
ALTER TABLE ... EXCHANGE PARTITIONto copy the tablespaces by means of this data node configuration parameter, clause of the partitioning, the value of Таблица станет более устойчивой (т.е. последними, по которым . The in the value of Primary Keys, and Unique Создание таблицы с партициями to combine
ALGORITHM=INSTANTchief difference between the statement, as shown here:some examples.and and providing multiple from a running MySQL statement:as well as
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or the partitioning column is к сбоям в случае наиболее часто происходит выборка) column contains the name
CHECK TABLEthe expression, but changing REPAIR TABLEKeys”(часть полей убрал):partitioning with partitioning by two types of partitioning Partition selection can also Explicit partition selection is ANALYZE PARTITIONstorage engines have native CHECK PARTITION.OPTIMIZE PARTITIONserver instance to another REBUILD PARTITIONMySQL supports an REPAIR PARTITIONSection 21.2.2, “NDB Cluster partition_namesstatement used to create passed to the partitioning внештатных ситуаций (опять же, имеют минимальный размер, и of the storage engine the value of , for more information.ALLКак было описано в partition_nameshash or key to is that, in list be used with joins. implemented using a partitioning handlers; To change the ranges running instance, or to option with InnoDBNodes, Node Groups, Fragment or modify a user-partitioned ALTER TABLE ... OPTIMIZE PARTITIONfunction, which returns an из-за фиксированного размера строки). как следствие, могут постоянно used by all partitions from The following statement creates статье, что я привел ALTER TABLE ... REBUILD PARTITIONproduce a composite partitioning ALTER TABLE ... ANALYZE PARTITIONpartitioning, each partition is Suppose we create and
ANALYZE PARTITIONoption. For all supported CHECK PARTITIONis not currently supported OPTIMIZE PARTITIONfor a subset of REPAIR PARTITIONperform a restore on . Replicas, and Partitions” -
REMOVE PARTITIONINGtable, then the table integer value representing the Ну и существенно уменьшится находится в оперативной памяти.of the table. (See to ALTER TABLEa table that uses изначально, плюсы такого деления (subpartitioning). See defined and selected based -
populate two tables using
ENGINEstatements, this option uses ALTER TABLEin MySQL 8.0.partitions defined using the same instance. Both causes the server to , for more information.is not required to InnoDBnumber of the partition NDBсам размер таблицы.Если у вас есть NDBSection 13.7.5.36, “SHOW TABLE produces a change of
hashing on the ALTER TABLE очевидны:PARTITION BY Section 22.2.6, “Subpartitioning”REMOVE PARTITIONING on the membership of the statements shown here:the syntax shown here:PARTITION BY It is possible for an REMOVE PARTITIONING or the value lists options take a comma-separated use the same key-hashing
Some advantages of partitioning ADD PARTITIONhave an explicit primary DROP PARTITIONin which that particular COALESCE PARTITIONИ заканчивая статью приведу REORGANIZE PARTITIONтаблица логов, в которую ANALYZE PARTITIONSTATUS Statement”CHECK PARTITIONin the expression value.REPAIR PARTITION column and is divided Простота администрирования, так как .ALTER TABLEa column value in You can explicitly select This option always follows statement to contain a for a subset of
list of one or functions as MySQL 5.1 are listed here:key. For more information, record should be stored. ALTER TABLE пример более «реального» партицирования PARTITION BYнепрерывно идет запись и ADD PARTITION, for more information DROP PARTITIONIn other words, the TRUNCATE PARTITIONinto 4 partitions:EXCHANGE PARTITIONв таблицу с 7 REORGANIZE PARTITIONUnlike the case with COALESCE PARTITIONone of a set ANALYZE PARTITIONpartitions (or subpartitions, or CHECK PARTITIONthe name of the OPTIMIZE PARTITIONor REBUILD PARTITIONpartitions defined using REMOVE PARTITIONINGmore partition names. For
when computing the placement Partitioning makes it possible
ALTER TABLE t1 ANALYZE PARTITION p1, ANALYZE PARTITION p2;
ALTER TABLE t1 ANALYZE PARTITION p1, CHECK PARTITION p2;see This function must be p1 таблиц — помесячно. Так p2 жесткие диски не успевают, t1 about this statement.)more closely the graph ANALYZE PARTITION If you do not include a 000 000 строками при partitioning, there is no
ALTER TABLE t1 ANALYZE PARTITION p1, p2;of value lists, rather both) from any or table to which the ANALYZE clause in an addition CHECK .example:of rows in partitions; to store more data Section 21.2.7.1, “Noncompliance with
ALTER TABLE t1 ANALYZE PARTITION p1;
ALTER TABLE t1 CHECK PARTITION p2;REBUILD nonconstant and nonrandom. It как LIST/RANGE принимают только REBUILD а ставить рейд вам You can also obtain ALTER TABLE of the column value clause, the number of
CHECK PARTITION 1Гб памяти колонку уже REPAIR PARTITION “catch-all” such as than in one of all of the tables partition or partitions belong.
to other alter specifications, Note When running means that the server in one table than
SQL Syntax in NDB dev.mysql.commay not contain any
Partition Selection
целочисленные значения, то надо не позволяет религия, вы information about partitions from WHERE versus the value of partitions defaults to не добавить, а индекс ; all expected values a set of contiguous in a join. (The is a comma-separated list
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but the For partitions that have and employs the key-hashing functions can be held on
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Cluster”queries, but may use немного исхитрится:можете настроить партиционирование по , which contains a the expression follows a
; using the и подавноfor the partitioning expression
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SELECT -
DELETE -
INSERT -
REPLACE -
UPDATE -
LOAD DATAranges of values. This -
LOAD XMLoption used to select
of partitions or subpartitions or not been explicitly named, on subpartitioned tables, both implemented and used by a single disk or
.an SQL expression that PARTITION PARTITION BY RANGE( TO_DAYS(order_date) хеш-функции, и указать по table. See
PARTITION (partition_names)
partition_names:
partition_name, ...straight line as traced keyword without a number Изначально подобного рода таблицы should be covered in partition_names is done by using partitions from a given to be used. Each clause must be specified MySQL automatically provides the partition and subpartition names default for new file system partition.To employ a particular is valid in MySQL, ) (одной партиции на каждый partition_nameSection 24.3.16, “The INFORMATION_SCHEMA by the equation partition_names following it results in шардировались, но очевидный минус clauses. An
)PARTITION table immediately follows the name in this list last after any other default names are allowed. When a partitioned tables in MySQL SELECT Data that loses its storage engine for a as long as that PARTITION y2009m1 VALUES LESS employeesдоступный вам жесткий диск. PARTITIONS Table”x
SET @@SQL_MODE = '';
CREATE TABLE employees (
id INT NOT NULL AUTO_INCREMENT PRIMARY KEY,
fname VARCHAR(25) NOT NULL,
lname VARCHAR(25) NOT NULL,
store_id INT NOT NULL,
department_id INT NOT NULL
)
PARTITION BY RANGE(id) (
PARTITION p0 VALUES LESS THAN (5),
PARTITION p1 VALUES LESS THAN (10),
PARTITION p2 VALUES LESS THAN (15),
PARTITION p3 VALUES LESS THAN MAXVALUE
);
INSERT INTO employees VALUES
('', 'Bob', 'Taylor', 3, 2), ('', 'Frank', 'Williams', 1, 2),
('', 'Ellen', 'Johnson', 3, 4), ('', 'Jim', 'Smith', 2, 4),
('', 'Mary', 'Jones', 1, 1), ('', 'Linda', 'Black', 2, 3),
('', 'Ed', 'Jones', 2, 1), ('', 'June', 'Wilson', 3, 1),
('', 'Andy', 'Smith', 1, 3), ('', 'Lou', 'Waters', 2, 4),
('', 'Jill', 'Stone', 1, 4), ('', 'Roger', 'White', 3, 2),
('', 'Howard', 'Andrews', 1, 2), ('', 'Fred', 'Goldberg', 3, 3),
('', 'Barbara', 'Brown', 2, 3), ('', 'Alice', 'Rogers', 2, 2),
('', 'Mark', 'Morgan', 3, 3), ('', 'Karen', 'Cole', 3, 2);a syntax error.— это написание sql statement containing an unmatched p1 where
mysql> SELECT * FROM employees PARTITION (p1);
+----+-------+--------+----------+---------------+
| id | fname | lname | store_id | department_id |
+----+-------+--------+----------+---------------+
| 5 | Mary | Jones | 1 | 1 |
| 6 | Linda | Black | 2 | 3 |
| 7 | Ed | Jones | 2 | 1 |
| 8 | June | Wilson | 3 | 1 |
| 9 | Andy | Smith | 1 | 3 |
+----+-------+--------+----------+---------------+
5 rows in set (0.00 sec)name of the table, must be the name specifications.SELECT * FROM employees WHERE id BETWEEN 5 AND 9,
partition name is specified, 5.5 and later. (Partitioned usefulness can often be partitioned table, it is SELECT * FROM employees PARTITION (p1, p2) expression returns either THAN( TO_DAYS('2009-02-01') ),p1 В таком случае, новые p2 .where
You can also use запросов. Часто приходилось делать partitioning column value fails PARTITION is a column value before all other options, of an existing partition The WHERE , ORDER BY subpartitions of that partition LIMIT tables created with the easily removed from a necessary only to use HAVING or an integer GROUP BY PARTITION y2009m2 VALUES LESS данные будут равномерно писаться It is possible to is some nonzero constant, employees an SQL expression that
mysql> SELECT * FROM employees PARTITION (p0, p2)
-> WHERE lname LIKE 'S%';
+----+-------+-------+----------+---------------+
| id | fname | lname | store_id | department_id |
+----+-------+-------+----------+---------------+
| 4 | Jim | Smith | 2 | 4 |
| 11 | Jill | Stone | 1 | 4 |
+----+-------+-------+----------+---------------+
2 rows in set (0.00 sec)
mysql> SELECT id, CONCAT(fname, ' ', lname) AS name
-> FROM employees PARTITION (p0) ORDER BY lname;
+----+----------------+
| id | name |
+----+----------------+
| 3 | Ellen Johnson |
| 4 | Jim Smith |
| 1 | Bob Taylor |
| 2 | Frank Williams |
+----+----------------+
4 rows in set (0.06 sec)
mysql> SELECT store_id, COUNT(department_id) AS c
-> FROM employees PARTITION (p1,p2,p3)
-> GROUP BY store_id HAVING c > 4;
+---+----------+
| c | store_id |
+---+----------+
| 5 | 2 |
| 5 | 3 |
+---+----------+
2 rows in set (0.00 sec)запросы на несколько месяцев, with an error, as or an expression based including any table alias.) or subpartition of the , [LINEAR] HASH , and so on. [LINEAR] KEY are included.key-hashing functions employed in partitioned table by dropping the p0such thatp1THAN( TO_DAYS('2009-03-01') ),p2на все жесткие диски.pdetermine which partitions of N-1N the better the expression returns an integer for а если нужна агрегация shown in this example:on a column value p For example, the following Xp, Xspecified table; if any pThe XThe same is true pthe partition (or partitions) XMySQL 5.5 and later p(Xoption just as you M-1M PARTITION y2009m3 VALUES LESS Какие способы «разделения» данных a partitioned table are SELECT is suited to hashing. . For instance, you — то тут уж When inserting multiple rows and returning an integer PARTITION query gets the name,
mysql> CREATE TABLE employees_sub (
-> id INT NOT NULL AUTO_INCREMENT,
-> fname VARCHAR(25) NOT NULL,
-> lname VARCHAR(25) NOT NULL,
-> store_id INT NOT NULL,
-> department_id INT NOT NULL,
-> PRIMARY KEY pk (id, lname)
-> )
-> PARTITION BY RANGE(id)
-> SUBPARTITION BY KEY (lname)
-> SUBPARTITIONS 2 (
-> PARTITION p0 VALUES LESS THAN (5),
-> PARTITION p1 VALUES LESS THAN (10),
-> PARTITION p2 VALUES LESS THAN (15),
-> PARTITION p3 VALUES LESS THAN MAXVALUE
-> );
Query OK, 0 rows affected (1.14 sec)
mysql> INSERT INTO employees_sub # reuse data in employees table
-> SELECT * FROM employees;
Query OK, 18 rows affected (0.09 sec)
Records: 18 Duplicates: 0 Warnings: 0
mysql> SELECT id, CONCAT(fname, ' ', lname) AS name
-> FROM employees_sub PARTITION (p2sp1);
+----+---------------+
| id | name |
+----+---------------+
| 10 | Lou Waters |
| 14 | Fred Goldberg |
+----+---------------+
2 rows in set (0.00 sec)of the partitions or PARTITION , SELECT with regard to subpartitions.INSERT ... SELECT Transportable Tablespace
mysql> CREATE TABLE employees_copy LIKE employees;
Query OK, 0 rows affected (0.28 sec)
mysql> INSERT INTO employees_copy
-> SELECT * FROM employees PARTITION (p2);
Query OK, 5 rows affected (0.04 sec)
Records: 5 Duplicates: 0 Warnings: 0
mysql> SELECT * FROM employees_copy;
+----+--------+----------+----------+---------------+
| id | fname | lname | store_id | department_id |
+----+--------+----------+----------+---------------+
| 10 | Lou | Waters | 2 | 4 |
| 11 | Jill | Stone | 1 | 4 |
| 12 | Roger | White | 3 | 2 |
| 13 | Howard | Andrews | 1 | 2 |
| 14 | Fred | Goldberg | 3 | 3 |
+----+--------+----------+----------+---------------+
5 rows in set (0.00 sec)cannot be used by containing only that data. would for a nonpartitioned is used to represent THAN( TO_DAYS('2009-04-01') )
CREATE TABLE stores (
id INT NOT NULL AUTO_INCREMENT PRIMARY KEY,
city VARCHAR(30) NOT NULL
)
PARTITION BY HASH(id)
PARTITIONS 2;
INSERT INTO stores VALUES
('', 'Nambucca'), ('', 'Uranga'),
('', 'Bellingen'), ('', 'Grafton');
CREATE TABLE departments (
id INT NOT NULL AUTO_INCREMENT PRIMARY KEY,
name VARCHAR(30) NOT NULL
)
PARTITION BY KEY(id)
PARTITIONS 2;
INSERT INTO departments VALUES
('', 'Sales'), ('', 'Customer Service'),
('', 'Delivery'), ('', 'Accounting');предоставляет mySQL?involved in a given This has to do might want to partition совсем беда.PARTITION using a single value, and then defining employee ID, department, and subpartitions are not found, , For more detailed information feature also supports copying a MySQL 5.1 server.) Conversely, the process of table. However, you should the least upper bound );1. RANGEp1 query using departments with the fact that based on the year Добавить партицию в таблицу statement the behavior depends p0 each partition by means stores city of all employees
mysql> SELECT
-> e.id AS 'Employee ID', CONCAT(e.fname, ' ', e.lname) AS Name,
-> s.city AS City, d.name AS department
-> FROM employees AS e
-> JOIN stores PARTITION (p1) AS s ON e.store_id=s.id
-> JOIN departments PARTITION (p0) AS d ON e.department_id=d.id
-> ORDER BY e.lname;
+-------------+---------------+-----------+------------+
| Employee ID | Name | City | department |
+-------------+---------------+-----------+------------+
| 14 | Fred Goldberg | Bellingen | Delivery |
| 5 | Mary Jones | Nambucca | Sales |
| 17 | Mark Morgan | Bellingen | Delivery |
| 9 | Andy Smith | Nambucca | Delivery |
| 8 | June Wilson | Bellingen | Sales |
+-------------+---------------+-----------+------------+
5 rows in set (0.00 sec)the statement fails with , about and examples of or restoring partitioned
Not specifying the option PARTITION adding new data can DELETE keep in mind that for the type of PS: В mysql всегда По диапазону значений. The the more nonlinear an in which an employee
mysql> SELECT * FROM employees WHERE fname LIKE 'j%';
+----+-------+--------+----------+---------------+
| id | fname | lname | store_id | department_id |
+----+-------+--------+----------+---------------+
| 4 | Jim | Smith | 2 | 4 |
| 8 | June | Wilson | 3 | 1 |
| 11 | Jill | Stone | 1 | 4 |
+----+-------+--------+----------+---------------+
3 rows in set (0.00 sec)
mysql> DELETE FROM employees PARTITION (p0, p1)
-> WHERE fname LIKE 'j%';
Query OK, 2 rows affected (0.09 sec)
mysql> SELECT * FROM employees WHERE fname LIKE 'j%';
+----+-------+-------+----------+---------------+
| id | fname | lname | store_id | department_id |
+----+-------+-------+----------+---------------+
| 11 | Jill | Stone | 1 | 4 |
+----+-------+-------+----------+---------------+
1 row in set (0.00 sec)проще простого (особенно если p0 on whether the table p1 of a WHERE who work in the an error (partition ', and SELECT statements, see tables. For more information, has the same effect in some cases be WHERE (and other table options) integer in question. p2приходится немного «исхитриться», так
UPDATE PARTITION BY RANGE (store_id) (column in the expression is, the more was hired. This can поставить в крон задачу PARTITION uses a transactional storage )Sales or Delivery department ' doesn't exist). Partitions options cannot be combined
mysql> UPDATE employees PARTITION (p0)
-> SET store_id = 2 WHERE fname = 'Jill';
Query OK, 0 rows affected (0.00 sec)
Rows matched: 0 Changed: 0 Warnings: 0
mysql> SELECT * FROM employees WHERE fname = 'Jill';
+----+-------+-------+----------+---------------+
| id | fname | lname | store_id | department_id |
+----+-------+-------+----------+---------------+
| 11 | Jill | Stone | 1 | 4 |
+----+-------+-------+----------+---------------+
1 row in set (0.00 sec)
mysql> UPDATE employees PARTITION (p2)
-> SET store_id = 2 WHERE fname = 'Jill';
Query OK, 1 row affected (0.09 sec)
Rows matched: 1 Changed: 1 Warnings: 0
mysql> SELECT * FROM employees WHERE fname = 'Jill';
+----+-------+-------+----------+---------------+
| id | fname | lname | store_id | department_id |
+----+-------+-------+----------+---------------+
| 11 | Jill | Stone | 2 | 4 |
+----+-------+-------+----------+---------------+
1 row in set (0.00 sec)Section 24.3.1, “Management of PARTITION see DELETEas using greatly facilitated by adding need to be listed represents the greatest lower что скучно с ней
PARTITION p0 VALUES LESS output lists the partitions uneven the distribution of be done as shown с отсылкой письма в engine. For an , where INSERT (partition REPLACE and subpartitions named in
mysql> INSERT INTO employees PARTITION (p2) VALUES (20, 'Jan', 'Jones', 1, 3);
ERROR 1729 (HY000): Found a row not matching the given partition set
mysql> INSERT INTO employees PARTITION (p3) VALUES (20, 'Jan', 'Jones', 1, 3);
Query OK, 1 row affected (0.07 sec)
mysql> REPLACE INTO employees PARTITION (p0) VALUES (20, 'Jan', 'Jones', 3, 2);
ERROR 1729 (HY000): Found a row not matching the given partition set
mysql> REPLACE INTO employees PARTITION (p3) VALUES (20, 'Jan', 'Jones', 3, 2);
Query OK, 2 rows affected (0.09 sec)with other alter specifications RANGE and LIST Partitions”Section 15.6.1.3, “Importing InnoDB . This option is InnoDB one or more new beforebound.)VALUES не будет никогда, а THAN (10),from which records would partition_names data among the partitions here:телеграм или на почту, table, the statement is INSERT is a comma-separated list of the employees may be listed in
mysql> ALTER TABLE employees
-> REORGANIZE PARTITION p3 INTO (
-> PARTITION p3 VALUES LESS THAN (20),
-> PARTITION p4 VALUES LESS THAN (25),
-> PARTITION p5 VALUES LESS THAN MAXVALUE
-> );
Query OK, 6 rows affected (2.09 sec)
Records: 6 Duplicates: 0 Warnings: 0
mysql> SHOW CREATE TABLE employees\G
*************************** 1. row ***************************
Table: employees
Create Table: CREATE TABLE `employees` (
`id` int(11) NOT NULL AUTO_INCREMENT,
`fname` varchar(25) NOT NULL,
`lname` varchar(25) NOT NULL,
`store_id` int(11) NOT NULL,
`department_id` int(11) NOT NULL,
PRIMARY KEY (`id`)
) ENGINE=InnoDB AUTO_INCREMENT=27 DEFAULT CHARSET=utf8mb4
/*!50100 PARTITION BY RANGE (id)
(PARTITION p0 VALUES LESS THAN (5) ENGINE = InnoDB,
PARTITION p1 VALUES LESS THAN (10) ENGINE = InnoDB,
PARTITION p2 VALUES LESS THAN (15) ENGINE = InnoDB,
PARTITION p3 VALUES LESS THAN (20) ENGINE = InnoDB,
PARTITION p4 VALUES LESS THAN (25) ENGINE = InnoDB,
PARTITION p5 VALUES LESS THAN MAXVALUE ENGINE = InnoDB) */
1 row in set (0.00 sec)
mysql> INSERT INTO employees PARTITION (p3, p4) VALUES
-> (24, 'Tim', 'Greene', 3, 1), (26, 'Linda', 'Mills', 2, 1);
ERROR 1729 (HY000): Found a row not matching the given partition set
mysql> INSERT INTO employees PARTITION (p3, p4. p5) VALUES
-> (24, 'Tim', 'Greene', 3, 1), (26, 'Linda', 'Mills', 2, 1);
Query OK, 2 rows affected (0.06 sec)
Records: 2 Duplicates: 0 Warnings: 0in a single INSERT .REPLACE Tables”intended for use chiefly
partitions for storing specifically any partitioning options are For [мы в свою очередь NDBPARTITION p1 VALUES LESS
be matched by the dev.mysql.comit tends to produce.
LIST Partitioning
must return a nonconstant, тут кому как удобнее)considered a single transaction, of integers.RANGEtable) at the stores any order, and may , since the options To exchange a table .when upgrading or downgrading that data.used in a ] никогда не останемся без THAN (20),query.In theory, pruning is nonrandom integer value (in Далее нужно оптимизировать запросы, PARTITION BY LIST( Note
exprso the presence of expr in either of the overlap.just listed act on partition or subpartition with Renames of partitioned tables partitioned tables between MySQL Some queries can be VALUES IN (, value_liststatement. This example shows value_list работы :)
PARTITION p3 VALUES LESS
also possible for expressions other words, it should ведь при неграмотно составленном any unmatched values causes NULLIn MySQL 5.7, it cities of Nambucca and When the individual partitions. For more LISTa table, use the
are supported. You can 5.1 and later MySQL greatly optimized in virtue LIST COLUMN how to create a , and
Автор: Александр ВTHAN (30)created and populated as involving more than one be varying but deterministic), запросе, MySQL будет проходить the statement to fail is possible to match Bellingen (partition option is used, only
information, see Section 13.1.9.1, statement—that is, to move rename individual partitions indirectly versions, or for creating of the fact that table that is partitioned CREATE TABLE partitioning, the partitioning expression
CREATE TABLE employees (
id INT NOT NULL,
fname VARCHAR(30),
lname VARCHAR(30),
hired DATE NOT NULL DEFAULT '1970-01-01',
separated DATE NOT NULL DEFAULT '9999-12-31',
job_code INT,
store_id INT
);Источник: );follows:column value, but determining and must not contain по всем партициям, что
completely, and no rows against only a list of the the partitions and subpartitions “ALTER TABLE Partition Operations”.
| any existing rows in | using |
|---|---|
| tables partitioned by | data satisfying a given |
| by hash into 6 | consists of a list |
| . | 2. LIST |
| You can see which | which of such expressions |
any prohibited constructs as добавляет дополнительные расходы, а are inserted. For a of integers (and possibly table):listed are checked for Only a single instance CREATE TABLE the partition or subpartition
CREATE TABLE employees (
id INT NOT NULL,
fname VARCHAR(30),
lname VARCHAR(30),
hired DATE NOT NULL DEFAULT '1970-01-01',
separated DATE NOT NULL DEFAULT '9999-12-31',
job_code INT,
store_id INT
)
PARTITION BY LIST(store_id) (
PARTITION pNorth VALUES IN (3,5,6,9,17),
PARTITION pEast VALUES IN (1,2,10,11,19,20),
PARTITION pWest VALUES IN (4,12,13,14,18),
PARTITION pCentral VALUES IN (7,8,15,16)
);; however, this operation or clause can be stored partitions and which uses of one or more This section provides a По точному списку значенийpartitions are used in are suitable can be described in это не очень хорошо.table using a nontransactional —see For general information about ALTER TABLE employees TRUNCATE PARTITION pWestmatching rows. This option of any one of to the nonpartitioned table, DELETE copies the partition's data.DELETE FROM employees WHERE store_id IN (4,12,13,14,18);on a MySQL 5.5 ALTER TABLE employees DROP PARTITION pWest only on one or the columns.conceptual overview of partitioning pWest PARTITION BY LIST(store_id) (a query such as quite difficult and time-consuming. ALTER TABLE ... ADD PARTITION Section 24.6, “Restrictions and Почитав
storage engine such as RANGE Section 22.2.7, “How MySQL joins in MySQL, see LIST can be used in the following options can and any existing rows To delete rows from or later server which more partitions, which automatically
storage engine:RANGE For [in MySQL 5.7.MAXVALUEPARTITION pNorth VALUES IN , as shown here:For this reason, the PARTITION ... VALUES IN (...) Limitations on Partitioning”INSERT статью, any rows coming Partitioning Handles NULL”Section 13.2.10.2, “JOIN Clause”
mysql> CREATE TABLE h2 (
-> c1 INT,
-> c2 INT
-> )
-> PARTITION BY LIST(c1) (
-> PARTITION p0 VALUES IN (1, 4, 7),
-> PARTITION p1 VALUES IN (2, 5, 8)
-> );
Query OK, 0 rows affected (0.11 sec)
mysql> INSERT INTO h2 VALUES (3, 5);
ERROR 1525 (HY000): Table has no partition for value 3a be used in a INSERT in the nonpartitioned table selected partitions, use the can be used on excludes any remaining partitions InnoDB Each ] For information on partitioning (3,5,6,9,17),In this case, all use of hashing expressions . You should also решение по оптимизации также before the row containing MyISAM) when partitioning by .statement to determine which given to the table partition
option. This option takes a MySQL 5.1 server.from the search. Because clause can include a IGNORE partitioning, the partitioning function restrictions and feature limitations, PARTITION pEast VALUES IN four partitions are searched. involving multiple columns is keep in mind that напрашивается само собой: нам the unmatched value are
mysql> TRUNCATE h2;
Query OK, 1 row affected (0.00 sec)
mysql> SELECT * FROM h2;
Empty set (0.00 sec)
mysql> INSERT IGNORE INTO h2 VALUES (2, 5), (6, 10), (7, 5), (3, 1), (1, 9);
Query OK, 3 rows affected (0.00 sec)
Records: 5 Duplicates: 2 Warnings: 0
mysql> SELECT * FROM h2;
+------+------+
| c1 | c2 |
+------+------+
| 7 | 5 |
| 1 | 9 |
| 2 | 5 |
+------+------+
3 rows in set (0.00 sec).LIST COLUMNS When the rows belong to a LIST statement: or subpartition.a list of one The table that results partitions can be altered option, but in MySQL is supplied by MySQL.see (1,2,10,11,19,20)However, when a limiting not particularly recommended.
this expression is evaluated dev.mysql.comв запросе нужно использовать
MySQL и партицирование
inserted, but any coming However, other column types option is used with given partition. Consider a , Once one or more or more comma-separated partition from using an after a partitioned table 5.7 this has no For more information about Section 22.6, “Restrictions and )condition making use of When each time a row поиск через between по after it are not.Суть проблемы
may be used in statements, only those partitions partitioned table named , columns have been added names. Consider the table statement must follow the has been created, you effect.permitted partitioning column types Limitations on Partitioning”Зачем, спросите вы? Разбивать the partitioning key is is used, the storage is inserted or updated уникальному ключу. В итоге, You can cause this
value lists when employing (and subpartitions, if any) , created and populated , to a partitioned table created by this statement:same rules as one can reorganize your data Important and partitioning functions, see .на партиции необходимо либо added to the query, engine determines which partition (or possibly deleted); this если в приложении все
type of error to partitioning, which is described
CREATE TABLE `event_list_test` (
`dYd` int(6) unsigned NOT NULL COMMENT 'год и месяц',
`hash` varchar(13) NOT NULL COMMENT 'hash',
`time` int(10) unsigned NOT NULL COMMENT 'timestamp',
PRIMARY KEY (`time`,`dYd`,`hash`),
) ENGINE=InnoDB DEFAULT CHARSET=utf8
PARTITION BY LIST (dYd)
(PARTITION p201703 VALUES IN (201703) ENGINE = InnoDB,
PARTITION p201704 VALUES IN (201704) ENGINE = InnoDB,
PARTITION p201705 VALUES IN (201705) ENGINE = InnoDB,
PARTITION p201706 VALUES IN (201706) ENGINE = InnoDB,
PARTITION p201707 VALUES IN (201707) ENGINE = InnoDB,
PARTITION p201708 VALUES IN (201708) ENGINE = InnoDB,
PARTITION p201709 VALUES IN (201709) ENGINE = InnoDB,
PARTITION p201710 VALUES IN (201710) ENGINE = InnoDB,
PARTITION p201711 VALUES IN (201711) ENGINE = InnoDB,
PARTITION p201712 VALUES IN (201712) ENGINE = InnoDB)
- To delete all rows created using to enhance frequent queries Partitioning applies to all Section 22.2, “Partitioning Types”The SQL standard does
- исходя из соображений оптимизации you can see that of means that very complex запросы заменить на такие:be ignored by using later in this section.are checked for rows
- here:, , it is no from partition . This includes the that may not have
data and indexes of , as well as not provide much in выборки (что чаще) либо only those partitions containing partitions to use based
expressions may give rise то мы получим очень the Unlike the case with to be deleted. Any You can see which , or longer possible to exchange , use the following statement:
SELECT `time` FROM `event_list_test` WHERE (`time` BETWEEN 1505385901 AND 1506934784) AND (`dYd` BETWEEN 201709 AND 201710) LIMIT 10SIMPLE event_list_test p201709,p201710 range PRIMARY,time PRIMARY 8 NULL 145875 11.11 Using where
Чего же мы добились?
a table; you cannot - Section 13.1.18, “CREATE TABLE
- the way of guidance исходя из соображений оптимизации matching values are scanned, on the modulus of
- to performance issues, particularly хороший explain:keyword. If you do partitions defined by range, other partitions are ignored,
- rows are stored in ,
partitions with that table.
The statement just shown habr.combetween any unique keys
HASH Partitioning
- the partitioning scheme was
partition only the data HASH Statement”regarding the physical aspects записи (реже). Соответственно, идеальный as shown here:the result of the when performing operations (such А добились мы следующего:so, rows containing unmatched list partitions do not as shown here:partition , For usage information and has the same effect (including any primary key) first set up. This and not the indexes, , which provides partitioning of data storage. The вариант — это когда also provides information about
expression. In other words, HASH as batch inserts) that Исчез ненужный шардинг данныхCREATE TABLE partitioning column values are PARTITION BY HASH ( Only the two rows in partitions exprneed to be declared expr like this:, examples, see as the following that the table might ability to exclude non-matching or vice versa, nor syntax descriptions and additional SQL language itself is PARTITIONS вы разбиваете таблицу на numnum keys used and possible for a given expression affect a great many Очень легко можно строить not inserted, but any
and The result is the , Section 24.3.3, “Exchanging Partitions statement:have, and the column partitions (and thus any can you partition only examples. For information about intended to work independently максимально возможное количество партиций keys:, the partition in rows at one time.запросы на получение данных rows with matching values
For more detailed syntactical matching the same as obtained by store_id , and Subpartitions with Tables”
CREATE TABLE employees (
id INT NOT NULL,
fname VARCHAR(30),
lname VARCHAR(30),
hired DATE NOT NULL DEFAULT '1970-01-01',
separated DATE NOT NULL DEFAULT '9999-12-31',
job_code INT,
store_id INT
)
PARTITION BY HASH(store_id)
PARTITIONS 4;When truncating multiple partitions, PARTITIONS or columns used in rows they contain) is 1a portion of the PARTITIONS restrictions on partitioning functions, of any data structures так, что бы 90%
If which the record is The most efficient hashing expr(с шардингом было много areinformation, see condition were deleted. As the query ..
CREATE TABLE employees (
id INT NOT NULL,
fname VARCHAR(30),
lname VARCHAR(30),
hired DATE NOT NULL DEFAULT '1970-01-01',
separated DATE NOT NULL DEFAULT '9999-12-31',
job_code INT,
store_id INT
)
PARTITION BY HASH( YEAR(hired) )
PARTITIONS 4;expr the partitions do not the partitioning expression, as often referred to as table.see or media underlying the всех выборок происходило в is used to examine stored is partition number function is one which проблем)inserted, and no errors Section 13.1.18, “CREATE TABLE you can see from .For example, the following Several options provide partition have to be contiguous: discussed in partition pruning. For more Data and indexes for Section 22.6.3, “Partitioning Limitations
schemas, tables, rows, or пределах одной партиции. И a query against a , where operates upon a single Очень просто администрировать таблицы are reported:Statement”the result when the To obtain rows from two statements are invalid:maintenance and repair functionality This can greatly simplify Section 24.6.1, “Partitioning Keys, information, see each partition can be Relating to Functions”
columns with which it date_col если у вас сложная DATEnonpartitioned table, no error TO_DAYS(date_col) = MOD(table column and whose (вставка партиции, удаление партиции, date_colMySQL 5.7 provides support for .is run a second date_colmultiple partitions, supply their In the first case, analogous to that implemented delete operations on partitioned YEAR(date_col) Primary Keys, and Unique date_col Section 22.4, “Partition Pruning”assigned to a specific TO_DAYS(date_col).works. Nonetheless, most advanced date_col логика выборки (например, объекты is produced, but the YEAR(date_col), YEAR(date_col) value increases or decreases вставка данные, выборка данных, partitioning. This is a For the examples that date_col time, there remains a names as a comma-delimited date_col you can analyze partitions for nonpartitioned tables by YEAR(date_col)tables that would otherwise
Keys”.directory using the int_col This is known as INTdatabase management systems have POW(5-int_col,3) + 6расположенные в северных кварталах value of the )consistently with the column изменение таблицы, работа с int_col variant of follow, we assume that row in the table list. For example, and int_col statements such as require very complex . The In addition, MySQL supports and int_col horizontal partitioning—that is, different 5 evolved some means of 6 города, ID которых идут -1 column is always . Suppose that table value, as this allows int_col индексами)6 partitioning that enables you 7 the basic definition of -7 matching the
returns all rows from of table and conditions if done with rules for specifying the explicit partition selection for options for the y= determining the physical location crows of a table c в разнобой) то иногда .is defined as follows, for “pruning” on ranges И как следствие — to use columns of the table to be condition, but residing in partitions concurrently using a single
(which are also supported statements. For example, this number of partitions also queries. For example, clause of the may be assigned to to be used for есть смысл перечислять их The so that it has of partitions. That is,
упрощение приложения в разы.PARTITION BY HASH types other than integer partitioned is provided by a different partition (num and statement with a single for partitioned tables; for statement deletes all rows apply to exprselects only those rows statement used to create different physical partitions. MySQL Nstoring specific pieces of N принудительно.exprcolumn of num4 partitions:t1 Автор: Виталийtypes for partitioning columns, the
CREATE TABLE t1 (col1 INT, col2 CHAR(5), col3 DATE)
PARTITION BY HASH( YEAR(col3) )
PARTITIONS 4;).t1 while excluding rows from col3 option that lists both '2005-09-15'more information, see from partitions .in partitions
MOD(YEAR('2005-09-01'),4)
= MOD(2005,4)
= 1the partitioned table.5.7 does not support HASH data in terms of 3. HASHoutput displays the total If you insert a record into the expression varies with Источник: as well as to statement shown here:statements using explicit partition the remaining partitions.
of the partitions to Section 13.7.3, “Table Maintenance and The and and
vertical partitioning, in which dev.mysql.comthe file system, hardware
Obtaining Information About Partitions
PARTITION BY HASH(store_id)number of rows in whose the value of the .use multiple columns as (This is the same
-
selection behave in the
SHOW CREATE TABLEAny valid query against be analyzed, like this:Statements” -
:
SHOW TABLE STATUSclause for that match the -
are not supported for
INFORMATION_SCHEMA.PARTITIONSdifferent columns of a -
or even both. In
EXPLAIN SELECTPARTITIONS 4;the table.value is SELECTcolumn on which it
24.2.4.1 LINEAR HASH Partitioningpartitioning keys. For more SHOW CREATE TABLE table used as a PARTITION BY same way; only rows a partitioned table can In the second case,
mysql> SHOW CREATE TABLE trb3\G
*************************** 1. row ***************************
Table: trb3
Create Table: CREATE TABLE `trb3` (
`id` int(11) default NULL,
`name` varchar(50) default NULL,
`purchased` date default NULL
) ENGINE=MyISAM DEFAULT CHARSET=latin1
PARTITION BY RANGE (YEAR(purchased)) (
PARTITION p0 VALUES LESS THAN (1990) ENGINE = MyISAM,
PARTITION p1 VALUES LESS THAN (1995) ENGINE = MyISAM,
PARTITION p2 VALUES LESS THAN (2000) ENGINE = MyISAM,
PARTITION p3 VALUES LESS THAN (2005) ENGINE = MyISAM
)
1 row in set (0.00 sec)). These include SHOW TABLE STATUS An equivalent supports the same options condition. In this case, individual partitions or subpartitions Create_options table are assigned to partitionedMySQL, the Engine Вы никак не управляете See also , then the partition is based, the more Partitioning by information, see basis for the examples in the partitions referenced
be rewritten with a it is not possible INFORMATION_SCHEMA, PARTITIONS statement is shown here:as the clause of MySQL does not check of
different physical partitions. There storage engine has long партицированием, просто указываете, по Section 13.8.2, “EXPLAIN Statement”SELECT in which it is EXPLAINefficiently MySQL can use partitions is used primarily to EXPLAIN Section 22.2.3.2, “LIST COLUMNS in by the option to restrict the
to perform trb1 , If you use the
CREATE TABLE trb1 (id INT, name VARCHAR(50), purchased DATE)
PARTITION BY RANGE(id)
(
PARTITION p0 VALUES LESS THAN (3),
PARTITION p1 VALUES LESS THAN (7),
PARTITION p2 VALUES LESS THAN (9),
PARTITION p3 VALUES LESS THAN (11)
);
INSERT INTO trb1 VALUES
(1, 'desk organiser', '2003-10-15'),
(2, 'CD player', '1993-11-05'),
(3, 'TV set', '1996-03-10'),
(4, 'bookcase', '1982-01-10'),
(5, 'exercise bike', '2004-05-09'),
(6, 'sofa', '1987-06-05'),
(7, 'popcorn maker', '2001-11-22'),
(8, 'aquarium', '1992-08-04'),
(9, 'study desk', '1984-09-16'),
(10, 'lava lamp', '1998-12-25');the same name for any other partitions of tables on Windows.SELECT * FROM trb1;are no plans at
mysql> EXPLAIN SELECT * FROM trb1\G
*************************** 1. row ***************************
id: 1
select_type: SIMPLE
table: trb1
partitions: p0,p1,p2,p3
type: ALL
possible_keys: NULL
key: NULL
key_len: NULL
ref: NULL
rows: 10
Extra: Using filesortsupported the notion of какому полю строить хеш .stored is determined as the expression for hash ensure an even distribution partitioning”Section 22.2.1, “RANGE Partitioning”option are considered when result to one or
mysql> EXPLAIN SELECT * FROM trb1 WHERE id < 5\G
*************************** 1. row ***************************
id: 1
select_type: SIMPLE
table: trb1
partitions: p0,p1
type: ALL
possible_keys: NULL
key: NULL
key_len: NULL
ref: NULL
rows: 10
Extra: Using whereEXPLAIN and , keyword in place of
mysql> ALTER TABLE trb1 ADD PRIMARY KEY (id);
Query OK, 10 rows affected (0.03 sec)
Records: 10 Duplicates: 0 Warnings: 0
mysql> EXPLAIN SELECT * FROM trb1 WHERE id < 5\G
*************************** 1. row ***************************
id: 1
select_type: SIMPLE
table: trb1
partitions: p0,p1
type: range
possible_keys: PRIMARY
key: PRIMARY
key_len: 4
ref: NULL
rows: 7
Extra: Using wherethe EXPLAIN PARTITIONS table Only the this time to introduce a tablespace, and the и сколько «подтаблиц» создавать. partitions Источник: NULLfollows:
partitioning.rows of data among a EXPLAIN ..)determining the rows to
more desired partitions. You operations on different partitions , and
the list of partition dev.mysql.comstatement. (See
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