If the database designer has created a Primary partition Index on a table, queries should incorporate the partitioning column.
如果数据库设计者已在表上创建了主分区索引,那么查询应当与分区列结合。
For example, one cannot use identity columns or timestamps for the partitioning column, but the partitioning column has to be part of the primary key.
例如,我们无法针对分区的列使用标识列或者时间戳,而分区列需要是主键的组成部分。
Because there is a predicate, cust_order_number between 100000 and 580000, on the partitioning column, the optimizer is able to limit the TBSCAN to the first nine partitions.
因为有一个谓词,cust_order_number处于100000到580000之间,在分区列上,优化器能够限制TBSCAN到头九个分区。
For each column in the partitioning key of the joined tables, an equijoin predicate must exist.
对于被合并的表的分区键内的每列,必须存在一个同等连接的谓语。
A partitioning key is a column (or group of columns) that is used to determine the partition in which a particular row of data is stored.
分区键是用于确定特定一行数据存储在哪个分区的一个列(或一组列)。
For TP, design decisions include selecting the column to use as the table partitioning key and number of partitions.
对于TP,设计决定包括选择用作表分区键的列和分区的数量。
If you choose a partitioning key based on your query workload, the partitioning key should typically consist of either a joined column or a set of columns that is frequently used in many queries.
如果基于查询工作负载选择一个分区键,那么此分区键通常应该包含一个合并列或常被用于很多查询的一组列。
TP will only benefit those queries that include the table partitioning key column.
TP只对那些包括表分区键列的查询有利。
Whether a column should be used as table partitioning key for TP is not affected by whether that column is also used an MDC dimension and vice versa.
一个列是否被用作MD c维对于是否应该将它作为表分区键没有影响,反之亦然。
The partitioning key needs to be on a column or set of columns that are highly unique thus ensuring that the data will be evenly distributed across all the partitions that the table is defined on.
分区键需要位于高度惟一的一列或一组列上,从而确保数据均匀分布在该表所定义的所有分区上。
Usually the table partitioning key will be a time-based column.
通常表分区键是基于时间的列。
Unlike other sharding solutions, Slice does not require adding any extra column to the existing schema to enable partitioning.
与其他的分区解决方案不同,Slice并不需要向现有模式中添加任何额外的列以支持分区。
DurationLabel: Identifies the duration that is associated with the Constant value specified if the partitioning key column has been assigned a date, time, or time stamp data type.
DurationLabel:如果分区键列的数据类型是日期、时间或时间戳,这个参数指定与Constan t值相关的时间单位。
In the following example, Table1 is created on database partitions 1, 2, 3, and 4, and is redistributed based on a partitioning key on column col1.
在如下的例子中,Table1创建于数据库分区1、2、3和4并且会基于列COL1上的一个分区键重新分配。
In my last column, I explained how you can use table partitioning to organize data across multiple storage objects based on values in one or more columns.
在我的上一期专栏中,我阐述了如何使用表分区,基于一列或多列中的值,跨多个存储对象组织数据。
The placement is determined by an internal hashing function that takes the values in the column or columns defined as a partitioning key and returns the database partition number.
这种安置是由一个内部的哈希函数决定的,该函数接受定义为分区键的列内的值并返回数据库分区号。
The partitioning key should not include a column with unevenly distributed data or with a small number of distinct values.
分区键不应该包括没有将数据均匀分布或具有少数不同值的列。
In addition to the partitioning key change, this procedure can move the table to a different table space, change column definitions, and more.
除了更改分区键,这个过程能够将表移到不同的表空间、更改列定义等。
If no primary key is specified, the default-partitioning key is the first non-long field column defined on the table.
而如果没有指定主键,默认的分区键则为该表上所定义的第一个不为long字段的列。
In order to use this technique, the SQL must provide a predicate on the first key column of the partitioning index.
为了使用这种技术,SQL必须提供分区索引的第一个键列上的一个谓词。
In order to use this technique, the SQL must provide a predicate on the first key column of the partitioning index.
为了使用这种技术,SQL必须提供分区索引的第一个键列上的一个谓词。
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