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 consists of one or more columns defined at table creation.
一个分区键由在表创建时定义的一个或多个列组成。
A partitioning key should include one to three columns.
一个分区键应该包括一至三个列。
The partitioning key for each table in a tablespace that is associated with a database partition group determines if the tables are collocated.
在与一个数据库分区组相关联的表空间中,每个表的分区键可以确定表是否是并置的。
In some cases, you might find that guidelines for choosing the proper partitioning key based on collocation and data balancing contradict one another.
在某些情况下,您可能会发现根据并置和数据平衡选择恰当的分区键的准则会相互矛盾。
Tables that will be joined on the partitioning key should have the same number of partitions and should break on the same values.
需要按分区键进行连接的表应该有相同数量的分区,并且应该在相同的值上断开。
The data model and the business relationship between tables can provide a more stable way of selecting a partitioning key than specific SQL statements.
这个数据模型以及表间的业务关系可以提供一种比sql语句更为稳定的选择分区键的方式。
Unnecessary columns should not be included in the partitioning key.
分区键中不应该包括不必要的列。
Based on your application's business processes, you need to identify which tables to partition with the correct partitioning key.
您需要根据应用程序的业务流程,确定用正确的分区键划分哪些表。
In a non-partitioned database, no partitioning key or partitioning map is required.
在一个非分区数据库中,不需要分区键或分区映射。
It is useful when a table has a finite set of values for the fragment key (or partitioning key) and queries on the table have an equality predicate on the fragment key.
如果表格有一定数量的片段键(或者分区键)值,而且在片段键上有同等谓词的表格上查询时,它会很有用处。
An inappropriate partitioning key can cause uneven data distribution.
不恰当的分区键可能导致数据分布不均匀。
If a good partitioning key is chosen, the data will be evenly distributed across the nodes, and for most, if not all, queries, the partitioning key will uniquely identify the node containing the data.
如果选定一个好的分区键,那么数据会均匀地分布在所有节点,对于大多数情况都是如此,如果不是这样,请进行查询,分区键将惟一地标识包含数据的节点。
In other words, all columns that are part of the partitioning key must be present in the primary key or unique index definition.
换句话说,作为分区键一部分的所有列都必须出现在主键或惟一索引定义中。
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。
Note that a new partitioning key is recommended (L_ORDERKEY) to replace the current one (L_PARTKEY), which is commented out.
注意,这里建议了一个新的分区键(L_ORDERKEY),用以替代当前的分区键(L_PARTKEY),后者被注释掉了。
A partitioning key is defined on a table with the CREATE table statement.
分区键是在一个表上用CREATEtable语句定义的。
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。
This example tests the data skew in a scenario in which the partitioning key was changed to S_NATIONKEY.
这个示例测试的是分区键被更改为S_NATIONKEY的场景中的数据倾斜。
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。
Have the corresponding columns of the partitioning key be partition compatible.
分区键的相应列是分区兼容的。
The primary key and any unique index of the table must be a superset of the associated partitioning key.
表的主键和所有惟一索引都必须是相关分区键的超集。
The hashing algorithm is applied to the value of the partitioning key, and generates a partition number between zero and 4095.
散列算法应用于分区键的值,产生 0 到 4095之间的一个分区号。
In addition, the partitioning key must still be based on relational data.
另外,分区键仍然必须基于关系数据。
The columns used in this definition are referred to as the table partitioning key columns.
该定义中使用的列被称为表分区键列。
The cost of applying the partitioning hash algorithm is proportional to the size of the partitioning key.
应用分区散列算法的代价与分区键的规模成比例。
This example tests the data skew in a scenario in which the partitioning key was changed from S_NATIONKEY to S_ID.
这个示例测试的是分区键从 S_NATIONKEY 更改为 S_ID 的场景中的数据倾斜。
An integer partitioning key is more efficient than a character key, which is more efficient than a decimal key.
整型分区键要比字符键高效,而字符键又比小数键高效。
If the partitioning key for a table to be loaded in the database is an integer that has possible values between 1 and 500,000, the partitioning key is hashed to a partition number between 0 and 4 095.
如果数据库中所装载的表的分区键是1到500,000之间的整数,则分区键被散列到0到4 095之间的一个分区号。
The following rules and recommendations apply to the partitioning key definition
如下的规则和建议适用于分区键定义
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