A star join query typically involves a fact table and several dimension tables, with join predicates between the fact table and each dimension table.
一个星型连接查询通常包含一个事实表和几个维度表，事实表和每个维度表之间都有连接谓词。
The optimizer considers star join optimization when appropriate and decides on star join plan based on cost considerations in order to come up with best execution plan for a star join query.
为了实现星型连接查询的最佳执行计划，优化器在适当的时候会考虑星型连接优化，并根据成本因素来决定星型连接计划。
All the new star join directives are query level directives that affect the execution of a query.
所有新的星型连接指令都是查询层次的指令，会影响查询的执行。
If star join directives are used in a query, directives override session environment setting.
如果查询中使用星型连接指令，指令会将会话环境设置覆盖。
Regardless of schema (3nf or Star), the Teradata query optimizer relies on statistics to help it determine the best way to access data.
不管哪种模式(3nf或Star)，Teradata查询优化器依赖于统计信息帮助确定最佳数据访问路径。
The optimizer can choose a star join plan only if a query involves tables from a star or snowflake schema that meets the following requirements.
只有查询中包含满足以下要求的星型或雪花模式的表时，优化器才可以选择星型连接计划。
To show how to interpret SET EXPLAIN output for star join plans, we use the same example query as before.
我们使用前面的同一个示例查询来说明如何解释星型连接计划的SETEXPLAIN输出。
Listing 9 shows the same query for the refined star schema.
清单9展示了用于改进的星型模式的同样的查询。
In this project, you would devise a scheme to efficiently evaluate queries over schemas that are "near" star schemas by transforming them to star schemas and using the C-Store query optimizer.
这专题要求改做「近似」星型图为星型图及使用C-Store查询优化器，设计一种有效评价查询的方案。
In this project, you would devise a scheme to efficiently evaluate queries over schemas that are "near" star schemas by transforming them to star schemas and using the C-Store query optimizer.
这专题要求改做「近似」星型图为星型图及使用C-Store查询优化器，设计一种有效评价查询的方案。
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