例如:select a from table order by 1 和 select a from table group by 1 ResolveHints.DisableHints Disable Hints Once 当配置项spark.sql.optimizer.disableHints被设置时删除spark时的所有hints。这将在Analyzer的最开始执行,以禁用hints功能。 ResolveHints.ResolveJoinStrategyHints Hints fixedPoint 允许的join...
SQL> SELECT OWNER, TABLE_NAME FROM DBA_LOGSTDBY_NOT_UNIQUE WHERE (OWNER, TABLE_N AME) NOT IN (SELECT DISTINCT OWNER, TABLE_NAME FROM DBA_LOGSTDBY_UNSUPPORTED) AND BAD_COLUMN = 'Y'; OWNER TABLE_NAME --- --- TSMSY SRS$ 提示: 关于DBA_LOGSTDBY_NOT_UNIQUE, 该视图显示所有既没主键也没唯...
用连接表达式中的相应值替换可以静态计算的属性,例如:SELECT * FROM table WHERE i = 5 AND j = i + 3 ==> SELECT * FROM table WHERE i = 5 AND j = 8 使用的方法:通过查看所有相等的谓词来填充属性 => 常量值的映射;使用这个映射,将属性的出现的地方替换为AND节点中相应的常量值。 【常量折叠和...
Logical read indicates total number of data pages needed to be accessed from data cache to process query. It is very possible that logical read will access same data pages many times, so count of logical read value may be higher than actual number of pages in a table. Usually the best wa...
CREATE TABLE yangjie=# create publication pub1 for table users; CREATE PUBLICATION 创建发布者pub1,并添加表users. 另一种用法是添加数据库中所有用户表到发布者alltables: create publication alltables for all tables; 创建订阅者: yangjie=# create subscription sub1 connection ‘host=192.168.102.30 port=...
Table 12.5 Logical Operators NameDescription AND, && Logical AND NOT, ! Negates value OR, || Logical OR XOR Logical XOR In SQL, all logical operators evaluate to TRUE, FALSE, or NULL (UNKNOWN). In MySQL, these are implemented as 1 (TRUE), 0 (FALSE), and NULL. Most of this is ...
Applies to: SQL Server This topic describes how to define a logical record relationship between merge table articles in SQL Server by using SQL Server Management Studio, Transact-SQL, or Replication Management Objects (RMO). Merge replication allows you to define a relationship between related rows...
It is a table in the sense that the results are in the form of rows and columns. The SELECT statement is the basis for querying any structured query language (SQL) database. The Oracle BI Server accepts logical requests to query objects in a repository, and users (or query tools) make...
Specifying the logical table joins is required so that the Analytics Server can have the necessary metadata to translate a logical request against the business model to SQL queries against the physical data sources. The logical join information provides the Analytics Server with the many-to-one rela...
Build Hash Indicates the build of a batch hash table for a memory optimized columnstore index.Applies to: SQL Server 2012 (11.x) only. Clustered Index Delete The Clustered Index Delete operator deletes rows from the clustered index specified in the Object property, listed in the Properties pane...