STORED AS ORC

"STORED AS ORC" is a clause used in HiveQL (Hive Query Language) to specify that data should be stored in the ORC (Optimized Row Columnar) file format. ORC is a high-performance file format designed for storing large amounts of structured data. It is optimized for querying and analytics and supports advanced compression techniques to minimize storage requirements. When data is stored as ORC, it can be queried faster and with greater efficiency than other file formats.

相关问题

stored as orc是什么意思

"stored as orc" 表示数据以 ORC 格式存储。ORC（Optimized Row Columnar）是一种优化的列存储文件格式，被广泛应用于大数据处理和分析领域。与传统的行存储相比，ORC 文件格式具有更高的压缩率和读取效率，能够提供更好的查询性能和存储利用率。因此，将数据存储为 ORC 格式可以提高数据处理的效率和性能。

以下建表语句正确的有（ ） 2分 CREATE TABLE table_b AS SELECT * FROM table_a; CREATE TABLE table_b STORED as ORC_TRANSACTION AS SELECT * FROM table_a; CREATE TABLE table_b STORED as TEXTFILE AS SELECT * FROM table_a; CREATE TABLE table_b STORED as HOLODESK AS SELECT * FROM table_a;

以下表语句中正确的是：

- CREATE TABLE table_b SELECT * FROM table_a;
该语句用创建一个名为table_b的表，将表table_a中的所有数据复制到新表中。

- CREATE table_b STORED as ORC_TRANSACTION AS * FROM table_a;
该语是错误的。ORC_TRANSACTION不是有效的存储格式。

- CREATE TABLE table_b STORED as TEXTFILE AS SELECT * FROM table_a;
该语句是正确的。它创建了一个名为table_b的表，并且将表table_a中的数据以TEXTFILE格式存储到新表中。

- CREATE TABLE table_b STORED as HOLODESK AS SELECT * FROM table_a;
该语句是错误的。HOLODESK不是一个有效的存储格式。

所以，正确的建表语句有两个：
1. CREATE TABLE table_b AS SELECT * FROM table_a;
2. CREATE TABLE table_b STORED as TEXTFILE AS SELECT * FROM table_a;