Combined row and columnar storage for in-memory databases for OLTP and analytics workloads

Columns of a table are stored in either row-major format or column-major format in an in-memory DBMS. For a given table, one set of columns is stored in column-major format; another set of columns for a table are stored in row-major format. This way of storing columns of a table is referred to herein as dual-major format. In addition, a row in a dual-major table is updated 'in-place', that is, updates are made directly to column-major columns without creating an interim row-major form of the column-major columns of the row. Users may submit database definition language ('DDL') commands that declare the row-major columns and column-major columns of a table. 表的列按行为主的格式或列为主的格式存储在内存DBMS中。对于给定的表，组列按列为主的格式存储；表的另组列按行为主的格式存储。存储表的列的这种方式在本文中被称为双主格式。此外，双主表中的行被"就地"更新，即，更新是直接对列为主的列进行的，而无需创建该行的列为主的列的临时行为主形式。用户可以提交声明表的行为主的列和列为主的列的数据库定义语言("DDL")命令。