Hive - Hadoop: The Definitive Guide - page 583

HiveQL
Hive's SQL dialect, called HiveQL, is a mixture of SQL-92, MySQL, and Oracle's SQL
dialect. The level of SQL-92 support has improved over time, and will likely continue to
get better. HiveQL also provides features from later SQL standards, such as window func-
tions (also known as analytic functions) from SQL:2003. Some of Hive's non-standard ex-
tensions to SQL were inspired by MapReduce, such as multitable inserts (see Multitable in-
sert ) and the TRANSFORM , MAP , and REDUCE clauses (see MapReduce Scripts ).
This chapter does not provide a complete reference to HiveQL; for that, see the Hive docu-
mentation . Instead, we focus on commonly used features and pay particular attention to
features that diverge from either SQL-92 or popular databases such as MySQL. Table 17-2
provides a high-level comparison of SQL and HiveQL.