LINEAR HASH Partitioning Type

Explore LINEAR HASH partitioning, a variation of HASH that uses a powers-of-two algorithm for faster partition management at the cost of distribution.

Syntax

PARTITION BY LINEAR HASH (partitioning_expression)
[PARTITIONS(number_of_partitions)]

Description

LINEAR HASH partitioning is a form of partitioning, similar to HASH partitioning, in which the server takes care of the partition in which to place the data, ensuring a relatively even distribution among the partitions.

LINEAR HASH partitioning makes use of a powers-of-two algorithm, while HASH partitioning uses the modulus of the hashing function's value. Adding, dropping, merging and splitting partitions is much faster than with the HASH partitioning type, however, data is less likely to be evenly distributed over the partitions.

Example

CREATE OR REPLACE TABLE t1 (c1 INT, c2 DATETIME) 
  PARTITION BY LINEAR HASH(TO_DAYS(c2)) 
  PARTITIONS 5;

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