[MDEV-14516] TokuDB duplicates PK columns in secondary index - Jira

XML

Word

Printable

Given the following table:

CREATE TABLE IF NOT EXISTS obj (

  `partition` SMALLINT UNSIGNED NOT NULL,

  oid BIGINT UNSIGNED NOT NULL,

  tid BIGINT UNSIGNED NOT NULL,

  data_id BIGINT UNSIGNED NULL,

  value_tid BIGINT UNSIGNED NULL,

  PRIMARY KEY (`partition`, oid, tid),

  KEY tid (`partition`, tid, oid),

  KEY (data_id)

) ENGINE=TokuDB;

tokuftdump shows that the 'tid' index duplicates all columns of the primary key whereas they're already in the secondary key. IOW, TokuDB stores:

<partition><tid><oid><partition><oid><tid> => ''

instead of only (like InnoDB):

<partition><tid><oid> => ''

This is quite space inefficient with all the obvious consequences (less efficient caches, more time to compress).

links to

TDB-86

Error rendering 'com.xiplink.jira.git.jira_git_plugin:git-issue-webpanel'. Please contact your Jira administrators.