Talk:Block nested loop

	This article is within the scope of WikiProject Computing, a collaborative effort to improve the coverage of computers, computing, and information technology on Wikipedia. If you would like to participate, please visit the project page, where you can join the discussion and see a list of open tasks.ComputingWikipedia:WikiProject ComputingTemplate:WikiProject ComputingComputing
???	This article has not yet received a rating on the project's importance scale.

Databases (inactive)

This article is within the scope of WikiProject Databases, a project which is currently considered to be inactive.DatabasesWikipedia:WikiProject DatabasesTemplate:WikiProject DatabasesDatabases

Untitled

This is referenced in the main SQL article.

block hashing is optional?

it's unclear if "block nested loop" always uses block hashing. sources show conflicting evidence

a mariadb article identifies "block nested loop" and "block hash join" as distinct, separate algorithms https://mariadb.com/kb/en/block-based-join-algorithms/

a highly cited research paper "join algorithm costs revisited" specifies blocks are hashed

"We assume that the memory based part of the join is based on hashing" https://citeseerx.ist.psu.edu/document?repid=rep1&type=pdf&doi=733b1e7c0a4d1f12188008e6e6eaa4cb40fd732d

a mysql article on "block nested loop" doesn't mention hashing https://dev.mysql.com/doc/refman/8.4/en/bnl-bka-optimization.html#bnl-optimization

what do you think? is block hashing optional or mandatory in block nested loops? in theory and in practice Asaf Spiegler (talk) 16:09, 3 December 2024 (UTC)[reply]