Geek Answers Handbook

MySQL / InnoDB and long queries

When executing queries using the myisam mechanism, since it is not transactional, long queries (as I understand it) do not affect data from other queries.

At InnoDB, one of the things that warns about is to avoid long queries. When InnoDB snapshots, does it still get stuck?

I ask about this: say that the request for some reason takes longer than usual and, ultimately, rolls back. Meanwhile, 200 other users have updated or inserted rows in the database. When a long request comes back, does it also remove updates / inserts that were made by other users? or lines in which other users are safe, unless they intersect with the one that rolls back?

+4
source share
2 answers

Are your queries influencing concurrency or not related to query types. Having many read requests will not affect concurrency in MyISAM or InnoDB (besides performance issues).

( InnoDB MyISAM) concurrency.

, , InnoDB, MyISAM - , . ( ), , , , . MyISAM , .

MyISAM , , ( ). , , InnoDB , , , . , InnoDB , , ( ).

ACID, InnoDB, .

( ) , , , . , , , , .

" " - . , , .

InnoDB .

+2

-, , multi-version concurrency control (MVCC) .

InnoDB MVCC, , SELECT. " ", InnoDB . " " " " ( ), . , , , .

, .

, ( , ), ( ), , . , . , , (.).

, " " . , - , .

, , , . " ". InnoDB .

+5

More articles:


All Articles