My understanding is that H2 is single-threaded, unless you use MULTI_THREADED or possibly MVCC. The second query needs to wait until the first completes.
This is explained in the docs here: http://www.h2database.com/html/features.html#multiple_connections On Saturday, 28 November 2015 06:44:50 UTC+1, Pierre N wrote: > > I have a long running query "delete from mytable" which last ~30 seconds > (deleting ~400 000 records). > > While this query is running, the database is totally locked, I can't > execute another query. > > Well I can execute the query, but it will be executed only after the > "delete" query is done. Even if it is a simple query like "select 1" or > "select 1 from dual" > > However if I start a long running query like "select > hash('sha256','aaaa',20000000);" I can execute in parallel "select 1" and > it will return immediatly. > > Why the "delete" statement is locking everything ? > -- You received this message because you are subscribed to the Google Groups "H2 Database" group. To unsubscribe from this group and stop receiving emails from it, send an email to h2-database+unsubscr...@googlegroups.com. To post to this group, send email to h2-database@googlegroups.com. Visit this group at http://groups.google.com/group/h2-database. For more options, visit https://groups.google.com/d/optout.
