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 [email protected]. To post to this group, send email to [email protected]. Visit this group at http://groups.google.com/group/h2-database. For more options, visit https://groups.google.com/d/optout.
