In that case you might want to consider a more full-featured database like PostgreSQL which is designed for uptime and multi-user availability. H2 is an embedded database, it's not really in the same design space.
kensystem wrote: > Hi Thomas, > > Yes both those reasons: the database (table) is large, and so users > have little perceived delay for their queries to run. > > Why does the database always need to be available (why is there a > desire to avoid maintenance windows)? Because it is a web based > application and users are accustomed to little or no downtime (DDL is > fast in pg and my). > > For example if one has a table storing GIS coordinates (millions of > records) and wants to add a column to store 'elevation' (in advance of > deploying code that would use that new column). 'waiting until the > column is added' can be many minutes for tables of multiple gigabytes, > and this blocking might consume all connection-pool cons (or server- > threads/connector as the case may be), causing outages for apps that > use the same database connection even if they aren't querying the > being-altered table.. one then needs to add code to the webapp that > rejects query to whatever table is being altered... this hasn't been > necessary with pg or my. > > If h2 can run DDL operations fast it will be one less thing for > everyone to worry about/explain. > > Best regards, > ken > > On Jun 23, 11:58 am, Thomas Mueller <[email protected]> > wrote: >> Hi, >> >> You have more or less described the feature, but I would like to >> understand *why* you need the feature. Why can't you just wait until >> column is added? Because you have a large database, or because the >> database needs to be always usable (if so, why),... Is there no >> "maintenance window", and if so, why not? >> >> Regards, >> Thomas -- You received this message because you are subscribed to the Google Groups "H2 Database" group. To post to this group, send email to [email protected]. To unsubscribe from this group, send email to [email protected]. For more options, visit this group at http://groups.google.com/group/h2-database?hl=en.
