I found something interesting while profiling our application that I'm hoping someone can explain. I noticed 8.3 MB of memory allocated to int16[] arrays. Digging down further I found that these all originated in NHibernate.Hql.Ast.ANTLR.HqlLexer for static readonly field DFA23_transition. Here is the variable definition

static readonly short[][] DFA23_transition = DFA.UnpackEncodedStringArray(DFA23_transitionS);

When setting a breakpoint on this the arrays first dimension is 346 and the second dimension varies between 0 - 65526

Total memory usage for the array ends up being around 8.3 meg. I then started looking at what causes this class to be used and narrowed it down to a named queries. We only have one named query defined in our hbm.xml files and if I remove that then I do not see this class get used.

Can anyone explain what this is doing and why its using so much memory. Our application is a web application and we have hundreds of instances running. 8.3mb doesn't seem like much but it adds up quick with that many instances.

I'm seeing the same issue with named queries in the mapping files.

Have you figured out a resolution other than removing the named queries?