JDBC compatible Main Memory Standalone database

I need a high performance main memory database for my Java Application

1] Please suggest the database which is

-JDBC compliant

-Standalone(i.e. Flat-File)

-supporting memory tables

-High performance

-B-TREE indexing

2] Is there any technique in JAVA to load the database in MEMORY while the program is running and store it back to 开发者_StackOverflowdisk (in compressed format) when program exists.

Please DO NOT suggest SQLITE since performance is the issue.

If you are suggesting HSQLDB or H2 with in-memory mode then tell me the way to store the database in a file and free the HEAP with the actionEvent.

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If you're looking for in-memory then JavaDb will likely be of use. However, you also refer to flat files, and I'm a little confused by this. Perhaps you want something like CsvJdbc, which puts a JDBC interface over a .csv implementation.