Does HSQLDB store all data in memory. Doesn memory run out as a result?
It stores all data in memory only if you want to. By default, CREATE TABLE results in a memory table, as this is the best type for smaller tables. For larger tables, use CREATE CACHED TABLE and adjust the cache size to suite your memory use requirements (as little as 8MB or so). See the System Management and Deployment Issues section of the Guide. There is no simple rule and no imposition on the part of HSQLDB as maximum flexibility is allowed using only a couple of settings. A popular use of HSQLDB is for OLAP, ETL, and data mining applications where huge Java memory allocations are used to hold millions of rows of data in memory.
