[xwiki-users] Performance tuning for growing wiki

Hi guys, Thanks again for great collaborative tool! We currently have about 1200 pages inside, many with objects, where several people search/read/edit info every day. And we are experiencing performance problems - at least once a day, sometimes more often wiki becomes unresponsive for 3-10 minutes while having high CPU load (my guess is either page file swapping or garbage collection by JVM), Out Of Memory errors becoming more often (sometimes wiki is stable for 1-2 weeks, sometimes fails several times a day). Additionally we've got repeating problems even with quite small attachments 500Kb-2Mb (I am aware of x27 DB storage trouble) According to recommendation in guides and some talks on the Internet I tend to try database tuning or change. Could you please recommend a good candidate among freely available databases or even give a hints on HSQLDB tuning (maybe changing default memory mode to cached)? I've taken a look at H2 vs. HSQLDB comparison but there are quite controversial opinions... Current servlet container configuration is -Xms700m -Xmx700m, no tuning for database, computer is a virtual machine on a farm with 2 GHz CPU and 1 Gb RAM. BTW, is this in general expected behavior for such configuration? Many thanks, Andrey