how does derby.storage.pageCacheSize parameter (https://db.apache.org/derby/ > docs/10.13/ref/rrefproper81359.html) work with database that has multiple > page sizes--tables with default 4096 bytes and tables with long/blob of > 32768 byte pages? > > Hi Peter,
I'm not 100% sure how this works; I think you should run some experiments. Here's what I *think* the behavior is: 1) The page cache is sized in 4K pages, so if you set pageCacheSize=1024, you get 4 meg of page cache memory 2) Tables with 4K pages simply use the cache as you expect. 3) Tables with 32K pages chew up 8 cache "pages" at a time, each 32K chunk of page cache holding 1 32K page from that large-page table. Some stuff I found while searching around, which might give you some ideas for experiments you could run: http://apache-database.10148.n7.nabble.com/out-of-memory-when-writing-blobs-td100948.html and https://issues.apache.org/jira/browse/DERBY-4537 Sorry I'm not of much more help here. bryan
