Hi, > One glaring problem is needing to restart the DB after handling in-doubt > transactions. Once that's fixed we'd be able to proceed further and run more > extensive tests.
I'm sorry about that. I'm afraid I will not have time to implement the required features in the near future. >>> All of them (I believe H2 included) loaded the entire >>> BLOB into memory >> For H2, this is no longer the case (actually since quite a long time). > Excellent! So what are the downsides of storing large files in the > database? Originally, this was about loading the BLOB in memory, but now you wrote about storing the BLOB in the database... H2 does store the BLOB in the database file, which means less files, but the disadvantage is that disk space is not returned to the file system immediately if you delete many BLOBs. > Obviously it's going to be slower than non-transactional files (by > how much?), Theoretically, it doesn't need to be slower. Currently, BLOB performance is about half as fast as it could be in theory (just a guess). > For every byte you'd store, it would use 3x more > disk and memory resources. Is that still the case? No, it never was like this. Why do you think so? >> H2 first stores the large object in the transaction log (WAL), and >> only then in the data area (like all other changes). > What do other databases do? They only store the BLOB once I believe. > While we're on the topic of WAL, can you answer this question? > http://dba.stackexchange.com/questions/8424/when-do-you-remove-entries-from-a-write-ahead-log-wal The first answer is correct for most databases. H2 delays writing the transaction log by default as documented, same as HSQLDB. This is accounted for in the benchmarks. See the H2 documentation. Regards, Thomas -- You received this message because you are subscribed to the Google Groups "H2 Database" group. To post to this group, send email to [email protected]. To unsubscribe from this group, send email to [email protected]. For more options, visit this group at http://groups.google.com/group/h2-database?hl=en.
