Hi, The PageStore is a classical storage system with redo and undo log, and overwrites old data (in a save way). The MVStore doesn't overwrite data immediately, but wait doing that for at least 1 minute. In theory, the PageStore needs less (measurable) disk space, but in practise, with solid state disks, the internal disk space usage is not actually all that different.
But I understand the MVStore disk space usage still needs to be improved, that's also a reason why the 1.4 branch is not marked as stable. However it was improved since version 1.4.185 until now. So I suggest to use the latest version of H2 and try again. Also with "shutdown defrag". Regards, Thomas On Wednesday, July 20, 2016, ck <[email protected]> wrote: > Also, > do you have some performance comparison between MVSTORE and old structure? > > I admin that > 1) MVStore is actually a future-proof way to store data and it is simply > exciting to write to database using Maps (which I blindly LOVE) and > without JDBC o SQL drivers > 2) The database read/write timings are efficient and fast (But I can't say > if it actually faster than before, as it was anyway always performant) > > The db is anyway in production and quite new, and it simply can't be 10x > or more bigger than normal. in 1 year it will be several gigs going this > way and this is simply not possible because it will cause problems in the > long run and 'sometimes' indefinitely in the future > > I think I will immediately jump to the MVS train when it is most stable > and secure, so please when it will, you should state it in big words in h2 > website as many could be interested > > Thank you > > > Il giorno martedì 19 luglio 2016 05:36:05 UTC+2, ck ha scritto: >> >> This is my first post on this group, >> Hello to everyone! :) >> >> I have a problem with my H2 DATABASE. >> I am seriously worried by the size it is getting, it is now about 350mb >> (Yeah I know it's not the largest one), but my worries go all to the future >> and how it will scale in the long run. >> >> Issues: >> - Trying to Export data as CSV using DataGrip (or any other Database >> Explorer) I get less than 50mb of real 'data' >> - Database seems filled with tons of 'unknown' data - I know the database >> stores indexes and such, but I tried DROPPING ALL OBJECTS, or DELETING >> TABLES , DELETING INFORMATION_SCHEMA just for test purpose and after all >> was cleaned it was around 250mb anyway. >> - After cleaning the whole DB which is now totally empty but still >> weights 250mb, the size changes after connect/disconnect, lowering abour >> 4mb each time >> - Deleting tables o creating tables and adding 1000 rows does not change >> file size (?) - and many times dropping tables/rows does not lower the DB >> Size (why?) >> - After cleaning the whole DB which is now totally empty, still weights >> 250mb, what is happening? >> >> >> Details: >> - I have INCREMENTAL IDS (with some jumping sequences, eg. from 10->40) >> - I store BLOBs >> - I store VARCHARs, many fixed to 125 chars, some with 250/500 or 2000 in >> a unique case >> - I use a JVM Web App that starts connection at program start and closes >> it at program closing (I used this approach because I thought it could be >> very slow and could waste tons of resources to 'reopen, commit, close' >> connection every single time, considering multiple people send multiple >> requests simultaneously. I am free too critics and I totally encourage >> opinions/advices about this. >> - Every query is immediately turned to a Map of results and the ResultSet >> is closed as soon as possible >> >> >> What is happening? I am mostly concerned about the fact it may get such a >> large db in production to cause slowdowns or crashes of the machine >> >> Might my question have some mistakes, feel free to correct me and >> apologize for my first post >> > -- > You received this message because you are subscribed to the Google Groups > "H2 Database" group. > To unsubscribe from this group and stop receiving emails from it, send an > email to [email protected] > <javascript:_e(%7B%7D,'cvml','h2-database%[email protected]');> > . > To post to this group, send email to [email protected] > <javascript:_e(%7B%7D,'cvml','[email protected]');>. > Visit this group at https://groups.google.com/group/h2-database. > For more options, visit https://groups.google.com/d/optout. > -- You received this message because you are subscribed to the Google Groups "H2 Database" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. To post to this group, send email to [email protected]. Visit this group at https://groups.google.com/group/h2-database. For more options, visit https://groups.google.com/d/optout.
