Hi, The setting LOCK_MODE is persistent, as documented: http://h2database.com/html/grammar.html#set_lock_mode - so the setting is stored in the database, and the next time you open it the same mode is used. So you only need to set it to 3 once (not each time).
For import, CREATE TABLE AS SELECT has the same effect than LOG=0. So if you use CREATE TABLE AS SELECT then you don't need to use LOG=0. LOG=0 will only improve performance if you use INSERT INTO .. SELECT. Regards, Thomas On Mon, Feb 11, 2013 at 6:02 PM, Ivan Staskov <[email protected]>wrote: > Hi, > > I create H2DB as a file and import the huge amount of data with Fast > Database Import options: > http://www.h2database.com/html/performance.html#fast_import. > "LOG=0;CACHE_SIZE=65536;LOCK_MODE=0;". > After import of data I open connections with 'MULTI_THREADED=TRUE' option > only for reading data. > It worked in the one of the old version of h2DB ("h2-1.2.145.jar"), I > didn't get any problem. > > Now, I'm using h2-1.3.164.jar. And my attempt to open connection with > 'MULTI_THREADED=TRUE' option leads to Exception: > > Cannot change the setting "LOCK_MODE=0 & MULTI_THREADED" when the > database is already open; SQL statement: > > SET MULTI_THREADED TRUE [90133-164] > > In the documentation for Fast Database Import I see: "Most of those > options are not recommended for regular use, that means you need to reset > them after use." > Additionally I see that the same problems was already discussed here: > https://groups.google.com/forum/?fromgroups=#!topic/h2-database/ZOw4ot12dRE > > My questions are: > - How can I rest the options of Fast Database Import that stored in the > h2db file? > - Should I always set 'MULTI_THREADED=TRUE:LOCK_MODE=3' options (explicit > set the 'default' option for LOCK_MODE)? > It seems that it solve my problems, at least Exception is not thrown. Is > it correct solution? > - Why H2DB doesn't release the options of the old connections, perhaps > exists some configuration to enable this mode? > > Thank you. > Ivan > > -- > 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 http://groups.google.com/group/h2-database?hl=en. > For more options, visit https://groups.google.com/groups/opt_out. > > > -- 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 http://groups.google.com/group/h2-database?hl=en. For more options, visit https://groups.google.com/groups/opt_out.
