Hi guys, so I have only 1 table called table1 in the database, but when I transfer the h2.jar file over to another pc (exported as a file along with all the other .jars in the project) and then the table is gone on the new pc.
How do I get it to stay? Thanks, Josh On Sat, Sep 21, 2013 at 9:34 PM, Pablo Beltran <[email protected]> wrote: > Hi, > > schema and table metadata is kept fully in memory > > > I see the problem. For instance, how much memory would require > (approximately) 10.000 schemes x 10 tables = 110.000 object medata? Would > that magnitude order be of Megas or Gigas? Megas might be acceptable. > Gigas, hmm... > > Regards, > Pablo. > > 2013/9/21 Thomas Mueller <[email protected]> > >> Hi, >> >> You are right of course. The problem I see is that you might end up with >> a lot of schemas and a lot of tables, if you try to keep all data in one >> database. For H2, schema and table metadata is kept fully in memory, I'm >> not sure about other database engines. And at some point you might want to >> keep some data that applies to all users. >> >> Regards, >> Thomas >> >> >> On Sat, Sep 21, 2013 at 9:19 AM, Pablo Beltran <[email protected]>wrote: >> >>> Hi Thomas, >>> >>> You are right, many schemas implies many tables. >>> >>> What I like of the may schemas approach (one per user) is that I can >>> partition the data very neatly and resolve the data isolation simply with >>> the connection: >>> >>> public Connection getConnection(String userId){ >>> Connection conn = pool.getConnection(); >>> * conn.createStatement().execute("set schema USER_"+userId);* >>> return conn; >>> } >>> >>> The code above ensures that the user views only his tables (and data) by >>> default. >>> >>> I'm not expert and you know much better the database internals, how it >>> scales and how to prevent future problems... I'll change my current model >>> (many schemas) to a single schema. >>> >>> Regards, >>> Pablo >>> >>> 2013/9/21 Thomas Mueller <[email protected]> >>> >>>> Hi >>>> >>>> You could do both, but I would use one schema. (the title of the mail >>>> is incorrect: many schemas is many tables, which is what I would avoid). >>>> >>>> Regards, Thomas >>>> Am 12.09.2013 17:54 schrieb "Pablo Beltran" <[email protected]>: >>>> >>>>> Hi, >>>>> >>>>> I need to store lot of data (even millions of records) on an small >>>>> bunch of tables for many users (thousands). What would be would be the >>>>> best >>>>> approach? >>>>> >>>>> 1. Create one schema per user, so each user would have its own private >>>>> table: select * from USER_N.TABLE_X >>>>> >>>>> 2. Create one table shared by all the users and add a new column to >>>>> identify the data by user: select * from PUBLIC.TABLE_X where user=N; >>>>> >>>>> Thanks! >>>>> Pablo. >>>>> >>>>> -- >>>>> 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. >>>>> For more options, visit https://groups.google.com/groups/opt_out. >>>>> >>>> -- >>>> You received this message because you are subscribed to a topic in the >>>> Google Groups "H2 Database" group. >>>> To unsubscribe from this topic, visit >>>> https://groups.google.com/d/topic/h2-database/jp_fVH9XqXU/unsubscribe. >>>> To unsubscribe from this group and all its topics, 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. >>>> 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. >>> For more options, visit https://groups.google.com/groups/opt_out. >>> >> >> -- >> You received this message because you are subscribed to a topic in the >> Google Groups "H2 Database" group. >> To unsubscribe from this topic, visit >> https://groups.google.com/d/topic/h2-database/jp_fVH9XqXU/unsubscribe. >> To unsubscribe from this group and all its topics, 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. >> 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. > 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. For more options, visit https://groups.google.com/groups/opt_out.
