Hi, The cache will prevent the pages are read twice. H2 reads all columns of the row unless only the columns in the index are read. Except for large CLOB and BLOB, which are not store in the table.
Regards, Thomas Am 12.04.2011 06:43 schrieb "Dario Simone" <[email protected]>: > Hi Thomas, > > Thanks for the reply. > > Does it make sense, that the overflow message only appears the first > time the query is executed? > The table I'm selecting actually has a large varchar column. I had > hoped to escape any performance issues by simply not selecting that > particular column - am I right in the assumption, that this will not > work and h2 still needs to load whole rows (including the overlong > column)? > > Would it be better to simply use a clob instead of the varchar or > should we extract the column to its own table? > > Thanks for your help, > Dario > > On Sat, Apr 9, 2011 at 10:15 AM, Thomas Mueller > <[email protected]> wrote: >> Hi, >> >> Overflow pages are used if a row doesn't fit in a page (for the >> configured page size). Usually there are few overflow pages. If you >> have a lot of them, possibly you should change your table structure or >> use different data types (CLOB / BLOB). >> >> 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. >> >> > > -- > 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. > -- 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.
