Nice, thanks! On Thursday, April 18, 2013 11:04:38 PM UTC-7, Noel Grandin wrote: > > My mistake, what you want is > CREATE AGGREGATE > See > http://h2database.com/html/grammar.html#create_aggregate > http://h2database.com/javadoc/org/h2/api/AggregateFunction.html > http://h2database.com/html/features.html#user_defined_functions > > On Thu, Apr 18, 2013 at 11:13 PM, Brian Craft > <[email protected]<javascript:>> > wrote: > > :) I have largish numerical data, like tens or hundreds of gigabytes. > The > > meta-data goes into relational tables, the raw data into varbinary > chunks. > > We could also use a document store for this, but I'm experimenting with > > using varbinary. Using group_concat allows queries that return the > meta-data > > and the data together. If I don't do a group_concat then I have to issue > two > > queries and manage joining the second query with the first in > application > > code. > > > > If you have objections or suggestions, I'm very much interested. > > > > As a quick work-around, it appears I can cast it back to binary, like > > cast(group_concat(x separator '') as binary). Not the best for > performance, > > most likely, though we're usually IO bound anyway. > > > > Alternatively I could try arrays of floats, but the group_concat > behavior is > > worse there: it is converted to ascii. > > > > Are there docs for CREATE ALIAS? I see some references in the text > search > > docs. It looks like it just sets up a binding to a java function. So > would I > > start by copying the group_concat function from the java source and > using > > CREATE ALIAS to set up a binding? > > > > > > On Thursday, April 18, 2013 1:46:10 PM UTC-7, Noel Grandin wrote: > >> > >> Why would you want to do that? The whole point of binary columns is > that > >> they are opaque to the database and should not be manipulated by the > >> database. > >> > >> But if you really want to you can always define your own function to do > >> so. See the > >> CREATE ALIAS > >> command. > >> > >> > >> On Thursday, 18 April 2013, Brian Craft wrote: > >>> > >>> It appears group_concat() converts binary columns to hex strings. Is > that > >>> correct? Is there any way to concat binary columns without them being > >>> converted to hex? Would I have any more luck with arrays? Will > group_concat > >>> even work with array columns? > >>> > >>> -- > >>> 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:>. > >>> To post to this group, send email to > >>> [email protected]<javascript:>. > > >>> 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] <javascript:>. > > To post to this group, send email to > > [email protected]<javascript:>. > > > Visit this group at http://groups.google.com/group/h2-database?hl=en. > > For more options, visit https://groups.google.com/groups/opt_out. > > > > >
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