Re: types used for JDBC BLOB and CLOB? - Mailing list pgsql-jdbc
From | Marc G. Fournier |
---|---|
Subject | Re: types used for JDBC BLOB and CLOB? |
Date | |
Msg-id | 20040823230510.M4215@ganymede.hub.org Whole thread Raw |
In response to | Re: types used for JDBC BLOB and CLOB? ("David Wall" <d.wall@computer.org>) |
List | pgsql-jdbc |
Perfect, thank you ... re: the lo_ calls ... ya, I figured that, but I needed something to act as a reference for this ;) Thanks ... On Mon, 23 Aug 2004, David Wall wrote: > If you want to use the BLOB JDBC calls, you will use the OID type for the > field in your table schema. > > You do NOT need to use the lo_ routines since they will be called for you if > you use the JDBC BLOB calls. > > David > > ----- Original Message ----- > From: "Marc G. Fournier" <scrappy@postgresql.org> > To: "Barry Lind" <blind@xythos.com> > Cc: "Marc G. Fournier" <scrappy@postgresql.org>; <pgsql-jdbc@postgresql.org> > Sent: Monday, August 23, 2004 3:06 PM > Subject: Re: [JDBC] types used for JDBC BLOB and CLOB? > > >> >> k .. I'm obviously missing something, and having never used BLOBs before, >> I'm not surprised ... >> >> Looking at: >> >> http://www.postgresql.org/docs/7.4/static/lo-implementation.html >> >> It states: >> >> "The large object implementation breaks large objects up into "chunks" and >> stores the chunks in rows in the database." >> >> When I create my schema for this, what type do I assign the field? Or is >> there a special 'table' created when you do the lo_creat to store the >> BLOBs in? (looking at docs, which references the libpq library vs JDBC, >> sorry) >> >> For instance, I notice in: >> >> http://www.postgresql.org/docs/7.4/static/lo-interfaces.html >> >> "Oid lo_creat(PGconn *conn, int mode);" >> >> So, lo_creat returns an OID ... is that what I'd store in a table, and >> when I needed the value, would call lo_open to actually access it as I >> need? >> >> The part that is confusing me is the point about 'chunks' above ... > from >> that, it seems that the data is stored in table within the database ... >> but if so, what type does one define to store it in? how would a >> 'pg_dump' show the schema? >> >> Hopefully this explains a bit better my confusion here :( >> >> >> On Mon, 23 Aug 2004, Barry Lind wrote: >> >>> Marc, >>> >>> The answer is it depends, but if they intend to use the jdbc BLOB/CLOB >>> interface it is server side LargeObjects, not bytea. However you can >>> use bytea, but then you need to use the get/setXXXStream() interfaces. >>> >>> Thanks, >>> --Barry >>> >>> -----Original Message----- >>> From: Marc G. Fournier [mailto:scrappy@postgresql.org] >>> Sent: Monday, August 23, 2004 11:52 AM >>> To: Barry Lind >>> Cc: Marc G. Fournier; pgsql-jdbc@postgresql.org >>> Subject: RE: [JDBC] types used for JDBC BLOB and CLOB? >>> >>> >>> 'k, I believe what the client is wanting to know is what the storage >>> type would be on the backend, that the would BLOB/CLOB map to ... bytea? >>> >>> On Mon, 23 Aug 2004, Barry Lind wrote: >>> >>>> Marc, >>>> >>>> If you are specifically talking about the JDBC types BLOB and CLOB >>>> those classes use the server LargeObject interface. If you are >>>> speaking generically about support for large objects then the jdbc >>>> driver supports the bytea datatype for the get/setBinaryStream() >>>> methods. So the answer is "it depends", on how you use the driver. >>>> The specifics for supporting binary objects are documented in a >>>> section on this topic in the postgresql jdbc driver documentation >>> chapter. >>>> >>>> Thanks, >>>> --Barry >>>> >>>> -----Original Message----- >>>> From: Marc G. Fournier [mailto:scrappy@postgresql.org] >>>> Sent: Monday, August 23, 2004 8:44 AM >>>> To: pgsql-jdbc@postgresql.org >>>> Subject: [JDBC] types used for JDBC BLOB and CLOB? >>>> >>>> >>>> Just been asked this, and I'm not sure of the answer ... based on >>>> reading the docs on bytea, I'm assuming that it is such, but can >>>> someone please confirm? >>>> >>>> Thanks ... >>>> >>>> ---- >>>> Marc G. Fournier Hub.Org Networking Services >>>> (http://www.hub.org) >>>> Email: scrappy@hub.org Yahoo!: yscrappy ICQ: >>>> 7615664 >>>> >>>> ---------------------------(end of >>>> broadcast)--------------------------- >>>> TIP 7: don't forget to increase your free space map settings >>>> >>>> >>> >>> ---- >>> Marc G. Fournier Hub.Org Networking Services >>> (http://www.hub.org) >>> Email: scrappy@hub.org Yahoo!: yscrappy ICQ: >>> 7615664 >>> >>> >> >> ---- >> Marc G. Fournier Hub.Org Networking Services > (http://www.hub.org) >> Email: scrappy@hub.org Yahoo!: yscrappy ICQ: > 7615664 >> >> ---------------------------(end of broadcast)--------------------------- >> TIP 4: Don't 'kill -9' the postmaster > > ---- Marc G. Fournier Hub.Org Networking Services (http://www.hub.org) Email: scrappy@hub.org Yahoo!: yscrappy ICQ: 7615664
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