BLOBs
I know that BLOBs are on the TODO list, but I had an idea.
I think the storage of a BLOB outside of the table is an elegant
solution and keeps table sizes down without the bloat of the stored
object. Granted, if you are searching with a regular expression or
using like or ilike clauses, you're likely to be a little slower but it
shouldn't be by much. More than likely, you won't be searching for
patterns in the BLOB but rather the fields in the table associated with
the BLOB.
Wouldn't it be wonderful if you used the methods you had already
implemented and instead create a behavoir similar to the following.
on an insert
take the data that was to be the blob...
create your externally "to be referenced" file
save the data to the file
store the reference to that file
on an update
take the data that was to be the blob...
create your externally "to be referenced" file
save the data to the file
store the reference to that file
delete the old referenced file
on a delete
delete the reference to your file
delete the external file
I was thinking that the BLOB column type might be a trigger for a macro
that could handle the lo_import, lo_export juggling...
I know it seems overly simplified, but having fought with MySQL and then
trying to wrestle with postgresql and importing,exporting BLOBs, it
seemed there might be a little more room for discussion, although I
doubt this may have added anything to it...
I'd love to see something done with BLOB support during 7.2.x *hint* :)
Besides, if someone could give me some pointers as to where I might be
able to start, I might try to contribute something myself.
Thomas
Thomas Swan <tswan@olemiss.edu> writes:
I know that BLOBs are on the TODO list, but I had an idea.
I think you just rediscovered TOAST.
regards, tom lane
Thomas Swan <tswan@olemiss.edu> writes:
I know that BLOBs are on the TODO list, but I had an idea.
I think you just rediscovered TOAST.
We have TOAST and people want to keep large objects for performance. I
think we could us an API that allows TOAST binary access and large
object access using the same API, and hopefully an improved one.
--
Bruce Momjian | http://candle.pha.pa.us
pgman@candle.pha.pa.us | (610) 853-3000
+ If your life is a hard drive, | 830 Blythe Avenue
+ Christ can be your backup. | Drexel Hill, Pennsylvania 19026Bruce Momjian wrote:
Thomas Swan <tswan@olemiss.edu> writes:
I know that BLOBs are on the TODO list, but I had an idea.
I think you just rediscovered TOAST.
We have TOAST and people want to keep large objects for performance. I
think we could us an API that allows TOAST binary access and large
object access using the same API, and hopefully an improved one.
I think I missed what I was trying to say in my original statement. I
think there's a way to use the existing API with performance benefits
left intact.
Take for example the table :
create table foo {
foo_id serial,
foo_name varchar(32),
foo_object BLOB,
);
On the insert statement "insert into foo (foo_name,foo_object) values
('My Object','{some escaped arbitrary string of binary data}');", flush
the {some escaped arbitrary string of binary data} to disk as a
temporary file. Then do the lo_import operation transparent to the user.
On a select, do the same thing (transparently) and return the data back
to user.
Personally, I like LO's being stored separately from the actual table.
Thomas Swan <tswan@olemiss.edu> writes:
I think I missed what I was trying to say in my original statement. I
think there's a way to use the existing API with performance benefits
left intact.
Take for example the table :
create table foo {
foo_id serial,
foo_name varchar(32),
foo_object BLOB,
);
On the insert statement "insert into foo (foo_name,foo_object) values
('My Object','{some escaped arbitrary string of binary data}');", flush
the {some escaped arbitrary string of binary data} to disk as a
temporary file. Then do the lo_import operation transparent to the user.
On a select, do the same thing (transparently) and return the data back
to user.
Personally, I like LO's being stored separately from the actual table.
I still think you've rediscovered TOAST. How is this better than (or
even significantly different from) foo_object being a toastable bytea
column?
regards, tom lane