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Thread: Large Objects in table

Large Objects in table

From
"Roland Giesler"
Date:
How does one create a BLOB in postgres?  V. 8.0.3

I have read about cio's and lo in previous versions, but cannot find detail
about how to do it in pg8.

I would like to store different report layouts in a column of a tables
called 'reports', but somehow the datatype elludes me.

Any pointer and help would be appreciated.

Thanks

Roland Giesler

Re: Large Objects in table

From
Rainer Bauer
Date:
"Roland Giesler" wrote:

>How does one create a BLOB in postgres?  V. 8.0.3
>
>I have read about cio's and lo in previous versions, but cannot find detail
>about how to do it in pg8.
>
>I would like to store different report layouts in a column of a tables
>called 'reports', but somehow the datatype elludes me.

How big are there reports?

If they are not too big, why don't you just use "bytea"?
See chapter "8.4. Binary Data Types"

Rainer

PS: I was struggling along the same lines, because when starting with postgres
the documentation seems to suggest to use the lo type for BLOB's (Chapter 28.
Large Objects). But I really could not find any reason to use them if the
objects are small (up to 200 KB).

Can any experienced Postgres user perhaps shed a light on this?

Re: Large Objects in table

From
"Roland Giesler"
Date:
Rainer Bauer wrote:
> How big are there reports?
Relatively small, I'd say about 100K, 500K maybe at the most.

> If they are not too big, why don't you just use "bytea"?
> See chapter "8.4. Binary Data Types"
I'm using Druid to design and maintain my database and pg complains when I
try to use bytea (Druid generates a script)?  I've read about TEXT type also
now.  It seems that (by using TOAST technology) TEXT type colums can contain
up to 1GB of data, but I'm not so sure of how that works, especially if the
report is some or other object (possibly a Java file, or at least non-text
(binary) type data)

> PS: I was struggling along the same lines, because when
> starting with postgres the documentation seems to suggest to
> use the lo type for BLOB's (Chapter 28.
> Large Objects). But I really could not find any reason to use
> them if the objects are small (up to 200 KB).
Yes, I find the documentation unclear on this.  Even the FAQ on "Large
Objects" is too brief to be of real value, imho.

> Can any experienced Postgres user perhaps shed a light on this?
Would be great, yes.

Roland

Re: Large Objects in table

From
Rainer Bauer
Date:
"Roland Giesler" wrote:

>I'm using Druid to design and maintain my database and pg complains when I
>try to use bytea (Druid generates a script)?

In that case I would definitely try to fix the problem Druid (or maybe the
JDBC driver) has with bytea.

Rainer

Re: Large Objects in table

From
"Roland Giesler"
Date:
Rainer Bauer wrote:
>> I'm using Druid to design and maintain my database and pg complains
>> when I try to use bytea (Druid generates a script)?
>
> In that case I would definitely try to fix the problem Druid
> (or maybe the JDBC driver) has with bytea.

It was pg that had the problem, but I'll look into it again and report back.
(Druid simply creates a sql script and then runs it on pg)

Roland