Thanks for the answers guys,
I ran a quick query lastnight select length(data) from pg_largeobject where loid = xxxx which prompted my post.
The query returned 'n' rows of 2048 bytes and an incomplete "page" of say
236, as I wasn't really thinking about it that much I assumed for some
reason that the data column was limited to a maximum of 2048 bytes by the
database. I was hoping to select this value (2048) from a query
(like \d tablename describes the columns and sizes) to build a buffer
either a) large enough or b) sensibly proportioned.
Although my question may not be relevant to this particular issue there
are times that I would like to now the size of a particular column, and I
believe
that it's possible to get this value from the database using a query and
pg_catalog etc, just not sure how to achieve this.
Thanks again,
Brett
"Brett Maton" <[EMAIL PROTECTED]> wrote in message news:[EMAIL PROTECTED]Hi NG,a
How do I find out the size of a column ?
I am retrieving large objects from the pg_largeobject table and creatingfiles, I would like to know the length of the data column so that I can
implement buffering instead of writing hundreds of small chunks to disk.
Any help would be appreciated.
Thanks in advance,
Bret
The column type for pg_largeobject.data is bytea with no length specified. That means, unfortunately, that there's no way to get the size of the column from the catalog. It does seem that the large object functions do split the data into 2k chunks, but it would probably be a simple thing to check the source to determine if this is always true. But it could always change in a future version.
Adam Ruth
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