Re: BLOB support

2011/6/2 Peter Eisentraut <peter_e@gmx.net>:
> On ons, 2011-06-01 at 22:00 +0200, Radosław Smogura wrote:
>> I partialy implemented following missing LOBs types. Requirement for this was
>> to give ability to create (B/C)LOB columns and add casting functionality e.g.
>> SET my_clob = 'My long text'.
>>
>> Idea is as follow:
>> 0. Blob is two state object: 1st in memory contains just bytea, serialized
>> contains Oid of large object.
>> 1. Each type has additional boolean haslobs, which is set recursivly.
>> 2. Relation has same bool haslobs (used to speed up tables without LOBs)
>> 3. When data are inserted/updated then "special" function is called and tuple
>> is modified in this way all LOBs are serialized to (old) LOB table and just
>> Oid is stored.
>> 4. When removed LOB is removed from (old) LOB table.
>
> Superficially, this looks like a reimplementation of TOAST.  What
> functionality exactly do you envision that the BLOB and CLOB types would
> need to have that would warrant treating them different from, say, bytea
> and text?
>

a streaming for bytea could be nice. A very large bytea are limited by
query size - processing long query needs too RAM,

Pavel

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