Re: [HACKERS] Remove 1MB size limit in tsvector

On Tue, 1 Aug 2017 14:56:54 -0400
Robert Haas <robertmhaas@gmail.com> wrote:

> On Tue, Aug 1, 2017 at 10:08 AM, Ildus Kurbangaliev
> <i.kurbangaliev@postgrespro.ru> wrote:
> > Historically tsvector type can't hold more than 1MB data.
> > I want to propose a patch that removes that limit.
> >
> > That limit is created by 'pos' field from WordEntry, which have only
> > 20 bits for storage.
> >
> > In the proposed patch I removed this field and instead of it I keep
> > offsets only at each Nth item in WordEntry's array.  
> 
> So this would break pg_upgrade for tsvector columns?
> 

I added a function that will convert old tsvectors on the fly. It's the
approach used in hstore before.

Regards,
Ildus Kurbangaliev