On Fri, 4 Dec 2015 22:13:58 +0900 Michael Paquier <michael.paqu...@gmail.com> wrote:
> On Fri, Dec 4, 2015 at 9:47 PM, Ildus Kurbangaliev > <i.kurbangal...@postgrespro.ru> wrote: > > Attached patch adds support of partial decompression for datums. > > It will be useful in many cases when extracting part of data is > > enough for big varlena structures. > > > > It is especially useful for expanded datums, because it provides > > storage for partial results. > > > > I have another patch, which removes the 1 Mb limit on tsvector using > > this feature. > > -1 for changing the shape of pglz_decompress directly and particularly > use metadata in it. The current format of those routines is close to > what lz4 offers in terms of compression and decompression of a string, > let's not break that we had a time hard enough in 9.5 cycle to get > something clean. Metadata is not used for current code, only for case with partial decompression. > > By the way, why don't you compress the multiple chunks and store the > related metadata at a higher level? There is no need to put that in > pglz itself. Yes, but this idea with chunks means that you are creating a whole new structure, but it can't be used if you want to optimize current structures. For example you can't just change arrays, but I think there are places where the partial decompression can be used. -- Ildus Kurbangaliev Postgres Professional: http://www.postgrespro.com Russian Postgres Company -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
