On Monday, July 01, 2013 1:36 PM Heikki Linnakangas wrote:
> On 26.06.2013 16:37, Amit Kapila wrote:
> > On Wednesday, June 26, 2013 2:15 AM Heikki Linnakangas wrote:
> >> Can you also try the attached patch, please? It's the same as
> before,
> >> but in this version, I didn't replace the prev and
On Mon, Jul 1, 2013 at 11:05:37AM +0300, Heikki Linnakangas wrote:
> On 26.06.2013 16:37, Amit Kapila wrote:
> >On Wednesday, June 26, 2013 2:15 AM Heikki Linnakangas wrote:
> >>Can you also try the attached patch, please? It's the same as before,
> >>but in this version, I didn't replace the prev
On 26.06.2013 16:37, Amit Kapila wrote:
On Wednesday, June 26, 2013 2:15 AM Heikki Linnakangas wrote:
Can you also try the attached patch, please? It's the same as before,
but in this version, I didn't replace the prev and next pointers in
PGLZ_HistEntry struct with int16s. That avoids some tabl
On Wednesday, June 26, 2013 2:15 AM Heikki Linnakangas wrote:
> On 19.06.2013 14:01, Amit Kapila wrote:
> > Observations
> > --
> > 1. For small data perforamce is always good with patch.
> > 2. For random small/large data performace is good.
> > 3. For medium and large text and same by
On 19.06.2013 14:01, Amit Kapila wrote:
Observations
--
1. For small data perforamce is always good with patch.
2. For random small/large data performace is good.
3. For medium and large text and same byte data(3K,5K text, 10K,100K,500K
same byte), performance is degraded.
Wow, that
On Tuesday, March 05, 2013 7:03 PM Heikki Linnakangas wrote:
> I spent some more time on this, and came up with the attached patch. It
> includes the changes I posted earlier, to use indexes instead of
> pointers in the hash table. In addition, it makes the hash table size
> variable, depending on
On Wed, Mar 6, 2013 at 6:32 AM, Joachim Wieland wrote:
> On Tue, Mar 5, 2013 at 8:32 AM, Heikki Linnakangas
> wrote:
>> With these tweaks, I was able to make pglz-based delta encoding perform
>> roughly as well as Amit's patch.
>
> Out of curiosity, do we know how pglz compares with other algorit
On 2013-03-06 11:31:06 -0600, Merlin Moncure wrote:
> On Wed, Mar 6, 2013 at 10:53 AM, Andres Freund wrote:
> > On 2013-03-06 09:36:19 -0600, Merlin Moncure wrote:
> >> On Wed, Mar 6, 2013 at 8:32 AM, Joachim Wieland wrote:
> >> > On Tue, Mar 5, 2013 at 8:32 AM, Heikki Linnakangas
> >> > wrote:
On Wed, Mar 6, 2013 at 10:53 AM, Andres Freund wrote:
> On 2013-03-06 09:36:19 -0600, Merlin Moncure wrote:
>> On Wed, Mar 6, 2013 at 8:32 AM, Joachim Wieland wrote:
>> > On Tue, Mar 5, 2013 at 8:32 AM, Heikki Linnakangas
>> > wrote:
>> >> With these tweaks, I was able to make pglz-based delta e
On 2013-03-06 09:08:10 -0800, Jeff Janes wrote:
> On Wed, Mar 6, 2013 at 8:53 AM, Andres Freund wrote:
>
> > On 2013-03-06 09:36:19 -0600, Merlin Moncure wrote:
> > > On Wed, Mar 6, 2013 at 8:32 AM, Joachim Wieland wrote:
> > > > On Tue, Mar 5, 2013 at 8:32 AM, Heikki Linnakangas
> > > > wrote:
On Wed, Mar 6, 2013 at 8:53 AM, Andres Freund wrote:
> On 2013-03-06 09:36:19 -0600, Merlin Moncure wrote:
> > On Wed, Mar 6, 2013 at 8:32 AM, Joachim Wieland wrote:
> > > On Tue, Mar 5, 2013 at 8:32 AM, Heikki Linnakangas
> > > wrote:
> > >> With these tweaks, I was able to make pglz-based delt
On 2013-03-06 09:36:19 -0600, Merlin Moncure wrote:
> On Wed, Mar 6, 2013 at 8:32 AM, Joachim Wieland wrote:
> > On Tue, Mar 5, 2013 at 8:32 AM, Heikki Linnakangas
> > wrote:
> >> With these tweaks, I was able to make pglz-based delta encoding perform
> >> roughly as well as Amit's patch.
> >
> >
On Wed, Mar 6, 2013 at 8:32 AM, Joachim Wieland wrote:
> On Tue, Mar 5, 2013 at 8:32 AM, Heikki Linnakangas
> wrote:
>> With these tweaks, I was able to make pglz-based delta encoding perform
>> roughly as well as Amit's patch.
>
> Out of curiosity, do we know how pglz compares with other algorit
On Tue, Mar 5, 2013 at 8:32 AM, Heikki Linnakangas
wrote:
> With these tweaks, I was able to make pglz-based delta encoding perform
> roughly as well as Amit's patch.
Out of curiosity, do we know how pglz compares with other algorithms, e.g. lz4 ?
--
Sent via pgsql-hackers mailing list (pgsql-
I spent some more time on this, and came up with the attached patch. It
includes the changes I posted earlier, to use indexes instead of
pointers in the hash table. In addition, it makes the hash table size
variable, depending on the length of the input. This further reduces the
startup cost on
* Alvaro Herrera (alvhe...@2ndquadrant.com) wrote:
> Surely we're not past feature freeze. If we were, we'd have to reject
> all remaining patches from the commitfest, which is not what we want to
> do at this stage, is it?
Actually, I think we're getting very close to exactly that point- we're
n
On 01.03.2013 17:37, Alvaro Herrera wrote:
Heikki Linnakangas wrote:
In summary, this seems like a pretty clear win for short values, and
a wash for long values. Not surprising, as this greatly lowers the
startup cost of pglz_compress(). We're past feature freeze, but how
would people feel abou
Heikki Linnakangas wrote:
> I spotted this while looking at Amit's WAL update delta encoding
> patch. My earlier suggestion to just use the pglz compressor for the
> delta encoding didn't work too well because the pglz compressor was
> too expensive, especially for small values. This patch might h
I spotted some low-hanging fruit in the pglz compression routine. It
uses a hash table to keep track of string prefixes it has seen:
#define PGLZ_HISTORY_LISTS 8192/* must be power of 2 */
#define PGLZ_HISTORY_SIZE 4096
/* --
* Statically allocated work a
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