From: Patrick Steinhardt <ps@pks.im>
Date: Wed, 22 May 2024 07:19:38 GMT
Subject: Re: [PATCH v3 08/11] refs/reftable: allow configuring restart interval
Message-ID: <Zk2ciqJje6cH11tz@tanuki>
In-Reply-To: <2zq4lspmqkcw6ssaxgc5txaubivwvghwgf4kmsmk3nfsizbmnf@twznyofqazml>

On Tue, May 21, 2024 at 06:50:58PM -0500, Justin Tobler wrote:
> On 24/05/13 10:18AM, Patrick Steinhardt wrote:
> > +reftable.restartInterval::
> > +	The interval at which to create restart points. The reftable backend
> > +	determines the restart points at file creation. Every 16 may be
> > +	more suitable for smaller block sizes (4k or 8k), every 64 for larger
> > +	block sizes (64k).
> > ++
> > +More frequent restart points reduces prefix compression and increases
> > +space consumed by the restart table, both of which increase file size.
> > ++
> > +Less frequent restart points makes prefix compression more effective,
> > +decreasing overall file size, with increased penalties for readers
> > +walking through more records after the binary search step.
> > ++
> > +A maximum of `65535` restart points per block is supported.
> > ++
> > +The default value is to create restart points every 16 records. A value of `0`
> > +will use the default value.
> 
> Out of curiousity, if for some reason we didn't want any prefix
> compression, would the best way to do this be via setting the restart
> interval to 1? I guess this means the number of references would also be
> limited by the maximum number of restart points.

Yup, exactly.

Patrick