Re: [SQL] Re: [GENERAL] lztext and compression ratios...

Bruce Momjian <pgman(at)candle(dot)pha(dot)pa(dot)us> writes:
>> Compressor | level | heap size | toastrel | toastidx | seconds
>> | | | size | size |
>> -----------+-------+-----------+----------+----------+--------
>> PGLZ | - | 425,984 | 950,272 | 32,768 | 5.20
>> zlib | 1 | 499,712 | 614,400 | 16,384 | 6.85
>> zlib | 3 | 499,712 | 557,056 | 16,384 | 6.75
>> zlib | 6 | 491,520 | 524,288 | 16,384 | 7.10
>> zlib | 9 | 491,520 | 524,288 | 16,384 | 7.21
>
>Consider that the 25% slowness gets us a 35% disk reduction, and that
>translates to fewer buffer blocks and disk accesses. Seems there is a
>clear tradeoff there.

Also, consider that in the vast majority of cases, reads greatly outnumber
writes for any given datum, and particularly so for web applications.

Could we get a benchmark that compared decompression speeds exclusively?

-Michael Robinson