Re: jsonb format is pessimal for toast compression

* Josh Berkus (josh(at)agliodbs(dot)com) wrote:
> TLDR: we want to go with Tom's latest patch and release beta3.

Having not even read the rest- yes please. We really need to get beta3
out and figure out when we're going to actually release 9.4...
Admittedly, the last month has been good and we've been fixing issues,
but it'd really be good to wrap 9.4 up.

> Conclusion: with Tom's patch, compressed JSONB is 55% smaller when
> compressed (EXTENDED). Extraction times are 50% to 70% slower, but this
> appears to be almost entirely due to decompression overhead. When not
> compressing (EXTERNAL), extraction times for patch versions are
> statistically the same as HEAD, and file sizes are similar to HEAD.

Not really a surprise.

> I polled at both PDXpgDay and at FOSS4G, asking some ~~ 80 Postgres
> users how they would feel about a compression vs. extraction time
> tradeoff. The audience was evenly split.

Also not a surprise.

> However, with the current patch, the user can choose. Users who know
> enough for performance tuning can set JSONB columns to EXTERNAL, and the
> the same performance as the unpatched version.

Agreed.

Thanks,

Stephen