Re: [HACKERS] compression in LO and other fields - Mailing list pgsql-hackers

From Hannu Krosing
Subject Re: [HACKERS] compression in LO and other fields
Date
Msg-id 382C8E8E.999C67A1@tm.ee
Whole thread Raw
In response to Re: [HACKERS] compression in LO and other fields  (wieck@debis.com (Jan Wieck))
Responses Re: [HACKERS] compression in LO and other fields  (wieck@debis.com (Jan Wieck))
Re: [HACKERS] compression in LO and other fields  (wieck@debis.com (Jan Wieck))
List pgsql-hackers
Jan Wieck wrote:
> 
>     Of course.
> 
>     Well, you asked for the rates on the smaller html files only.
>     78  files,  131  bytes  min, 10000 bytes max, 4582 bytes avg,
>     357383 bytes total.
> 
>     gzip -9 outputs 145659 bytes (59.2%)
>     gzip -1 outputs 155113 bytes (56.6%)
>     my code outputs 184109 bytes (48.5%)
> 
>     67 files, 2000 bytes min, 10000 bytes max,  5239  bytes  avg,
>     351006 bytes total.
> 
>     gzip -9 outputs 141772 bytes (59.6%)
>     gzip -1 outputs 151150 bytes (56.9%)
>     my code outputs 179428 bytes (48.9%)
> 
>     The  threshold will surely be a tuning parameter of interest.
>     Another tuning option must be to allow/deny  compression  per
>     table  at  all.   Then  we  could  have both options, using a
>     compressing field type to define which portion of a tuple  to
>     compress, or allow to compress the entire tuples.

The next step would be tweaking the costs for sequential scans vs.
index scans.

I guess that the indexes would stay uncompressed ?

------
Hannu


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