Re: [HACKERS] lztext and parser - Mailing list pgsql-hackers

From wieck@debis.com (Jan Wieck)
Subject Re: [HACKERS] lztext and parser
Date
Msg-id m11qyHW-0003kGC@orion.SAPserv.Hamburg.dsh.de
Whole thread Raw
In response to Re: [HACKERS] lztext and parser  (Karel Zak - Zakkr <zakkr@zf.jcu.cz>)
List pgsql-hackers
Karel wrote:

> In the lztext_eq(lztext *lz1, lztext *lz2) you use lztext_cmp().
> I'm not sure if it is good, because you must decompress fistly, but
> you don't need information about '<' or '>', you need '=' only. Why
> you not use memcmp() (or other method) for this, and comparate this
> without decompression? Two equal string is equal in a compressed form,
> or not?

    For now, yes. But the current lztext implementation is only a
    starting poing (still). The final  version  might  have  some
    runtime customizable parameters for the compression algorithm
    (good match size and minimum compression rate). Then, if some
    data is stored and the parameters change after, this wouldn't
    be true any more.

> All in this letter is comments and suggestions, you can always remove
> this letter to /dev/null :-)

    Would never do so. All  suggestions  are  welcome  and  might
    trigger another idea in someone elses head.


Jan

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