Tom Lane wrote: > I got interested enough in the psql-with-flex problem to go off and > solve it. Attached is a working patch, which I'm now debating whether > to apply. Comments solicited... > > The patch removes about 200 lines of very spaghetti-ish code in > mainloop.c. However, it adds an 875-line flex source file, which > might be thought a bad tradeoff :-(. One bright spot is that about > half of that total is a direct copy of the main backend lexer, so > it's not really as much new, separately maintainable code as all that. > Also, Andrew Dunstan's patch for supporting dollar-quoting would add > about 100 lines to mainloop.c, versus only a dozen or so lines in the > flex implementation. Once that's taken into account I don't think there > is a lot of difference in effective SLOC to maintain. I'm also of the > opinion that the new C code in psqlscan.l is much more straightforward > than the code removed from mainloop.c, though having just written it, > I'm no doubt pretty biased. > > Bruce was asking about speed. On normal-size queries I cannot measure > any difference at all. For testing purposes I made up a file containing > a single 750K query (just a "SELECT big-honking-string-constant", with > the string literal broken into lines of 75 bytes). The client-side > (psql) CPU time to run this file looks about like this on my machine: > > PGCLIENTENCODING > UNICODE SJIS > > CVS tip 1.57 1.82 > > flex implementation 0.93 2.33
Advertising
Looks good. I withdraw my performance concerns. Thanks for testing. -- Bruce Momjian | http://candle.pha.pa.us [EMAIL PROTECTED] | (610) 359-1001 + If your life is a hard drive, | 13 Roberts Road + Christ can be your backup. | Newtown Square, Pennsylvania 19073 ---------------------------(end of broadcast)--------------------------- TIP 6: Have you searched our list archives? http://archives.postgresql.org
