On Mon, Sep 26, 2005 at 12:54:05PM -0500, Announce wrote: > Is there an performance benefit to using int2 (instead of int4) in cases > where i know i will be well within its numeric range? I want to conserve > storage space and gain speed anywhere i can, but i know some apps simply end > up casting 2byte data to 4byte (like Java int/short). > > These int2 values will be used in primary and foreign key fields and I know > that i must explicitly use tick marks (ex: where int2_column = '12') in > order to make use of indexes, but my question is IS IT WORTH IT? IS THERE > ANY REAL GAIN FOR DOING THIS?
> An simple scenario would be: > > Songs > ------- > song_id serial pkey > genre int2 fkey > title varchar Not in this case, because the varchar column that follows the int2 column needs 4-byte alignment, so after the int2 column there must be 2 bytes of padding. If you had two consecutive int2 fields you would save some the space. Or int2/bool/bool (bool has 1-byte alignment), etc. This assumes you are in a tipical x86 environment ... in other environments the situation may be different. -- Alvaro Herrera Valdivia, Chile ICBM: S 39º 49' 17.7", W 73º 14' 26.8" Voy a acabar con todos los humanos / con los humanos yo acabaré voy a acabar con todos / con todos los humanos acabaré (Bender) ---------------------------(end of broadcast)--------------------------- TIP 1: if posting/reading through Usenet, please send an appropriate subscribe-nomail command to [EMAIL PROTECTED] so that your message can get through to the mailing list cleanly