Re: [GENERAL] Faster data type for one-length values

[André Volpato]

Tom Lane escreveu: =?ISO-8859-1?Q?Andr=E9_Volpato?= <[EMAIL PROTECTED]> writes: I need to store one-length values like '1', '2', '3' or '4' . Today, this field is indexed with btree and is of type smallint (int2). How much performance will be improved if I change it to "char" (1 byte length) ? The improvement will be zero. Because of alignment restrictions, you don't save any space from making an index entry smaller than 4 bytes. If you have several such fields adjacent in a table row, making them all narrower can save space, but it doesn't help for standalone index entries. regards, tom lane Tom, The ammount of space saved seems pretty clear to me. What are you saying is that the index behaviour is the same, for all types smaller than 4 bytes ?  For query performance, in a search is based on that standalone indexed field, would be any difference using : a. char(1) ;  b. int2;  c. "char" Thanks again ! -- []´s, André Volpato ECOM Tecnologia Ltda [EMAIL PROTECTED] (41) 3014 2322