"Greg Sabino Mullane" <[EMAIL PROTECTED]> writes: > CREATE TABLE rating ( > movie SMALLINT NOT NULL, > person INTEGER NOT NULL, > rating SMALLINT NOT NULL, > viewed DATE NOT NULL > );
You would probably be better off putting the two smallints first followed by the integer and date. Otherwise both the integer and the date field will have an extra two bytes of padding wasting 4 bytes of space. If you reorder the fields that way you'll be down to 28 bytes of tuple header overhead and 12 bytes of data. There's actually another 4 bytes in the form of the line pointer so a total of 44 bytes per record. Ie, almost 73% of the disk i/o you're seeing is actually per-record overhead. -- Gregory Stark EnterpriseDB http://www.enterprisedb.com ---------------------------(end of broadcast)--------------------------- TIP 9: In versions below 8.0, the planner will ignore your desire to choose an index scan if your joining column's datatypes do not match