cache table vs. indexed table, and multiblock reads

        two quick questions:

1. when would it make sense to use a cache table versus a fully indexed one? as i understand it, the main advantage of a cache table is that it disables buffer aging, so that small lookup tables that are read via full-table-scans will be read into the buffer cache like regular data, instead of being placed at the "old" end of the stack, so that it will be overwritten immediately. fully indexing a table, on the other hand, prevents the full table scan from ever happening, but is mostly useful for the same sorts of tables. how should i pick between the two?
2. i've often been told that, if your os file system caching algorithm supports block read-ahead (e.g. solaris), it is advantageous to use increase the number of oracle blocks that are read at once via the multiblock_read paramater; i've never been able to get a good answer as to what value to set that paramater to, however. i recently picked up the oracle press advanced tuning guide for some more insight into this; all that book says, however, is to tune the multiblock reads to the optimal value for your operating system. does anyone know of any better rules that "set it to the best value", which seems to be what the book says? (i'm interested in solaris in particular, but would rather understand how to figure out the "optimal value" for any os if i understand how that os caches file reads.)

	tia,
	sweth.

--
Sweth Chandramouli
IS Coordinator, The George Washington University <sweth_at_gwu.edu> / (202) 994 - 8521 (V) / (202) 994 - 0458 (F) <a href="http://astaroth.nit.gwu.edu/~sweth/disc.html">*</a> Received on Wed May 05 1999 - 11:55:16 CDT