-----BEGIN PGP SIGNED MESSAGE----- Hash: SHA1 Peter, et al --
...and then Peter Brawley said... % % Your reference to "having the table sorted" suggests physical table sorting, Right... % but a basic characteristic of a relational DBMS is that data retrieval does % not depend on physical row order. The actual order of rows in a MySql table OK. That's what I figured, especially since I didn't see anything about how to insert a record sorted or unsorted or such, but couldn't find anything authoritative. % is entirely arbitrary, and shouldn't be your concern except perhaps for huge % OLAP tables. Right. That's why, when they're needed, database architects are *really* needed :-) % % So I think the question you are asking comes down to this: when does an % index provide a performance advantage? One answer is: when the rows you are That's the second question, figuring that indexed fields are what is going to make things faster :-) % retrieving form a very small subset of the table you are querying, the % effect of the index then vbeing to greatly diminish the number of rows that % have to be physically read to return the desired result set. That sounds like this case... A hundred or a thousand clients, and I want the card or cards for just one of them. And so... How does this look? Assuming a table 'clients' with a client ID and a table 'cards' with a card ID (since multiple related clients might use the same card, or more particularly since I will probably separate the actual card numbers behind a security scheme), is create table ccards ( # ID number id int not null default 0 auto_increment primary key , client int , # references client.id index (client) , # fast indexed lookups type varchar(10) , # MC, Visa, AmEx, Disc, ... maybe a set()? card int # references cards.id ) ; a valid definition? And, meanwhile, how about create table clients ( # ID number id int not null default 0 auto_increment primary key , # last, first names lname varchar(40) , index (lname) , fname varchar(40) , index (fname) , mname varchar(40) , ... ) ; for a client table with indexed first and last name fields? % % PB I'll ask about char vs varchar and text next time :-) Thanks & HAND mysql query, :-D - -- David T-G * There is too much animal courage in (play) [EMAIL PROTECTED] * society and not sufficient moral courage. (work) [EMAIL PROTECTED] -- Mary Baker Eddy, "Science and Health" http://www.justpickone.org/davidtg/ Shpx gur Pbzzhavpngvbaf Qrprapl Npg! -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.0.7 (FreeBSD) iD8DBQE9/NpGGb7uCXufRwARAt2AAJ9THBEarHIK5/42BMlNZw7JPAqIvACeJi2X hVVy3K3LPq0dlCNHipKw/VY= =rdKs -----END PGP SIGNATURE----- --------------------------------------------------------------------- Before posting, please check: http://www.mysql.com/manual.php (the manual) http://lists.mysql.com/ (the list archive) To request this thread, e-mail <[EMAIL PROTECTED]> To unsubscribe, e-mail <[EMAIL PROTECTED]> Trouble unsubscribing? Try: http://lists.mysql.com/php/unsubscribe.php