On Fri, Jul 10, 2009 at 13:07, workerholic@xxxxxxxxxxxx<workerholic@xxxxxxxxxxxx> wrote: > hi andrew i think you understand my problem a little, > but if 100 user load this query at the same time, the two mysql server had a > lot to do! > so i think to cache this query as xml to the application server local make > thinks faster, > but, i would like to have the same performance to read this xml document as > read the query from mysql server... > i dont know why php is so slow to read the xml file... It will be slower to read a file than data from an SQL database by sheer design --- regardless of whether it's XML, CSV, plain text, etc. And MySQL is faster still because it's run as a server with it's own processing engine, completely independent of the PHP engine and spawned process. Other factors involved are disk seek time, memory capabilities, et cetera, but the SQL-vs-file point is the biggest. For PHP to locate something within the file, it must load the entire file into memory or read it byte-by-byte, line-by-line, from an exact offset (given explicitly). SQL databases such as MySQL work similarly, but don't catalog all data in quite the same linear fashion. Further, MySQL is capable of indexing, allowing it to return the data far faster. There's a time and a place for each, but it sounds as though what you're attempting to do would not be best-served by caching it in an XML sheet. Also, something to keep in mind (with no offense intended by any means): if you have two database servers (using replication) for load-balancing and they - combined - cannot handle 100 simultaneous connections and queries, you may want to re-evaluate your infrastructure and architecture. -- </Daniel P. Brown> daniel.brown@xxxxxxxxxxxx || danbrown@xxxxxxx http://www.parasane.net/ || http://www.pilotpig.net/ Check out our great hosting and dedicated server deals at http://twitter.com/pilotpig -- PHP General Mailing List (http://www.php.net/) To unsubscribe, visit: http://www.php.net/unsub.php