Ashley Sheridan wrote: > On Wed, 2008-10-29 at 19:49 -0500, Micah Gersten wrote: > >> Ashley Sheridan wrote: >> >>> On Wed, 2008-10-29 at 19:43 -0500, Micah Gersten wrote: >>> >>> >>>> Ashley Sheridan wrote: >>>> >>>> >>>>> On Wed, 2008-10-29 at 19:25 -0500, Micah Gersten wrote: >>>>> >>>>> >>>>> >>>>>> Ashley Sheridan wrote: >>>>>> >>>>>> >>>>>> >>>>>>> On Thu, 2008-10-30 at 08:55 +1100, Chris wrote: >>>>>>> >>>>>>> >>>>>>> >>>>>>> >>>>>>>> Waynn Lue wrote: >>>>>>>> >>>>>>>> >>>>>>>> >>>>>>>> >>>>>>>>> I sent an email to the mysql list, but it reminded me of a question I >>>>>>>>> had >>>>>>>>> for people structuring their PHP code. What's the general way that >>>>>>>>> people >>>>>>>>> structure their connections? Right now, I spawn off two >>>>>>>>> mysql_connect calls >>>>>>>>> at the top of the file that includes my database calls, using "true" >>>>>>>>> for the >>>>>>>>> fourth parameters, so as to create two new connections. Then I use >>>>>>>>> those >>>>>>>>> two connections for two different databases I have to query from. >>>>>>>>> >>>>>>>>> Is it better just to use mysql_select_db within the query function >>>>>>>>> every >>>>>>>>> time for the same connection? Should I use mysql_connect every time >>>>>>>>> without >>>>>>>>> using "true", so as to re-use connections. Should I be using pconnect >>>>>>>>> instead? >>>>>>>>> >>>>>>>>> I spent some time looking for answers to these questions, but am >>>>>>>>> getting >>>>>>>>> conflicting answers. Some people think relying on the re-use of these >>>>>>>>> functions is good, some think that explicit management is better. In >>>>>>>>> general, how have people on the list found them? For example, is >>>>>>>>> having >>>>>>>>> constant mysql_select_db calls a problem? >>>>>>>>> >>>>>>>>> >>>>>>>>> >>>>>>>> Are they connecting as the same user and on the same server? Then you >>>>>>>> can replace with a mysql_select_db call. >>>>>>>> >>>>>>>> If they aren't both of those, you have no choice. >>>>>>>> >>>>>>>> No idea if it'll make much of a difference (performance wise etc) but >>>>>>>> I'd leave it as two connections. >>>>>>>> >>>>>>>> >>>>>>>> >>>>>>>> >>>>>>> How difficult would it be to converge the 2 databases into one? This >>>>>>> would obviously use less memory (not sure exactly how big the footprint >>>>>>> of each connection is though) and will slightly speed up page display >>>>>>> time (as you only have to wait for one connection to be made rather than >>>>>>> two) >>>>>>> >>>>>>> >>>>>>> Ash >>>>>>> www.ashleysheridan.co.uk >>>>>>> >>>>>>> >>>>>>> >>>>>>> >>>>>>> >>>>>> Generally you want separation of data. MySQL doesn't have a problem >>>>>> accessing another DB on the same server with the same connection. Also, >>>>>> how would database convergence use less memory? >>>>>> >>>>>> . >>>>>> Thank you, >>>>>> >>>>>> >>>>>> >>>>> For arguments sake, open 1000 database connections, all to different >>>>> databases. Now tell me that each connection doesn't have a footprint. At >>>>> the end of the day, whist it may seem fine for a script to have 2 >>>>> connections open, the least open the better. Imagine 100 users >>>>> simultaneously accessing a page that opens 10 connections. Suddenly you >>>>> have 200 connections open, not a great idea. If you could amalgamate the >>>>> db's, you'd have half as many connections open. >>>>> >>>>> If you're still having trouble understanding why having two database >>>>> connections open is bad (regardless of whether they are on the same >>>>> server or not) the I think web development is the wrong career for you. >>>>> >>>>> >>>>> Ash >>>>> www.ashleysheridan.co.uk >>>>> >>>>> >>>>> >>>> The answer in your case is not to combine the DBs necessarily, but >>>> consolidate the connections used. Like I said, you can use 2 MySQL DBs >>>> on the same connection in PHP. There's no reason to sacrifice >>>> separation of data. >>>> >>>> Thank you, >>>> Micah Gersten >>>> >>>> >>> I'm sure if you look at the OP codes on your suggestion, you'd still use >>> the same memory as having two separate connections open, unless you >>> closed one first. Thing is, opening and closing database connections has >>> its own overheads. >>> >>> >>> Ash >>> www.ashleysheridan.co.uk >>> >>> >> How is using one connection the same as having 2 open? You just change >> databases if you want to, or use the fully qualified table name >> (database.table) in your query. What extra overhead is there in that? >> >> Thank you, >> Micah Gersten > Having one connection open at a time has only the overhead of the > opening and closing of connections. As far as I know, you can't have two > databases open on one connection, but please correct me if I am wrong. > > > Ash > www.ashleysheridan.co.uk > With MySQL, you can change the DB from query to query with mysql_select_db. The alternative as I stated in my last post is to use the fully qualified table name (database.table) in your query. MySQL doesn't care which DB you have open if you do that. In both of these cases, the same connection is used.
Thank you, Micah Gersten onShore Networks Internal Developer http://www.onshore.com -- PHP General Mailing List (http://www.php.net/) To unsubscribe, visit: http://www.php.net/unsub.php
