RE: CFLOCK Cached Query
Should I CFLOCK the following query? CFQUERY NAME="Request.GetListings" DATASOURCE="#request.DSN#" USERNAME="#request.USER#" PASSWORD="#request.PASS#" cachedwithin="#createtimespan(0,0,15,0)#" SELECT ID,org_name,contact,city,website_bt,email_bt,classified_bt, fax_bt,TList FROM Orgs (nolock) WHERE Class = #VAL(request.hdg_id)# CFIF "#CLIENT.CITY#" IS NOT "All Cities" AND City = '#CLIENT.CITY#'/CFIF ORDER BY org_name /CFQUERY For different values of request.hdg_id or CLIENT.CITY, CF will cache the correct dataset for NEXT/PREVIOUS display of results on a page (since CF caches reference the SQL too, and not just the cfquery name). There are potentially many DIFFERENT datasets, ALL titled Request.GetListings (in the CF template, that is). For example, CF will cache one dataset where CLIENT.CITY is New York, and another dataset where CLIENT.CITY is Chicago, and they apparently happily co-exist. But what happens if we followed Allaire's best practices (in CF4.5 syntax): cflock scope="application" timeout="2" type="exclusive" cfset application.GetListings = Request.GetListings /cflock Would the potentially several queries/datasets all named Request.GetListings (in the CF template) be kept distinct when they are named application.GetListings? First, you shouldn't CFLOCK the query. All CFLOCK does is limit who can execute the code at a given time. You don't have any memory variables within the query that need to be protected from concurrent accesses, so you don't need to use CFLOCK. Second, cached queries aren't stored the same way as persistent memory variables are stored. That is, they're not simply identified by name. You're only going to have one variable called Request.GetListings (or Application.GetListings) and that variable will contain whatever you put into it. Query caching only comes into play when you execute a CFQUERY tag with a caching attribute - CF looks to see whether there's a matching recordset already cached. Dave Watts, CTO, Fig Leaf Software http://www.figleaf.com/ voice: (202) 797-5496 fax: (202) 797-5444 -- Archives: http://www.mail-archive.com/cf-talk@houseoffusion.com/ To Unsubscribe visit http://www.houseoffusion.com/index.cfm?sidebar=listsbody=lists/cf_talk or send a message to [EMAIL PROTECTED] with 'unsubscribe' in the body.
RE: CFLOCK Cached Query
So are you saying we don't need to follow Allaire's Best Practices recommendation? (This is where the cflock example below came from.) Or, is your statement "First, you..." referring to something else? best, paul At 12:04 PM 10/2/00 -0400, you wrote: cflock scope="application" timeout="2" type="exclusive" cfset application.GetListings = Request.GetListings /cflock First, you shouldn't CFLOCK the query. All CFLOCK does is limit who can execute the code at a given time. You don't have any memory variables within the query that need to be protected from concurrent accesses, so you don't need to use CFLOCK. -- Archives: http://www.mail-archive.com/cf-talk@houseoffusion.com/ To Unsubscribe visit http://www.houseoffusion.com/index.cfm?sidebar=listsbody=lists/cf_talk or send a message to [EMAIL PROTECTED] with 'unsubscribe' in the body.
RE: CFLOCK Cached Query
cflock scope="application" timeout="2" type="exclusive" cfset application.GetListings = Request.GetListings /cflock First, you shouldn't CFLOCK the query. All CFLOCK does is limit who can execute the code at a given time. You don't have any memory variables within the query that need to be protected from concurrent accesses, so you don't need to use CFLOCK. ... So are you saying we don't need to follow Allaire's Best Practices recommendation? (This is where the cflock example below came from.) Or, is your statement "First, you..." referring to something else? I was saying that you shouldn't place the CFQUERY tag within a CFLOCK, which was your original question, as I understood it: Should I CFLOCK the following query? CFQUERY NAME="Request.GetListings" DATASOURCE="#request.DSN#" USERNAME="#request.USER#" PASSWORD="#request.PASS#" cachedwithin="#createtimespan(0,0,15,0)#" SELECT ID,org_name,contact,city,website_bt,email_bt,classified_bt, fax_bt,TList FROM Orgs (nolock) WHERE Class = #VAL(request.hdg_id)# CFIF "#CLIENT.CITY#" IS NOT "All Cities" AND City = '#CLIENT.CITY#'/CFIF ORDER BY org_name /CFQUERY Dave Watts, CTO, Fig Leaf Software http://www.figleaf.com/ voice: (202) 797-5496 fax: (202) 797-5444 -- Archives: http://www.mail-archive.com/cf-talk@houseoffusion.com/ To Unsubscribe visit http://www.houseoffusion.com/index.cfm?sidebar=listsbody=lists/cf_talk or send a message to [EMAIL PROTECTED] with 'unsubscribe' in the body.
RE: CFLOCK Cached Query
The question I have is whether there's any advantage in scoping a Query cached in a CFQUERY tag as Application.GetListings contrasted with scoping it as Request.GetListings. I would argue that there isn't any advantage, and should be avoided. When you do this, you're storing the data in two places: the Application scoped variable, and the query caching memory. If I were to read the code later, I'd be confused about which set of data you really wanted to use. Dave Watts, CTO, Fig Leaf Software http://www.figleaf.com/ voice: (202) 797-5496 fax: (202) 797-5444 -- Archives: http://www.mail-archive.com/cf-talk@houseoffusion.com/ To Unsubscribe visit http://www.houseoffusion.com/index.cfm?sidebar=listsbody=lists/cf_talk or send a message to [EMAIL PROTECTED] with 'unsubscribe' in the body.
RE: CFLOCK Cached Query
Thank you, Dave. This confirms my inclination to use Request-scope for cached queries. But I didn't realize an Application-scope cached query would store two sets of data. best, paul At 03:29 PM 10/2/00 -0400, you wrote: The question I have is whether there's any advantage in scoping a Query cached in a CFQUERY tag as Application.GetListings contrasted with scoping it as Request.GetListings. I would argue that there isn't any advantage, and should be avoided. When you do this, you're storing the data in two places: the Application scoped variable, and the query caching memory. If I were to read the code later, I'd be confused about which set of data you really wanted to use. Dave Watts, CTO, Fig Leaf Software http://www.figleaf.com/ voice: (202) 797-5496 fax: (202) 797-5444 -- Archives: http://www.mail-archive.com/cf-talk@houseoffusion.com/ To Unsubscribe visit http://www.houseoffusion.com/index.cfm?sidebar=listsbody=lists/cf_talk or send a message to [EMAIL PROTECTED] with 'unsubscribe' in the body.
