Re: To cache or not to cache

This isn't directly related to the OP's question, but it sparked my curiousity:

When I ask for info about the user (say $user->get('zipcode')) I first check if the data is currently defined in the instance. If not, I check the session cache (currently Cache::Filecache) and finally, if it hasn't been found, I query the DB.

How much overhead do you (OP and others reading this) think this adds per request? I guess the value would be highly dependent on how frequently the request makes it to the DB request phase.

I wonder if maybe a persistent DBI connection might provide more overall value than locally caching the data.

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It's all fine and dandy until someone has to look at the code.

Comment on Re: To cache or not to cache

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Re^2: To cache or not to cache by blogical (Pilgrim) on Mar 13, 2006 at 18:12 UTC
Hopefully it reduces the overhead over the course of a session. It seems better than pre-loading everything that might be needed into the instance for every request, or calling the DB for each piece individually as it is requested over the course of the session. Look as close to home as possible first (memory->cache->DB) Trade a little memory/storage space for the length of the request/session to cut down on DB calls. Try to avoid DB calls by retrieving relevant info on the first call. Reusable data migrates into the cache, and lives there until the session ends- hopefully quicker and lower cost than DB calls. I'm using a persistant dbhandle (or it WILL persist when I get this onto mod_perl). But calling also requires figuring out where to get the data from, forming the request, dealing with the call...	[reply]

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Re^2: To cache or not to cache
by blogical (Pilgrim) on Mar 13, 2006 at 18:12 UTC

Look as close to home as possible first (memory->cache->DB)
Trade a little memory/storage space for the length of the request/session to cut down on DB calls.
Try to avoid DB calls by retrieving relevant info on the first call.
Reusable data migrates into the cache, and lives there until the session ends- hopefully quicker and lower cost than DB calls.

I'm using a persistant dbhandle (or it WILL persist when I get this onto mod_perl). But calling also requires figuring out where to get the data from, forming the request, dealing with the call...

[reply]