I'd be _extremely_ leery of doing this on a network store. In theory, it should work just fine, but bridging theory and practice may very well cost you many sleepless nights. sqlite is in many ways easier than mysql, but mysql isn't _that_ much harder to use, and it just won't have this class of issue.
-scott [Ironically, one of the many inputs to my position on storing databases on a network filesystem was an experience using NFS for mysql storage :-).] On 2/1/07, Philip Butler <[EMAIL PROTECTED]> wrote:
And this is when I'll step back and listen to the experts... Since it is a low-load situation, file/record locking on SQLite seems like it would be acceptable to me. As for data corruption - that's bad -- very bad. However, with automated backups some degree of comfort may be realized. With the db systems that I have designed, I have an automatic process that dumps the db to a text file every 4 hours or so. These are kept for a couple of days. I sleep easy at night knowing this... Phil On Feb 1, 2007, at 7:59 PM, Anil Gulati -X ((agulati - Michael Page at Cisco)) wrote: > Thanks for replying Phil... > > Actually I am not running separate websites - but I have to deploy to > multiple webservers which will all serve the same pages. Each > webserver > will have their own copy of the SQLite code, but they need to load the > data from a network file server to share the same data. > > I guess this is why I am asking for feedback: it seems that this > case is > a marginal case for SQLite and I am just trying to assess performance > and corruption possibilities in more detail than is presented on the > SQLite web pages. > > The main point that encourages me to try SQLite is that it is > recommended for 99.9% of websites. I believe my traffic is very low > and > SQLite should be recommended from that point of view. > > However, although the likelihood of two users simultaneously > updating a > particular record is going to be very low I believe it is going to > happen that two users will try to update the database simultaneously. > > I know that SQLite has some file locking features that have even been > improved in v 3.0. So: > - will simultaneous *database* access result in corruption? > - will simultaneous *record* access result in corruption? > - if not, when *can* corruption occur? > > I don't mind making the users wait in the unlikely event of a record > collision, or even drop data once in a blue moon, but corruption is > not > acceptable. > > Thanks again. > Anil. > > -----Original Message----- > From: Philip Butler [mailto:[EMAIL PROTECTED] > Sent: Friday, 2 February 2007 11:39 AM > To: sqlite-users@sqlite.org > Subject: Re: [sqlite] Appropriate uses for SQLite > > I am not an expert on SQLite - but if you are running separate > websites > from your multiple servers, then why not use 4 instances of SQLite ?? > That is unless the websites need to share the same database/tables. > > If they do need to share the same database/tables, then PostgreSQL or > MySQL may be the more appropriate choice. They are designed to be > distributed (hence their increased overhead) while SQLite is > designed to > be lean-and-mean. > > Just my 2 cents worth... > > Phil > > On Feb 1, 2007, at 7:03 PM, Anil Gulati -X ((agulati - Michael Page at > Cisco)) wrote: > >> Hi SQLite users >> >> Thank you for your attention - I am just hoping for some >> clarification > >> of usability of SQLite. >> Referring to: http://www.sqlite.org/whentouse.html >> - SQLite works well in websites >> - Other RDBMS may work better for Client/Server applications >> - SQLite will work over a network file system, but because of the >> latency associated with most network file systems, performance will >> not be great >> >> I am trying to decide whether I can use SQLite for a website that >> runs > >> on 4 load-balanced servers using networked file storage mounted by >> all > >> servers for common data access. SQLite will have to load its database >> from the network file space. >> >> These servers run multiple web-sites, hence the additional servers, >> but my pages are not high hit-rate. The sites I am planning >> anticipate > >> a maximum of 200 users altogether. Current raw, uncompressed data >> (mostly >> text) is about 2MB growing to around 4MB. The current starter >> database > >> of 1.6MB raw compresses to 963KB. >> >> My concerns are: >> >> 1. Network file system >> How bad is the latency introduced from using a network file system? >> >> 2. Concurrent access >> I can't understand how SQLite is recommended for 99.9% of websites >> but > >> only *high* concurrency is not recommended? I currently use a flat- >> file system which uses a single file per record. If users happen to >> write to the same record simultaneously one of the updates will be >> lost but corruption is highly unlikely, if not impossible. It seems >> that for SQLite the risk for concurrent access is always data >> corruption, which would be unacceptable for me. >> >> The issue is that there may be short periods where multiple users >> will > >> be updating around the same time and I want to make sure that the >> possibility of corruption is extremely low. I am asking for more >> detailed information on the above issues to clarify my decision. >> >> All feedback gratefully received. >> Thanks. >> Anil. > > ---------------------------------------------------------------------- > ------- > To unsubscribe, send email to [EMAIL PROTECTED] > ---------------------------------------------------------------------- > ------- ----------------------------------------------------------------------------- To unsubscribe, send email to [EMAIL PROTECTED] -----------------------------------------------------------------------------
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