Re: Database changes
This WebDNA talk-list message is from 1998
It keeps the original formatting.
numero = 16151
interpreted = N
texte = >>Whenever I make a change to a database, then use fetch to reload the >>database file to the server, the changes are never appearant on the web >>site. I have tried the [closedatabase] tag in a web page, and the >>$flushdatabases command in a URL string, but cannot affectuate the >>changes I made to the database file. > >Hmm. That is the correct procedure -- upload the new database, then issue a FlushDatabases command (or embedded [flushdatabases]) should force it to unload everything and reload from disk the next time a db is needed.Wait a minute, Grant, I hate to disagree with you, but I do *not* agree with you upload procedure here. Maybe I am misunderstanding what you're trying to explain, so please correct me if I'm wrong, but this is my understanding ...Flushdatabases does not simply purge the RAM-cached data, it actually writes all the open databases to disk *before* purging WebCat's RAM database caches. So if you upload a new db file *before* issuing the [flushdatabase] command (which is wha you're suggesting) the new db will be overwritten by the older RAM-cached version.In other words, there is still no way to get the data out of WebCat's RAM cache without having it written to disk, thus overwriting the newly uploaded file. That's been a problem with WebCat all along for people who need to replace existing databases with new ones.The correct procedure when uploading a new replacement db file to the server is to perform the $flushdatabases command first, THEN upload the file.But this only works when no one happens to request a page that calls that database in the meantime, because if that happens, WebCat will reload the old db back into RAM before you're finished replacing the old db with the new one... and then, once that old db is in RAM again, there's no way to purge that RAM data without rewriting it to disk.So on a busy server, this generally means having to suspend new connections or quitting the server in order to make absolutely sure that your newly-uploaded db does not get overwritten by WebCat.Sincerely, Ken Grome ken@iav.com 808-737-6499 WebDNA Solutions http://webdna.net/
Associated Messages, from the most recent to the oldest:
>>Whenever I make a change to a database, then use fetch to reload the >>database file to the server, the changes are never appearant on the web >>site. I have tried the
[closedatabase] tag in a web page, and the >>$flushdatabases command in a URL string, but cannot affectuate the >>changes I made to the database file. > >Hmm. That is the correct procedure -- upload the new database, then issue a FlushDatabases command (or embedded
[flushdatabases]) should force it to unload everything and reload from disk the next time a db is needed.Wait a minute, Grant, I hate to disagree with you, but I do *not* agree with you upload procedure here. Maybe I am misunderstanding what you're trying to explain, so please correct me if I'm wrong, but this is my understanding ...Flushdatabases does not simply purge the RAM-cached data, it actually writes all the open databases to disk *before* purging WebCat's RAM database caches. So if you upload a new db file *before* issuing the [flushdatabase] command (which is wha you're suggesting) the new db will be overwritten by the older RAM-cached version.In other words, there is still no way to get the data out of WebCat's RAM cache without having it written to disk, thus overwriting the newly uploaded file. That's been a problem with WebCat all along for people who need to replace existing databases with new ones.The correct procedure when uploading a new replacement db file to the server is to perform the $flushdatabases command first, THEN upload the file.But this only works when no one happens to request a page that calls that database in the meantime, because if that happens, WebCat will reload the old db back into RAM before you're finished replacing the old db with the new one... and then, once that old db is in RAM again, there's no way to purge that RAM data without rewriting it to disk.So on a busy server, this generally means having to suspend new connections or quitting the server in order to make absolutely sure that your newly-uploaded db does not get overwritten by WebCat.Sincerely, Ken Grome ken@iav.com 808-737-6499 WebDNA Solutions http://webdna.net/
Kenneth Grome
DOWNLOAD WEBDNA NOW!
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