I'll start to provide some more details of how the Custom Scan plugin works today. I really want anyone that ideas how to improve the performance of browsing the Custom Scan data to post in this thread.
Custom Scan is a generic scanning module where you can add your own scanning modules. The purpose is to add additional data to the tracks, artists, albums that already exists in SlimServer, not to add completely new tracks, artists, albums as the normal SlimServer scanning does. To simplify this process for the scanning module, the main Custom Scan plugin will iterate through all SlimServer tracks and send them track by track to each scanning module. The scanning module use the track object to get more information and returns the attribute it likes to add or update. The Custom Scan main module then writes this information to the track. The two scanning modules that are relevant in this discussion is: - *Custom Tag*: Scans additional tags which the user has specified for each track in the SlimServer library. - *Mixed Tag*: Reads the album, artist, genre, year information from the standard SlimServer tables and copy it to the Custom Scan tables, it also takes a copy of the Custom Tag scanned data. The purpose of the Custom Tag scanning module is to make SlimServer aware of custom tags not normally handled by SlimServer. The purpose of the Mixed Tag scanninng module is to make SlimServer standard data appear in the same way as the data scanned by Custom Tag. The reason is to make it easy to create a browse menu where some menu levels are custom tags and other are standard SlimServer data. The information scanned with Custom Scan plugin is obviously not used by the standard SlimServer code since it doesn't know anything about the Custom Scan tables it creates. There is also not possible to add this data to the standard SlimServer tables since there are no custom columns available. So the way you use the data is with the Custom Browse plugin which makes it possible to create browse menus based on any SQL statement towards any tables in the SlimServer database. The information scanned by the Custom Tag and Mixed Tag scanning modules is today stored in a single table "customscan_track_attributes", the columns in this table relevant for this discussion is: - track (same as tracks.id) - module (which module the data comes from) - attr (the tag name) - value (the actual value of the scanned attribute in text form) - valuesort (the actual value of the scanned attribute in sort form) - extravalue (the actual value of the scanned attribute in id form, this is only used for the data copied from the SlimServer tables and contains the values from tracks.id, albums.id, genres.id, contributors.id) Since the information is stored in a single table today it gets pretty easy to create code that browses through several attributes. It doesn't have to care which table the attribute is stored and it doesn't have to care if the attribute is related to tracks or albums or artists. The obvious disadvantage of this solution is the performance in a large library with many custom tags. For some browse menus this could result in that a 4,500,000 row table is joined with itself four/five times to get the result. The user of course expect the result to come very fast when browsing, a right click shouldn't really take more than a second or two. I've setup a number of different indexes, but I expect that with a 4,500,000 row table index can make some things fast but a five time join on this table, it is probably impossible to get 1-2 second response time independent which index that are used. But if someone are good at setting up database index with MySQL, I'm really interesting in help regarding this. Now over to my thoughts regarding the purposed solutions, I'll to this in a separate post coming soon.... -- erland Erland Isaksson 'My homepage' (http://erland.homeip.net) 'My download page' (http://erland.homeip.net/download) (Developer of 'TrackStat, SQLPlayList, DynamicPlayList, Custom Browse, Custom Scan, Custom Skip, Multi Library and Database Query plugins' (http://wiki.erland.homeip.net/index.php/Category:SlimServer)) ------------------------------------------------------------------------ erland's Profile: http://forums.slimdevices.com/member.php?userid=3124 View this thread: http://forums.slimdevices.com/showthread.php?t=38714 _______________________________________________ plugins mailing list plugins@lists.slimdevices.com http://lists.slimdevices.com/lists/listinfo/plugins
