Pardon my ignorance, but what is the purpose of this database of blank tiles? I'm just curious, as I know little to nothing about what the [EMAIL PROTECTED] server does and how it does it. Is there a wiki page anywhere that explains how the infrastructure works?
-Jeremy ----- Original Message ----- From: "Martijn van Oosterhout" <[EMAIL PROTECTED]> To: "Christopher Schmidt" <[EMAIL PROTECTED]> Cc: <[email protected]> Sent: Saturday, December 22, 2007 10:35 AM Subject: Re: [Tilesathome] [EMAIL PROTECTED] server performance > On Dec 22, 2007 3:43 PM, Christopher Schmidt <[EMAIL PROTECTED]> > wrote: >> In the long term, we need to come up with some more efficient way of >> storing blank tiles than the current database. > > It should be said that we arn't using the current format as > efficiently as possible. For example, we could make the clients > produce less blank tiles, and we could get the server to store them > more efficiently, we're not taking full advantage of the fallback > system. Some random ideas: > > - Clients create a blank sea/land tile whenever they find something > blank. The client could immediately check to see if the tile above it > is also blank and if so store a 0-byte file instead. That's one less > entry in the DB to clean up later. > - When the server has the list of blank tiles to insert, it could run > one pass over the list to see if it's mostly sea of mostly land and > whatever it is, insert a blank tile with that type at zoom-12 and then > only insert the other types. > > The latter idea is I think where we could make some real gains bt it's > currently impossible to do on the client side because client only have > the option of uploading a blank tile *or* a real tile at zoom-12, not > both. > >> For the record, I ran the cleanblanktiles script yesterday, so the blank >> tile db is as clean as that code makes it. I don't know if there are >> further optimizations that can be made there -- perhaps someone else can >> comment -- but I've done everything I know how to do. > > I'd never looked at the cleanblanktiles before but it certainly looks > like its missing some possible optimisations. Especially my second > suggestion above would remove many z17 blank tiles, which are half the > current DB. > > Have a nice day, > > -- > Martijn van Oosterhout <[EMAIL PROTECTED]> http://svana.org/kleptog/ > > _______________________________________________ > Tilesathome mailing list > [email protected] > http://lists.openstreetmap.org/cgi-bin/mailman/listinfo/tilesathome > > > -- > No virus found in this incoming message. > Checked by AVG Free Edition. > Version: 7.5.516 / Virus Database: 269.17.6/1192 - Release Date: > 12/21/2007 1:17 PM > > _______________________________________________ Tilesathome mailing list [email protected] http://lists.openstreetmap.org/cgi-bin/mailman/listinfo/tilesathome
