Hello Mats, I've run into exactly the same thing on both version 2 and 3, commented on it here before too. What Someone suggested here and it works, is to initially open and read the file as if it were a data file. I do it 64K at a time. Then close it and open with sqlite, in my case that took the 30 second initial stall and dropped it to about 1-2 seconds. I haven't tried memory mapping and scanning forward but, that might work too. The DB where it had the most affect is about 10 megs.
This seems to pre-load the windows file cache. C Monday, May 1, 2006, 5:25:23 AM, you wrote: MG> Hi, MG> We ran into an interesting "feature" with SQLite recently. We're MG> building a large and complex system which uses a MySQL database; but in MG> case of a network failure we also build a backup SQLite database every MG> night and transfer to the client. So when the network goes kaboom MG> (which, unfortunately, happens), the application seamlessly switches to MG> the local SQLite database and the users rarely notice anything at all. MG> However, we noticed an interesting thing. When we first open the SQLite MG> database and start running queries on it, the first query always takes MG> an enormous time to complete: up to 30-45 seconds. It's not a really MG> complex query, mainly just a lookup from a large table, and subsequent MG> queries typically run in less than 200 milliseconds. But we've been MG> totally unable to explain this initial delay. And, furthermore, when we MG> vary the query, sometimes there's additional delays of similar time MG> before everything runs smoothly again. MG> It almost seems like the first time we use a particular index, the MG> entire index is rebuilt on-the-fly, and then, after that, it is used. MG> But we've been unable to spot any differences in the binary files. MG> Since our database framework presently do not have support for the 3.x MG> branch, we're using version 2.8.17. The database generated every night MG> by one of our nightly processes is typically 50-80 MB in size. MG> Any light upon what goes wrong would be much appreciated. :) MG> regards, MG> Mats Gefvert MG> Visionutveckling AB -- Best regards, Teg mailto:[EMAIL PROTECTED]
