On Tue, 21 Apr 2009 08:02:45 +0000 (GMT), Martin Pfeifle <[email protected]> wrote:
>Hi, >I have a question regarding the retrieval of BLOBs. >Assume you have a table mytable(id, blob) and the page size is 1k. >If we now carry out an sql-query like "select blob from mytable >where id=4711" and the blob size is 100k. >Am I then correct that the pager asks 100 times for a page of >size 1k (going through the linked list of overflow pages) >and that in whatever virtual file system, we do 100 times >a seek operation to the currently requested page. >Is this correct or am I here mistaken? >Best Martin That's correct, though the number of seeks might be lower because some (many) of those overflow pages will be sequential, depending on the fragmentation rate. I think you would benefit from a larger page size. Run benchmarks to find the optimum for your environment and application. -- ( Kees Nuyt ) c[_] _______________________________________________ sqlite-users mailing list [email protected] http://sqlite.org:8080/cgi-bin/mailman/listinfo/sqlite-users
