Re: [sqlite] Question regarding I/O under the new VFS model

2007-10-11 Thread Mark Spiegel
Thank you Dr. Hipp. The DB info makes perfect sense. Since I have to accommodate the initial read in the DB file you don't need to check on the change counter. I'll handle it already. With regard to the journal files, I understand that they will for the most part be written sequentially

Re: [sqlite] Question regarding I/O under the new VFS model

2007-10-11 Thread drh
Mark Spiegel <[EMAIL PROTECTED]> wrote: > > I take this to mean that paged-aligned sector I/O will always be used > for all the DB types. Will there ever be an I/O to a DB file that will > not follow these rules. When first opening a database, 100 bytes are ready from the very beginning of

[sqlite] Question regarding I/O under the new VFS model

2007-10-11 Thread Mark Spiegel
I'm working with implementing my own VFS. If the developer(s) could answer a couple of questions, it would be helpful. In section 2.1.4 of the SQLite 3.4.2 to 3.5.0 document, reference is made to "a database file will be doing page-aligned sector reads and writes in random order" regarding