sorry, I don't know where sqlite stores any kind of data like index or raw table, my suspect is that, since sqlite usually looks for a free page, the pages are randomly distributed over the file or added at the end if no free page has been found.
what I don't understand: what makes you thinking that you may miss some bytes of a tree (and thus of a page) ? That is sqlite internal, except you are using your own vfs, I guess, ...do you ? by the way: did your application crash prior or nearby you had this corrupted DB ? > I've reviewed the code over and over again, but am yet to find it. But it > is a good bit of very complicated code (blowfish and compression code). > > That's why I was asking about the format of the database. Since I'm able > to > successfully do a .dump but the integrity_check whines, I'm thinking that > maybe if I focus on where what could cause that, it might give me a clue. > > For example, if the tree is stored at the end of file maybe I'm falling > out > the loop without writing the final bytes. But if the tree is not > localized > to one area of the file, I'll have to rethink my approach. > > > -----Original Message----- > From: sqlite-users-boun...@sqlite.org > [mailto:sqlite-users-boun...@sqlite.org] On Behalf Of Marcus Grimm > Sent: Wednesday, May 27, 2009 2:44 PM > To: General Discussion of SQLite Database > Subject: Re: [sqlite] corrupt database recovery > > so, if you think it is a coding error on your side it will > be a hard work to find the source. I can only image side effects > on an used API like sqlite3 with the classics: > > - stack frame overload in a function that calls sqlite functions > - using a local stack variable as a return pointer and reuse > this external. > - memory overwriting on malloc'ed pointers or reusing of allready > free'd memory pages. > > one and two might be found using a code review and identify > local variables or particular arrays that are written: > So wherever you call anything from sqlite check the stack > declaration and review the usage of these variables... > of course just don't do number two... ;) > > memory errors might be detected using special debug versions of the > malloc/free library, by code review, or manually by adding some > test variables whereever you malloc or free a pointer. > > I'm sure you allready did some of these... anyway, good luck > > are you using threads? would be another beautiful issue to trace...;) > > Marcus > > > >> It is a server class machine running Windows 2003 with 4 GB. No, it's a >> local drive with 20GB free on it. >> >> I'm sure that it's a coding error on my part. SQLite is very stable, in >> my >> opinion. I'm just trying to get a rough idea on where I'm screwing up >> the >> database. >> >> >> -----Original Message----- >> From: sqlite-users-boun...@sqlite.org >> [mailto:sqlite-users-boun...@sqlite.org] On Behalf Of John Elrick >> Sent: Wednesday, May 27, 2009 12:58 PM >> To: General Discussion of SQLite Database >> Subject: Re: [sqlite] corrupt database recovery >> >> What platform? Any chance they are using a network drive? >> >> >> John >> >> Gene wrote: >>> My code is outside the database layer. So I do all my database work, >>> then >>> compress and encrypt it. No errors are returned anywhere. I'm >>> guessing >>> that it's going to be an uninitialized variable or byte alignment >>> problems >>> somewhere. >>> >>> This code is running on hundreds of machines without a problem and I've >>> never reproduced it but every now and again I get a support ticket >>> showing >> a >>> corrupt database. So I'm trying to figure out WHERE to look. >>> >>> -----Original Message----- >>> From: sqlite-users-boun...@sqlite.org >>> [mailto:sqlite-users-boun...@sqlite.org] On Behalf Of John Elrick >>> Sent: Wednesday, May 27, 2009 10:59 AM >>> To: General Discussion of SQLite Database >>> Subject: Re: [sqlite] corrupt database recovery >>> >>> Gene Allen wrote: >>> >>>> Ok...it's happened again and I've decided that I need to track this >>>> down >>>> once and for all! >>>> >>>> Here is what I'm seeing: I get errors when I do a integrity_check (see >>>> below), but I can .dump it to a text file and then .read it into >>>> another >>>> database ok. >>>> >>>> It seems to me that I'm screwing up an index or something. Are >>>> indexes >>>> stored at the end of the database file? All I can think of is that my >>>> compression/encryption routines are messing something up and I'm >>>> trying >> to >>>> figure out 'where' to look. >>>> >>>> I guess the real question is, what would I have to do to make an >>>> integrity_check fail, but still let a dump work correctly? >>>> >>>> Many thanks for any advice on tracking down this ugliness. >>>> >>>> >>> >>> SNIP >>> >>> Personally, I'd refactor the code to allow me to verify the operation >>> of >>> the compression/encryption routines independently of the database >>> operation. How are you injecting the compression/encryption into the >>> database layer? >>> >>> >>> John >>> _______________________________________________ >>> sqlite-users mailing list >>> sqlite-users@sqlite.org >>> http://sqlite.org:8080/cgi-bin/mailman/listinfo/sqlite-users >>> >>> _______________________________________________ >>> sqlite-users mailing list >>> sqlite-users@sqlite.org >>> http://sqlite.org:8080/cgi-bin/mailman/listinfo/sqlite-users >>> >>> ------------------------------------------------------------------------ >>> >>> >>> No virus found in this incoming message. >>> Checked by AVG - www.avg.com >>> Version: 8.0.238 / Virus Database: 270.12.39/2133 - Release Date: >>> 05/25/09 >> 08:16:00 >>> >>> >> >> _______________________________________________ >> sqlite-users mailing list >> sqlite-users@sqlite.org >> http://sqlite.org:8080/cgi-bin/mailman/listinfo/sqlite-users >> >> _______________________________________________ >> sqlite-users mailing list >> sqlite-users@sqlite.org >> http://sqlite.org:8080/cgi-bin/mailman/listinfo/sqlite-users >> > > > _______________________________________________ > sqlite-users mailing list > sqlite-users@sqlite.org > http://sqlite.org:8080/cgi-bin/mailman/listinfo/sqlite-users > > _______________________________________________ sqlite-users mailing list sqlite-users@sqlite.org http://sqlite.org:8080/cgi-bin/mailman/listinfo/sqlite-users
