On Wed, Apr 6, 2011 at 6:36 AM, Dan Kennedy <danielk1...@gmail.com> wrote: > On 04/05/2011 04:49 PM, Filip Navara wrote: >> Hello, >> >> we are having problem with database that originated on computer of one >> of our customers. >> >> The database is used in WAL mode with auto_vacuum=1 and page_size=1024. >> >> When running the "pragma incremental_vacuum(1);" command the WAL file >> grows to 14Mb, while we would expect it to grow only to about 4Kb (1Kb >> per page + some overhead). This causes the transaction to run for much >> longer time than expected and eventually the WAL file grows to several >> gigabytes when we try to run incremental_vacuum for 4096 pages. >> >> Additional facts: >> - The database was created with SQLite 3.7.5 running on Windows >> - "pragma integrity_check;" reports ok >> - Some free trunk list pages contain weird values in the "number of >> entries" field >> >> I have attached most of the dumps that I could create with the regular >> SQLite tools (showdb dbheader, sqlite3_analyzer output, beginning of >> the free list dump). I'm willing to send the whole database file >> (~5Gb) to sqlite developers on request. >> >> My questions are: >> - Is is expected behavior that "pragma incremental_vacuum(1);" can >> create 14Mb WAL file even though the page size is just 1Kb? >> - If not, is it a know bug? If yes, in what circumstances? >> - Is the free list corrupted? And if it is, how could this happen and >> should "pragma integrity_check;" verify it? > > Was there a *-wal file in the file-system when you ran the > [showdb] tool? [showdb] just reads the database file, it is > not smart enough to know when it should read pages out of the > wal file instead of the db. So if there is a wal file that > contains content, [showdb] could report corruption. > > Also, can you try with this patch? > > http://www.sqlite.org/src/ci/311d0b613d > > It might help with the 14MB wal files. > > Dan.
Hi Dan, there was no -wal file when I ran the showdb tool. I recompiled sqlite from the current 3.7.6 snapshot (sqlite-amalgamation-201104052208.zip) and verified that it contained your patch. Unfortunately it didn't help with the large WAL file for this particular database. Best regards, Filip Navara _______________________________________________ sqlite-users mailing list sqlite-users@sqlite.org http://sqlite.org:8080/cgi-bin/mailman/listinfo/sqlite-users
