I've already posted here question about getting SQLITE_BUSY when calling sqlite3_prepare in single thread application dependent on database size. Now I get more detailed diagnostic.
I have simple database but with considerable amount of records in some tables. Sql commands looks like: Begin transaction delete from some_table (most of records) select from sqlite_master insert into some_table commit transaction I get SQLITE_BUSY trying to select from sqlite_master. Looking into sqlite code I found that sqlite get exclusive lock on database file when database exceeds some limit. And after this it makes one more lock which of cause ends with error. Here you can find two fragments of sqlite trace. First is for smaller database: First: OPEN 1980 LOCK 1980 1 was 0(0) UNLOCK 1980 to 0 was 1(0) LOCK 1980 1 was 0(0) UNLOCK 1980 to 0 was 1(0) LOCK 1980 1 was 0(0) LOCK 1980 2 was 1(0) OPEN 1972 - journal file OPEN 1968 LOCK 1968 1 was 0(0) TEST WR-LOCK 1968 1 (remote) UNLOCK 1968 to 0 was 1(0) LOCK 1968 1 was 0(0) TEST WR-LOCK 1968 1 (remote) UNLOCK 1968 to 0 was 1(0) UNLOCK 1968 to 0 was 0(0) CLOSE 1968 LOCK 1980 4 was 2(0) unreadlock = 1 CLOSE 1972 UNLOCK 1980 to 1 was 4(0) UNLOCK 1980 to 0 was 1(0) UNLOCK 1980 to 0 was 0(0) CLOSE 1980 And second: OPEN 1980 LOCK 1980 1 was 0(0) UNLOCK 1980 to 0 was 1(0) LOCK 1980 1 was 0(0) UNLOCK 1980 to 0 was 1(0) LOCK 1980 1 was 0(0) LOCK 1980 2 was 1(0) OPEN 1972 - journal file LOCK 1980 4 was 2(0) - exclusive lock unreadlock = 1 OPEN 1968 LOCK 1968 1 was 0(0) LOCK FAILED 1968 trying for 1 but got 0 UNLOCK 1968 to 0 was 0(0) CLOSE 1968 CLOSE 1972 UNLOCK 1980 to 1 was 4(0) UNLOCK 1980 to 0 was 1(0) UNLOCK 1980 to 0 was 0(0) CLOSE 1980
