nBackup          52435 ext/sqlite3/libsqlite/sqlite3.c   int nBackup;       /* Number of backup operations reading this btree */
nBackup          62094 ext/sqlite3/libsqlite/sqlite3.c   return p->nBackup!=0;
nBackup          62510 ext/sqlite3/libsqlite/sqlite3.c     p->pSrc->nBackup++;
nBackup          62914 ext/sqlite3/libsqlite/sqlite3.c     p->pSrc->nBackup--;