OP_IdxIsNull     3598 ext/sqlite/libsqlite/src/vdbe.c case OP_IdxIsNull: {
OP_IdxIsNull      857 ext/sqlite/libsqlite/src/where.c       sqliteVdbeAddOp(v, OP_IdxIsNull, nColumn, cont);
OP_IdxIsNull     1120 ext/sqlite/libsqlite/src/where.c       sqliteVdbeAddOp(v, OP_IdxIsNull, nEqColumn + (score & 1), cont);