work consistently on replication
Row-based replication does not execute CREATE .. SELECT but instead
CREATE TABLE. CREATE .. SELECT creates implict system fields on
unusual place: in-between declared fields and select fields. That was
done because select_field_pos logic requires select fields go last in
create_list.
So, CREATE .. SELECT on master and CREATE TABLE on slave create system
fields on different positions and replication gets field mismatch.
To fix this we've changed CREATE .. SELECT to create implicit system
fields on usual place in the end and updated select_field_pos for
handling this case.
Implicit system-versioned table does not contain system fields in SHOW
CREATE. Therefore after mysqldump recovery such table has system
fields in the last place in frm image. The original table meanwhile
does not guarantee these system fields on last place because adding
new fields via ALTER TABLE places them last. Thus the order of fields
may be different between master and slave, so row-based replication
may fail.
To fix this on ALTER TABLE we now place system-invisible fields always
last in frm image. If the table was created via old revision and has
an incorrect order of fields it can be fixed via any copy operation of
ALTER TABLE, f.ex.:
ALTER TABLE t1 FORCE;
To check the order of fields in frm file one can use hexdump:
hexdump -C t1.frm
Note, the replication fails only when all 3 conditions are met:
1. row-based or mixed mode replication;
2. table has new fields added via ALTER TABLE;
3. table was rebuilt on some, but not all nodes via mysqldump image.
Otherwise it will operate properly even with incorrect order of
fields.
