Something like a bug in pt-online-schema-change deleted many rows after i Alter the table and add a unique key to a col.
Actually it ignored errors about duplicate keys and removed any duplicate row i think!
BTW i got a disk image from hard drive in another server and i searched it for my lost data , Fortunately i could find my lost data inside image.
Notice : pt-online-schema-change always makes a new table and old table then copy data from one to another then delete and rename them.
SO if i can recover table_old and “undrop” it from disk image , of course i can get my data back.
I Found this :
BUT unfortunately it has very weak document : I separated pages in different subdirectory but please look what docs said :
“Now that we have split the pages into separate subdirectories, we need to determine which index holds the data we are interested in recovering. In most cases, we want to recover from the table’s PRIMARY index, which contains the full rows. There are several ways to accomplish this.” Document says.
Really thanks to the writer who mentioned there are several ways to accomplish this !
Can anyone tell me what’s one of this ways ?
I Really need your helps.