InnoDB table SELECT returns ERROR 2006 (HY000): MySQL server has gone away (after power outage)

This looks oddly familiar.

I have seen this occur with one of my web hosting client's DB servers. There was a particular table that crashed mysqld every single time you accessed it, even with SHOW CREATE TABLE.

The problem stems from a corrupt data dictionary. There is really no way to correct it. You could attempt to alter the tablespace_id within the .ibd file but the headache stems from locating the tablespace_id list internal to ibdata1.

Even if you create a MyISAM table with the same name in the same database as the original InnoDB table, you cannot convert it to InnoDB because the tablespace_id is already associated with the table name. This, of course, is a corrupted state. It's like having a pidgeon hole in ibdata1 that you cannot patch up without some exploratory surgery.

You may have to mysqldump everything except the database that houses the corrupt table. You would then have to mysqldump every table in that database except the corrupt table. Remember, it is the data dictionary's view of the table that is screwed up, not necessarily the table's data.

The only sure way to clean everything up is to perform the mysqldumps as I just specified, shutdown mysql, rm -rf all DB folders except /var/lib/mytsql/mysql, delete ibdata1, delete ib_logfile0, delete ib_logfile1, startup mysql, reload all mysqldumps. See my StackOverflow post about cleaning up your InnoDB infrastructure.

Since you are not using innodb_file_per_table, any tables with this corrupt state of things within ibdata1 are lost as casualities of war. My condolences.

For future reference, click here to see an artistic conception of InnoDB and its Internals.

You seem to hit the worst possible case: A corrupt innodb tablespace without a backup to restore from (which is likely much quicker).

There is a free innodb recovery tool offered by Percona, and this blog walks through how to use it to restore your corrupted data, without a backup.

There is this very important caveat:

The time between the deletion of rows and the database stop is crucial. If pages are reused you can’t recover the data.

Unfortunately, you are about to get much more experience in repairing corrupted innodb than I have ever done, personally.