------------------------------------------------------------
revno: 3529
revision-id: marko.makela@oracle.com-20100629125518-m3am4ia1ffjr0d0j
parent: jimmy.yang@oracle.com-20100629024137-690sacm5sogruzvb
committer: Marko Mäkelä <marko.makela@oracle.com>
branch nick: 5.1-innodb
timestamp: Tue 2010-06-29 15:55:18 +0300
message:
  Bug#54358: READ UNCOMMITTED access failure of off-page DYNAMIC or COMPRESSED
  columns

  When the server crashes after a record stub has been inserted and
  before all its off-page columns have been written, the record will
  contain incomplete off-page columns after crash recovery. Such records
  may only be accessed at the READ UNCOMMITTED isolation level or when
  rolling back a recovered transaction in recv_recovery_rollback_active().
  Skip these records at the READ UNCOMMITTED isolation level.

  TODO: Add assertions for checking the above assumptions hold when an
  incomplete BLOB is encountered.

  btr_rec_copy_externally_stored_field(): Return NULL if the field is
  incomplete.

  row_prebuilt_t::templ_contains_blob: Clarify what "BLOB" means in this
  context. Hint: MySQL BLOBs are not the same as InnoDB BLOBs.

  row_sel_store_mysql_rec(): Return FALSE if not all columns could be
  retrieved. Previously this function always returned TRUE.  Assert that
  the record is not delete-marked.

  row_sel_push_cache_row_for_mysql(): Return FALSE if not all columns
  could be retrieved.

  row_search_for_mysql(): Skip records containing incomplete off-page
  columns. Assert that the transaction isolation level is READ
  UNCOMMITTED.

  rb://380 approved by Jimmy Yang