Class Innodb::UndoRecord
In: lib/innodb/undo_record.rb
Parent: Object

A single undo log record.

Methods

cursor   dump   get   has_previous_version?   header   key   key_string   new   new_subordinate   next   offset   page   pos_header   pos_record   prev   prev_by_history   read_record   read_record_fields   record_size   roll_ptr   row   row_string   size_header   string   table_id   trx_id   type   undo_no   undo_record  

Constants

TYPE = { 11 => :insert, 12 => :update_existing, 13 => :update_deleted, 14 => :delete, }   Possible undo record types.
TYPE_MASK = 0x0f
COMPILATION_INFO_MASK = 0x70
COMPILATION_INFO_SHIFT = 4
COMPILATION_INFO_NO_ORDER_CHANGE_BV = 1
COMPILATION_INFO_NO_SIZE_CHANGE_BV = 2
EXTERN_FLAG = 0x80

Attributes

index_page  [RW] 
position  [R] 
undo_log  [RW] 
undo_page  [R] 

Public Class methods

Public Instance methods

cursor(position)

Return a BufferCursor starting before the header.

pos_header()

The header really starts 2 bytes before the undo record position, as the pointer to the previous record is written there.

prev_by_history()

Find the previous row version by following the roll_ptr from one undo record to the next (backwards through the record version history). Since we are operating without the benefit of knowing about active transactions and without protection from purge, check that everything looks sane before returning it.

size_header()

The size of the header.

[Validate]