Drizzled Public API Documentation

read_view_struct Struct Reference

#include <read0read.h>

List of all members.

Public Member Functions

 UT_LIST_NODE_T (read_view_t) view_list

Public Attributes

ulint type
undo_no_t undo_no
trx_id_t low_limit_no
trx_id_t low_limit_id
trx_id_t up_limit_id
ulint n_trx_ids
trx_id_ttrx_ids
trx_id_t creator_trx_id

Detailed Description

Read view lists the trx ids of those transactions for which a consistent read should not see the modifications to the database.

Definition at line 125 of file read0read.h.


Member Function Documentation

List of read views in trx_sys


Member Data Documentation

The read should not see any transaction with trx id >= this value. In other words, this is the "high water mark".

Definition at line 138 of file read0read.h.

Referenced by lock_print_info_all_transactions(), read_cursor_view_create_for_mysql(), read_view_oldest_copy_or_open_new(), read_view_open_now(), and read_view_print().

The view does not need to see the undo logs for transactions whose transaction number is strictly smaller (<) than this value: they can be removed in purge if not needed by other views

Definition at line 132 of file read0read.h.

Referenced by read_cursor_view_create_for_mysql(), read_view_oldest_copy_or_open_new(), read_view_open_now(), read_view_print(), and trx_purge_fetch_next_rec().

Number of cells in the trx_ids array

Definition at line 147 of file read0read.h.

Referenced by read_cursor_view_create_for_mysql(), read_view_oldest_copy_or_open_new(), read_view_open_now(), and read_view_print().

Additional trx ids which the read should not see: typically, these are the active transactions at the time when the read is serialized, except the reading transaction itself; the trx ids in this array are in a descending order. These trx_ids should be between the "low" and "high" water marks, that is, up_limit_id and low_limit_id.

Definition at line 148 of file read0read.h.

VIEW_NORMAL, VIEW_HIGH_GRANULARITY

Definition at line 126 of file read0read.h.

Referenced by read_cursor_view_create_for_mysql(), read_view_open_now(), read_view_print(), and row_vers_build_for_consistent_read().

0 or if type is VIEW_HIGH_GRANULARITY transaction undo_no when this high-granularity consistent read view was created

Definition at line 127 of file read0read.h.

Referenced by read_cursor_view_create_for_mysql(), read_view_open_now(), read_view_print(), and row_vers_build_for_consistent_read().

The read should see all trx ids which are strictly smaller (<) than this value. In other words, this is the "low water mark".

Definition at line 142 of file read0read.h.

Referenced by lock_print_info_all_transactions(), read_cursor_view_create_for_mysql(), read_view_oldest_copy_or_open_new(), read_view_open_now(), and read_view_print().


The documentation for this struct was generated from the following file: