MySQL 5.6.14 Source Code Document
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#include <read0read.h>
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_t * | trx_ids |
trx_id_t | creator_trx_id |
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.
read_view_t::UT_LIST_NODE_T | ( | read_view_t | ) |
List of read views in trx_sys
trx_id_t read_view_t::creator_trx_id |
trx id of creating transaction, or 0 used in purge
Definition at line 157 of file read0read.h.
trx_id_t read_view_t::low_limit_id |
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.
trx_id_t read_view_t::low_limit_no |
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.
ulint read_view_t::n_trx_ids |
Number of cells in the trx_ids array
Definition at line 147 of file read0read.h.
trx_id_t* read_view_t::trx_ids |
Additional trx ids which the read should not see: typically, these are the read-write 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.
ulint read_view_t::type |
VIEW_NORMAL, VIEW_HIGH_GRANULARITY
Definition at line 126 of file read0read.h.
undo_no_t read_view_t::undo_no |
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.
trx_id_t read_view_t::up_limit_id |
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.