MDBX_txn_info Struct Reference

Information about the transaction. More...

#include <mdbx.h>

Public Attributes
uint64_t	txn_id
uint64_t	txn_reader_lag
uint64_t	txn_space_used
uint64_t	txn_space_limit_soft
uint64_t	txn_space_limit_hard
uint64_t	txn_space_retired
uint64_t	txn_space_leftover
uint64_t	txn_space_dirty

Detailed Description

Information about the transaction.

See also

mdbx_txn_info

Member Data Documentation

txn_id

uint64_t MDBX_txn_info::txn_id

The ID of the transaction. For a READ-ONLY transaction, this corresponds to the snapshot being read.

txn_reader_lag

uint64_t MDBX_txn_info::txn_reader_lag

For READ-ONLY transaction: the lag from a recent MVCC-snapshot, i.e. the number of committed transaction since read transaction started. For WRITE transaction (provided if scan_rlt=true): the lag of the oldest reader from current transaction (i.e. at least 1 if any reader running).

txn_space_dirty

uint64_t MDBX_txn_info::txn_space_dirty

For READ-ONLY transaction (provided if scan_rlt=true): The space that actually become available for reuse when only this transaction will be finished. For WRITE transaction: The summarized size of the dirty database pages that generated during this transaction.

txn_space_leftover

uint64_t MDBX_txn_info::txn_space_leftover

For READ-ONLY transaction: the space available for writer(s) and that must be exhausted for reason to call the Handle-Slow-Readers callback for this read transaction. For WRITE transaction: the space inside transaction that left to MDBX_TXN_FULL error.

txn_space_limit_hard

uint64_t MDBX_txn_info::txn_space_limit_hard

Upper bound for size the database file, i.e. the value size_upper argument of the appropriate call of mdbx_env_set_geometry().

txn_space_limit_soft

uint64_t MDBX_txn_info::txn_space_limit_soft

Current size of database file.

txn_space_retired

uint64_t MDBX_txn_info::txn_space_retired

For READ-ONLY transaction: The total size of the database pages that were retired by committed write transactions after the reader's MVCC-snapshot, i.e. the space which would be freed after the Reader releases the MVCC-snapshot for reuse by completion read transaction. For WRITE transaction: The summarized size of the database pages that were retired for now due Copy-On-Write during this transaction.

txn_space_used

uint64_t MDBX_txn_info::txn_space_used

Used space by this transaction, i.e. corresponding to the last used database page.

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

• mdbx.h