libmdbx (2022-08-02T12:00:30+03:00)
One of the fastest compact embeddable key-value ACID database without WAL.
mdbx::env::reader_info Struct Reference

Reader information. More...

#include <mdbx.h++>

Public Member Functions

 reader_info (int slot, mdbx_pid_t pid, mdbx_tid_t thread, uint64_t txnid, uint64_t lag, size_t used, size_t retained) noexcept

Public Attributes

int slot
 The reader lock table slot number. More...
mdbx_pid_t pid
 The reader process ID. More...
mdbx_tid_t thread
 The reader thread ID. More...
uint64_t transaction_id
uint64_t transaction_lag
size_t bytes_used
size_t bytes_retained

Detailed Description

Reader information.

Member Data Documentation

◆ bytes_retained

size_t mdbx::env::reader_info::bytes_retained

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.

◆ bytes_used

size_t mdbx::env::reader_info::bytes_used

The number of last used page in the MVCC-snapshot which being read, i.e. database file can't shrinked beyond this.

◆ pid

mdbx_pid_t mdbx::env::reader_info::pid

The reader process ID.

◆ slot

int mdbx::env::reader_info::slot

The reader lock table slot number.

◆ thread

mdbx_tid_t mdbx::env::reader_info::thread

The reader thread ID.

◆ transaction_id

uint64_t mdbx::env::reader_info::transaction_id

The ID of the transaction being read, i.e. the MVCC-snapshot number.

◆ transaction_lag

uint64_t mdbx::env::reader_info::transaction_lag

The lag from a recent MVCC-snapshot, i.e. the number of committed write transactions since the current read transaction started.

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