hamsterdb Embedded Database 1.1.15
Data Fields
ham_freelist_page_statistics_t Struct Reference

#include <hamsterdb_stats.h>

Data Fields

ham_freelist_slotsize_stats_t per_size [HAM_FREELIST_SLOT_SPREAD]
ham_u32_t last_start
ham_u32_t persisted_bits
ham_u32_t insert_count
ham_u32_t delete_count
ham_u32_t extend_count
ham_u32_t fail_count
ham_u32_t search_count
ham_u32_t rescale_monitor

Detailed Description

freelist statistics as they are persisted on disc.

Stats are kept with each freelist entry record, but we also keep some derived data in the nonpermanent space with each freelist: it's not required to keep a freelist page in cache just so the statistics + our operational mode combined can tell us it's a waste of time to go there.

Definition at line 118 of file hamsterdb_stats.h.


Field Documentation

Definition at line 150 of file hamsterdb_stats.h.

Definition at line 151 of file hamsterdb_stats.h.

Definition at line 152 of file hamsterdb_stats.h.

count the number of insert operations where this freelist page played a role

Definition at line 149 of file hamsterdb_stats.h.

(bit) offset which tells us which free slot is the EVER LAST created one; after all, freelistpage:maxbits is a scandalously optimistic lie: all it tells us is how large the freelist page _itself_ can grow, NOT how many free slots we actually have _alive_ in there.

0: special case, meaning: not yet initialized...

Definition at line 131 of file hamsterdb_stats.h.

Definition at line 120 of file hamsterdb_stats.h.

total number of available bits in the page ~ all the chunks which actually represent a chunk in the DB storage space.

(Note that a freelist can be larger (_max_bits) than the actual number of storage pages currently sitting in the database file.)

The number of chunks already in use in the database therefore ~ persisted_bits - _allocated_bits.

Definition at line 143 of file hamsterdb_stats.h.

Definition at line 155 of file hamsterdb_stats.h.

Definition at line 153 of file hamsterdb_stats.h.


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