btr_search_sys_t::search_part_t Class Reference

#include <btr0sea.h>

Public Member Functions
void	initialize (size_t hash_size)

Public Attributes
rw_lock_t	latch
	The latch protecting the adaptive search part: this latch protects the (1) positions of records on those pages where a hash index has been built. More...
hash_table_t *	hash_table
	The adaptive hash table, mapping dtuple_hash values to rec_t pointers on index pages. More...
std::atomic< buf_block_t * >	free_block_for_heap
	A pointer to a free block that the heap in the hash table may use for adding new hash nodes. More...

Member Function Documentation

initialize()

void btr_search_sys_t::search_part_t::initialize

(

size_t

hash_size

)

Member Data Documentation

free_block_for_heap

std::atomic<buf_block_t *> btr_search_sys_t::search_part_t::free_block_for_heap

A pointer to a free block that the heap in the hash table may use for adding new hash nodes.

Changes to nullptr are done under appropriate X-latched rwlock. Changes from nullptr to non-nullptr are done without any protection. Changes from non-null to a different non-null are prohibited.

hash_table

hash_table_t* btr_search_sys_t::search_part_t::hash_table

The adaptive hash table, mapping dtuple_hash values to rec_t pointers on index pages.

For any hash value at most one pointer is hold. Is protected by the part's latch. It is in a separate cache line to not collide with the possible multiple readers that are registering for the latching.

latch

rw_lock_t btr_search_sys_t::search_part_t::latch

The latch protecting the adaptive search part: this latch protects the (1) positions of records on those pages where a hash index has been built.

NOTE: It does not protect values of non-ordering fields within a record from being updated in-place! We can use fact (1) to perform unique searches to indexes.

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The documentation for this class was generated from the following files:

• storage/innobase/include/btr0sea.h
• storage/innobase/btr/btr0sea.cc