InnoDB Plugin  1.0
Data Structures | Macros | Functions | Variables
btr0sea.h File Reference
#include "univ.i"
#include "rem0rec.h"
#include "dict0dict.h"
#include "btr0types.h"
#include "mtr0mtr.h"
#include "ha0ha.h"
#include "btr0sea.ic"
Include dependency graph for btr0sea.h:

Go to the source code of this file.

Data Structures

struct  btr_search_t
struct  btr_search_sys_t


#define BTR_SEARCH_MAGIC_N   1112765
#define BTR_SEA_TIMEOUT   10000


UNIV_INTERN void btr_search_sys_create (ulint hash_size)
UNIV_INTERN void btr_search_sys_free (void)
UNIV_INTERN void btr_search_disable (void)
UNIV_INTERN void btr_search_enable (void)
UNIV_INLINE btr_search_tbtr_search_get_info (dict_index_t *index))
UNIV_INTERN btr_search_tbtr_search_info_create (mem_heap_t *heap)
UNIV_INTERN ulint btr_search_info_get_ref_count (btr_search_t *info)
UNIV_INLINE void btr_search_info_update (dict_index_t *index, btr_cur_t *cursor)
UNIV_INTERN ibool btr_search_guess_on_hash (dict_index_t *index, btr_search_t *info, const dtuple_t *tuple, ulint mode, ulint latch_mode, btr_cur_t *cursor, ulint has_search_latch, mtr_t *mtr)
UNIV_INTERN void btr_search_move_or_delete_hash_entries (buf_block_t *new_block, buf_block_t *block, dict_index_t *index)
UNIV_INTERN void btr_search_drop_page_hash_index (buf_block_t *block)
UNIV_INTERN void btr_search_drop_page_hash_when_freed (ulint space, ulint zip_size, ulint page_no)
UNIV_INTERN void btr_search_update_hash_node_on_insert (btr_cur_t *cursor)
UNIV_INTERN void btr_search_update_hash_on_insert (btr_cur_t *cursor)
UNIV_INTERN void btr_search_update_hash_on_delete (btr_cur_t *cursor)
UNIV_INTERN ibool btr_search_validate (void)



Detailed Description

The index tree adaptive search

Created 2/17/1996 Heikki Tuuri

Macro Definition Documentation

#define BTR_SEA_TIMEOUT   10000
We do this many searches before trying to keep the search latch

over calls from MySQL. If we notice someone waiting for the latch, we again set this much timeout. This is to reduce contention.

After change in n_fields or n_bytes in info, this many rounds are waited

before starting the hash analysis again: this is to save CPU time when there is no hope in building a hash index.

#define BTR_SEARCH_MAGIC_N   1112765

value of btr_search_t::magic_n, used in assertions

Limit of consecutive searches for trying a search shortcut using

the hash index

Limit of consecutive searches for trying a search shortcut on the search


Function Documentation

UNIV_INTERN void btr_search_disable ( void  )

Disable the adaptive hash search system and empty the index.

UNIV_INTERN void btr_search_drop_page_hash_index ( buf_block_t block)

Drops a page hash index. in: block containing index page, s- or x-latched, or an index page for which we know that block->buf_fix_count == 0

UNIV_INTERN void btr_search_drop_page_hash_when_freed ( ulint  space,
ulint  zip_size,
ulint  page_no 

Drops a possible page hash index when a page is evicted from the buffer pool or freed in a file segment. in: page number

spacein: space id
zip_sizein: compressed page size in bytes or 0 for uncompressed pages
UNIV_INTERN void btr_search_enable ( void  )

Enable the adaptive hash search system.

UNIV_INLINE btr_search_t* btr_search_get_info ( dict_index_t index)

Returns search info for an index.

search info; search mutex reserved
indexin: index
UNIV_INTERN ibool btr_search_guess_on_hash ( dict_index_t index,
btr_search_t info,
const dtuple_t tuple,
ulint  mode,
ulint  latch_mode,
btr_cur_t cursor,
ulint  has_search_latch,
mtr_t mtr 

Tries to guess the right search position based on the hash search info of the index. Note that if mode is PAGE_CUR_LE, which is used in inserts, and the function returns TRUE, then cursor->up_match and cursor->low_match both have sensible values.

TRUE if succeeded in: mtr
indexin: index
infoin: index search info
tuplein: logical record
modein: PAGE_CUR_L, ...
latch_modein: BTR_SEARCH_LEAF, ...
cursorout: tree cursor
has_search_latchin: latch mode the caller currently has on btr_search_latch: RW_S_LATCH, RW_X_LATCH, or 0
UNIV_INTERN btr_search_t* btr_search_info_create ( mem_heap_t heap)

Creates and initializes a search info struct.

own: search info struct in: heap where created
UNIV_INTERN ulint btr_search_info_get_ref_count ( btr_search_t info)

Returns the value of ref_count. The value is protected by btr_search_latch.

ref_count value. in: search info.
UNIV_INLINE void btr_search_info_update ( dict_index_t index,
btr_cur_t cursor 

Updates the search info. in: cursor which was just positioned

Updates the search info.

indexin: index of the cursor
cursorin: cursor which was just positioned
UNIV_INTERN void btr_search_move_or_delete_hash_entries ( buf_block_t new_block,
buf_block_t block,
dict_index_t index 

Moves or deletes hash entries for moved records. If new_page is already hashed, then the hash index for page, if any, is dropped. If new_page is not hashed, and page is hashed, then a new hash index is built to new_page with the same parameters as page (this often happens when a page is split). in: record descriptor

new_blockin: records are copied to this page
blockin: index page from which records were copied, and the copied records will be deleted from this page
UNIV_INTERN void btr_search_sys_create ( ulint  hash_size)

Creates and initializes the adaptive search system at a database start. in: hash index hash table size

UNIV_INTERN void btr_search_sys_free ( void  )

Frees the adaptive search system at a database shutdown.

UNIV_INTERN void btr_search_update_hash_node_on_insert ( btr_cur_t cursor)

Updates the page hash index when a single record is inserted on a page. in: cursor which was positioned to the place to insert using btr_cur_search_..., and the new record has been inserted next to the cursor

UNIV_INTERN void btr_search_update_hash_on_delete ( btr_cur_t cursor)

Updates the page hash index when a single record is deleted from a page. in: cursor which was positioned on the record to delete using btr_cur_search_..., the record is not yet deleted

UNIV_INTERN void btr_search_update_hash_on_insert ( btr_cur_t cursor)

Updates the page hash index when a single record is inserted on a page. in: cursor which was positioned to the place to insert using btr_cur_search_..., and the new record has been inserted next to the cursor

UNIV_INTERN ibool btr_search_validate ( void  )

Validates the search system.

TRUE if ok

Variable Documentation

btr_search_sys_t* btr_search_sys

The adaptive hash index