mariadb/sql/vector_mhnsw.h
Sergei Golubchik 9f80e3fbb7 MDEV-35032 streaming mode for mhnsw search
support SQL semantics for SELECT ... WHERE ... ORDER BY ... LIMIT

* switch from returning k nearest neighbors to returning
  as many as needed, in k-neighbor chunks, with increasing distance
* make search_layer() skips nodes that are closer than a threshold
* read_next keeps a search context - list of k found nodes,
  threshold, ctx, etc.
* when the list of found nodes is exhausted, it repeats the search
  starting from last found nodes and a threshold
* search context kepts ctx->refcount incremented, so ctx won't go away
* but commit_lock is unlocked between calls, so InnoDB can modify the table
* use ctx version to detect that, switch to MHNSW_Trx when it happens

bugfix:
* use the correct lock in ha_external_lock() for the graph table
* InnoDB didn't reset locks on ha_external_lock(F_UNLCK) and previous
  LOCK_X leaked into the next statement
2024-11-05 14:00:51 -08:00

39 lines
1.5 KiB
C

/*
Copyright (c) 2024, MariaDB plc
This program is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; version 2 of the License.
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program; if not, write to the Free Software
Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1335 USA
*/
#include <my_global.h>
#include "item.h"
#include "m_string.h"
#include "structs.h"
#include "table.h"
/*
This will become a vector index plugin API, or, perhaps,
a hlindex plugin API. When we'll have more than one implementation.
*/
const LEX_CSTRING mhnsw_hlindex_table_def(THD *thd, uint ref_length);
int mhnsw_insert(TABLE *table, KEY *keyinfo);
int mhnsw_read_first(TABLE *table, KEY *keyinfo, Item *dist, ulonglong limit);
int mhnsw_read_next(TABLE *table);
int mhnsw_read_end(TABLE *table);
int mhnsw_invalidate(TABLE *table, const uchar *rec, KEY *keyinfo);
int mhnsw_delete_all(TABLE *table, KEY *keyinfo, bool truncate);
void mhnsw_free(TABLE_SHARE *share);
bool mhnsw_uses_distance(const TABLE *table, KEY *keyinfo, const Item *dist);
extern ha_create_table_option mhnsw_index_options[];
extern st_plugin_int *mhnsw_plugin;