MySQL 8.4.3
Source Code Documentation
ha_example Class Reference

Class definition for the storage engine. More...

#include <ha_example.h>

Inheritance diagram for ha_example:
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Public Member Functions

 ha_example (handlerton *hton, TABLE_SHARE *table_arg)
 
 ~ha_example () override=default
 
const char * table_type () const override
 The name that will be used for display purposes. More...
 
enum ha_key_alg get_default_index_algorithm () const override
 Replace key algorithm with one supported by SE, return the default key algorithm for SE if explicit key algorithm was not provided. More...
 
bool is_index_algorithm_supported (enum ha_key_alg key_alg) const override
 Check if SE supports specific key algorithm. More...
 
ulonglong table_flags () const override
 This is a list of flags that indicate what functionality the storage engine implements. More...
 
ulong index_flags (uint inx, uint part, bool all_parts) const override
 This is a bitmap of flags that indicates how the storage engine implements indexes. More...
 
uint max_supported_record_length () const override
 unireg.cc will call max_supported_record_length(), max_supported_keys(), max_supported_key_parts(), uint max_supported_key_length() to make sure that the storage engine can handle the data it is about to send. More...
 
uint max_supported_keys () const override
 unireg.cc will call this to make sure that the storage engine can handle the data it is about to send. More...
 
uint max_supported_key_parts () const override
 unireg.cc will call this to make sure that the storage engine can handle the data it is about to send. More...
 
uint max_supported_key_length () const override
 unireg.cc will call this to make sure that the storage engine can handle the data it is about to send. More...
 
double scan_time () override
 Called in test_quick_select to determine if indexes should be used. More...
 
double read_time (uint, uint, ha_rows rows) override
 This method will never be called if you do not implement indexes. More...
 
int open (const char *name, int mode, uint test_if_locked, const dd::Table *table_def) override
 We implement this in ha_example.cc; it's a required method. More...
 
int close (void) override
 We implement this in ha_example.cc; it's a required method. More...
 
int write_row (uchar *buf) override
 We implement this in ha_example.cc. More...
 
int update_row (const uchar *old_data, uchar *new_data) override
 We implement this in ha_example.cc. More...
 
int delete_row (const uchar *buf) override
 We implement this in ha_example.cc. More...
 
int index_read_map (uchar *buf, const uchar *key, key_part_map keypart_map, enum ha_rkey_function find_flag) override
 We implement this in ha_example.cc. More...
 
int index_next (uchar *buf) override
 We implement this in ha_example.cc. More...
 
int index_prev (uchar *buf) override
 We implement this in ha_example.cc. More...
 
int index_first (uchar *buf) override
 We implement this in ha_example.cc. More...
 
int index_last (uchar *buf) override
 We implement this in ha_example.cc. More...
 
int rnd_init (bool scan) override
 Unlike index_init(), rnd_init() can be called two consecutive times without rnd_end() in between (it only makes sense if scan=1). More...
 
int rnd_end () override
 
int rnd_next (uchar *buf) override
 required More...
 
int rnd_pos (uchar *buf, uchar *pos) override
 required More...
 
void position (const uchar *record) override
 required More...
 
int info (uint) override
 required More...
 
int extra (enum ha_extra_function operation) override
 extra() is called whenever the server wishes to send a hint to the storage engine. More...
 
int external_lock (THD *thd, int lock_type) override
 required More...
 
int delete_all_rows (void) override
 Used to delete all rows in a table, including cases of truncate and cases where the optimizer realizes that all rows will be removed as a result of an SQL statement. More...
 
ha_rows records_in_range (uint inx, key_range *min_key, key_range *max_key) override
 Given a starting key and an ending key, estimate the number of rows that will exist between the two keys. More...
 
int delete_table (const char *from, const dd::Table *table_def) override
 Used to delete a table. More...
 
int rename_table (const char *from, const char *to, const dd::Table *from_table_def, dd::Table *to_table_def) override
 Renames a table from one name to another via an alter table call. More...
 
int create (const char *name, TABLE *form, HA_CREATE_INFO *create_info, dd::Table *table_def) override
 required More...
 
THR_LOCK_DATA ** store_lock (THD *thd, THR_LOCK_DATA **to, enum thr_lock_type lock_type) override
 required More...
 
- Public Member Functions inherited from handler
void unbind_psi ()
 
void rebind_psi ()
 
void start_psi_batch_mode ()
 Put the handler in 'batch' mode when collecting table io instrumented events. More...
 
void end_psi_batch_mode ()
 End a batch started with start_psi_batch_mode. More...
 
bool end_psi_batch_mode_if_started ()
 If a PSI batch was started, turn if off. More...
 
 handler (handlerton *ht_arg, TABLE_SHARE *share_arg)
 
virtual ~handler (void)
 
virtual std::string explain_extra () const
 Return extra handler specific text for EXPLAIN. More...
 
virtual handlerclone (const char *name, MEM_ROOT *mem_root)
 
void init ()
 This is called after create to allow us to set up cached variables. More...
 
void ha_set_record_buffer (Record_buffer *buffer)
 Set a record buffer that the storage engine can use for multi-row reads. More...
 
Record_bufferha_get_record_buffer () const
 Get the record buffer that was set with ha_set_record_buffer(). More...
 
bool ha_is_record_buffer_wanted (ha_rows *const max_rows) const
 Does this handler want to get a Record_buffer for multi-row reads via the ha_set_record_buffer() function? And if so, what is the maximum number of records to allocate space for in the buffer? More...
 
int ha_open (TABLE *table, const char *name, int mode, int test_if_locked, const dd::Table *table_def)
 
int ha_close (void)
 Close handler. More...
 
int ha_index_init (uint idx, bool sorted)
 Initialize use of index. More...
 
int ha_index_end ()
 End use of index. More...
 
int ha_rnd_init (bool scan)
 Initialize table for random read or scan. More...
 
int ha_rnd_end ()
 End use of random access. More...
 
int ha_rnd_next (uchar *buf)
 Read next row via random scan. More...
 
int ha_rnd_pos (uchar *buf, uchar *pos)
 Read row via random scan from position. More...
 
int ha_index_read_map (uchar *buf, const uchar *key, key_part_map keypart_map, enum ha_rkey_function find_flag)
 Read [part of] row via [part of] index. More...
 
int ha_index_read_last_map (uchar *buf, const uchar *key, key_part_map keypart_map)
 
int ha_index_read_idx_map (uchar *buf, uint index, const uchar *key, key_part_map keypart_map, enum ha_rkey_function find_flag)
 Initializes an index and read it. More...
 
int ha_index_next (uchar *buf)
 Reads the next row via index. More...
 
int ha_index_prev (uchar *buf)
 Reads the previous row via index. More...
 
int ha_index_first (uchar *buf)
 Reads the first row via index. More...
 
int ha_index_last (uchar *buf)
 Reads the last row via index. More...
 
int ha_index_next_same (uchar *buf, const uchar *key, uint keylen)
 Reads the next same row via index. More...
 
int ha_reset ()
 Check handler usage and reset state of file to after 'open'. More...
 
int ha_index_or_rnd_end ()
 
Table_flags ha_table_flags () const
 The cached_table_flags is set at ha_open and ha_external_lock. More...
 
int ha_external_lock (THD *thd, int lock_type)
 These functions represent the public interface to users of the handler class, hence they are not virtual. More...
 
int ha_write_row (uchar *buf)
 
int ha_update_row (const uchar *old_data, uchar *new_data)
 Update the current row. More...
 
int ha_delete_row (const uchar *buf)
 
void ha_release_auto_increment ()
 
int ha_check_for_upgrade (HA_CHECK_OPT *check_opt)
 
int ha_check (THD *thd, HA_CHECK_OPT *check_opt)
 to be actually called to get 'check()' functionality More...
 
int ha_repair (THD *thd, HA_CHECK_OPT *check_opt)
 Repair table: public interface. More...
 
void ha_start_bulk_insert (ha_rows rows)
 Start bulk insert. More...
 
int ha_end_bulk_insert ()
 End bulk insert. More...
 
int ha_bulk_update_row (const uchar *old_data, uchar *new_data, uint *dup_key_found)
 Bulk update row: public interface. More...
 
int ha_delete_all_rows ()
 Delete all rows: public interface. More...
 
int ha_truncate (dd::Table *table_def)
 Truncate table: public interface. More...
 
int ha_optimize (THD *thd, HA_CHECK_OPT *check_opt)
 Optimize table: public interface. More...
 
int ha_analyze (THD *thd, HA_CHECK_OPT *check_opt)
 Analyze table: public interface. More...
 
bool ha_check_and_repair (THD *thd)
 Check and repair table: public interface. More...
 
int ha_disable_indexes (uint mode)
 Disable indexes: public interface. More...
 
int ha_enable_indexes (uint mode)
 Enable indexes: public interface. More...
 
int ha_discard_or_import_tablespace (bool discard, dd::Table *table_def)
 Discard or import tablespace: public interface. More...
 
int ha_rename_table (const char *from, const char *to, const dd::Table *from_table_def, dd::Table *to_table_def)
 Rename table: public interface. More...
 
int ha_delete_table (const char *name, const dd::Table *table_def)
 Delete table: public interface. More...
 
void ha_drop_table (const char *name)
 Drop table in the engine: public interface. More...
 
int ha_create (const char *name, TABLE *form, HA_CREATE_INFO *info, dd::Table *table_def)
 Create a table in the engine: public interface. More...
 
int ha_load_table (const TABLE &table, bool *skip_metadata_update)
 Loads a table into its defined secondary storage engine: public interface. More...
 
int ha_unload_table (const char *db_name, const char *table_name, bool error_if_not_loaded)
 Unloads a table from its defined secondary storage engine: public interface. More...
 
virtual int parallel_scan_init (void *&scan_ctx, size_t *num_threads, bool use_reserved_threads, size_t max_desired_threads)
 Initializes a parallel scan. More...
 
virtual int parallel_scan (void *scan_ctx, void **thread_ctxs, Load_init_cbk init_fn, Load_cbk load_fn, Load_end_cbk end_fn)
 Run the parallel read of data. More...
 
virtual void parallel_scan_end (void *scan_ctx)
 End of the parallel scan. More...
 
virtual bool bulk_load_check (THD *thd) const
 Check if the table is ready for bulk load. More...
 
virtual size_t bulk_load_available_memory (THD *thd) const
 Get the total memory available for bulk load in SE. More...
 
virtual void * bulk_load_begin (THD *thd, size_t data_size, size_t memory, size_t num_threads)
 Begin parallel bulk data load to the table. More...
 
virtual int bulk_load_execute (THD *thd, void *load_ctx, size_t thread_idx, const Rows_mysql &rows, Bulk_load::Stat_callbacks &wait_cbk)
 Execute bulk load operation. More...
 
virtual int bulk_load_end (THD *thd, void *load_ctx, bool is_error)
 End bulk load operation. More...
 
bool ha_get_se_private_data (dd::Table *dd_table, bool reset)
 Submit a dd::Table object representing a core DD table having hardcoded data to be filled in by the DDSE. More...
 
void adjust_next_insert_id_after_explicit_value (ulonglong nr)
 
int update_auto_increment ()
 
virtual void print_error (int error, myf errflag)
 Print error that we got from handler function. More...
 
virtual bool get_error_message (int error, String *buf)
 Return an error message specific to this handler. More...
 
uint get_dup_key (int error)
 
virtual bool get_foreign_dup_key (char *child_table_name, uint child_table_name_len, char *child_key_name, uint child_key_name_len)
 Retrieves the names of the table and the key for which there was a duplicate entry in the case of HA_ERR_FOREIGN_DUPLICATE_KEY. More...
 
virtual void change_table_ptr (TABLE *table_arg, TABLE_SHARE *share)
 Change the internal TABLE_SHARE pointer. More...
 
const TABLE_SHAREget_table_share () const
 
const TABLEget_table () const
 
virtual double index_only_read_time (uint keynr, double records)
 Calculate cost of 'index only' scan for given index and number of records. More...
 
virtual Cost_estimate table_scan_cost ()
 Cost estimate for doing a complete table scan. More...
 
virtual Cost_estimate index_scan_cost (uint index, double ranges, double rows)
 Cost estimate for reading a number of ranges from an index. More...
 
virtual Cost_estimate read_cost (uint index, double ranges, double rows)
 Cost estimate for reading a set of ranges from the table using an index to access it. More...
 
virtual double page_read_cost (uint index, double reads)
 Cost estimate for doing a number of non-sequentially accesses against the storage engine. More...
 
virtual double worst_seek_times (double reads)
 Provide an upper cost-limit of doing a specified number of seek-and-read key lookups. More...
 
virtual longlong get_memory_buffer_size () const
 Return an estimate on the amount of memory the storage engine will use for caching data in memory. More...
 
double table_in_memory_estimate () const
 Return an estimate of how much of the table that is currently stored in main memory. More...
 
double index_in_memory_estimate (uint keyno) const
 Return an estimate of how much of the index that is currently stored in main memory. More...
 
int ha_sample_init (void *&scan_ctx, double sampling_percentage, int sampling_seed, enum_sampling_method sampling_method, const bool tablesample)
 Initialize sampling. More...
 
int ha_sample_next (void *scan_ctx, uchar *buf)
 Get the next record for sampling. More...
 
int ha_sample_end (void *scan_ctx)
 End sampling. More...
 
virtual ha_rows multi_range_read_info_const (uint keyno, RANGE_SEQ_IF *seq, void *seq_init_param, uint n_ranges, uint *bufsz, uint *flags, bool *force_default_mrr, Cost_estimate *cost)
 Get cost and other information about MRR scan over a known list of ranges. More...
 
virtual ha_rows multi_range_read_info (uint keyno, uint n_ranges, uint keys, uint *bufsz, uint *flags, Cost_estimate *cost)
 Get cost and other information about MRR scan over some sequence of ranges. More...
 
virtual int multi_range_read_init (RANGE_SEQ_IF *seq, void *seq_init_param, uint n_ranges, uint mode, HANDLER_BUFFER *buf)
 Initialize the MRR scan. More...
 
int ha_multi_range_read_next (char **range_info)
 
int ha_read_range_first (const key_range *start_key, const key_range *end_key, bool eq_range, bool sorted)
 
int ha_read_range_next ()
 
bool has_transactions ()
 
virtual uint extra_rec_buf_length () const
 
virtual bool is_ignorable_error (int error)
 Determine whether an error can be ignored or not. More...
 
virtual bool is_fatal_error (int error)
 Determine whether an error is fatal or not. More...
 
int ha_records (ha_rows *num_rows)
 Wrapper function to call records() in storage engine. More...
 
int ha_records (ha_rows *num_rows, uint index)
 Wrapper function to call records_from_index() in storage engine. More...
 
virtual ha_rows estimate_rows_upper_bound ()
 Return upper bound of current number of records in the table (max. More...
 
virtual enum row_type get_real_row_type (const HA_CREATE_INFO *create_info) const
 Get real row type for the table created based on one specified by user, CREATE TABLE options and SE capabilities. More...
 
virtual void column_bitmaps_signal ()
 Signal that the table->read_set and table->write_set table maps changed The handler is allowed to set additional bits in the above map in this call. More...
 
uint get_index (void) const
 
virtual bool start_bulk_update ()
 
virtual bool start_bulk_delete ()
 
virtual int exec_bulk_update (uint *dup_key_found)
 After this call all outstanding updates must be performed. More...
 
virtual void end_bulk_update ()
 Perform any needed clean-up, no outstanding updates are there at the moment. More...
 
virtual int end_bulk_delete ()
 Execute all outstanding deletes and close down the bulk delete. More...
 
void set_end_range (const key_range *range, enum_range_scan_direction direction)
 Set the end position for a range scan. More...
 
int compare_key (key_range *range)
 Compare if found key (in row) is over max-value. More...
 
int compare_key_icp (const key_range *range) const
 
int compare_key_in_buffer (const uchar *buf) const
 Check if the key in the given buffer (which is not necessarily TABLE::record[0]) is within range. More...
 
virtual int ft_init ()
 
virtual FT_INFOft_init_ext (uint flags, uint inx, String *key)
 
virtual FT_INFOft_init_ext_with_hints (uint inx, String *key, Ft_hints *hints)
 
int ha_ft_read (uchar *buf)
 
int ha_read_first_row (uchar *buf, uint primary_key)
 Read first row (only) from a table. More...
 
virtual int rnd_pos_by_record (uchar *record)
 This function only works for handlers having HA_PRIMARY_KEY_REQUIRED_FOR_POSITION set. More...
 
virtual uint32 calculate_key_hash_value (Field **field_array)
 
int ha_extra (enum ha_extra_function operation)
 Request storage engine to do an extra operation: enable,disable or run some functionality. More...
 
virtual int extra_opt (enum ha_extra_function operation, ulong cache_size)
 
virtual const handlertonhton_supporting_engine_pushdown ()
 Get the handlerton of the storage engine if the SE is capable of pushing down some of the AccessPath functionality. More...
 
virtual bool start_read_removal (void)
 Start read (before write) removal on the current table. More...
 
virtual ha_rows end_read_removal (void)
 End read (before write) removal and return the number of rows really written. More...
 
virtual bool was_semi_consistent_read ()
 
virtual void try_semi_consistent_read (bool)
 Tell the engine whether it should avoid unnecessary lock waits. More...
 
virtual void unlock_row ()
 Unlock last accessed row. More...
 
virtual int start_stmt (THD *thd, thr_lock_type lock_type)
 Start a statement when table is locked. More...
 
virtual void get_auto_increment (ulonglong offset, ulonglong increment, ulonglong nb_desired_values, ulonglong *first_value, ulonglong *nb_reserved_values)
 Reserves an interval of auto_increment values from the handler. More...
 
void set_next_insert_id (ulonglong id)
 
void restore_auto_increment (ulonglong prev_insert_id)
 
virtual void update_create_info (HA_CREATE_INFO *create_info)
 Update create info as part of ALTER TABLE. More...
 
virtual int assign_to_keycache (THD *, HA_CHECK_OPT *)
 
virtual int preload_keys (THD *, HA_CHECK_OPT *)
 
virtual int indexes_are_disabled (void)
 Check if indexes are disabled. More...
 
virtual void append_create_info (String *packet)
 
virtual void init_table_handle_for_HANDLER ()
 
uint max_record_length () const
 
uint max_keys () const
 
uint max_key_parts () const
 
uint max_key_length () const
 
uint max_key_part_length (HA_CREATE_INFO *create_info) const
 
virtual uint max_supported_key_part_length (HA_CREATE_INFO *create_info) const
 
virtual uint min_record_length (uint options) const
 
virtual bool low_byte_first () const
 
virtual ha_checksum checksum () const
 
virtual bool is_crashed () const
 Check if the table is crashed. More...
 
virtual bool auto_repair () const
 Check if the table can be automatically repaired. More...
 
virtual uint lock_count (void) const
 Get number of lock objects returned in store_lock. More...
 
virtual bool primary_key_is_clustered () const
 Check if the primary key is clustered or not. More...
 
virtual int cmp_ref (const uchar *ref1, const uchar *ref2) const
 Compare two positions. More...
 
virtual const Itemcond_push (const Item *cond)
 Push condition down to the table handler. More...
 
virtual Itemidx_cond_push (uint keyno, Item *idx_cond)
 Push down an index condition to the handler. More...
 
virtual void cancel_pushed_idx_cond ()
 Reset information about pushed index conditions. More...
 
virtual uint number_of_pushed_joins () const
 Reports number of tables included in pushed join which this handler instance is part of. More...
 
virtual const TABLEmember_of_pushed_join () const
 If this handler instance is part of a pushed join sequence returned TABLE instance being root of the pushed query? More...
 
virtual const TABLEparent_of_pushed_join () const
 If this handler instance is a child in a pushed join sequence returned TABLE instance being my parent? More...
 
virtual table_map tables_in_pushed_join () const
 
int ha_index_read_pushed (uchar *buf, const uchar *key, key_part_map keypart_map)
 
int ha_index_next_pushed (uchar *buf)
 
virtual bool check_if_incompatible_data (HA_CREATE_INFO *create_info, uint table_changes)
 Part of old, deprecated in-place ALTER API. More...
 
virtual enum_alter_inplace_result check_if_supported_inplace_alter (TABLE *altered_table, Alter_inplace_info *ha_alter_info)
 Check if a storage engine supports a particular alter table in-place. More...
 
bool ha_prepare_inplace_alter_table (TABLE *altered_table, Alter_inplace_info *ha_alter_info, const dd::Table *old_table_def, dd::Table *new_table_def)
 Public functions wrapping the actual handler call. More...
 
bool ha_inplace_alter_table (TABLE *altered_table, Alter_inplace_info *ha_alter_info, const dd::Table *old_table_def, dd::Table *new_table_def)
 Public function wrapping the actual handler call. More...
 
bool ha_commit_inplace_alter_table (TABLE *altered_table, Alter_inplace_info *ha_alter_info, bool commit, const dd::Table *old_table_def, dd::Table *new_table_def)
 Public function wrapping the actual handler call. More...
 
void ha_notify_table_changed (Alter_inplace_info *ha_alter_info)
 Public function wrapping the actual handler call. More...
 
virtual void use_hidden_primary_key ()
 use_hidden_primary_key() is called in case of an update/delete when (table_flags() and HA_PRIMARY_KEY_REQUIRED_FOR_DELETE) is defined but we don't have a primary key More...
 
virtual int bulk_update_row (const uchar *old_data, uchar *new_data, uint *dup_key_found)
 This method is similar to update_row, however the handler doesn't need to execute the updates at this point in time. More...
 
virtual int truncate (dd::Table *table_def)
 Quickly remove all rows from a table. More...
 
virtual int optimize (THD *, HA_CHECK_OPT *)
 
virtual int analyze (THD *, HA_CHECK_OPT *)
 
virtual bool check_and_repair (THD *thd)
 Check and repair the table if necessary. More...
 
virtual int disable_indexes (uint mode)
 Disable indexes for a while. More...
 
virtual int enable_indexes (uint mode)
 Enable indexes again. More...
 
virtual int discard_or_import_tablespace (bool discard, dd::Table *table_def)
 Discard or import tablespace. More...
 
virtual void drop_table (const char *name)
 
virtual bool get_se_private_data (dd::Table *dd_table, bool reset)
 
virtual int get_extra_columns_and_keys (const HA_CREATE_INFO *create_info, const List< Create_field > *create_list, const KEY *key_info, uint key_count, dd::Table *table_obj)
 Adjust definition of table to be created by adding implicit columns and indexes necessary for the storage engine. More...
 
virtual bool set_ha_share_ref (Handler_share **arg_ha_share)
 
void set_ha_table (TABLE *table_arg)
 
int get_lock_type () const
 
virtual Partition_handlerget_partition_handler ()
 
bool ha_upgrade_table (THD *thd, const char *dbname, const char *table_name, dd::Table *dd_table, TABLE *table_arg)
 Set se_private_id and se_private_data during upgrade. More...
 
void ha_set_primary_handler (handler *primary_handler)
 Store a pointer to the handler of the primary table that corresponds to the secondary table in this handler. More...
 
handlerha_get_primary_handler () const
 Get a pointer to a handler for the table in the primary storage engine, if this handler is for a table in a secondary storage engine. More...
 
void ha_mv_key_capacity (uint *num_keys, size_t *keys_length) const
 Return max limits for a single set of multi-valued keys. More...
 
virtual void set_external_table_offload_error (const char *)
 Propagates the secondary storage engine offload failure reason for a query to the external engine when the offloaded query fails in the secondary storage engine. More...
 
virtual void external_table_offload_error () const
 Identifies and throws the propagated external engine query offload or exec failure reason given by the external engine handler. More...
 

Private Member Functions

Example_shareget_share ()
 Get the share. More...
 

Private Attributes

THR_LOCK_DATA lock
 MySQL lock. More...
 
Example_shareshare
 Shared lock info. More...
 

Additional Inherited Members

- Public Types inherited from handler
enum  enum_range_scan_direction { RANGE_SCAN_ASC , RANGE_SCAN_DESC }
 
enum  { NONE = 0 , INDEX , RND , SAMPLING }
 
typedef ulonglong Table_flags
 
using Load_init_cbk = std::function< bool(void *cookie, ulong ncols, ulong row_len, const ulong *col_offsets, const ulong *null_byte_offsets, const ulong *null_bitmasks)>
 This callback is called by each parallel load thread at the beginning of the parallel load for the adapter scan. More...
 
using Load_cbk = std::function< bool(void *cookie, uint nrows, void *rowdata, uint64_t partition_id)>
 This callback is called by each parallel load thread when processing of rows is required for the adapter scan. More...
 
using Load_end_cbk = std::function< void(void *cookie)>
 This callback is called by each parallel load thread when processing of rows has ended for the adapter scan. More...
 
typedef void(* my_gcolumn_template_callback_t) (const TABLE *, void *)
 Callback function that will be called by my_prepare_gcolumn_template once the table has been opened. More...
 
- Static Public Member Functions inherited from handler
static bool my_prepare_gcolumn_template (THD *thd, const char *db_name, const char *table_name, my_gcolumn_template_callback_t myc, void *ib_table)
 Callback to allow InnoDB to prepare a template for generated column processing. More...
 
static bool my_eval_gcolumn_expr_with_open (THD *thd, const char *db_name, const char *table_name, const MY_BITMAP *const fields, uchar *record, const char **mv_data_ptr, ulong *mv_length)
 Callback for generated columns processing. More...
 
static bool my_eval_gcolumn_expr (THD *thd, TABLE *table, const MY_BITMAP *const fields, uchar *record, const char **mv_data_ptr, ulong *mv_length)
 Callback for computing generated column values. More...
 
- Public Attributes inherited from handler
handlertonht
 
ucharref
 Pointer to current row. More...
 
uchardup_ref
 Pointer to duplicate row. More...
 
ha_statistics stats
 
range_seq_t mrr_iter
 
RANGE_SEQ_IF mrr_funcs
 
HANDLER_BUFFERmulti_range_buffer
 
uint ranges_in_seq
 
bool mrr_is_output_sorted
 
bool mrr_have_range
 
KEY_MULTI_RANGE mrr_cur_range
 
key_rangeend_range
 End value for a range scan. More...
 
bool m_virt_gcol_in_end_range = false
 Flag which tells if end_range contains a virtual generated column. More...
 
uint errkey
 
uint key_used_on_scan
 
uint active_index
 
uint ref_length
 Length of ref (1-8 or the clustered key length) More...
 
FT_INFOft_handler
 
enum handler:: { ... }  inited
 
bool implicit_emptied
 
const Itempushed_cond
 
Itempushed_idx_cond
 
uint pushed_idx_cond_keyno
 
ulonglong next_insert_id
 next_insert_id is the next value which should be inserted into the auto_increment column: in a inserting-multi-row statement (like INSERT SELECT), for the first row where the autoinc value is not specified by the statement, get_auto_increment() called and asked to generate a value, next_insert_id is set to the next value, then for all other rows next_insert_id is used (and increased each time) without calling get_auto_increment(). More...
 
ulonglong insert_id_for_cur_row
 insert id for the current row (autogenerated; if not autogenerated, it's 0). More...
 
Discrete_interval auto_inc_interval_for_cur_row
 Interval returned by get_auto_increment() and being consumed by the inserter. More...
 
uint auto_inc_intervals_count
 Number of reserved auto-increment intervals. More...
 
PSI_tablem_psi
 Instrumented table associated with this handler. More...
 
std::mt19937 * m_random_number_engine {nullptr}
 
double m_sampling_percentage
 
- Protected Member Functions inherited from handler
virtual int multi_range_read_next (char **range_info)
 Get next record in MRR scan. More...
 
virtual int records (ha_rows *num_rows)
 Number of rows in table. More...
 
virtual int records_from_index (ha_rows *num_rows, uint index)
 Number of rows in table counted using the secondary index chosen by optimizer. More...
 
virtual int index_read_idx_map (uchar *buf, uint index, const uchar *key, key_part_map keypart_map, enum ha_rkey_function find_flag)
 Positions an index cursor to the index specified in argument. More...
 
virtual int index_next_same (uchar *buf, const uchar *key, uint keylen)
 
virtual int index_read_last_map (uchar *buf, const uchar *key, key_part_map keypart_map)
 The following functions works like index_read, but it find the last row with the current key value or prefix. More...
 
virtual int read_range_first (const key_range *start_key, const key_range *end_key, bool eq_range_arg, bool sorted)
 Read first row between two ranges. More...
 
virtual int read_range_next ()
 Read next row between two endpoints. More...
 
virtual int ft_read (uchar *)
 
virtual int index_read_pushed (uchar *, const uchar *, key_part_map)
 
virtual int index_next_pushed (uchar *)
 
virtual bool prepare_inplace_alter_table (TABLE *altered_table, Alter_inplace_info *ha_alter_info, const dd::Table *old_table_def, dd::Table *new_table_def)
 Allows the storage engine to update internal structures with concurrent writes blocked. More...
 
virtual bool inplace_alter_table (TABLE *altered_table, Alter_inplace_info *ha_alter_info, const dd::Table *old_table_def, dd::Table *new_table_def)
 Alter the table structure in-place with operations specified using HA_ALTER_FLAGS and Alter_inplace_info. More...
 
virtual bool commit_inplace_alter_table (TABLE *altered_table, Alter_inplace_info *ha_alter_info, bool commit, const dd::Table *old_table_def, dd::Table *new_table_def)
 Commit or rollback the changes made during prepare_inplace_alter_table() and inplace_alter_table() inside the storage engine. More...
 
virtual void notify_table_changed (Alter_inplace_info *ha_alter_info)
 Notify the storage engine that the table definition has been updated. More...
 
void ha_statistic_increment (ulonglong System_status_var::*offset) const
 
THDha_thd () const
 
PSI_table_shareha_table_share_psi (const TABLE_SHARE *share) const
 Acquire the instrumented table information from a table share. More...
 
virtual int index_read (uchar *buf, const uchar *key, uint key_len, enum ha_rkey_function find_flag)
 
virtual int index_read_last (uchar *buf, const uchar *key, uint key_len)
 
Handler_shareget_ha_share_ptr ()
 Get an initialized ha_share. More...
 
void set_ha_share_ptr (Handler_share *arg_ha_share)
 Set ha_share to be used by all instances of the same table/partition. More...
 
void lock_shared_ha_data ()
 Take a lock for protecting shared handler data. More...
 
void unlock_shared_ha_data ()
 Release lock for protecting ha_share. More...
 
- Protected Attributes inherited from handler
TABLE_SHAREtable_share
 
TABLEtable
 
Table_flags cached_table_flags {0}
 
ha_rows estimation_rows_to_insert
 
KEY_PART_INFOrange_key_part
 
bool eq_range
 
bool in_range_check_pushed_down
 

Detailed Description

Class definition for the storage engine.

Constructor & Destructor Documentation

◆ ha_example()

ha_example::ha_example ( handlerton hton,
TABLE_SHARE table_arg 
)

◆ ~ha_example()

ha_example::~ha_example ( )
overridedefault

Member Function Documentation

◆ close()

int ha_example::close ( void  )
overridevirtual

We implement this in ha_example.cc; it's a required method.

Closes a table.

Called from sql_base.cc, sql_select.cc, and table.cc. In sql_select.cc it is only used to close up temporary tables or during the process where a temporary table is converted over to being a myisam table.

For sql_base.cc look at close_data_tables().

See also
sql_base.cc, sql_select.cc and table.cc

Implements handler.

◆ create()

int ha_example::create ( const char *  name,
TABLE form,
HA_CREATE_INFO create_info,
dd::Table table_def 
)
overridevirtual

required

create() is called to create a database.

The variable name will have the name of the table.

When create() is called you do not need to worry about opening the table. Also, the .frm file will have already been created so adjusting create_info is not necessary. You can overwrite the .frm file at this point if you wish to change the table definition, but there are no methods currently provided for doing so.

Called from handle.cc by ha_create_table().

See also
ha_create_table() in handle.cc

Implements handler.

◆ delete_all_rows()

int ha_example::delete_all_rows ( void  )
overridevirtual

Used to delete all rows in a table, including cases of truncate and cases where the optimizer realizes that all rows will be removed as a result of an SQL statement.

Called from item_sum.cc by Item_func_group_concat::clear(), Item_sum_count_distinct::clear(), and Item_func_group_concat::clear(). Called from sql_delete.cc by mysql_delete(). Called from sql_select.cc by JOIN::reinit(). Called from sql_union.cc by st_query_block_query_expression::exec().

See also
Item_func_group_concat::clear(), Item_sum_count_distinct::clear() and Item_func_group_concat::clear() in item_sum.cc; mysql_delete() in sql_delete.cc; JOIN::reinit() in sql_select.cc and st_query_block_query_expression::exec() in sql_union.cc.

Reimplemented from handler.

◆ delete_row()

int ha_example::delete_row ( const uchar buf)
overridevirtual

We implement this in ha_example.cc.

This will delete a row.

It's not an obligatory method; skip it and and MySQL will treat it as not implemented.

buf will contain a copy of the row to be deleted. The server will call this right after the current row has been called (from either a previous rnd_nexT() or index call).

If you keep a pointer to the last row or can access a primary key it will make doing the deletion quite a bit easier. Keep in mind that the server does not guarantee consecutive deletions. ORDER BY clauses can be used.

Called in sql_acl.cc and sql_udf.cc to manage internal table information. Called in sql_delete.cc, sql_insert.cc, and sql_select.cc. In sql_select it is used for removing duplicates while in insert it is used for REPLACE calls.

See also
sql_acl.cc, sql_udf.cc, sql_delete.cc, sql_insert.cc and sql_select.cc

Reimplemented from handler.

◆ delete_table()

int ha_example::delete_table ( const char *  from,
const dd::Table table_def 
)
overridevirtual

Used to delete a table.

By the time delete_table() has been called all opened references to this table will have been closed (and your globally shared references released). The variable name will just be the name of the table. You will need to remove any files you have created at this point.

If you do not implement this, the default delete_table() is called from handler.cc and it will delete all files with the file extensions from handlerton::file_extensions.

Called from handler.cc by delete_table and ha_create_table(). Only used during create if the table_flag HA_DROP_BEFORE_CREATE was specified for the storage engine.

See also
delete_table and ha_create_table() in handler.cc

Reimplemented from handler.

◆ external_lock()

int ha_example::external_lock ( THD thd,
int  lock_type 
)
overridevirtual

required

This create a lock on the table.

If you are implementing a storage engine that can handle transacations look at ha_berkely.cc to see how you will want to go about doing this. Otherwise you should consider calling flock() here. Hint: Read the section "locking functions for mysql" in lock.cc to understand this.

Called from lock.cc by lock_external() and unlock_external(). Also called from sql_table.cc by copy_data_between_tables().

See also
lock.cc by lock_external() and unlock_external() in lock.cc; the section "locking functions for mysql" in lock.cc; copy_data_between_tables() in sql_table.cc.

Reimplemented from handler.

◆ extra()

int ha_example::extra ( enum ha_extra_function  operation)
overridevirtual

extra() is called whenever the server wishes to send a hint to the storage engine.

The myisam engine implements the most hints. ha_innodb.cc has the most exhaustive list of these hints.

See also
ha_innodb.cc

Reimplemented from handler.

◆ get_default_index_algorithm()

enum ha_key_alg ha_example::get_default_index_algorithm ( ) const
inlineoverridevirtual

Replace key algorithm with one supported by SE, return the default key algorithm for SE if explicit key algorithm was not provided.

See also
handler::adjust_index_algorithm().

Reimplemented from handler.

◆ get_share()

Example_share * ha_example::get_share ( )
private

Get the share.

Example of simple lock controls.

The "share" it creates is a structure we will pass to each example handler. Do you have to have one of these? Well, you have pieces that are used for locking, and they are needed to function.

◆ index_first()

int ha_example::index_first ( uchar buf)
overridevirtual

We implement this in ha_example.cc.

index_first() asks for the first key in the index.

It's not an obligatory method; skip it and and MySQL will treat it as not implemented.

Called from opt_range.cc, opt_sum.cc, sql_handler.cc, and sql_select.cc.

See also
opt_range.cc, opt_sum.cc, sql_handler.cc and sql_select.cc

Reimplemented from handler.

◆ index_flags()

ulong ha_example::index_flags ( uint  inx,
uint  part,
bool  all_parts 
) const
inlineoverridevirtual

This is a bitmap of flags that indicates how the storage engine implements indexes.

The current index flags are documented in handler.h. If you do not implement indexes, just return zero here.

part is the key part to check. First key part is 0. If all_parts is set, MySQL wants to know the flags for the combined index, up to and including 'part'.

Implements handler.

◆ index_last()

int ha_example::index_last ( uchar buf)
overridevirtual

We implement this in ha_example.cc.

index_last() asks for the last key in the index.

It's not an obligatory method; skip it and and MySQL will treat it as not implemented.

Called from opt_range.cc, opt_sum.cc, sql_handler.cc, and sql_select.cc.

See also
opt_range.cc, opt_sum.cc, sql_handler.cc and sql_select.cc

Reimplemented from handler.

◆ index_next()

int ha_example::index_next ( uchar buf)
overridevirtual

We implement this in ha_example.cc.

Used to read forward through the index.

It's not an obligatory method; skip it and and MySQL will treat it as not implemented.

Reimplemented from handler.

◆ index_prev()

int ha_example::index_prev ( uchar buf)
overridevirtual

We implement this in ha_example.cc.

Used to read backwards through the index.

It's not an obligatory method; skip it and and MySQL will treat it as not implemented.

Reimplemented from handler.

◆ index_read_map()

int ha_example::index_read_map ( uchar buf,
const uchar key,
key_part_map  keypart_map,
enum ha_rkey_function  find_flag 
)
overridevirtual

We implement this in ha_example.cc.

Positions an index cursor to the index specified in the handle.

It's not an obligatory method; skip it and and MySQL will treat it as not implemented.

Fetches the row if available. If the key value is null, begin at the first key of the index.

Reimplemented from handler.

◆ info()

int ha_example::info ( uint  )
overridevirtual

required

info() is used to return information to the optimizer.

See my_base.h for the complete description.

Currently this table handler doesn't implement most of the fields really needed. SHOW also makes use of this data.

You will probably want to have the following in your code:

if (records < 2)
records = 2;
virtual int records(ha_rows *num_rows)
Number of rows in table.
Definition: handler.cc:3147

The reason is that the server will optimize for cases of only a single record. If, in a table scan, you don't know the number of records, it will probably be better to set records to two so you can return as many records as you need. Along with records, a few more variables you may wish to set are: records deleted data_file_length index_file_length delete_length check_time Take a look at the public variables in handler.h for more information.

Called in filesort.cc, ha_heap.cc, item_sum.cc, opt_sum.cc, sql_delete.cc, sql_delete.cc, sql_derived.cc, sql_select.cc, sql_select.cc, sql_select.cc, sql_select.cc, sql_select.cc, sql_show.cc, sql_show.cc, sql_show.cc, sql_show.cc, sql_table.cc, sql_union.cc, and sql_update.cc.

See also
filesort.cc, ha_heap.cc, item_sum.cc, opt_sum.cc, sql_delete.cc, sql_delete.cc, sql_derived.cc, sql_select.cc, sql_select.cc, sql_select.cc, sql_select.cc, sql_select.cc, sql_show.cc, sql_show.cc, sql_show.cc, sql_show.cc, sql_table.cc, sql_union.cc and sql_update.cc

Implements handler.

◆ is_index_algorithm_supported()

bool ha_example::is_index_algorithm_supported ( enum ha_key_alg  key_alg) const
inlineoverridevirtual

Check if SE supports specific key algorithm.

Note
This method is never used for FULLTEXT or SPATIAL keys. We rely on handler::ha_table_flags() to check if such keys are supported.

Reimplemented from handler.

◆ max_supported_key_length()

uint ha_example::max_supported_key_length ( ) const
inlineoverridevirtual

unireg.cc will call this to make sure that the storage engine can handle the data it is about to send.

Return real limits of your storage engine here; MySQL will do min(your_limits, MySQL_limits) automatically.

There is no need to implement ..._key_... methods if your engine doesn't support indexes.

Reimplemented from handler.

◆ max_supported_key_parts()

uint ha_example::max_supported_key_parts ( ) const
inlineoverridevirtual

unireg.cc will call this to make sure that the storage engine can handle the data it is about to send.

Return real limits of your storage engine here; MySQL will do min(your_limits, MySQL_limits) automatically.

There is no need to implement ..._key_... methods if your engine doesn't support indexes.

Reimplemented from handler.

◆ max_supported_keys()

uint ha_example::max_supported_keys ( ) const
inlineoverridevirtual

unireg.cc will call this to make sure that the storage engine can handle the data it is about to send.

Return real limits of your storage engine here; MySQL will do min(your_limits, MySQL_limits) automatically.

There is no need to implement ..._key_... methods if your engine doesn't support indexes.

Reimplemented from handler.

◆ max_supported_record_length()

uint ha_example::max_supported_record_length ( ) const
inlineoverridevirtual

unireg.cc will call max_supported_record_length(), max_supported_keys(), max_supported_key_parts(), uint max_supported_key_length() to make sure that the storage engine can handle the data it is about to send.

Return real limits of your storage engine here; MySQL will do min(your_limits, MySQL_limits) automatically.

Reimplemented from handler.

◆ open()

int ha_example::open ( const char *  name,
int  mode,
uint  test_if_locked,
const dd::Table table_def 
)
overridevirtual

We implement this in ha_example.cc; it's a required method.

Used for opening tables.

The name will be the name of the file.

A table is opened when it needs to be opened; e.g. when a request comes in for a SELECT on the table (tables are not open and closed for each request, they are cached).

Called from handler.cc by handler::ha_open(). The server opens all tables by calling ha_open() which then calls the handler specific open().

See also
handler::ha_open() in handler.cc

Implements handler.

◆ position()

void ha_example::position ( const uchar record)
overridevirtual

required

position() is called after each call to rnd_next() if the data needs to be ordered.

You can do something like the following to store the position:

my_store_ptr(ref, ref_length, current_position);
uchar * ref
Pointer to current row.
Definition: handler.h:4587
uint ref_length
Length of ref (1-8 or the clustered key length)
Definition: handler.h:4655
void my_store_ptr(uchar *buff, size_t pack_length, my_off_t pos)
Definition: ptr_cmp.cc:44

The server uses ref to store data. ref_length in the above case is the size needed to store current_position. ref is just a byte array that the server will maintain. If you are using offsets to mark rows, then current_position should be the offset. If it is a primary key like in BDB, then it needs to be a primary key.

Called from filesort.cc, sql_select.cc, sql_delete.cc, and sql_update.cc.

See also
filesort.cc, sql_select.cc, sql_delete.cc and sql_update.cc

Implements handler.

◆ read_time()

double ha_example::read_time ( uint  ,
uint  ,
ha_rows  rows 
)
inlineoverridevirtual

This method will never be called if you do not implement indexes.

Reimplemented from handler.

◆ records_in_range()

ha_rows ha_example::records_in_range ( uint  inx,
key_range min_key,
key_range max_key 
)
overridevirtual

Given a starting key and an ending key, estimate the number of rows that will exist between the two keys.

end_key may be empty, in which case determine if start_key matches any rows.

Called from opt_range.cc by check_quick_keys().

See also
check_quick_keys() in opt_range.cc

Reimplemented from handler.

◆ rename_table()

int ha_example::rename_table ( const char *  from,
const char *  to,
const dd::Table from_table_def,
dd::Table to_table_def 
)
overridevirtual

Renames a table from one name to another via an alter table call.

If you do not implement this, the default rename_table() is called from handler.cc and it will delete all files with the file extensions from handlerton::file_extensions.

Called from sql_table.cc by mysql_rename_table().

See also
mysql_rename_table() in sql_table.cc

Reimplemented from handler.

◆ rnd_end()

int ha_example::rnd_end ( void  )
overridevirtual

Reimplemented from handler.

◆ rnd_init()

int ha_example::rnd_init ( bool  scan)
overridevirtual

Unlike index_init(), rnd_init() can be called two consecutive times without rnd_end() in between (it only makes sense if scan=1).

rnd_init() is called when the system wants the storage engine to do a table scan.

In this case, the second call should prepare for the new table scan (e.g if rnd_init() allocates the cursor, the second call should position the cursor to the start of the table; no need to deallocate and allocate it again. This is a required method.

See the example in the introduction at the top of this file to see when rnd_init() is called.

Called from filesort.cc, records.cc, sql_handler.cc, sql_select.cc, sql_table.cc, and sql_update.cc.

See also
filesort.cc, records.cc, sql_handler.cc, sql_select.cc, sql_table.cc and sql_update.cc

Implements handler.

◆ rnd_next()

int ha_example::rnd_next ( uchar buf)
overridevirtual

required

This is called for each row of the table scan.

When you run out of records you should return HA_ERR_END_OF_FILE. Fill buff up with the row information. The Field structure for the table is the key to getting data into buf in a manner that will allow the server to understand it.

Called from filesort.cc, records.cc, sql_handler.cc, sql_select.cc, sql_table.cc, and sql_update.cc.

See also
filesort.cc, records.cc, sql_handler.cc, sql_select.cc, sql_table.cc and sql_update.cc

Implements handler.

◆ rnd_pos()

int ha_example::rnd_pos ( uchar buf,
uchar pos 
)
overridevirtual

required

This is like rnd_next, but you are given a position to use to determine the row.

The position will be of the type that you stored in ref. You can use ha_get_ptr(pos,ref_length) to retrieve whatever key or position you saved when position() was called.

Called from filesort.cc, records.cc, sql_insert.cc, sql_select.cc, and sql_update.cc.

See also
filesort.cc, records.cc, sql_insert.cc, sql_select.cc and sql_update.cc

Implements handler.

◆ scan_time()

double ha_example::scan_time ( )
inlineoverridevirtual

Called in test_quick_select to determine if indexes should be used.

Reimplemented from handler.

◆ store_lock()

THR_LOCK_DATA ** ha_example::store_lock ( THD thd,
THR_LOCK_DATA **  to,
enum thr_lock_type  lock_type 
)
overridevirtual

required

The idea with handler::store_lock() is: The statement decides which locks should be needed for the table.

For updates/deletes/inserts we get WRITE locks, for SELECT... we get read locks.

Before adding the lock into the table lock handler (see thr_lock.c), mysqld calls store lock with the requested locks. Store lock can now modify a write lock to a read lock (or some other lock), ignore the lock (if we don't want to use MySQL table locks at all), or add locks for many tables (like we do when we are using a MERGE handler).

Berkeley DB, for example, changes all WRITE locks to TL_WRITE_ALLOW_WRITE (which signals that we are doing WRITES, but are still allowing other readers and writers).

When releasing locks, store_lock() is also called. In this case one usually doesn't have to do anything.

In some exceptional cases MySQL may send a request for a TL_IGNORE; This means that we are requesting the same lock as last time and this should also be ignored. (This may happen when someone does a flush table when we have opened a part of the tables, in which case mysqld closes and reopens the tables and tries to get the same locks at last time). In the future we will probably try to remove this.

Called from lock.cc by get_lock_data().

Note
In this method one should NEVER rely on table->in_use, it may, in fact, refer to a different thread! (this happens if get_lock_data() is called from mysql_lock_abort_for_thread() function)
See also
get_lock_data() in lock.cc

Implements handler.

◆ table_flags()

ulonglong ha_example::table_flags ( void  ) const
inlineoverridevirtual

This is a list of flags that indicate what functionality the storage engine implements.

The current table flags are documented in handler.h

Implements handler.

◆ table_type()

const char * ha_example::table_type ( ) const
inlineoverridevirtual

The name that will be used for display purposes.

Implements handler.

◆ update_row()

int ha_example::update_row ( const uchar old_data,
uchar new_data 
)
overridevirtual

We implement this in ha_example.cc.

Yes, update_row() does what you expect, it updates a row.

It's not an obligatory method; skip it and and MySQL will treat it as not implemented.

old_data will have the previous row record in it, while new_data will have the newest data in it. Keep in mind that the server can do updates based on ordering if an ORDER BY clause was used. Consecutive ordering is not guaranteed.

Currently new_data will not have an updated auto_increament record. You can do this for example by doing:

int update_auto_increment()
Definition: handler.cc:3788
TABLE * table
Definition: handler.h:4579
static int record
Definition: mysqltest.cc:195
uchar * record[2]
Definition: table.h:1453
Field * next_number_field
Definition: table.h:1506

Called from sql_select.cc, sql_acl.cc, sql_update.cc, and sql_insert.cc.

See also
sql_select.cc, sql_acl.cc, sql_update.cc and sql_insert.cc

Reimplemented from handler.

◆ write_row()

int ha_example::write_row ( uchar buf)
overridevirtual

We implement this in ha_example.cc.

write_row() inserts a row.

It's not an obligatory method; skip it and and MySQL will treat it as not implemented.

No extra() hint is given currently if a bulk load is happening. buf() is a byte array of data. You can use the field information to extract the data from the native byte array type.

Example of this would be:

for (Field **field=table->field ; *field ; field++)
{
...
}
Definition: field.h:575
Field ** field
Definition: table.h:1449

See ha_tina.cc for an example of extracting all of the data as strings. ha_berekly.cc has an example of how to store it intact by "packing" it for ha_berkeley's own native storage type.

See the note for update_row() on auto_increments. This case also applies to write_row().

Called from item_sum.cc, item_sum.cc, sql_acl.cc, sql_insert.cc, sql_insert.cc, sql_select.cc, sql_table.cc, sql_udf.cc, and sql_update.cc.

See also
item_sum.cc, item_sum.cc, sql_acl.cc, sql_insert.cc, sql_insert.cc, sql_select.cc, sql_table.cc, sql_udf.cc and sql_update.cc

Reimplemented from handler.

Member Data Documentation

◆ lock

THR_LOCK_DATA ha_example::lock
private

MySQL lock.

◆ share

Example_share* ha_example::share
private

Shared lock info.


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