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#ifndef PARTITION_HANDLER_INCLUDED
#define PARTITION_HANDLER_INCLUDED
/*
Copyright (c) 2005, 2025, Oracle and/or its affiliates.
This program is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License, version 2.0,
as published by the Free Software Foundation.
This program is designed to work with certain software (including
but not limited to OpenSSL) that is licensed under separate terms,
as designated in a particular file or component or in included license
documentation. The authors of MySQL hereby grant you an additional
permission to link the program and your derivative works with the
separately licensed software that they have either included with
the program or referenced in the documentation.
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, version 2.0, 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 02110-1301 USA
*/
#include <assert.h>
#include <string.h>
#include <sys/types.h>
#include <memory>
#include <string>
#include <vector>
#include "my_base.h" // ha_rows.
#include "my_bitmap.h"
#include "my_compiler.h"
#include "my_inttypes.h"
#include "my_sys.h"
#include "mysql/psi/mysql_mutex.h"
#include "priority_queue.h"
#include "sql/handler.h" // Handler_share
#include "sql/key.h" // key_rec_cmp
#include "sql/sql_partition.h" // part_id_range
class Field;
class THD;
class partition_info;
struct mysql_mutex_t;
template <class Key, class Value>
class collation_unordered_map;
namespace dd {
class Table;
} // namespace dd
struct TABLE;
struct TABLE_SHARE;
#define PARTITION_BYTES_IN_POS 2
struct MEM_ROOT;
static const uint NO_CURRENT_PART_ID = UINT_MAX32;
/**
bits in Partition_handler::alter_flags():
HA_PARTITION_FUNCTION_SUPPORTED indicates that the function is
supported at all.
HA_INPLACE_CHANGE_PARTITION means that changes to partitioning can be done
through in-place ALTER TABLE API but special mark-up in partition_info
object is required for this.
*/
#define HA_PARTITION_FUNCTION_SUPPORTED (1L << 0)
#define HA_INPLACE_CHANGE_PARTITION (1L << 1)
enum enum_part_operation {
OPTIMIZE_PARTS = 0,
ANALYZE_PARTS,
CHECK_PARTS,
REPAIR_PARTS,
ASSIGN_KEYCACHE_PARTS,
PRELOAD_KEYS_PARTS
};
/** Struct used for partition_name_hash */
struct PART_NAME_DEF {
uchar *partition_name;
uint length;
uint32 part_id;
bool is_subpart;
};
/**
Initialize partitioning (currently only PSI keys).
*/
void partitioning_init();
/**
Partition specific Handler_share.
*/
class Partition_share : public Handler_share {
public:
Partition_share();
~Partition_share() override;
/** Set if auto increment is used an initialized. */
bool auto_inc_initialized;
/**
Mutex protecting next_auto_inc_val.
Initialized if table uses auto increment.
*/
mysql_mutex_t *auto_inc_mutex;
/** First non reserved auto increment value. */
ulonglong next_auto_inc_val;
/**
Hash of partition names. Initialized by the first handler instance of a
table_share calling populate_partition_name_hash().
After that it is read-only, i.e. no locking required for reading.
*/
std::unique_ptr<
collation_unordered_map<std::string, unique_ptr_my_free<PART_NAME_DEF>>>
partition_name_hash;
/**
Initializes and sets auto_inc_mutex.
Only needed to be called if the table have an auto increment.
Must hold TABLE_SHARE::LOCK_ha_data when calling.
*/
bool init_auto_inc_mutex(TABLE_SHARE *table_share);
/**
Release reserved auto increment values not used.
@param thd Thread.
@param table_share Table Share
@param next_insert_id Next insert id (first non used auto inc value).
@param max_reserved End of reserved auto inc range.
*/
void release_auto_inc_if_possible(THD *thd, TABLE_SHARE *table_share,
const ulonglong next_insert_id,
const ulonglong max_reserved);
/** lock mutex protecting auto increment value next_auto_inc_val. */
inline void lock_auto_inc() {
assert(auto_inc_mutex);
mysql_mutex_lock(auto_inc_mutex);
}
/** unlock mutex protecting auto increment value next_auto_inc_val. */
inline void unlock_auto_inc() {
assert(auto_inc_mutex);
mysql_mutex_unlock(auto_inc_mutex);
}
/**
Populate partition_name_hash with partition and subpartition names
from part_info.
@param part_info Partition info containing all partitions metadata.
@return Operation status.
@retval false Success.
@retval true Failure.
*/
bool populate_partition_name_hash(partition_info *part_info);
/** Get partition name.
@param part_id Partition id (for subpartitioned table only subpartition
names will be returned.)
@return partition name or NULL if error.
*/
const char *get_partition_name(size_t part_id) const;
private:
const uchar **partition_names;
/**
Insert [sub]partition name into partition_name_hash
@param name Partition name.
@param part_id Partition id.
@param is_subpart True if subpartition else partition.
@return Operation status.
@retval false Success.
@retval true Failure.
*/
bool insert_partition_name_in_hash(const char *name, uint part_id,
bool is_subpart);
};
/**
Class for partitioning specific operations.
Returned from handler::get_partition_handler().
*/
class Partition_handler {
public:
Partition_handler() = default;
virtual ~Partition_handler() = default;
/**
Get dynamic table information from partition.
@param[out] stat_info Statistics struct to fill in.
@param[out] check_sum Check sum value to fill in if supported.
@param[in] part_id Partition to report for.
@note stat_info and check_sum are initialized by caller.
check_sum is only expected to be updated if HA_HAS_CHECKSUM.
*/
virtual void get_dynamic_partition_info(ha_statistics *stat_info,
ha_checksum *check_sum,
uint part_id) = 0;
/**
Get default number of partitions.
Used during creating a partitioned table.
@param info Create info.
@return Number of default partitions.
*/
virtual int get_default_num_partitions(HA_CREATE_INFO *info
[[maybe_unused]]) {
return 1;
}
/**
Setup auto partitioning.
Called for engines with HA_USE_AUTO_PARTITION to setup the partition info
object
@param[in,out] part_info Partition object to setup.
*/
virtual void set_auto_partitions(partition_info *part_info [[maybe_unused]]) {
}
/**
Get number of partitions for table in SE
@param name normalized path(same as open) to the table
@param[out] num_parts Number of partitions
@retval false for success
@retval true for failure, for example table didn't exist in engine
*/
virtual bool get_num_parts(const char *name [[maybe_unused]],
uint *num_parts) {
*num_parts = 0;
return false;
}
/**
Set the partition info object to be used by the handler.
@param part_info Partition info to be used by the handler.
@param early True if called when part_info only created and parsed,
but not setup, checked or fixed.
*/
virtual void set_part_info(partition_info *part_info, bool early) = 0;
/**
Truncate partitions.
Truncate all partitions matching table->part_info->read_partitions.
Handler level wrapper for truncating partitions, will ensure that
mark_trx_read_write() is called and also checks locking assertions.
@param[in,out] table_def dd::Table object for the table. Engines
which support atomic DDL are allowed to
adjust this object. Changes will be saved
to the data-dictionary.
@return Operation status.
@retval 0 Success.
@retval != 0 Error code.
*/
int truncate_partition(dd::Table *table_def);
/**
Exchange partition.
@param[in] part_id Id of partition to be exchanged.
@param[in,out] part_table_def dd::Table object for partitioned table.
@param[in,out] swap_table_def dd::Table object for non-partitioned
table.
@note Both tables are locked in exclusive mode.
@note Changes to dd::Table object done by this method will be saved
to data-dictionary only if storage engine supporting atomic
DDL (i.e. with HTON_SUPPORTS_ATOMIC_DDL flag).
@return Operation status.
@retval 0 Success.
@retval != 0 Error code.
*/
int exchange_partition(uint part_id, dd::Table *part_table_def,
dd::Table *swap_table_def);
/**
Alter flags.
Given a set of alter table flags, return which is supported.
@param flags Alter table operation flags.
@return Supported alter table flags.
*/
virtual uint alter_flags(uint flags [[maybe_unused]]) const { return 0; }
/**
Get partition row type from SE
@param table partition table
@param part_id Id of partition for which row type to be retrieved
@return Partition row type.
*/
virtual enum row_type get_partition_row_type(const dd::Table *table,
uint part_id) = 0;
private:
/**
Truncate partition.
Low-level primitive for handler, implementing
Partition_handler::truncate_partition().
@sa Partition_handler::truncate_partition().
*/
virtual int truncate_partition_low(dd::Table *) {
return HA_ERR_WRONG_COMMAND;
}
/**
Exchange partition.
Low-level primitive which implementation to be provided by SE.
@sa Partition_handler::exchange_partition().
*/
virtual int exchange_partition_low(uint part_id [[maybe_unused]],
dd::Table *part_table_def [[maybe_unused]],
dd::Table *swap_table_def
[[maybe_unused]]) {
return HA_ERR_WRONG_COMMAND;
}
/**
Return the table handler.
For some partitioning specific functions it is still needed to access
the handler directly for transaction handling (mark_trx_read_write())
and to assert correct locking.
@return handler or NULL if not supported.
*/
virtual handler *get_handler() { return nullptr; }
};
/// Maps compare function to strict weak ordering required by Priority_queue.
struct Key_rec_less {
typedef int (*key_compare_fun)(KEY **, uchar *, uchar *);
explicit Key_rec_less(KEY **keys)
: m_keys(keys), m_fun(key_rec_cmp), m_max_at_top(false) {}
bool operator()(uchar *first, uchar *second) {
const int cmpval =
(*m_fun)(m_keys, first + m_rec_offset, second + m_rec_offset);
return m_max_at_top ? cmpval < 0 : cmpval > 0;
}
KEY **m_keys;
key_compare_fun m_fun;
uint m_rec_offset;
bool m_max_at_top;
};
/**
Partition_helper is a helper class that implements most generic partitioning
functionality such as:
table scan, index scan (both ordered and non-ordered),
insert (write_row()), delete and update.
And includes ALTER TABLE ... ADD/COALESCE/DROP/REORGANIZE/... PARTITION
support.
It also implements a cache for the auto increment value and check/repair for
rows in wrong partition.
How to use it:
Inherit it and implement:
- *_in_part() functions for row operations.
- write_row_in_new_part() for handling 'fast' alter partition.
*/
class Partition_helper {
typedef Priority_queue<uchar *, std::vector<uchar *>, Key_rec_less>
Prio_queue;
public:
Partition_helper(handler *main_handler);
virtual ~Partition_helper();
/**
Set partition info.
To be called from Partition_handler.
@param part_info Partition info to use.
@param early True if called when part_info only created and parsed,
but not setup, checked or fixed.
*/
virtual void set_part_info_low(partition_info *part_info, bool early);
/**
Initialize variables used before the table is opened.
@param mem_root Memory root to allocate things from (not yet used).
@return Operation status.
@retval false success.
@retval true failure.
*/
bool init_partitioning(MEM_ROOT *mem_root [[maybe_unused]]) {
#ifndef NDEBUG
m_key_not_found_partitions.bitmap = nullptr;
#endif
return false;
}
/**
INSERT/UPDATE/DELETE functions.
@see handler.h
@{
*/
/**
Insert a row to the partitioned table.
@returns Operation status.
@returns 0 Success
@returns != 0 Error code
*/
int ph_write_row(uchar *buf);
/**
Update an existing row in the partitioned table.
Yes, update_row() does what you expect, it updates a row. 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.
If the new record belongs to a different partition than the old record
then it will be inserted into the new partition and deleted from the old.
new_data is always record[0]
old_data is always record[1]
@return Operation status.
@returns 0 Success
@returns != 0 Error code
*/
int ph_update_row(const uchar *old_data, uchar *new_data);
/**
Delete an existing row in the partitioned table.
This will delete a row. buf will contain a copy of the row to be deleted.
The server will call this right after the current row has been read
(from either a previous rnd_xxx() or index_xxx() 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 no guarantee consecutive deletions.
ORDER BY clauses can be used.
buf is either record[0] or record[1]
@param buf The record in MySQL Row Format.
@return Operation status.
@retval 0 Success
@retval != 0 Error code
*/
int ph_delete_row(const uchar *buf);
/** @} */
/** Release unused auto increment values. */
void ph_release_auto_increment();
/**
Calculate key hash value from an null terminated array of fields.
Support function for KEY partitioning.
@param field_array An array of the fields in KEY partitioning
@return hash_value calculated
@note Uses the hash function on the character set of the field.
Integer and floating point fields use the binary character set by default.
*/
static uint32 ph_calculate_key_hash_value(Field **field_array);
/**
MODULE full table scan
This module is used for the most basic access method for any table
handler. This is to fetch all data through a full table scan. No
indexes are needed to implement this part.
It contains one method to start the scan (rnd_init) that can also be
called multiple times (typical in a nested loop join). Then proceeding
to the next record (rnd_next) and closing the scan (rnd_end).
To remember a record for later access there is a method (position)
and there is a method used to retrieve the record based on the stored
position.
The position can be a file position, a primary key, a ROWID dependent
on the handler below.
unlike index_init(), rnd_init() can be called two times
without rnd_end() in between (it only makes sense if scan=1).
then the second call should prepare for the new table scan
(e.g if rnd_init allocates the cursor, second call should
position it to the start of the table, no need to deallocate
and allocate it again.
@see handler.h
@{
*/
int ph_rnd_init(bool scan);
int ph_rnd_end();
int ph_rnd_next(uchar *buf);
void ph_position(const uchar *record);
/** @} */
/**
MODULE index scan
This part of the handler interface is used to perform access through
indexes. The interface is defined as a scan interface but the handler
can also use key lookup if the index is a unique index or a primary
key index.
Index scans are mostly useful for SELECT queries but are an important
part also of UPDATE, DELETE, REPLACE and CREATE TABLE table AS SELECT
and so forth.
Naturally an index is needed for an index scan and indexes can either
be ordered, hash based. Some ordered indexes can return data in order
but not necessarily all of them.
There are many flags that define the behavior of indexes in the
various handlers. These methods are found in the optimizer module.
-------------------------------------------------------------------------
index_read is called to start a scan of an index. The find_flag defines
the semantics of the scan. These flags are defined in
include/my_base.h
index_read_idx is the same but also initializes index before calling doing
the same thing as index_read. Thus it is similar to index_init followed
by index_read. This is also how we implement it.
index_read/index_read_idx does also return the first row. Thus for
key lookups, the index_read will be the only call to the handler in
the index scan.
index_init initializes an index before using it and index_end does
any end processing needed.
@{
*/
int ph_index_init_setup(uint key_nr, bool sorted);
/*
These methods are used to jump to next or previous entry in the index
scan. There are also methods to jump to first and last entry.
*/
int ph_index_first(uchar *buf);
int ph_index_last(uchar *buf);
int ph_index_next(uchar *buf);
int ph_index_next_same(uchar *buf, uint keylen);
int ph_index_prev(uchar *buf);
int ph_index_read_map(uchar *buf, const uchar *key, key_part_map keypart_map,
enum ha_rkey_function find_flag);
int ph_index_read_last_map(uchar *buf, const uchar *key,
key_part_map keypart_map);
int ph_index_read_idx_map(uchar *buf, uint index, const uchar *key,
key_part_map keypart_map,
enum ha_rkey_function find_flag);
int ph_read_range_first(const key_range *start_key, const key_range *end_key,
bool eq_range_arg, bool sorted);
int ph_read_range_next();
/** @} */
/**
Functions matching Partition_handler API.
@{
*/
/**
Get statistics from a specific partition.
@param[out] stat_info Area to report values into.
@param[out] check_sum Check sum of partition.
@param[in] part_id Partition to report from.
*/
virtual void get_dynamic_partition_info_low(ha_statistics *stat_info,
ha_checksum *check_sum,
uint part_id);
/**
Prepare for reorganizing partitions by setting up
partition_info::read_partitions according to the partition_info
mark-up.
This is helper method which can also be used by SEs implementing
support for reorganizing partitions through ALTER TABLE INPLACE
SE API.
*/
void prepare_change_partitions();
/** @} */
protected:
/* Common helper functions to be used by inheriting engines. */
/*
open/close functions.
*/
/**
Set m_part_share, Allocate internal bitmaps etc. used by open tables.
@return Operation status.
@returns false success.
@returns true failure.
*/
bool open_partitioning(Partition_share *part_share);
/**
Close partitioning for a table.
Frees memory and release other resources.
*/
void close_partitioning();
/**
Lock auto increment value if needed.
*/
void lock_auto_increment();
/**
unlock auto increment.
*/
inline void unlock_auto_increment() {
/*
If m_auto_increment_safe_stmt_log_lock is true, we have to keep the lock.
It will be set to false and thus unlocked at the end of the statement by
ha_partition::release_auto_increment.
*/
if (m_auto_increment_lock && !m_auto_increment_safe_stmt_log_lock) {
m_part_share->unlock_auto_inc();
m_auto_increment_lock = false;
}
}
/**
Get a range of auto increment values.
Can only be used if the auto increment field is the first field in an index.
This method is called by update_auto_increment which in turn is called
by the individual handlers as part of write_row. We use the
part_share->next_auto_inc_val, or search all
partitions for the highest auto_increment_value if not initialized or
if auto_increment field is a secondary part of a key, we must search
every partition when holding a mutex to be sure of correctness.
@param[in] increment Increment value.
@param[in] nb_desired_values Number of desired values.
@param[out] first_value First auto inc value reserved
or MAX if failure.
@param[out] nb_reserved_values Number of values reserved.
*/
void get_auto_increment_first_field(ulonglong increment,
ulonglong nb_desired_values,
ulonglong *first_value,
ulonglong *nb_reserved_values);
/**
Initialize the record priority queue used for sorted index scans.
@return Operation status.
@retval 0 Success.
@retval != 0 Error code.
*/
int init_record_priority_queue();
/**
Destroy the record priority queue used for sorted index scans.
*/
void destroy_record_priority_queue();
/*
Administrative support functions.
*/
/** Print partitioning specific error.
@param error Error code.
@return false if error is printed else true.
*/
bool print_partition_error(int error);
/**
Print a message row formatted for ANALYZE/CHECK/OPTIMIZE/REPAIR TABLE.
Modeled after mi_check_print_msg.
@param thd Thread context.
@param len Needed length for message buffer.
@param msg_type Message type.
@param db_name Database name.
@param table_name Table name.
@param op_name Operation name.
@param fmt Message (in printf format with additional arguments).
@return Operation status.
@retval false for success else true.
*/
bool print_admin_msg(THD *thd, uint len, const char *msg_type,
const char *db_name, const char *table_name,
const char *op_name, const char *fmt, ...)
MY_ATTRIBUTE((format(printf, 8, 9)));
/**
Check/fix misplaced rows.
@param read_part_id Partition to check/fix.
@param repair If true, move misplaced rows to correct partition.
@return Operation status.
@retval 0 Success
@retval != 0 Error
*/
int check_misplaced_rows(uint read_part_id, bool repair);
/**
Set used partitions bitmap from Alter_info.
@return false if success else true.
*/
bool set_altered_partitions();
/**
Copy partitions as part of ALTER TABLE of partitions.
SE and prepare_change_partitions has done all the preparations,
now it is time to actually copy the data from the reorganized
partitions to the new partitions.
@param[out] deleted Number of records deleted.
@return Operation status
@retval 0 Success
@retval >0 Error code
*/
virtual int copy_partitions(ulonglong *const deleted);
private:
enum partition_index_scan_type {
PARTITION_INDEX_READ = 1,
PARTITION_INDEX_FIRST,
PARTITION_INDEX_FIRST_UNORDERED,
PARTITION_INDEX_LAST,
PARTITION_INDEX_READ_LAST,
PARTITION_READ_RANGE,
PARTITION_NO_INDEX_SCAN
};
/** handler to use (ha_innopart etc.) */
handler *m_handler;
/*
Access methods to protected areas in handler to avoid adding
friend class Partition_helper in class handler.
*/
virtual THD *get_thd() const = 0;
virtual TABLE *get_table() const = 0;
virtual bool get_eq_range() const = 0;
virtual void set_eq_range(bool eq_range) = 0;
virtual void set_range_key_part(KEY_PART_INFO *key_part) = 0;
/*
Implementation of per partition operation by instantiated engine.
These must be implemented in the 'real' partition_helper subclass.
*/
/**
Write a row in the specified partition.
@see handler::write_row().
@param part_id Partition to write to.
@param buf Buffer with data to write.
@return Operation status.
@retval 0 Success.
@retval != 0 Error code.
*/
virtual int write_row_in_part(uint part_id, uchar *buf) = 0;
/**
Update a row in the specified partition.
@see handler::update_row().
@param part_id Partition to update in.
@param old_data Buffer containing old row.
@param new_data Buffer containing new row.
@return Operation status.
@retval 0 Success.
@retval != 0 Error code.
*/
virtual int update_row_in_part(uint part_id, const uchar *old_data,
uchar *new_data) = 0;
/**
Delete an existing row in the specified partition.
@see handler::delete_row().
@param part_id Partition to delete from.
@param buf Buffer containing row to delete.
@return Operation status.
@retval 0 Success.
@retval != 0 Error code.
*/
virtual int delete_row_in_part(uint part_id, const uchar *buf) = 0;
/**
Initialize the shared auto increment value.
@param no_lock If HA_STATUS_NO_LOCK should be used in info(HA_STATUS_AUTO).
Also sets stats.auto_increment_value.
*/
virtual int initialize_auto_increment(bool no_lock) = 0;
/** Release auto_increment in all underlying partitions. */
virtual void release_auto_increment_all_parts() {}
/** Save or persist the current max auto increment. */
virtual void save_auto_increment(ulonglong nr [[maybe_unused]]) {}
/**
Per partition equivalent of rnd_* and index_* functions.
@see class handler.
*/
virtual int rnd_init_in_part(uint part_id, bool table_scan) = 0;
int ph_rnd_next_in_part(uint part_id, uchar *buf);
virtual int rnd_next_in_part(uint part_id, uchar *buf) = 0;
virtual int rnd_end_in_part(uint part_id, bool scan) = 0;
virtual void position_in_last_part(uchar *ref, const uchar *row) = 0;
virtual int index_first_in_part(uint part, uchar *buf) = 0;
virtual int index_last_in_part(uint part, uchar *buf) = 0;
virtual int index_prev_in_part(uint part, uchar *buf) = 0;
virtual int index_next_in_part(uint part, uchar *buf) = 0;
virtual int index_next_same_in_part(uint part, uchar *buf, const uchar *key,
uint length) = 0;
virtual int index_read_map_in_part(uint part, uchar *buf, const uchar *key,
key_part_map keypart_map,
enum ha_rkey_function find_flag) = 0;
virtual int index_read_last_map_in_part(uint part, uchar *buf,
const uchar *key,
key_part_map keypart_map) = 0;
/**
Do read_range_first in the specified partition.
If buf is set, then copy the result there instead of table->record[0].
*/
virtual int read_range_first_in_part(uint part, uchar *buf,
const key_range *start_key,
const key_range *end_key,
bool sorted) = 0;
/**
Do read_range_next in the specified partition.
If buf is set, then copy the result there instead of table->record[0].
*/
virtual int read_range_next_in_part(uint part, uchar *buf) = 0;
virtual int index_read_idx_map_in_part(uint part, uchar *buf, uint index,
const uchar *key,
key_part_map keypart_map,
enum ha_rkey_function find_flag) = 0;
/**
Initialize engine specific resources for the record priority queue
used duing ordered index reads for multiple partitions.
@param used_parts Number of partitions used in query
(number of set bits in m_part_info->read_partitions).
@return Operation status.
@retval 0 Success.
@retval != 0 Error code.
*/
virtual int init_record_priority_queue_for_parts(uint used_parts
[[maybe_unused]]) {
return 0;
}
/**
Destroy and release engine specific resources used by the record
priority queue.
*/
virtual void destroy_record_priority_queue_for_parts() {}
/**
Checksum for a partition.
@param part_id Partition to checksum.
*/
virtual ha_checksum checksum_in_part(uint part_id [[maybe_unused]]) const {
assert(0);
return 0;
}
/**
Copy a cached row.
Used when copying a row from the record priority queue to the return buffer.
For some engines, like InnoDB, only marked columns must be copied,
to preserve non-read columns.
@param[out] to_rec Buffer to copy to.
@param[in] from_rec Buffer to copy from.
*/
virtual void copy_cached_row(uchar *to_rec, const uchar *from_rec) {
memcpy(to_rec, from_rec, m_rec_length);
}
/**
write row to new partition.
@param new_part New partition to write to.
@return Operation status.
@retval 0 Success.
@retval != 0 Error code.
*/
virtual int write_row_in_new_part(uint new_part) = 0;
/* Internal helper functions*/
/**
Update auto increment value if current row contains a higher value.
*/
inline void set_auto_increment_if_higher();
/**
Common routine to set up index scans.
Find out which partitions we'll need to read when scanning the specified
range.
If we need to scan only one partition, set m_ordered_scan_ongoing=false
as we will not need to do merge ordering.
@return Operation status.
@returns 0 Success
@returns !=0 Error code
*/
int partition_scan_set_up(uchar *buf, bool idx_read_flag);
/**
Common routine to handle index_next with unordered results.
These routines are used to scan partitions without considering order.
This is performed in two situations.
1) In read_multi_range this is the normal case
2) When performing any type of index_read, index_first, index_last where
all fields in the partition function is bound. In this case the index
scan is performed on only one partition and thus it isn't necessary to
perform any sort.
@return Operation status.
@returns HA_ERR_END_OF_FILE End of scan
@returns 0 Success
@returns other Error code
*/
int handle_unordered_next(uchar *buf, bool is_next_same);
/**
Handle index_next when changing to new partition.
This routine is used to start the index scan on the next partition.
Both initial start and after completing scan on one partition.
@param[out] buf Read row in MySQL Row Format
@return Operation status.
@retval HA_ERR_END_OF_FILE End of scan
@retval 0 Success
@retval other Error code
*/
int handle_unordered_scan_next_partition(uchar *buf);
/**
Common routine to start index scan with ordered results.
@returns Operation status
@returns HA_ERR_END_OF_FILE End of scan
@returns HA_ERR_KEY_NOT_FOUND End of scan
@returns 0 Success
@returns other Error code
*/
int handle_ordered_index_scan(uchar *buf);
/**
Add index_next/prev results from partitions without exact match.
If there where any partitions that returned HA_ERR_KEY_NOT_FOUND when
ha_index_read_map was done, those partitions must be included in the
following index_next/prev call.
@returns Operation status
@returns HA_ERR_END_OF_FILE End of scan
@returns 0 Success
@returns other Error code
*/
int handle_ordered_index_scan_key_not_found();
/**
Common routine to handle index_prev with ordered results.
@param[out] buf Read row in MySQL Row Format.