ha_innopart.h

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/* The InnoDB Partition handler: the interface between MySQL and InnoDB. */
 
#ifndef ha_innopart_h
#define ha_innopart_h
 
#include <stddef.h>
#include <sys/types.h>
 
#include "ha_innodb.h"
#include "my_compiler.h"
#include "my_inttypes.h"
#include "partitioning/partition_handler.h"
#include "row0mysql.h"
#include "ut0bitset.h"
 
/* Forward declarations */
class Altered_partitions;
class partition_info;
 
/* Error Text */
static constexpr auto PARTITION_IN_SHARED_TABLESPACE =
    "InnoDB : A partitioned table"
    " is not allowed in a shared tablespace.";
 
/** HA_DUPLICATE_POS and HA_READ_BEFORE_WRITE_REMOVAL is not
set from ha_innobase, but cannot yet be supported in ha_innopart.
Full text and geometry is not yet supported. */
const handler::Table_flags HA_INNOPART_DISABLED_TABLE_FLAGS =
    (HA_CAN_FULLTEXT | HA_CAN_FULLTEXT_EXT | HA_CAN_GEOMETRY |
     HA_DUPLICATE_POS | HA_READ_BEFORE_WRITE_REMOVAL);
 
typedef Bitset Sql_stat_start_parts;
 
/** InnoDB partition specific Handler_share. */
class Ha_innopart_share : public Partition_share {
 private:
  /** Array of all included table definitions (one per partition). */
  dict_table_t **m_table_parts;
 
  /** Instead of INNOBASE_SHARE::idx_trans_tbl. Maps MySQL index number
  to InnoDB index per partition. */
  dict_index_t **m_index_mapping;
 
  /** Total number of partitions. */
  uint m_tot_parts;
 
  /** Number of indexes. */
  uint m_index_count;
 
  /** Reference count. */
  uint m_ref_count;
 
  /** Pointer back to owning TABLE_SHARE. */
  TABLE_SHARE *m_table_share;
 
 public:
  Ha_innopart_share(TABLE_SHARE *table_share);
 
  ~Ha_innopart_share() override;
 
  /** Set innodb table for given partition.
  @param[in]    part_id Partition number.
  @param[in]    table   Table. */
  inline void set_table_part(uint part_id, dict_table_t *table) {
    ut_ad(m_table_parts != nullptr);
    ut_ad(part_id < m_tot_parts);
    m_table_parts[part_id] = table;
  }
  /** Get table reference for given partition.
  @param[in]    part_id Partition number
  @return       InnoDB table reference. */
  inline dict_table_t **get_table_part_ref(uint part_id) {
    return (&m_table_parts[part_id]);
  }
 
  /** Return innodb table for given partition.
  @param[in]    part_id Partition number.
  @return       InnoDB table. */
  inline dict_table_t *get_table_part(uint part_id) const {
    ut_ad(m_table_parts != nullptr);
    ut_ad(part_id < m_tot_parts);
    return (m_table_parts[part_id]);
  }
 
  /** Return innodb index for given partition and key number.
  @param[in]    part_id Partition number.
  @param[in]    keynr   Key number.
  @return       InnoDB index. */
  dict_index_t *get_index(uint part_id, uint keynr);
 
  /** Get MySQL key number corresponding to InnoDB index.
  Calculates the key number used inside MySQL for an Innobase index. We will
  first check the "index translation table" for a match of the index to get
  the index number. If there does not exist an "index translation table",
  or not able to find the index in the translation table, then we will fall back
  to the traditional way of looping through dict_index_t list to find a
  match. In this case, we have to take into account if we generated a
  default clustered index for the table
  @param[in]    part_id Partition the index belongs to.
  @param[in]    index   Index to return MySQL key number for.
  @return       the key number used inside MySQL or UINT_MAX if key is not
  found. */
  uint get_mysql_key(uint part_id, const dict_index_t *index);
 
  /** Return whether share has opened InnoDB tables for partitions. */
  bool has_table_parts() const { return (m_table_parts != nullptr); }
 
  /** Increment share and InnoDB tables reference counters. */
  void increment_ref_counts();
 
  /** Open InnoDB tables for partitions and return them as array.
  @param[in,out]        thd             Thread context
  @param[in]    table           MySQL table definition
  @param[in]    dd_table        Global DD table object
  @param[in]    part_info       Partition info (partition names to use)
  @param[in]    table_name      Table name (db/table_name)
  @return       Array on InnoDB tables on success else nullptr. */
  static dict_table_t **open_table_parts(THD *thd, const TABLE *table,
                                         const dd::Table *dd_table,
                                         partition_info *part_info,
                                         const char *table_name);
 
  /** Initialize the share with table and indexes per partition.
  @param[in]    part_info       Partition info (partition names to use).
  @param[in]    table_parts     Array of InnoDB tables for partitions.
  @return       false on success else true. */
  bool set_table_parts_and_indexes(partition_info *part_info,
                                   dict_table_t **table_parts);
 
  /** Close the table partitions.
  If all instances are closed, also release the resources.*/
  void close_table_parts();
 
  /** Close InnoDB tables for partitions.
  @param[in]    table_parts     Array of InnoDB tables for partitions.
  @param[in]    tot_parts       Number of partitions. */
  static void close_table_parts(dict_table_t **table_parts, uint tot_parts);
 
  /** @return the TABLE SHARE object */
  const TABLE_SHARE *get_table_share() const { return (m_table_share); }
 
  /** Get the number of partitions
  @return number of partitions */
  uint get_num_parts() const {
    ut_ad(m_tot_parts != 0);
    return (m_tot_parts);
  }
 
  /** Set up the virtual column template for partition table, and points
  all m_table_parts[]->vc_templ to it.
  @param[in]    table           MySQL TABLE object
  @param[in]    ib_table        InnoDB dict_table_t
  @param[in]    name            Table name (db/table_name) */
  void set_v_templ(TABLE *table, dict_table_t *ib_table, const char *name);
 
 private:
  /** Disable default constructor. */
  Ha_innopart_share() = default;
 
  /** Open one partition
  @param[in,out]        client          Data dictionary client
  @param[in]    thd             Thread THD
  @param[in]    table           MySQL table definition
  @param[in]    dd_part         dd::Partition
  @param[in]    part_name       Table name of this partition
  @param[out]   part_dict_table InnoDB table for partition
  @retval       false   On success
  @retval       true    On failure */
  static bool open_one_table_part(dd::cache::Dictionary_client *client,
                                  THD *thd, const TABLE *table,
                                  const dd::Partition *dd_part,
                                  const char *part_name,
                                  dict_table_t **part_dict_table);
};
 
/** Get explicit specified tablespace for one (sub)partition, checking
from lowest level
@param[in]      tablespace      table-level tablespace if specified
@param[in]      part            Partition to check
@param[in]      sub_part        Sub-partition to check, if no, just NULL
@return Tablespace name, if nullptr or [0] = '\0' then nothing specified */
const char *partition_get_tablespace(const char *tablespace,
                                     const partition_element *part,
                                     const partition_element *sub_part);
 
/** The class defining a partitioning aware handle to an InnoDB table.
Based on ha_innobase and extended with
- Partition_helper for re-using common partitioning functionality
- Partition_handler for providing partitioning specific api calls.
Generic partitioning functions are implemented in Partition_helper.
Lower level storage functions are implemented in ha_innobase.
Partition_handler is inherited for implementing the handler level interface
for partitioning specific functions, like truncate_partition.
InnoDB specific functions related to partitioning is implemented here. */
class ha_innopart : public ha_innobase,
                    public Partition_helper,
                    public Partition_handler {
 public:
  ha_innopart(handlerton *hton, TABLE_SHARE *table_arg);
 
  ~ha_innopart() override = default;
 
  /** Clone this handler, used when needing more than one cursor
  to the same table.
  @param[in]    name            Table name.
  @param[in]    mem_root        mem_root to allocate from.
  @retval       Pointer to clone or NULL if error. */
  handler *clone(const char *name, MEM_ROOT *mem_root) override;
 
  /** \defgroup ONLINE_ALTER_TABLE_INTERFACE On-line ALTER TABLE interface
  @see handler0alter.cc
  @{ */
 
  /** Check if InnoDB supports a particular alter table in-place.
  @param[in]    altered_table   TABLE object for new version of table.
  @param[in,out]        ha_alter_info   Structure describing changes to be done
  by ALTER TABLE and holding data used during in-place alter.
  @retval       HA_ALTER_INPLACE_NOT_SUPPORTED  Not supported
  @retval       HA_ALTER_INPLACE_NO_LOCK        Supported
  @retval       HA_ALTER_INPLACE_SHARED_LOCK_AFTER_PREPARE      Supported, but
  requires lock during main phase and exclusive lock during prepare
  phase.
  @retval       HA_ALTER_INPLACE_NO_LOCK_AFTER_PREPARE  Supported, prepare
  phase requires exclusive lock. */
  enum_alter_inplace_result check_if_supported_inplace_alter(
      TABLE *altered_table, Alter_inplace_info *ha_alter_info) override;
 
  /** Prepare in-place ALTER for table.
  Allows InnoDB to update internal structures with concurrent
  writes blocked (provided that check_if_supported_inplace_alter()
  did not return HA_ALTER_INPLACE_NO_LOCK).
  This will be invoked before inplace_alter_table().
  @param[in]    altered_table   TABLE object for new version of table.
  @param[in,out]        ha_alter_info   Structure describing changes to be done
  by ALTER TABLE and holding data used during in-place alter.
  @param[in]    old_table_def   dd::Table object describing old
  version of the table.
  @param[in,out]        new_table_def   dd::Table object for the new version
  of the table. Can be adjusted by this call. Changes to the table
  definition will be persisted in the data-dictionary at statement
  commit time.
  @retval       true    Failure.
  @retval       false   Success. */
  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) override;
 
  /** Alter the table structure in-place.
  Alter the table structure in-place with operations
  specified using HA_ALTER_FLAGS and Alter_inplace_information.
  The level of concurrency allowed during this operation depends
  on the return value from check_if_supported_inplace_alter().
  @param[in]    altered_table   TABLE object for new version of table.
  @param[in,out]        ha_alter_info   Structure describing changes to be done
  by ALTER TABLE and holding data used during in-place alter.
  @param[in]    old_table_def   dd::Table object describing old
  version of the table.
  @param[in,out]        new_table_def   dd::Table object for the new version
  of the table. Can be adjusted by this call. Changes to the table
  definition will be persisted in the data-dictionary at statement
  commit time.
  @retval       true    Failure.
  @retval       false   Success. */
  bool inplace_alter_table(TABLE *altered_table,
                           Alter_inplace_info *ha_alter_info,
                           const dd::Table *old_table_def,
                           dd::Table *new_table_def) override;
 
  /** Commit or rollback.
  Commit or rollback the changes made during
  prepare_inplace_alter_table() and inplace_alter_table() inside
  the storage engine. Note that the allowed level of concurrency
  during this operation will be the same as for
  inplace_alter_table() and thus might be higher than during
  prepare_inplace_alter_table(). (E.g concurrent writes were
  blocked during prepare, but might not be during commit).
  @param[in]    altered_table   TABLE object for new version of table.
  @param[in,out]        ha_alter_info   Structure describing changes to be done
                                  by ALTER TABLE and holding data used during
  in-place alter.
  @param[in]    commit          true => Commit, false => Rollback.
  @param[in]    old_table_def   dd::Table object describing old
  version of the table.
  @param[in,out]        new_table_def   dd::Table object for the new version
  of the table. Can be adjusted by this call. Changes to the table
  definition will be persisted in the data-dictionary at statement
  commit time.
  @retval       true    Failure.
  @retval       false   Success. */
  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) override;
  /** @} */
 
  /** Allows InnoDB to update internal structures with concurrent
  writes blocked (given that check_if_supported_inplace_alter()
  did not return HA_ALTER_INPLACE_NO_LOCK).
  This is for 'ALTER TABLE ... PARTITION' and a corresponding function
  to inplace_alter_table().
  This will be invoked before inplace_alter_partition().
 
  @param[in,out]        altered_table   TABLE object for new version of table
  @param[in,out]        ha_alter_info   Structure describing changes to be done
                                  by ALTER TABLE and holding data used during
                                  in-place alter.
  @param[in]    old_dd_tab      Table definition before the ALTER
  @param[in,out]        new_dd_tab      Table definition after the ALTER
  @retval true  Failure
  @retval false Success */
  bool prepare_inplace_alter_partition(TABLE *altered_table,
                                       Alter_inplace_info *ha_alter_info,
                                       const dd::Table *old_dd_tab,
                                       dd::Table *new_dd_tab);
 
  /** Alter the table structure in-place with operations
  specified using HA_ALTER_FLAGS and Alter_inplace_information.
  This is for 'ALTER TABLE ... PARTITION' and a corresponding function
  to inplace_alter_table().
  The level of concurrency allowed during this operation depends
  on the return value from check_if_supported_inplace_alter().
 
  @param[in,out]        ha_alter_info   Structure describing changes to be done
                                  by ALTER TABLE and holding data used
                                  during in-place alter.
  @retval       true    Failure
  @retval       false   Success */
  bool inplace_alter_partition(Alter_inplace_info *ha_alter_info);
 
  /** Prepare to commit or roll back ALTER TABLE...ALGORITHM=INPLACE.
  This is for 'ALTER TABLE ... PARTITION' and a corresponding function
  to commit_inplace_alter_table().
  @param[in,out]        altered_table   TABLE object for new version of table.
  @param[in,out]        ha_alter_info   ALGORITHM=INPLACE metadata
  @param[in]    commit          true=Commit, false=Rollback.
  @param[in]    old_dd_tab      old table
  @param[in,out]        new_dd_tab      new table
  @retval       true    on failure (my_error() will have been called)
  @retval       false   on success */
  bool commit_inplace_alter_partition(TABLE *altered_table,
                                      Alter_inplace_info *ha_alter_info,
                                      bool commit, const dd::Table *old_dd_tab,
                                      dd::Table *new_dd_tab);
 
  // TODO: should we implement init_table_handle_for_HANDLER() ?
  // (or is sql_stat_start handled correctly anyway?)
  /** Optimize table.
  This is mapped to "ALTER TABLE tablename ENGINE=InnoDB", which rebuilds
  the table in MySQL.
  @param[in]    thd             Connection thread handle.
  @param[in]    check_opt       Currently ignored.
  @return       0 for success else error code. */
  int optimize(THD *thd, HA_CHECK_OPT *check_opt) override;
 
  /** Set DD discard attribute for tablespace.
  @param[in]    table_def       dd table
  @param[in]    discard         True if this table is discarded
  @return       0 or error number. */
  int set_dd_discard_attribute(dd::Table *table_def, bool discard);
 
  int discard_or_import_tablespace(bool discard, dd::Table *table_def) override;
 
  /** Compare key and rowid.
  Helper function for sorting records in the priority queue.
  a/b points to table->record[0] rows which must have the
  key fields set. The bytes before a and b store the rowid.
  This is used for comparing/sorting rows first according to
  KEY and if same KEY, by rowid (ref).
 
  @param[in]    key_info        Null terminated array of index
  information.
  @param[in]    a               Pointer to record+ref in first record.
  @param[in]    b               Pointer to record+ref in second record.
  @return Return value is SIGN(first_rec - second_rec)
  @retval       0       Keys are equal.
  @retval       -1      second_rec is greater than first_rec.
  @retval       +1      first_rec is greater than second_rec. */
  static int key_and_rowid_cmp(KEY **key_info, uchar *a, uchar *b);
 
  int extra(enum ha_extra_function operation) override;
 
  void print_error(int error, myf errflag) override;
 
  bool is_ignorable_error(int error) override;
 
  int start_stmt(THD *thd, thr_lock_type lock_type) override;
 
  ha_rows records_in_range(uint inx, key_range *min_key,
                           key_range *max_key) override;
 
  ha_rows estimate_rows_upper_bound() override;
 
  uint alter_table_flags(uint flags);
 
  void update_create_info(HA_CREATE_INFO *create_info) override;
 
  int create(const char *name, TABLE *form, HA_CREATE_INFO *create_info,
             dd::Table *table_def) override;
 
  /** Drop a table.
  @param[in]    name            table name
  @param[in,out]        dd_table        data dictionary table
  @return error number
  @retval 0 on success */
  int delete_table(const char *name, const dd::Table *dd_table) override;
 
  /** Rename a table.
  @param[in]    from            table name before rename
  @param[in]    to              table name after rename
  @param[in]    from_table      data dictionary table before rename
  @param[in,out]        to_table        data dictionary table after rename
  @return       error number
  @retval       0 on success */
  int rename_table(const char *from, const char *to,
                   const dd::Table *from_table, dd::Table *to_table) override;
 
  int check(THD *thd, HA_CHECK_OPT *check_opt) override;
 
  /** Repair a partitioned table.
  Only repairs records in wrong partitions (moves them to the correct
  partition or deletes them if not in any partition).
  @param[in]    thd             MySQL THD object/thread handle.
  @param[in]    repair_opt      Repair options.
  @return       0 or error code. */
  int repair(THD *thd, HA_CHECK_OPT *repair_opt) override;
 
  /** Get the current auto_increment value.
  @param[in]    offset                  Table auto-inc offset.
  @param[in]    increment               Table auto-inc increment.
  @param[in]    nb_desired_values       Number of required values.
  @param[out]   first_value             The auto increment value.
  @param[out]   nb_reserved_values      Number of reserved values. */
  void get_auto_increment(ulonglong offset, ulonglong increment,
                          ulonglong nb_desired_values, ulonglong *first_value,
                          ulonglong *nb_reserved_values) override;
 
  /* Get partition row type
  @param[in] partition_table partition table
  @param[in] part_id Id of partition for which row type to be retrieved
  @return Partition row type. */
  enum row_type get_partition_row_type(const dd::Table *partition_table,
                                       uint part_id) override;
 
  int cmp_ref(const uchar *ref1, const uchar *ref2) const override;
 
  int read_range_first(const key_range *start_key, const key_range *end_key,
                       bool eq_range_arg, bool sorted) override {
    return (Partition_helper::ph_read_range_first(start_key, end_key,
                                                  eq_range_arg, sorted));
  }
 
  void position(const uchar *record) override {
    Partition_helper::ph_position(record);
  }
 
  /* TODO: Implement these! */
  bool check_if_incompatible_data(HA_CREATE_INFO *info [[maybe_unused]],
                                  uint table_changes
                                  [[maybe_unused]]) override {
    ut_d(ut_error);
    ut_o(return (COMPATIBLE_DATA_NO));
  }
 
  int delete_all_rows() override { return (handler::delete_all_rows()); }
 
  int disable_indexes(uint mode [[maybe_unused]]) override {
    return (HA_ERR_WRONG_COMMAND);
  }
 
  int enable_indexes(uint mode [[maybe_unused]]) override {
    return (HA_ERR_WRONG_COMMAND);
  }
 
  int ft_init() override {
    ut_d(ut_error);
    ut_o(return (HA_ERR_WRONG_COMMAND));
  }
 
  FT_INFO *ft_init_ext(uint flags [[maybe_unused]], uint inx [[maybe_unused]],
                       String *key [[maybe_unused]]) override {
    ut_d(ut_error);
    ut_o(return (nullptr));
  }
 
  FT_INFO *ft_init_ext_with_hints(uint inx [[maybe_unused]],
                                  String *key [[maybe_unused]],
                                  Ft_hints *hints [[maybe_unused]]) override {
    ut_d(ut_error);
    ut_o(return (nullptr));
  }
 
  int ft_read(uchar *buf [[maybe_unused]]) override {
    ut_d(ut_error);
    ut_o(return (HA_ERR_WRONG_COMMAND));
  }
 
  bool get_foreign_dup_key(char *child_table_name [[maybe_unused]],
                           uint child_table_name_len [[maybe_unused]],
                           char *child_key_name [[maybe_unused]],
                           uint child_key_name_len [[maybe_unused]]) override {
    ut_d(ut_error);
    ut_o(return (false));
  }
 
  int read_range_next() override {
    return (Partition_helper::ph_read_range_next());
  }
 
  uint32_t calculate_key_hash_value(Field **field_array) override {
    return (Partition_helper::ph_calculate_key_hash_value(field_array));
  }
 
  Table_flags table_flags() const override {
    return (ha_innobase::table_flags() | HA_CAN_REPAIR);
  }
 
  void release_auto_increment() override {
    Partition_helper::ph_release_auto_increment();
  }
 
  /** Implementing Partition_handler interface @see partition_handler.h
  @{ */
 
  /** See Partition_handler. */
  void get_dynamic_partition_info(ha_statistics *stat_info,
                                  ha_checksum *check_sum,
                                  uint part_id) override {
    Partition_helper::get_dynamic_partition_info_low(stat_info, check_sum,
                                                     part_id);
  }
 
  uint alter_flags(uint flags [[maybe_unused]]) const override {
    return (HA_PARTITION_FUNCTION_SUPPORTED | HA_INPLACE_CHANGE_PARTITION);
  }
 
  Partition_handler *get_partition_handler() override {
    return (static_cast<Partition_handler *>(this));
  }
 
  void set_part_info(partition_info *part_info, bool early) override {
    Partition_helper::set_part_info_low(part_info, early);
  }
 
  void initialize_partitioning(partition_info *part_info, bool early) {
    Partition_helper::set_part_info_low(part_info, early);
  }
 
  handler *get_handler() override { return (static_cast<handler *>(this)); }
  /** @} */
 
  /** Get number of threads that would be spawned for parallel read.
  @param[out]   scan_ctx              A scan context created by this method
                                      that has to be used in
                                      parallel_scan
  @param[out]   num_threads           Number of threads to be spawned
  @param[in]    use_reserved_threads  true if reserved threads are to be used
                                      if we exhaust the max cap of number of
                                      parallel read threads that can be
                                      spawned at a time
  @param[in]    max_desired_threads   Maximum number of desired read threads;
                                      passing 0 has no effect, it is ignored;
                                      upper-limited by the current value of
                                      innodb_parallel_read_threads.
  @return error code
  @return 0 on success */
  int parallel_scan_init(void *&scan_ctx, size_t *num_threads,
                         bool use_reserved_threads,
                         size_t max_desired_threads) override;
 
  using Reader = Parallel_reader_adapter;
 
  /** Start parallel read of data.
  @param[in] scan_ctx           Scan context created by parallel_scan_init
  @param[in] thread_ctxs        context for each of the spawned threads
  @param[in] init_fn            callback called by each parallel load
                                thread at the beginning of the parallel load.
  @param[in] load_fn            callback called by each parallel load
                                thread when processing of rows is required.
  @param[in] end_fn             callback called by each parallel load
                                thread when processing of rows has ended.
  @return error code
  @return 0 on success */
  int parallel_scan(void *scan_ctx, void **thread_ctxs, Reader::Init_fn init_fn,
                    Reader::Load_fn load_fn, Reader::End_fn end_fn) override;
  /** Run the parallel read of data.
  @param[in]      parallel_scan_ctx a scan context created by
                                    parallel_scan_init
  */
  void parallel_scan_end(void *parallel_scan_ctx) override;
 
 private:
  /** Pointer to Ha_innopart_share on the TABLE_SHARE. */
  Ha_innopart_share *m_part_share;
 
  struct saved_prebuilt_t {
    /** saved m_prebuilt->ins_node */
    ins_node_t *m_ins_node;
 
    /** saved m_prebuilt->upd_node */
    upd_node_t *m_upd_node;
 
    /** saved m_prebuilt->blob_heap */
    mem_heap_t *m_blob_heap;
 
    /** saved m_prebuilt->trx_id (which in turn reflects table->def_trx_id) */
    trx_id_t m_trx_id;
 
    /** saved m_prebuilt->row_read_type  */
    ulint m_row_read_type;
 
    /** save m_prebuilt->new_rec_lock[] values */
    decltype(row_prebuilt_t::new_rec_lock) m_new_rec_lock;
  };
  /* Per partition information storing last values of m_prebuilt when we've last
  finished using given partition, so we can restore it when we return to it.
  Synchronized with m_prebuilt when changing partitions:
  set_partition(part_id) copies to m_prebuilt from m_parts[part_id]
  update_partition(part_id) copies to m_parts[part_id] from m_prebuilt
 
  NOTE: these are not the only fields synchronized with m_prebuilt.
  */
  ut::unique_ptr<saved_prebuilt_t[]> m_parts;
 
  /** byte array for sql_stat_start bitset */
  byte *m_bitset;
 
  /** sql_stat_start per partition. */
  Sql_stat_start_parts m_sql_stat_start_parts;
 
  /** persistent cursors per partition. */
  btr_pcur_t *m_pcur_parts;
 
  /** persistent cluster cursors per partition. */
  btr_pcur_t *m_clust_pcur_parts;
 
  /** map from part_id to offset in above two arrays. */
  uint16_t *m_pcur_map;
 
  /** Original m_prebuilt->pcur. */
  btr_pcur_t *m_pcur;
 
  /** Original m_prebuilt->clust_pcur. */
  btr_pcur_t *m_clust_pcur;
 
  /** New partitions during ADD/REORG/... PARTITION. */
  Altered_partitions *m_new_partitions;
 
  /** Can reuse the template for the previous partition. */
  bool m_reuse_mysql_template;
 
  /** Clear used ins_nodes and upd_nodes. */
  void clear_ins_upd_nodes();
 
  /** Clear the blob heaps for all partitions */
  void clear_blob_heaps();
 
  /** Reset state of file to after 'open'. This function is called
  after every statement for all tables used by that statement. */
  int reset() override;
 
  /** Changes the active index of a handle.
  @param[in]    part_id Use this partition.
  @param[in]    keynr   Use this index; MAX_KEY means always clustered index,
  even if it was internally generated by InnoDB.
  @return       0 or error number. */
  int change_active_index(uint part_id, uint keynr);
 
  /** Move to next partition and set its index.
  @return       0 for success else error number. */
  int next_partition_index();
 
  /** Internally called for initializing auto increment value.
  Should never be called, but defined to catch such errors.
  @return 0 on success else error code. */
  int innobase_initialize_autoinc();
 
  /** Get the index for the current partition
  @param[in]    keynr   MySQL index number.
  @return InnoDB index or NULL. */
  dict_index_t *innobase_get_index(uint keynr) override;
 
  /** Get the index for a handle.
  Does not change active index.
  @param[in]    keynr   Use this index; MAX_KEY means always clustered index,
  even if it was internally generated by InnoDB.
  @param[in]    part_id From this partition.
  @return       NULL or index instance. */
  dict_index_t *innopart_get_index(uint part_id, uint keynr);
 
  /** Change active partition.
  Copies needed info into m_prebuilt from the partition specific memory.
  @param[in]    part_id Partition to set as active. */
  void set_partition(uint part_id);
 
  /** Update active partition.
  Copies needed info from m_prebuilt into the partition specific memory.
  @param[in]    part_id Partition to set as active. */
  void update_partition(uint part_id);
 
  /** TRUNCATE an InnoDB partitioned table.
  @param[in]            name            table name
  @param[in]            form            table definition
  @param[in,out]        table_def       dd::Table describing table to be
  truncated. Can be adjusted by SE, the changes will be saved into
  the data-dictionary at statement commit time.
  @return       error number
  @retval 0 on success */
  int truncate_impl(const char *name, TABLE *form, dd::Table *table_def);
 
  /** @defgroup PARTITION_HANDLER_HELPERS Helpers needed by Partition_helper
  @see partition_handler.h
  @{ */
 
  /** Set the autoinc column max value.
  This should only be called once from ha_innobase::open().
  Therefore there's no need for a covering lock.
  @param[in]    no_lock If locking should be skipped. Not used!
  @return       0 for success or error code. */
  int initialize_auto_increment(bool no_lock) override;
 
  /** Save currently highest auto increment value.
  @param[in]    nr      Auto increment value to save. */
  void save_auto_increment(ulonglong nr) override;
 
  /** Setup the ordered record buffer and the priority queue.
  @param[in]    used_parts      Number of used partitions in query.
  @return false for success, else true. */
  int init_record_priority_queue_for_parts(uint used_parts) override;
 
  /** Destroy the ordered record buffer and the priority queue. */
  void destroy_record_priority_queue_for_parts() override;
 
  /** Create the Altered_partitoins object
  @param[in]    ha_alter_info   thd DDL operation
  @retval true  On failure
  @retval false On success */
  bool prepare_for_copy_partitions(Alter_inplace_info *ha_alter_info);
 
  /** write row to new partition.
  @param[in]    new_part        New partition to write to.
  @return 0 for success else error code. */
  int write_row_in_new_part(uint new_part) override;
 
  /** Write a row in specific partition.
  Stores a row in an InnoDB database, to the table specified in this
  handle.
  @param[in]    part_id Partition to write to.
  @param[in]    record  A row in MySQL format.
  @return error code. */
  int write_row_in_part(uint part_id, uchar *record) override;
 
  /** Update a row in partition.
  Updates a row given as a parameter to a new value.
  @param[in]    part_id Partition to update row in.
  @param[in]    old_row Old row in MySQL format.
  @param[in]    new_row New row in MySQL format.
  @return       0 or error number. */
  int update_row_in_part(uint part_id, const uchar *old_row,
                         uchar *new_row) override;
 
  /** Deletes a row in partition.
  @param[in]    part_id Partition to delete from.
  @param[in]    record  Row to delete in MySQL format.
  @return       0 or error number. */
  int delete_row_in_part(uint part_id, const uchar *record) override;
 
  /** Return first record in index from a partition.
  @param[in]    part    Partition to read from.
  @param[out]   record  First record in index in the partition.
  @return error number or 0. */
  int index_first_in_part(uint part, uchar *record) override;
 
  /** Return last record in index from a partition.
  @param[in]    part    Partition to read from.
  @param[out]   record  Last record in index in the partition.
  @return error number or 0. */
  int index_last_in_part(uint part, uchar *record) override;
 
  /** Return previous record in index from a partition.
  @param[in]    part    Partition to read from.
  @param[out]   record  Last record in index in the partition.
  @return error number or 0. */
  int index_prev_in_part(uint part, uchar *record) override;
 
  /** Return next record in index from a partition.
  @param[in]    part    Partition to read from.
  @param[out]   record  Last record in index in the partition.
  @return error number or 0. */
  int index_next_in_part(uint part, uchar *record) override;
 
  /** Return next same record in index from a partition.
  This routine is used to read the next record, but only if the key is
  the same as supplied in the call.
  @param[in]    part    Partition to read from.
  @param[out]   record  Last record in index in the partition.
  @param[in]    key     Key to match.
  @param[in]    length  Length of key.
  @return error number or 0. */
  int index_next_same_in_part(uint part, uchar *record, const uchar *key,
                              uint length) override;
 
  /** Start index scan and return first record from a partition.
  This routine starts an index scan using a start key. The calling
  function will check the end key on its own.
  @param[in]    part    Partition to read from.
  @param[out]   record  First matching record in index in the partition.
  @param[in]    key     Key to match.
  @param[in]    keypart_map     Which part of the key to use.
  @param[in]    find_flag       Key condition/direction to use.
  @return error number or 0. */
  int index_read_map_in_part(uint part, uchar *record, const uchar *key,
                             key_part_map keypart_map,
                             enum ha_rkey_function find_flag) override;
 
  /** Return last matching record in index from a partition.
  @param[in]    part    Partition to read from.
  @param[out]   record  Last matching record in index in the partition.
  @param[in]    key     Key to match.
  @param[in]    keypart_map     Which part of the key to use.
  @return error number or 0. */
  int index_read_last_map_in_part(uint part, uchar *record, const uchar *key,
                                  key_part_map keypart_map) override;
 
  /** Start index scan and return first record from a partition.
  This routine starts an index scan using a start and end key.
  @param[in]    part            Partition to read from.
  @param[in,out]        record          First matching record in index in the
  partition, if NULL use table->record[0] as return buffer.
  @param[in]    start_key       Start key to match.
  @param[in]    end_key         End key to match.
  @param[in]    sorted          Return rows in sorted order.
  @return       error number or 0. */
  int read_range_first_in_part(uint part, uchar *record,
                               const key_range *start_key,
                               const key_range *end_key, bool sorted) override;
 
  /** Return next record in index range scan from a partition.
  @param[in]    part    Partition to read from.
  @param[in,out]        record  First matching record in index in the partition,
  if NULL use table->record[0] as return buffer.
  @return       error number or 0. */
  int read_range_next_in_part(uint part, uchar *record) override;
 
  /** Start index scan and return first record from a partition.
  This routine starts an index scan using a start key. The calling
  function will check the end key on its own.
  @param[in]    part    Partition to read from.
  @param[out]   record  First matching record in index in the partition.
  @param[in]    index   Index to read from.
  @param[in]    key     Key to match.
  @param[in]    keypart_map     Which part of the key to use.
  @param[in]    find_flag       Key condition/direction to use.
  @return error number or 0. */
  int index_read_idx_map_in_part(uint part, uchar *record, uint index,
                                 const uchar *key, key_part_map keypart_map,
                                 enum ha_rkey_function find_flag) override;
 
  /** Initialize sampling.
  @param[out] scan_ctx  A scan context created by this method that has to be
  used in sample_next
  @param[in]  sampling_percentage percentage of records that need to be
  sampled
  @param[in]  sampling_seed       random seed that the random generator will
  use
  @param[in]  sampling_method     sampling method to be used; currently only
  SYSTEM sampling is supported
  @param[in]  tablesample         true if the sampling is for tablesample
  @return 0 for success, else one of the HA_xxx values in case of error. */
  int sample_init(void *&scan_ctx, double sampling_percentage,
                  int sampling_seed, enum_sampling_method sampling_method,
                  const bool tablesample) override;
 
  /** Get the next record for sampling.
  @param[in]  scan_ctx  Scan context of the sampling
  @param[in]  buf       buffer to place the read record
  @return 0 for success, else one of the HA_xxx values in case of error. */
  int sample_next(void *scan_ctx, uchar *buf) override;
 
  /** End sampling.
  @param[in] scan_ctx  Scan context of the sampling
  @return 0 for success, else one of the HA_xxx values in case of error. */
  int sample_end(void *scan_ctx) override;
 
  /** Initialize random read/scan of a specific partition.
  @param[in]    part_id         Partition to initialize.
  @param[in]    scan            True for scan else random access.
  @return error number or 0. */
  int rnd_init_in_part(uint part_id, bool scan) override;
 
  /** Get next row during scan of a specific partition.
  Also used to read the FIRST row in a table scan.
  @param[in]    part_id Partition to read from.
  @param[out]   buf     Next row.
  @return error number or 0. */
  int rnd_next_in_part(uint part_id, uchar *buf) override;
 
  /** End random read/scan of a specific partition.
  @param[in]    part_id         Partition to end random read/scan.
  @param[in]    scan            True for scan else random access.
  @return error number or 0. */
  int rnd_end_in_part(uint part_id, bool scan) override;
 
  /** Return position for cursor in last used partition.
  Stores a reference to the current row to 'ref' field of the handle. Note
  that in the case where we have generated the clustered index for the
  table, the function parameter is illogical: we MUST ASSUME that 'record'
  is the current 'position' of the handle, because if row ref is actually
  the row id internally generated in InnoDB, then 'record' does not contain
  it. We just guess that the row id must be for the record where the handle
  was positioned the last time.
  @param[out]   ref_arg Pointer to buffer where to write the position.
  @param[in]    record  Record to position for. */
  void position_in_last_part(uchar *ref_arg, const uchar *record) override;
 
  /** Read row using position using given record to find.
  This works as position()+rnd_pos() functions, but does some
  extra work,calculating m_last_part - the partition to where
  the 'record' should go.
  Only useful when position is based on primary key
  (HA_PRIMARY_KEY_REQUIRED_FOR_POSITION).
  @param[in]    record  Current record in MySQL Row Format.
  @return       0 for success else error code. */
  int rnd_pos_by_record(uchar *record) override;
 
  /** Copy a cached MySQL row.
  If requested, also avoids overwriting non-read columns.
  @param[out]   buf             Row in MySQL format.
  @param[in]    cached_row      Which row to copy. */
  void copy_cached_row(uchar *buf, const uchar *cached_row) override;
  /** @} */
 
  /** @defgroup PRIVATE_HANDLER InnoDB Partitioning Private Handler
  Functions specific for native InnoDB partitioning.
  @see handler.h
  @{ */
 
  /** Open an InnoDB table.
  @param[in]    name            table name
  @param[in]    mode            access mode
  @param[in]    test_if_locked  test if the file to be opened is locked
  @param[in]    table_def       dd::Table describing table to be opened
  @retval 1 if error
  @retval 0 if success */
  int open(const char *name, int mode, uint test_if_locked,
           const dd::Table *table_def) override;
 
  int close() override;
 
  double scan_time() override;
 
  /** Was the last returned row semi consistent read.
  In an UPDATE or DELETE, if the row under the cursor was locked by
  another transaction, and the engine used an optimistic read of the last
  committed row value under the cursor, then the engine returns 1 from
  this function. MySQL must NOT try to update this optimistic value. If
  the optimistic value does not match the WHERE condition, MySQL can
  decide to skip over this row. This can be used to avoid unnecessary
  lock waits.
 
  If this method returns true, it will also signal the storage
  engine that the next read will be a locking re-read of the row.
  @see handler.h and row0mysql.h
  @return       true if last read was semi consistent else false. */
  bool was_semi_consistent_read() override;
 
  /** Try semi consistent read.
  Tell the engine whether it should avoid unnecessary lock waits.
  If yes, in an UPDATE or DELETE, if the row under the cursor was locked
  by another transaction, the engine may try an optimistic read of
  the last committed row value under the cursor.
  @see handler.h and row0mysql.h
  @param[in]    yes     Should semi-consistent read be used. */
  void try_semi_consistent_read(bool yes) override;
 
  /** Removes a lock on a row.
  Removes a new lock set on a row, if it was not read optimistically.
  This can be called after a row has been read in the processing of
  an UPDATE or a DELETE query. @see ha_innobase::unlock_row(). */
  void unlock_row() override;
 
  int index_init(uint index, bool sorted) override;
 
  int index_end() override;
 
  int rnd_init(bool scan) override {
    return (Partition_helper::ph_rnd_init(scan));
  }
 
  int rnd_end() override { return (Partition_helper::ph_rnd_end()); }
 
  int external_lock(THD *thd, int lock_type) override;
 
  THR_LOCK_DATA **store_lock(THD *thd, THR_LOCK_DATA **to,
                             thr_lock_type lock_type) override;
 
  int write_row(uchar *record) override {
    bool entered = false;
    auto trx = m_prebuilt->trx;
 
    /* Enter innodb to order Auto INC partition lock after Innodb. No need to
    enter if there are tickets left. Currently we cannot handle re-enter
    without exit if no more tickets left.
 
    1. We avoid consuming the last ticket as there could be another enter
    call from innobase.
 
    2. If we enter innodb here, there is at least one more ticket left as
    the minimum value for "innodb_concurrency_tickets" is 1 */
 
    if (!trx->declared_to_be_inside_innodb) {
      auto err = srv_concurrency_enter();
      if (err != 0) {
        return (err);
      }
      entered = true;
    }
 
    auto err = Partition_helper::ph_write_row(record);
 
    if (entered) {
      srv_concurrency_exit();
    }
 
    return (err);
  }
 
  int update_row(const uchar *old_record, uchar *new_record) override {
    return (Partition_helper::ph_update_row(old_record, new_record));
  }
 
  int delete_row(const uchar *record) override {
    return (Partition_helper::ph_delete_row(record));
  }
  /** @} */
 
  /** Delete all rows in the requested partitions.
  Done by deleting the partitions and recreate them again.
  @param[in,out]        dd_table        dd::Table object for partitioned table
  which partitions need to be truncated. Can be adjusted by this call.
  Changes to the table definition will be persisted in the data-dictionary
  at statement commit time.
  @return       0 or error number. */
  int truncate_partition_low(dd::Table *dd_table) override;
 
  /** Exchange partition.
  Low-level primitive which implementation is provided here.
  @param[in]    part_id                 The id of the partition to be exchanged
  @param[in]    part_table              partitioned table to be exchanged
  @param[in]    swap_table              table to be exchanged
  @return error number
  @retval 0     on success */
  int exchange_partition_low(uint part_id, dd::Table *part_table,
                             dd::Table *swap_table) override;
 
  /** Access methods to protected areas in handler to avoid adding
  friend class Partition_helper in class handler.
  @see partition_handler.h
  @{ */
 
  THD *get_thd() const override { return ha_thd(); }
 
  TABLE *get_table() const override { return table; }
 
  bool get_eq_range() const override { return eq_range; }
 
  void set_eq_range(bool eq_range_arg) override { eq_range = eq_range_arg; }
 
  void set_range_key_part(KEY_PART_INFO *key_part) override {
    range_key_part = key_part;
  }
  /** @} */
 
  /** Fill in data_dir_path and tablespace name from internal data
  dictionary.
  @param[in,out]        part_elem               Partition element to fill.
  @param[in]    ib_table                InnoDB table to copy from.
  @param[in]    display_tablespace      Display tablespace name if
                                          set. */
  void update_part_elem(partition_element *part_elem, dict_table_t *ib_table,
                        bool display_tablespace);
 
 protected:
  /** Protected handler:: functions specific for native InnoDB partitioning.
  @see handler.h
  @{ */
 
  int rnd_next(uchar *record) override {
    return (Partition_helper::ph_rnd_next(record));
  }
 
  int rnd_pos(uchar *record, uchar *pos) override;
 
  int records(ha_rows *num_rows) override;
 
  int index_next(uchar *record) override {
    return (Partition_helper::ph_index_next(record));
  }
 
  int index_next_same(uchar *record, const uchar *, uint keylen) override {
    return (Partition_helper::ph_index_next_same(record, keylen));
  }
 
  int index_prev(uchar *record) override {
    return (Partition_helper::ph_index_prev(record));
  }
 
  int index_first(uchar *record) override {
    return (Partition_helper::ph_index_first(record));
  }
 
  int index_last(uchar *record) override {
    return (Partition_helper::ph_index_last(record));
  }
 
  int index_read_last_map(uchar *record, const uchar *key,
                          key_part_map keypart_map) override {
    return (Partition_helper::ph_index_read_last_map(record, key, keypart_map));
  }
 
  int index_read_map(uchar *buf, const uchar *key, key_part_map keypart_map,
                     enum ha_rkey_function find_flag) override {
    return (
        Partition_helper::ph_index_read_map(buf, key, keypart_map, find_flag));
  }
 
  int index_read_idx_map(uchar *buf, uint index, const uchar *key,
                         key_part_map keypart_map,
                         enum ha_rkey_function find_flag) override {
    return (Partition_helper::ph_index_read_idx_map(buf, index, key,
                                                    keypart_map, find_flag));
  }
  /** @} */
 
  /** Updates and return statistics.
  Returns statistics information of the table to the MySQL interpreter,
  in various fields of the handle object.
  @param[in]    flag            Flags for what to update and return.
  @param[in]    is_analyze      True if called from "::analyze()".
  @return       HA_ERR_* error code or 0. */
  int info_low(uint flag, bool is_analyze) override;
 
  bool can_reuse_mysql_template() const override {
    return m_reuse_mysql_template;
  }
};
#endif /* ha_innopart_h */