mariadb/storage/innobase/include/read0read.h
aivanov@mysql.com d33b523271 Applied innodb-5.1-ss269 snapshot.
Fixed BUGS:
  #3300: "UPDATE statement with no index column in where condition locks
    all rows"
    Implement semi-consistent read to reduce lock conflicts at the cost
    of breaking serializability.
    ha_innobase::unlock_row(): reset the "did semi consistent read" flag
    ha_innobase::was_semi_consistent_read(),
    ha_innobase::try_semi_consistent_read(): new methods
    row_prebuilt_t, row_create_prebuilt(): add field row_read_type for
    keeping track of semi-consistent reads
    row_vers_build_for_semi_consistent_read(),
    row_sel_build_committed_vers_for_mysql(): new functions
    row_search_for_mysql(): implement semi-consistent reads

  #9802: "Foreign key checks disallow alter table".
    Added test cases.

  #12456: "Cursor shows incorrect data - DML does not affect,
    probably caching"
    This patch implements a high-granularity read view to be used with
    cursors. In this high-granularity consistent read view modifications 
    done by the creating transaction after the cursor is created or 
   future transactions are not visible. But those modifications that 
   transaction did before the cursor was created are visible.

  #12701: "Support >4GB buffer pool and log files on 64-bit Windows"
    Do not call os_file_create_tmpfile() at runtime. Instead, create all
    tempfiles at startup and guard access to them with mutexes.

  #13778: "If FOREIGN_KEY_CHECKS=0, one can create inconsistent FOREIGN KEYs".
    When FOREIGN_KEY_CHECKS=0 we still need to check that datatypes between
    foreign key references are compatible.

  #14189: "VARBINARY and BINARY variables: trailing space ignored with InnoDB"
    innobase_init(): Assert that
    DATA_MYSQL_BINARY_CHARSET_COLL == my_charset_bin.number.
    dtype_get_pad_char(): Do not pad VARBINARY or BINARY columns.
    row_ins_cascade_calc_update_vec(): Refuse ON UPDATE CASCADE when trying
    to change the length of a VARBINARY column that refers to or is referenced
    by a BINARY column. BINARY columns are no longer padded on comparison,
    and thus they cannot be padded on storage either.

  #14747: "Race condition can cause btr_search_drop_page_hash_index() to crash"
    Note that buf_block_t::index should be protected by btr_search_latch
    or an s-latch or x-latch on the index page.
    btr_search_drop_page_hash_index(): Read block->index while holding
    btr_search_latch and use the cached value in the loop.  Remove some
    redundant assertions.

  #15108: "mysqld crashes when innodb_log_file_size is set > 4G"

  #15308: "Problem of Order with Enum Column in Primary Key"

  #15550: "mysqld crashes in printing a FOREIGN KEY error in InnoDB"
    row_ins_foreign_report_add_err(): When printing the parent record,
    use the index in the parent table rather than the index in the child table.

  #15653: "Slow inserts to InnoDB if many thousands of .ibd files"
    Keep track on unflushed modifications to file spaces.  When there are tens
    of thousands of file spaces, flushing all files in fil_flush_file_spaces()
    would be very slow.
    fil_flush_file_spaces(): Only flush unflushed file spaces.
    fil_space_t, fil_system_t: Add a list of unflushed spaces.

  #15991: "innodb-file-per-table + symlink database + rename = cr"
   os_file_handle_error(): Map the error codes EXDEV, ENOTDIR, and EISDIR
   to the new code OS_FILE_PATH_ERROR. Treat this code as OS_FILE_PATH_ERROR.
   This fixes the crash on RENAME TABLE when the .ibd file is a symbolic link
   to a different file system.

  #16157: "InnoDB crashes when main location settings are empty"
    This patch is from Heikki.

  #16298: "InnoDB segfaults in INSERTs in upgrade of 4.0 -> 5.0 tables
    with VARCHAR BINARY"
    dict_load_columns(): Set the charset-collation code
    DATA_MYSQL_BINARY_CHARSET_COLL for those binary string columns
    that lack a charset-collation code, i.e., the tables were created
    with an older version of MySQL/InnoDB than 4.1.2.

  #16229: "MySQL/InnoDB uses full explicit table locks in trigger processing"
    Take a InnoDB table lock only if user has explicitly requested a table
    lock. Added some additional comments to store_lock() and external_lock().

  #16387: "InnoDB crash when dropping a foreign key <table>_ibfk_0"
    Do not mistake TABLENAME_ibfk_0 for auto-generated id.
    dict_table_get_highest_foreign_id(): Ignore foreign constraint
    identifiers starting with the pattern TABLENAME_ibfk_0.

  #16582: "InnoDB: Error in an adaptive hash index pointer to page"
    Account for a race condition when dropping the adaptive hash index
    for a B-tree page.
    btr_search_drop_page_hash_index(): Retry the operation if a hash index
    with different parameters was built meanwhile.  Add diagnostics for the
    case that hash node pointers to the page remain.
    btr_search_info_update_hash(), btr_search_info_update_slow():
    Document the parameter "info" as in/out.

  #16814: "SHOW INNODB STATUS format error in LATEST FOREIGN KEY ERROR
    section"
    Add a missing newline to the LAST FOREIGN KEY ERROR section in SHOW
    INNODB STATUS output.
    dict_foreign_error_report(): Always print a newline after invoking
    dict_print_info_on_foreign_key_in_create_format().

  #16827: "Better InnoDB error message if ibdata files omitted from my.cnf"

  #17126: "CHECK TABLE on InnoDB causes a short hang during check of adaptive
    hash"
    CHECK TABLE blocking other queries, by releasing the btr_search_latch
    periodically during the adaptive hash table validation.

  #17405: "Valgrind: conditional jump or move depends on unititialised values"
    buf_block_init(): Reset magic_n, buf_fix_count and io_fix to avoid
    testing uninitialized variables.
2006-03-10 19:22:21 +03:00

169 lines
5.7 KiB
C

/******************************************************
Cursor read
(c) 1997 Innobase Oy
Created 2/16/1997 Heikki Tuuri
*******************************************************/
#ifndef read0read_h
#define read0read_h
#include "univ.i"
#include "ut0byte.h"
#include "ut0lst.h"
#include "trx0trx.h"
#include "read0types.h"
/*************************************************************************
Opens a read view where exactly the transactions serialized before this
point in time are seen in the view. */
read_view_t*
read_view_open_now(
/*===============*/
/* out, own: read view struct */
dulint cr_trx_id, /* in: trx_id of creating
transaction, or (0, 0) used in
purge */
mem_heap_t* heap); /* in: memory heap from which
allocated */
/*************************************************************************
Makes a copy of the oldest existing read view, or opens a new. The view
must be closed with ..._close. */
read_view_t*
read_view_oldest_copy_or_open_new(
/*==============================*/
/* out, own: read view struct */
dulint cr_trx_id, /* in: trx_id of creating
transaction, or (0, 0) used in
purge */
mem_heap_t* heap); /* in: memory heap from which
allocated */
/*************************************************************************
Closes a read view. */
void
read_view_close(
/*============*/
read_view_t* view); /* in: read view */
/*************************************************************************
Closes a consistent read view for MySQL. This function is called at an SQL
statement end if the trx isolation level is <= TRX_ISO_READ_COMMITTED. */
void
read_view_close_for_mysql(
/*======================*/
trx_t* trx); /* in: trx which has a read view */
/*************************************************************************
Checks if a read view sees the specified transaction. */
UNIV_INLINE
ibool
read_view_sees_trx_id(
/*==================*/
/* out: TRUE if sees */
read_view_t* view, /* in: read view */
dulint trx_id);/* in: trx id */
/*************************************************************************
Prints a read view to stderr. */
void
read_view_print(
/*============*/
read_view_t* view); /* in: read view */
/*************************************************************************
Create a consistent cursor view for mysql to be used in cursors. In this
consistent read view modifications done by the creating transaction or future
transactions are not visible. */
cursor_view_t*
read_cursor_view_create_for_mysql(
/*==============================*/
trx_t* cr_trx);/* in: trx where cursor view is created */
/*************************************************************************
Close a given consistent cursor view for mysql and restore global read view
back to a transaction read view. */
void
read_cursor_view_close_for_mysql(
/*=============================*/
trx_t* trx, /* in: trx */
cursor_view_t* curview); /* in: cursor view to be closed */
/*************************************************************************
This function sets a given consistent cursor view to a transaction
read view if given consistent cursor view is not NULL. Otherwise, function
restores a global read view to a transaction read view. */
void
read_cursor_set_for_mysql(
/*======================*/
trx_t* trx, /* in: transaction where cursor is set */
cursor_view_t* curview);/* in: consistent cursor view to be set */
/* Read view lists the trx ids of those transactions for which a consistent
read should not see the modifications to the database. */
struct read_view_struct{
ulint type; /* VIEW_NORMAL, VIEW_HIGH_GRANULARITY */
dulint undo_no; /* (0, 0) or if type is VIEW_HIGH_GRANULARITY
transaction undo_no when this high-granularity
consistent read view was created */
ibool can_be_too_old; /* TRUE if the system has had to purge old
versions which this read view should be able
to access: the read view can bump into the
DB_MISSING_HISTORY error */
dulint low_limit_no; /* The view does not need to see the undo
logs for transactions whose transaction number
is strictly smaller (<) than this value: they
can be removed in purge if not needed by other
views */
dulint low_limit_id; /* The read should not see any transaction
with trx id >= this value */
dulint up_limit_id; /* The read should see all trx ids which
are strictly smaller (<) than this value */
ulint n_trx_ids; /* Number of cells in the trx_ids array */
dulint* trx_ids; /* Additional trx ids which the read should
not see: typically, these are the active
transactions at the time when the read is
serialized, except the reading transaction
itself; the trx ids in this array are in a
descending order */
dulint creator_trx_id; /* trx id of creating transaction, or
(0, 0) used in purge */
UT_LIST_NODE_T(read_view_t) view_list;
/* List of read views in trx_sys */
};
/* Read view types */
#define VIEW_NORMAL 1 /* Normal consistent read view
where transaction does not see changes
made by active transactions except
creating transaction. */
#define VIEW_HIGH_GRANULARITY 2 /* High-granularity read view where
transaction does not see changes
made by active transactions and own
changes after a point in time when this
read view was created. */
/* Implement InnoDB framework to support consistent read views in
cursors. This struct holds both heap where consistent read view
is allocated and pointer to a read view. */
struct cursor_view_struct{
mem_heap_t* heap;
/* Memory heap for the cursor view */
read_view_t* read_view;
/* Consistent read view of the cursor*/
ulint n_mysql_tables_in_use;
/* number of Innobase tables used in the
processing of this cursor */
};
#ifndef UNIV_NONINL
#include "read0read.ic"
#endif
#endif