* preserve DESC index property in the parser
* store it in the frm (only for HA_KEY_ALG_BTREE)
* read it from the frm
* show it in SHOW CREATE
* skip DESC indexes in opt_range.cc and opt_sum.cc
* ORDER BY test
This includes a fix of MDEV-27432.
This is loosely based on the InnoDB changes in
mysql/mysql-server@97fd8b1b69
that I had developed in 2015 or 2016.
For each B-tree key field, we will allow a flag ASC/DESC to be associated.
When PRIMARY KEY fields are internally appended to secondary indexes,
the ASC/DESC attribute will be inherited, so that covering index scans
will work as expected.
Note: Until the subsequent commit, the DESC attribute will be ignored
(no HA_REVERSE_SORT flag will be written to .frm files).
dict_field_t::descending: A new flag to denote descending order.
cmp_data(), cmp_dfield_dfield(): Add a new parameter descending.
cmp_dtuple_rec(), cmp_dtuple_rec_with_match(): Add a parameter "index".
dtuple_coll_eq(): Replaces dtuple_coll_cmp().
cmp_dfield_dfield_eq_prefix(): Replaces cmp_dfield_dfield_like_prefix().
dict_index_t::is_btree(): Check whether the index is a regular
B-tree index (not SPATIAL, FULLTEXT, or the ibuf.index,
or a corrupted index.
btr_cur_search_to_nth_level_func(): Only attempt to use
the adaptive hash index if index->is_btree().
This function may also be invoked on ibuf.index, and
cmp_dtuple_rec_with_match_bytes() will no longer work on ibuf.index
because it assumes that the index and record fields exactly match.
The ibuf.index is a special variadic index tree.
Thanks to Thirunarayanan Balathandayuthapani for fixing some bugs:
MDEV-27439, MDEV-27374/MDEV-27445.
The error message modified.
Then the TABLE_SHARE::error_table_name() implementation taken from 10.3,
to be used as a name of the table in this message.
crashes server
This bug is the result of merging the Oracle MySQL follow-up fix
BUG#22963169 MYSQL CRASHES ON CREATE FULLTEXT INDEX
without merging the base bug fix:
Bug#79475 Insert a token of 84 4-bytes chars into fts index causes
server crash.
Unlike the above mentioned fixes in MySQL, our fix will not change
the storage format of fulltext indexes in InnoDB or XtraDB
when a character encoding with mbmaxlen=2 or mbmaxlen=3
and the length of a word is between 128 and 84*mbmaxlen bytes.
The Oracle fix would allocate 2 length bytes for these cases.
Compatibility with other MySQL and MariaDB releases is ensured by
persisting the used maximum length in the SYS_COLUMNS table in the
InnoDB data dictionary.
This fix also removes some unnecessary strcmp() calls when checking
for the legacy default collation my_charset_latin1
(my_charset_latin1.name=="latin1_swedish_ci").
fts_create_one_index_table(): Store the actual length in bytes.
This metadata will be written to the SYS_COLUMNS table.
fts_zip_initialize(): Initialize only the first byte of the buffer.
Actually the code should not even care about this first byte, because
the length is set as 0.
FTX_MAX_WORD_LEN: Define as HA_FT_MAXCHARLEN * 4 aka 336 bytes,
not as 254 bytes.
row_merge_create_fts_sort_index(): Set the actual maximum length of the
column in bytes, similar to fts_create_one_index_table().
row_merge_fts_doc_tokenize(): Remove the redundant parameter word_dtype.
Use the actual maximum length of the column. Calculate the extra_size
in the same way as row_merge_buf_encode() does.
