Analysis:
========
Increasing the length of the indexed varchar column is not an instant operation for
innodb.
Fix:
===
- Introduce the new handler flag 'Alter_inplace_info::ALTER_COLUMN_INDEX_LENGTH' to
indicate the index length differs due to change of column length changes.
- InnoDB makes the ALTER_COLUMN_INDEX_LENGTH flag as instant operation.
This is a port of Mysql fix.
commit 913071c0b16cc03e703308250d795bc381627e37
Author: Nisha Gopalakrishnan <nisha.gopalakrishnan@oracle.com>
Date: Wed May 30 14:54:46 2018 +0530
BUG#26848813: INDEXED COLUMN CAN'T BE CHANGED FROM VARCHAR(15)
TO VARCHAR(40) INSTANTANEOUSLY
ha_innobase::commit_inplace_alter_table(): Do not crash if
innobase_update_foreign_cache() returns an error. It can return
an error on ALTER TABLE if an inconsistent FOREIGN KEY constraint
was created earlier when SET foreign_key_checks=0 was in effect.
Instead, report a warning to the client that constraints cannot
be loaded.
Problem:
========
Server fails to notify the engine by not setting the ADD_PK_INDEX and
DROP_PK_INDEX When there is a
i) Change in candidate for primary key.
ii) New candidate for primary key.
Fix:
====
Server sets the ADD_PK_INDEX and DROP_PK_INDEX while doing alter for the
above problematic case.
on startup innodb is checking whether files "ib_logfileN"
(for N from 1 to 100) exist, and whether they're readable.
A non-existent file aborted the scan.
A directory instead of a file made InnoDB to fail.
Now it treats "directory exists" as "file doesn't exist".
MDEV-11369 (instant ADD COLUMN) introduced a regression in the case the
leftmost leaf page of the clustered index is empty except for the
hidden metadata record.
btr_pcur_store_position(): If the only record in the leftmost leaf page
is the metadata record, store the position before the first user record
in the tree.
InnoDB does not allow creating multiple FULLTEXT INDEX
in ALGORITHM=INPLACE. This constraint was not being properly
enforced after MariaDB started to support ALGORITHM=INSTANT
and instant ADD COLUMN.
As a side effect of this bug, we again allow ALGORITHM=INPLACE
to rebuild a table when one FULLTEXT INDEX survives.
Also, we are returning a more accurate reason for refusing LOCK=NONE.
innobase_fulltext_exist(): Return the number of fulltext indexes.
ha_innobase::check_if_supported_inplace_alter(): If the table
needs to be rebuilt, refuse the operation if multiple fulltext
indexes would remain.
dict_table_t::init_instant(): Correctly initialize the length of
variable-length instantly dropped columns.
row_ins_index_entry_set_vals(): For variable-length instantly dropped
columns, write 0 bytes of data. For dropped fixed-length NOT NULL
columns, write the fixed length of NUL bytes as data.
This was introduced in 1a7a018939
MDEV-16557 Remove INNOBASE_SHARE::idx_trans_tbl
ha_innobase::innobase_get_index: remove incorrect assertion.
Index nullability is checked in subsequent ifs.
Closes#1079
btr_cur_pessimistic_insert(): Do not attempt to convert the
metadata BLOB to external storage if it has already been converted.
It could have been converted by btr_cur_pessimistic_update().
Relax some over-zealous assertions.
dtuple_convert_big_rec(): Assert that the metadata BLOB has
not been converted yet.
dict_table_t::instant_column(): Correctly compute the value of
metadata_changed. The original computation in
commit 003720755f would essentially
invoke memcmp(x,x,y), which can only return 0.
