MDEV-25506 (3 of 3): Do not delete .ibd files before commit

This is a complete rewrite of DROP TABLE, also as part of other DDL,
such as ALTER TABLE, CREATE TABLE...SELECT, TRUNCATE TABLE.

The background DROP TABLE queue hack is removed.
If a transaction needs to drop and create a table by the same name
(like TRUNCATE TABLE does), it must first rename the table to an
internal #sql-ib name. No committed version of the data dictionary
will include any #sql-ib tables, because whenever a transaction
renames a table to a #sql-ib name, it will also drop that table.
Either the rename will be rolled back, or the drop will be committed.

Data files will be unlinked after the transaction has been committed
and a FILE_RENAME record has been durably written. The file will
actually be deleted when the detached file handle returned by
fil_delete_tablespace() will be closed, after the latches have been
released. It is possible that a purge of the delete of the SYS_INDEXES
record for the clustered index will execute fil_delete_tablespace()
concurrently with the DDL transaction. In that case, the thread that
arrives later will wait for the other thread to finish.

HTON_TRUNCATE_REQUIRES_EXCLUSIVE_USE: A new handler flag.
ha_innobase::truncate() now requires that all other references to
the table be released in advance. This was implemented by Monty.

ha_innobase::delete_table(): If CREATE TABLE..SELECT is detected,
we will "hijack" the current transaction, drop the table in
the current transaction and commit the current transaction.
This essentially fixes MDEV-21602. There is a FIXME comment about
making the check less failure-prone.

ha_innobase::truncate(), ha_innobase::delete_table():
Implement a fast path for temporary tables. We will no longer allow
temporary tables to use the adaptive hash index.

dict_table_t::mdl_name: The original table name for the purpose of
acquiring MDL in purge, to prevent a race condition between a
DDL transaction that is dropping a table, and purge processing
undo log records of DML that had executed before the DDL operation.
For #sql-backup- tables during ALTER TABLE...ALGORITHM=COPY, the
dict_table_t::mdl_name will differ from dict_table_t::name.

dict_table_t::parse_name(): Use mdl_name instead of name.

dict_table_rename_in_cache(): Update mdl_name.

For the internal FTS_ tables of FULLTEXT INDEX, purge would
acquire MDL on the FTS_ table name, but not on the main table,
and therefore it would be able to run concurrently with a
DDL transaction that is dropping the table. Previously, the
DROP TABLE queue hack prevented a race between purge and DDL.
For now, we introduce purge_sys.stop_FTS() to prevent purge from
opening any table, while a DDL transaction that may drop FTS_
tables is in progress. The function fts_lock_table(), which will
be invoked before the dictionary is locked, will wait for
purge to release any table handles.

trx_t::drop_table_statistics(): Drop statistics for the table.
This replaces dict_stats_drop_index(). We will drop or rename
persistent statistics atomically as part of DDL transactions.
On lock conflict for dropping statistics, we will fail instantly
with DB_LOCK_WAIT_TIMEOUT, because we will be holding the
exclusive data dictionary latch.

trx_t::commit_cleanup(): Separated from trx_t::commit_in_memory().
Relax an assertion around fts_commit() and allow DB_LOCK_WAIT_TIMEOUT
in addition to DB_DUPLICATE_KEY. The call to fts_commit() is
entirely misplaced here and may obviously break the consistency
of transactions that affect FULLTEXT INDEX. It needs to be fixed
separately.

dict_table_t::n_foreign_key_checks_running: Remove (MDEV-21175).
The counter was a work-around for missing meta-data locking (MDL)
on the SQL layer, and not really needed in MariaDB.

ER_TABLE_IN_FK_CHECK: Replaced with ER_UNUSED_28.

HA_ERR_TABLE_IN_FK_CHECK: Remove.

row_ins_check_foreign_constraints(): Do not acquire
dict_sys.latch either. The SQL-layer MDL will protect us.

This was reviewed by Thirunarayanan Balathandayuthapani
and tested by Matthias Leich.

1 files changed, 0 insertions, 52 deletions

diff --git a/mysql-test/suite/gcol/r/innodb_virtual_stats.result b/mysql-test/suite/gcol/r/innodb_virtual_stats.result
index c0f595263df..74a0480883d 100644
--- a/mysql-test/suite/gcol/r/innodb_virtual_stats.result
+++ b/mysql-test/suite/gcol/r/innodb_virtual_stats.result
@@ -38,10 +38,6 @@ idxa	n_diff_pfx01	a
 idxa	n_diff_pfx02	a,DB_ROW_ID
 idxa	n_leaf_pages	Number of leaf pages in the index
 idxa	size	Number of pages in the index
-idxb	n_diff_pfx01	b
-idxb	n_diff_pfx02	b,DB_ROW_ID
-idxb	n_leaf_pages	Number of leaf pages in the index
-idxb	size	Number of pages in the index
 vidxcd	n_diff_pfx01	c
 vidxcd	n_diff_pfx02	c,d
 vidxcd	n_diff_pfx03	c,d,DB_ROW_ID
@@ -58,14 +54,6 @@ index_name	stat_name	stat_description
 GEN_CLUST_INDEX	n_diff_pfx01	DB_ROW_ID
 GEN_CLUST_INDEX	n_leaf_pages	Number of leaf pages in the index
 GEN_CLUST_INDEX	size	Number of pages in the index
-idxb	n_diff_pfx01	b
-idxb	n_diff_pfx02	b,DB_ROW_ID
-idxb	n_leaf_pages	Number of leaf pages in the index
-idxb	size	Number of pages in the index
-vidxcd	n_diff_pfx01	d
-vidxcd	n_diff_pfx02	d,DB_ROW_ID
-vidxcd	n_leaf_pages	Number of leaf pages in the index
-vidxcd	size	Number of pages in the index
 ALTER TABLE t ADD INDEX vidxe (e), ALGORITHM=INPLACE;
 select count(*) from t;
 count(*)
@@ -77,18 +65,6 @@ index_name	stat_name	stat_description
 GEN_CLUST_INDEX	n_diff_pfx01	DB_ROW_ID
 GEN_CLUST_INDEX	n_leaf_pages	Number of leaf pages in the index
 GEN_CLUST_INDEX	size	Number of pages in the index
-idxb	n_diff_pfx01	b
-idxb	n_diff_pfx02	b,DB_ROW_ID
-idxb	n_leaf_pages	Number of leaf pages in the index
-idxb	size	Number of pages in the index
-vidxcd	n_diff_pfx01	d
-vidxcd	n_diff_pfx02	d,DB_ROW_ID
-vidxcd	n_leaf_pages	Number of leaf pages in the index
-vidxcd	size	Number of pages in the index
-vidxe	n_diff_pfx01	e
-vidxe	n_diff_pfx02	e,DB_ROW_ID
-vidxe	n_leaf_pages	Number of leaf pages in the index
-vidxe	size	Number of pages in the index
 ALTER TABLE t ADD COLUMN f INT GENERATED ALWAYS AS(a + a), ADD INDEX vidxf (f), ALGORITHM=INPLACE;
 select count(*) from t;
 count(*)
@@ -100,22 +76,6 @@ index_name	stat_name	stat_description
 GEN_CLUST_INDEX	n_diff_pfx01	DB_ROW_ID
 GEN_CLUST_INDEX	n_leaf_pages	Number of leaf pages in the index
 GEN_CLUST_INDEX	size	Number of pages in the index
-idxb	n_diff_pfx01	b
-idxb	n_diff_pfx02	b,DB_ROW_ID
-idxb	n_leaf_pages	Number of leaf pages in the index
-idxb	size	Number of pages in the index
-vidxcd	n_diff_pfx01	d
-vidxcd	n_diff_pfx02	d,DB_ROW_ID
-vidxcd	n_leaf_pages	Number of leaf pages in the index
-vidxcd	size	Number of pages in the index
-vidxe	n_diff_pfx01	e
-vidxe	n_diff_pfx02	e,DB_ROW_ID
-vidxe	n_leaf_pages	Number of leaf pages in the index
-vidxe	size	Number of pages in the index
-vidxf	n_diff_pfx01	f
-vidxf	n_diff_pfx02	f,DB_ROW_ID
-vidxf	n_leaf_pages	Number of leaf pages in the index
-vidxf	size	Number of pages in the index
 ALTER TABLE t DROP INDEX vidxcd;
 SELECT index_name, stat_name, stat_description
 FROM mysql.innodb_index_stats
@@ -124,16 +84,4 @@ index_name	stat_name	stat_description
 GEN_CLUST_INDEX	n_diff_pfx01	DB_ROW_ID
 GEN_CLUST_INDEX	n_leaf_pages	Number of leaf pages in the index
 GEN_CLUST_INDEX	size	Number of pages in the index
-idxb	n_diff_pfx01	b
-idxb	n_diff_pfx02	b,DB_ROW_ID
-idxb	n_leaf_pages	Number of leaf pages in the index
-idxb	size	Number of pages in the index
-vidxe	n_diff_pfx01	e
-vidxe	n_diff_pfx02	e,DB_ROW_ID
-vidxe	n_leaf_pages	Number of leaf pages in the index
-vidxe	size	Number of pages in the index
-vidxf	n_diff_pfx01	f
-vidxf	n_diff_pfx02	f,DB_ROW_ID
-vidxf	n_leaf_pages	Number of leaf pages in the index
-vidxf	size	Number of pages in the index
 DROP TABLE t;