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24156 commits

Author SHA1 Message Date
Marko Mäkelä
bfab4ab000 MDEV-18867 fixup: Remove DBUG injection
In commit 75e82f71f1 the code to
rename internal tables for FULLTEXT INDEX that had been
created on Microsoft Windows using incompatible names
was removed. Let us also remove the related fault injection.
2023-11-02 15:27:52 +02:00
Thirunarayanan Balathandayuthapani
b4de67da45 MDEV-32638 MariaDB crashes with foreign_key_checks=0 when changing a column and adding a foreign key at the same time
Problem:
=======
 - InnoDB fails to find the foreign key index for the newly
added foreign key relation. This is caused by commit
5f09b53bdb (MDEV-31086).

FIX:
===
In check_col_is_in_fk_indexes(), while iterating through
the newly added foreign key relationship, InnoDB should
consider that foreign key relation may not have foreign index
when foreign key check is disabled.
2023-11-02 14:33:05 +05:30
Marko Mäkelä
15ae97b1c2 MDEV-32578 row_merge_fts_doc_tokenize() handles parser plugin inconsistently
When mysql/mysql-server@0c954c2289
added a plugin interface for FULLTEXT INDEX tokenization to MySQL 5.7,
fts_tokenize_ctx::processed_len got a second meaning, which is only
partly implemented in row_merge_fts_doc_tokenize().

This inconsistency could cause a crash when using FULLTEXT...WITH PARSER.
A test case that would crash MySQL 8.0 when using an n-gram parser and
single-character words would fail to crash in MySQL 5.7, because the
buf_full condition in row_merge_fts_doc_tokenize() was not met.

This change is inspired by
mysql/mysql-server@38e9a0779a
that appeared in MySQL 5.7.44.
2023-10-27 13:13:49 +03:00
Alexander Barkov
df72c57d6f MDEV-30048 Prefix keys for CHAR work differently for MyISAM vs InnoDB
Also fixes: MDEV-30050 Inconsistent results of DISTINCT with NOPAD

Problem:

Key segments for CHAR columns where compared using strnncollsp()
for engines MyISAM and Aria.

This did not work correct in case if the engine applyied trailing
space compression.

Fix:

Replacing ha_compare_text() calls to new functions:

- ha_compare_char_varying()
- ha_compare_char_fixed()
- ha_compare_word()
- ha_compare_word_prefix()
- ha_compare_word_or_prefix()

The code branch corresponding to comparison of CHAR column keys
(HA_KEYTYPE_TEXT segment type) now uses ha_compare_char_fixed()
which calls strnncollsp_nchars().

This patch does not change the behavior for the rest of the code:
- comparison of VARCHAR/TEXT column keys
  (HA_KEYTYPE_VARTEXT1, HA_KEYTYPE_VARTEXT2 segments types)
- comparison in the fulltext code
2023-10-24 03:35:48 +04:00
Thirunarayanan Balathandayuthapani
7d89dcf1ae MDEV-32527 Server aborts during alter operation when table doesn't have foreign index
Problem:
========
InnoDB fails to find the foreign key index for the
foreign key relation in the table while iterating the
foreign key constraints during alter operation. This is
caused by commit 5f09b53bdb
(MDEV-31086).

Fix:
====
In check_col_is_in_fk_indexes(), while iterating through
the foreign key relationship, InnoDB should consider that
foreign key relation may not have foreign index when
foreign key check is disabled.
2023-10-20 15:23:22 +05:30
Daniel Black
e467e8d8c2 MDEV-30825 innodb_compression_algorithm=0 (none) increments Innodb_num_pages_page_compression_error
fil_page_compress_low returns 0 for both innodb_compression_algorithm=0
and where there is compression errors. On the two callers to this
function, don't increment the compression errors if the algorithm was
none.

Reviewed by: Marko Mäkelä
2023-10-18 19:18:50 +11:00
Yuchen Pei
5c6fceec76
MDEV-28998 remove a known reference to a SPIDER_CONN when it is freed 2023-10-13 15:17:54 +11:00
Thirunarayanan Balathandayuthapani
4045ead9db MDEV-32337 Assertion `pos < table->n_def' failed in dict_table_get_nth_col
While checking for altered column in foreign key constraints,
InnoDB fails to ignore virtual columns. This issue caused
by commit 5f09b53bdb4e973e7c7ec2c53a24c98321223f98(MDEV-31086).
2023-10-12 14:49:27 +05:30
Thirunarayanan Balathandayuthapani
a2312b6fb2 MDEV-32017 Auto-increment no longer works for explicit FTS_DOC_ID
- InnoDB should avoid the sync commit operation when
there is nothing in fulltext cache. This is caused by
commit 1248fe7277 (MDEV-27582)
2023-10-12 14:48:43 +05:30
Marko Mäkelä
3f1a256234 MDEV-31890: Remove COMPILE_FLAGS
The cmake configuration step is single-threaded and already consuming
too much time. We should not make it worse by adding invocations like
MY_CHECK_CXX_COMPILER_FLAG().

Let us prefer something that works on any supported version
of GCC (4.8.5 or later) or clang, as well as recent versions
of the Intel C compiler.

This replaces commit 1fde785315
2023-10-11 15:59:56 +03:00
Sergei Golubchik
3e2b1295bd MDEV-30658 fix failing test
followup for 96ae37abc5
2023-10-11 12:01:54 +02:00
Sergei Golubchik
69089c715c fix groonga to compile with -Werror=enum-int-mismatch
gcc 13.2.1
2023-10-11 11:48:09 +02:00
Yuchen Pei
2556fe1ab1
MDEV-31996 Create connection on demand in spider_db_delete_all_rows
When spider_db_delete_all_rows() is called, the supplied spider->conns
may have already been freed. The existing mechanism has spider_trx own
the connections in trx_conn_hash and it may free a conn during the
cleanup after a query. When running a delete query and if the table is
in the table cache, ha_spider::open() would not be called which would
recreate the conn. So we recreate the conn when necessary during
delete by calling spider_check_trx_and_get_conn().

We also reduce code duplication as delete_all_rows() and truncate()
has almost identical code, and there's no need to assign
wide_handler->sql_command in these functions because it has already
been correctly assigned.
2023-10-11 16:42:35 +11:00
Vlad Lesin
96ae37abc5 MDEV-30658 lock_row_lock_current_waits counter in information_schema.innodb_metrics may become negative
MONITOR_OVLD_ROW_LOCK_CURRENT_WAIT monitor should has
MONITOR_DISPLAY_CURRENT flag set in its definition, as it shows the
current state and does not accumulate anything.

Reviewed by: Marko Mäkelä
2023-10-05 18:27:54 +03:00
Alexander Barkov
e2da748c29 MDEV-28835 Assertion `(length % 4) == 0' failed in my_lengthsp_utf32 on INSERT
Problem:

Item_func_date_format::val_str() and make_date_time() did not take into
account that the format string and the result string
(separately or at the same time) can be of a tricky character set
like UCS2, UTF16, UTF32. As a result, DATE_FORMAT() could generate
an ill-formed result which crashed on DBUG_ASSERTs testing well-formedness
in other parts of the code.

Fix:

1. class String changes
   Removing String::append_with_prefill(). It was not compatible with
   tricky character sets. Also it was inconvenient to use and required
   too much duplicate code on the caller side.
   Adding String::append_zerofill() instead. It's compatible with tricky
   character sets and is easier to use.
   Adding helper methods Static_binary_string::q_append_wc() and
   String::append_wc(), to append a single wide character
   (a Unicode code point in my_wc_t).

2. storage/spider changes
   Removing spider_string::append_with_prefill().
   It used String::append_with_prefix() inside, but it was unused itself.

3. Changing tricky charset incompatible code pieces in make_date_time()
   to compatible replacements:

   - Fixing the loop scanning the format string to iterate in terms
     of Unicode code points (using mb_wc()) rather than in terms
     of "char" items.
   - Using append_wc(my_wc_t) instead of append(char) to append
     a single character to the result string.
   - Using append_zerofill() instead of append_with_prefill() to
     append date/time numeric components to the result string.
2023-10-04 08:51:48 +04:00
Daniel Black
ca66a2cbfa MDEV-18200 MariaBackup full backup failed with InnoDB: Failing assertion: success
There are many filesystem related errors that can occur with
MariaBackup. These already outputed to stderr with a good description of
the error. Many of these are permission or resource (file descriptor)
limits where the assertion and resulting core crash doesn't offer
developers anything more than the log message. To the user, assertions
and core crashes come across as poor error handling.

As such we return an error and handle this all the way up the stack.
2023-09-26 08:55:52 +10:00
Yuchen Pei
b6773f5819
MDEV-31936 Simplify deinit_spider.inc
Spider is part of the server, and there's no need to check the
version.

All spider plugins are uninstalled in clean_up_spider.inc

DROP SERVER IF EXISTS makes things easier
2023-09-25 12:15:14 +10:00
Vladislav Vaintroub
1ee0d09a2b MDEV-32228 speedup opening tablespaces on Windows
is_file_on_ssd() is more expensive than it should be.
It caches the results by volume name, but still calls GetVolumePathName()
every time, which, as procmon shows, opens multiple directories in
filesystem hierarchy (db directory, datadir, and all ancestors)

The fix is to cache SSD status by volume serial ID, which is cheap to
retrieve with GetFileInformationByHandleEx()
2023-09-22 21:07:50 +02:00
Daniel Black
cba102408c MDEV-29993: myrocks_hotbackup.1 and test suite files installed when engine is disabled 2023-09-20 08:18:57 +10:00
Marko Mäkelä
76b688f100 MDEV-30024 InnoDB: tried to purge non-delete-marked of a virtual column prefix
row_vers_vc_matches_cluster(): Invoke dtype_get_at_most_n_mbchars()
to extract the correct number of bytes corresponding to the number
of characters in a virtual column prefix index, just like we do in
row_sel_sec_rec_is_for_clust_rec().

The test case would occasionally reproduce the failure when this
fix is not present.
2023-09-19 09:31:34 +03:00
Yuchen Pei
18990f0073
MDEV-32157 MDEV-28856 Spider: Tests, documentation, small fixes and cleanups
Removed some redundant hint related string literals from
spd_db_conn.cc

Clean up SPIDER_PARAM_*_[CHAR]LEN[S]

Adding tests covering monitoring_kind=2. What it does is that it reads
from mysql.spider_link_mon_servers with matching db_name, table_name,
link_id, and does not do anything about that...

How monitoring_* can be useful: in the deprecated spider high
availability feature, when one remote fails, spider will try another
remote, which apparently makes use of these table parameters.

A test covering the query_cache_sync table param. Some further tests
on some spider table params.

Wrapper should be case insensitive.

Code documentation on spider priority binary tree.

Add an assertion that static_key_cardinality is always -1. All tests
pass still
2023-09-15 13:15:33 +10:00
Yuchen Pei
3b3200e24a
MDEV-32157 MDEV-28856 Spider: drop server in tests
This helps eliminate "server exists" failures

Also, spider/bugfix.mdev_29676, when enabled after MDEV-29525 is
pushed will fail because we have not --recorded the result. But the
failure will only emerge when working on MDEV-31138 where we manually
re-enable this test, so let's worry about that then.
2023-09-15 13:12:55 +10:00
Yuchen Pei
96760d3acc
MDEV-31787 MDEV-26151 Add a test exercising non-0 spider_casual_read
Also:
- clean up spider_check_and_get_casual_read_conn() and
  spider_check_and_set_autocommit()
- remove a couple of commented out code blocks
2023-09-15 11:15:41 +10:00
Yuchen Pei
d59334da94
MDEV-31673 [fixup] Fixing indentation from previous mdev-31673 patch 2023-09-15 11:01:16 +10:00
Yuchen Pei
d8e9f3d981
MDEV-31673 MDEV-29502 Remove spider_db_handler::need_lock_before_set_sql_for_exec
This function trivially returns false
2023-09-14 16:37:34 +10:00
Marko Mäkelä
65c99207e0 MDEV-23841: Memory leak in innodb_monitor_validate()
innodb_monitor_validate(): Let item_val_str() allocate the memory
in THD, so that it will be available to innodb_monitor_update().
In this way, there is no need to allocate another buffer, and
no problem if the call to innodb_monitor_update() is skipped due
to an invalid value that is passed to another configuration parameter.

There are some other callers to st_mysql_sys_var::val_str()
that validate configuration parameters that are related to FULLTEXT INDEX,
but they will allocate memory by invoking thd_strmake().
2023-09-11 10:27:21 +03:00
Sergei Golubchik
fba4abf3b9 MDEV-32128 wrong table name in innodb's "row too big" errors 2023-09-08 19:15:33 +02:00
Sergei Golubchik
a6c0184534 MDEV-31970 ASAN errors in grn_obj_unlink / ha_mroonga::clear_indexes upon index operations
from upstream
2023-09-08 19:12:35 +02:00
Sergei Golubchik
3267606bcd MDEV-31966 Server crash upon inserting into Mroonga table with compressed column 2023-09-08 19:12:35 +02:00
Sergei Golubchik
53fd63254f remove groonga examples
to follow the similar upstream change
2023-09-08 19:12:35 +02:00
Daniel Black
1815719a5b oqgraph: remove clang warnings
-Wdeprecated-copy-with-user-provided-copy was causing a few errors on
things that where defined in a way that was implicit. By removing code
it now compiles without warnings.

tested with fc38 / clang-16
2023-09-08 10:50:15 +01:00
Marko Mäkelä
34c283ba1b MDEV-32132 DROP INDEX followed by CREATE INDEX may corrupt data
ibuf_set_bitmap_for_bulk_load(): Port a bug fix that was made as part of
commit 165564d3c3 (MDEV-30009)
in MariaDB Server 10.5.19.
2023-09-08 11:28:21 +03:00
Thirunarayanan Balathandayuthapani
d1fca0baab MDEV-32060 Server aborts when table doesn't have referenced index
- Server aborts when table doesn't have referenced index.
This is caused by 5f09b53bdb (MDEV-31086).
While iterating the foreign key constraints, we fail to
consider that InnoDB doesn't have referenced index for
it when foreign key check is disabled.
2023-09-01 17:54:07 +05:30
Dmitry Shulga
1fde785315 MDEV-31890: Compilation failing on MacOS (unknown warning option -Wno-unused-but-set-variable)
For clang compiler the compiler's flag -Wno-unused-but-set-variable
was set based on compiler version. This approach could result in
false positive detection for presence of compiler option since
only first three groups of digits in compiler version taken into account
and it could lead to inaccuracy in determining of supported compiler's
features.

Correct way to detect options supported by a compiler is to use
the macros  MY_CHECK_CXX_COMPILER_FLAG and to check the result of
variable with prefix have_CXX__
So, to check whether compiler does support the option
 -Wno-unused-but-set-variable
the macros
 MY_CHECK_CXX_COMPILER_FLAG(-Wno-unused-but-set-variable)
should be called and the result variable
 have_CXX__Wno_unused_but_set_variable
be tested for assigned value.
2023-08-28 16:47:00 +07:00
Marko Mäkelä
02878f128e MDEV-31813 SET GLOBAL innodb_max_purge_lag_wait hangs if innodb_read_only
innodb_max_purge_lag_wait_update(): Return immediately if we are
in high_level_read_only mode.

srv_wake_purge_thread_if_not_active(): Relax a debug assertion.
If srv_read_only_mode holds, purge_sys.enabled() will not hold
and this function will do nothing.

trx_t::commit_in_memory(): Remove a redundant condition before
invoking srv_wake_purge_thread_if_not_active().
2023-08-24 10:08:51 +03:00
Yuchen Pei
e9f3ca6125
MDEV-31117 Fix spider connection info parsing
Spider connection string is a comma-separated parameter definitions,
where each definition is of the form "<param_title> <param_value>",
where <param_value> is quote delimited on both ends, with backslashes
acting as an escaping prefix.

Despite the simple syntax, the existing spider connection string
parser was poorly-written, complex, hard to reason and error-prone,
causing issues like the one described in MDEV-31117. For example it
treated param title the same way as param value when assigning, and
have nonsensical fields like delim_title_len and delim_title.

Thus as part of the bugfix, we clean up the spider comment connection
string parsing, including:

- Factoring out some code from the parsing function
- Simplify the struct `st_spider_param_string_parse`
- And any necessary changes caused by the above changes
2023-08-23 11:21:14 +10:00
Marko Mäkelä
5a8a8fc953 MDEV-31928 Assertion xid ... < 128 failed in trx_undo_write_xid()
trx_undo_write_xid(): Correct an off-by-one error in a debug assertion.
2023-08-17 10:31:55 +03:00
Marko Mäkelä
518fe51988 MDEV-31254 InnoDB: Trying to read doublewrite buffer page
buf_read_page_low(): Remove an error message that could be triggered
by buf_read_ahead_linear() or buf_read_ahead_random().

This is a backport of commit c9eff1a144
from MariaDB Server 10.5.
2023-08-17 10:31:44 +03:00
Marko Mäkelä
44df6f35aa MDEV-31875 ROW_FORMAT=COMPRESSED table: InnoDB: ... Only 0 bytes read
buf_read_ahead_random(), buf_read_ahead_linear(): Avoid read-ahead
of the last page(s) of ROW_FORMAT=COMPRESSED tablespaces that use
a page size of 1024 or 2048 bytes. We invoke os_file_set_size() on
integer multiples of 4096 bytes in order to be compatible with
the requirements of innodb_flush_method=O_DIRECT regardless of the
physical block size of the underlying storage.

This change must be null-merged to MariaDB Server 10.5 and later.
There, out-of-bounds read-ahead should be handled gracefully
by simply discarding the buffer page that had been allocated.

Tested by: Matthias Leich
2023-08-17 10:31:28 +03:00
Kristian Nielsen
900c4d6920 MDEV-31655: Parallel replication deadlock victim preference code errorneously removed
Restore code to make InnoDB choose the second transaction as a deadlock
victim if two transactions deadlock that need to commit in-order for
parallel replication. This code was erroneously removed when VATS was
implemented in InnoDB.

Also add a test case for InnoDB choosing the right deadlock victim.
Also fixes this bug, with testcase that reliably reproduces:

MDEV-28776: rpl.rpl_mark_optimize_tbl_ddl fails with timeout on sync_with_master

Note: This should be null-merged to 10.6, as a different fix is needed
there due to InnoDB locking code changes.

Signed-off-by: Kristian Nielsen <knielsen@knielsen-hq.org>
2023-08-15 16:35:30 +02:00
Kristian Nielsen
920789e9d4 MDEV-31482: Lock wait timeout with INSERT-SELECT, autoinc, and statement-based replication
Remove the exception that InnoDB does not report auto-increment locks waits
to the parallel replication.

There was an assumption that these waits could not cause conflicts with
in-order parallel replication and thus need not be reported. However, this
assumption is wrong and it is possible to get conflicts that lead to hangs
for the duration of --innodb-lock-wait-timeout. This can be seen with three
transactions:

1. T1 is waiting for T3 on an autoinc lock
2. T2 is waiting for T1 to commit
3. T3 is waiting on a normal row lock held by T2

Here, T3 needs to be deadlock killed on the wait by T1.

Note: This should be null-merged to 10.6, as a different fix is needed
there due to InnoDB lock code changes.

Signed-off-by: Kristian Nielsen <knielsen@knielsen-hq.org>
2023-08-15 16:34:09 +02:00
Thirunarayanan Balathandayuthapani
0ede90dd31 MDEV-31869 Server aborts when table does drop column
- InnoDB aborts when table is dropping the column. This is
caused by 5f09b53bdb (MDEV-31086).
While iterating the altered table fields, we fail to consider
the dropped columns.
2023-08-08 13:24:23 +05:30
Aleksey Midenkov
69b118a346 Revert "MDEV-30528 Assertion in dtype_get_at_most_n_mbchars"
This reverts commit add0c01bae

Duplicates must be avoided in FTS_DOC_ID_INDEX
2023-07-31 16:57:18 +03:00
Lena Startseva
9854fb6fa7 MDEV-31003: Second execution for ps-protocol
This patch adds for "--ps-protocol" second execution
of queries "SELECT".
Also in this patch it is added ability to disable/enable
(--disable_ps2_protocol/--enable_ps2_protocol) second
execution for "--ps-prototocol" in testcases.
2023-07-26 17:15:00 +07:00
Aleksey Midenkov
14cc7e7d6e MDEV-25644 UPDATE not working properly on transaction precise system versioned table
First UPDATE under START TRANSACTION does nothing (nstate= nstate),
but anyway generates history. Since update vector is empty we get into
(!uvect->n_fields) branch which only adds history row, but does not do
update. After that we get current row with wrong (old) row_start value
and because of that second UPDATE tries to insert history row again
because it sees trx->id != row_start which is the guard to avoid
inserting multiple trx_id-based history rows under same transaction
(because we have same trx_id and we get duplicate error and this bug
demostrates that). But this try anyway fails because PK is based on
row_end which is constant under same transaction, so PK didn't change.

The fix moves vers_make_update() to an earlier stage of
calc_row_difference(). Therefore it prepares update vector before
(!uvect->n_fields) check and never gets into that branch, hence no
need to handle versioning inside that condition anymore.

Now trx->id and row_start are equal after first UPDATE and we don't
try to insert second history row.

== Cleanups and improvements ==

ha_innobase::update_row():

vers_set_fields and vers_ins_row are cleaned up into direct condition
check. SQLCOM_ALTER_TABLE check now is not used as this is dead code,
assertion is done instead.

upd_node->is_delete is set in calc_row_difference() just to keep
versioning code as much in one place as possible. vers_make_delete()
is still located in row_update_for_mysql() as this is required for
ha_innodbase::delete_row() as well.

row_ins_duplicate_error_in_clust():

Restrict DB_FOREIGN_DUPLICATE_KEY to the better conditions.
VERSIONED_DELETE is used specifically to help lower stack to
understand what caused current insert. Related to MDEV-29813.
2023-07-20 18:22:31 +03:00
Aleksey Midenkov
add0c01bae MDEV-30528 Assertion in dtype_get_at_most_n_mbchars
1. Exclude merging history rows into fts index.

The check !history_fts && (index->type & DICT_FTS) was just incorrect
attempt to avoid history in fts index.

2. Don't check for duplicates for history rows.
2023-07-20 18:22:30 +03:00
Daniel Black
5a44700aaa MDEV-31625 connect engine file_type=DBF insert fails
Add the end of file marker x1A to the DBF file and handle it
correctly to preserve interoperability with Libreoffice, and others
that have followed the DBF spec.

The file open mode of "a+" was problematic because Linux and the OSX,
the previous main development mode are inconsistent (see man fopen).
The main problem per the bug report was the inability to fseek back to the
beginning to update the records in the header.

As such the "a+" mode is remove and "w+b" is used inserting to a new file
and "r+b" is used for appending to the file.

In DBFFAM::CloseTableFile move PlugCloseFile down to close the file in
all modes.

The year unlike the comments is always since 1900. Use the
YYYY-MM-DD as an unabigious form during tracing.

Thanks for Mr. Zoltan Duna for the descriptive bug report.
2023-07-20 11:56:42 +01:00
Yuchen Pei
e1d31a10af
MDEV-31524 Fixing spider table param / variable overriding
The existing (incorrect) overriding mechanism is:

Non-minus-one var value overrides table param overrides default value.

Before MDEV-27169, unspecified var value is -1. So if the user sets
both the var to be a value other than -1 and the table param, the var
value will prevail, which is incorrect.

After MDEV-27169, unspecified var value is default value. So if the
user does not set the var but sets the table param, the default value
will prevail, which is even more incorrect.

This patch fixes it so that table param, if specified, always
overrides var value, and the latter if not specified or set to -1,
falls back to the default value

We achieve this by replacing all such overriding in spd_param.cc with
macros that override in the correct way, and removing all the
"overriding -1" lines involving table params in
spider_set_connect_info_default() except for those table params not
defined as sysvar/thdvar in spd_params.cc

We also introduced macros for non-overriding sysvar and thdvar, so
that the code is cleaner and less error-prone

In server versions where MDEV-27169 has not been applied, we also
backport the patch, that is, replacing -1 default values with real
default values

In server versions where MDEV-28006 has not been applied, we do the
same for udf params
2023-07-13 13:22:24 +10:00
Vlad Lesin
1bfd3cc457 MDEV-10962 Deadlock with 3 concurrent DELETEs by unique key
PROBLEM:
A deadlock was possible when a transaction tried to "upgrade" an already
held Record Lock to Next Key Lock.

SOLUTION:
This patch is based on observations that:
(1) a Next Key Lock is equivalent to Record Lock combined with Gap Lock
(2) a GAP Lock never has to wait for any other lock
In case we request a Next Key Lock, we check if we already own a Record
Lock of equal or stronger mode, and if so, then we change the requested
lock type to GAP Lock, which we either already have, or can be granted
immediately, as GAP locks don't conflict with any other lock types.
(We don't consider Insert Intention Locks a Gap Lock in above statements).

The reason of why we don't upgrage Record Lock to Next Key Lock is the
following.

Imagine a transaction which does something like this:

for each row {
    request lock in LOCK_X|LOCK_REC_NOT_GAP mode
    request lock in LOCK_S mode
}

If we upgraded lock from Record Lock to Next Key lock, there would be
created only two lock_t structs for each page, one for
LOCK_X|LOCK_REC_NOT_GAP mode and one for LOCK_S mode, and then used
their bitmaps to mark all records from the same page.

The situation would look like this:

request lock in LOCK_X|LOCK_REC_NOT_GAP mode on row 1:
// -> creates new lock_t for LOCK_X|LOCK_REC_NOT_GAP mode and sets bit for
// 1
request lock in LOCK_S mode on row 1:
// -> notices that we already have LOCK_X|LOCK_REC_NOT_GAP on the row 1,
// so it upgrades it to X
request lock in LOCK_X|LOCK_REC_NOT_GAP mode on row 2:
// -> creates a new lock_t for LOCK_X|LOCK_REC_NOT_GAP mode (because we
// don't have any after we've upgraded!) and sets bit for 2
request lock in LOCK_S mode on row 2:
// -> notices that we already have LOCK_X|LOCK_REC_NOT_GAP on the row 2,
// so it upgrades it to X
    ...etc...etc..

Each iteration of the loop creates a new lock_t struct, and in the end we
have a lot (one for each record!) of LOCK_X locks, each with single bit
set in the bitmap. Soon we run out of space for lock_t structs.

If we create LOCK_GAP instead of lock upgrading, the above scenario works
like the following:

// -> creates new lock_t for LOCK_X|LOCK_REC_NOT_GAP mode and sets bit for
// 1
request lock in LOCK_S mode on row 1:
// -> notices that we already have LOCK_X|LOCK_REC_NOT_GAP on the row 1,
// so it creates LOCK_S|LOCK_GAP only and sets bit for 1
request lock in LOCK_X|LOCK_REC_NOT_GAP mode on row 2:
// -> reuses the lock_t for LOCK_X|LOCK_REC_NOT_GAP by setting bit for 2
request lock in LOCK_S mode on row 2:
// -> notices that we already have LOCK_X|LOCK_REC_NOT_GAP on the row 2,
// so it reuses LOCK_S|LOCK_GAP setting bit for 2

In the end we have just two locks per page, one for each mode:
LOCK_X|LOCK_REC_NOT_GAP and LOCK_S|LOCK_GAP.
Another benefit of this solution is that it avoids not-entirely
const-correct, (and otherwise looking risky) "upgrading".

The fix was ported from
mysql/mysql-server@bfba840dfa
mysql/mysql-server@75cefdb1f7

Reviewed by: Marko Mäkelä
2023-07-06 15:06:10 +03:00
Yuchen Pei
922db0642b
MDEV-31421 Fix spider test cleanup
This fixes mdev_26541.test, and the new clean_up_spider.inc will be
useful for other tests where part of deinit_spider does not apply,
e.g. those testing spider initialisation only.
2023-07-04 10:39:25 +10:00