Commit graph

1479 commits

Author SHA1 Message Date
Vladislav Vaintroub
f53321cbdb MDEV-20471 Assertion during cleanup of failed CREATE TABLE LIKE <sequence>
While cleaning up a failed CREATE TABLE LIKE <sequence>, `mysql_rm_table_no_locks`
erroneously attempted to remove all tables involved in the query, including
the source table (sequence).

Fix to temporarily modify `table_list` to ensure that only the intended
table is removed during the cleanup.
2023-10-19 11:57:39 +02:00
Marko Mäkelä
699cfee595 MDEV-32518 Fix ./mtr main.log_slow_debug main.subselect
Clean up after main.log_slow_debug.
2023-10-19 08:11:28 +03:00
Monty
3f663d273b Removed fixed temporay file paths in mtr 2023-10-18 17:51:14 +03:00
Dmitry Shulga
ac15141448 MDEV-32369: Memory leak when executing PS for query with IN subquery
The memory allocated for an instance of the class Item_direct_ref_to_item
was leaked on second execution of a query run as a prepared statement and
involving conversion of strings with different character sets.

The reason of leaking the memory was caused by the fact that a statement
arena could be already set by the moment the method
Type_std_attributes::agg_item_set_converter() is called.
2023-10-18 11:15:16 +07:00
Sergei Golubchik
6f83537876 MDEV-24283 Assertion `bitmap_is_set(&m_part_info->read_partitions, m_part_spec.start_part)' failed in ha_partition::handle_ordered_index_scan
ha_partition should not try to search the index
if all partitions were pruned away.

The fix originally by Nayuta Yanagisawa
2023-10-17 14:32:05 +02:00
Sergei Golubchik
81c88ab7cd MDEV-28820 MyISAM wrong server status flags
MyISAM tables no longer take transactional metadata locks
unless there already is an active transaction.
2023-10-17 14:32:05 +02:00
Sergei Golubchik
f293b2b211 cleanup 2023-10-17 14:32:05 +02:00
Sergei Golubchik
e46ae59265 MDEV-27523 main.delayed fails with wrong error code or timeout when executed after main.deadlock_ftwrl
don't forget to reset mdl_context.m_deadlock_overweight when
taking the THD out of the cache - the history of previous connections
should not affect the weight in deadlock victim selection

(small cleanup of the test to help the correct merge)
2023-10-17 14:32:05 +02:00
Alexander Barkov
eb19638418 MDEV-32244 Wrong bit encoding using COALESCE
When aggregating pairs BIT+NULL and NULL+BIT for result, e.g.
in COALESCE(), preserve the BIT data type (ignore explicit NULLs).

The same fix applied to YEAR.
2023-10-17 12:46:31 +04:00
Igor Babaev
b1c8ea83a5 MDEV-32064 Crash when searching for the best split of derived table
This bug could affect queries with IN subqueries in WHERE clause and using
derived tables to which split optimization potentially could be applied.

When looking for the best split of a splittable derived table T any key
access from a semi-join materialized table used for lookups S to table T
must be excluded from consideration because in the current implementation
of such tables as S the values from its records cannot be used to access
other tables.

Approved by Oleksandr Byelkin <sanja@mariadb.com>
2023-10-16 11:15:57 -07:00
Sergei Petrunia
0ca699bff7 Revert accidentally pushed: commit e8c9cdc2f8
Author: Sergei Petrunia <sergey@mariadb.com>
Date:   Wed Oct 11 19:02:25 2023 +0300

    MDEV-32301: Server crashes at Arg_comparator::compare_row

    In  Item_bool_rowready_func2::build_clone(): if we're setting
      clone->cmp.comparators=0
    also set
      const_item_cache=0
    as the Item is currently in a state where one cannot compute it.
2023-10-16 18:47:24 +03:00
Sergei Petrunia
208ed0d8c6 MDEV-32324: Server crashes inside filesort at my_decimal::to_binary
A subquery in form "(SELECT not_null_value LIMIT 1 OFFSET 1)" will
produce no rows which will translate into scalar SQL NULL value.

The code in Item_singlerow_subselect::fix_length_and_dec() failed to
take the LIMIT/OFFSET clause into account and used to set
item_subselect->maybe_null=0, despite that SQL NULL will be produced.

If such subselect was used in ORDER BY, this would cause a crash in
filesort() code when it would get a NULL value for a not-nullable item.

also made subselect_engine::no_tables() const function.
2023-10-16 18:18:23 +03:00
Sergei Petrunia
e8c9cdc2f8 MDEV-32301: Server crashes at Arg_comparator::compare_row
In  Item_bool_rowready_func2::build_clone(): if we're setting
  clone->cmp.comparators=0
also set
  const_item_cache=0
as the Item is currently in a state where one cannot compute it.
2023-10-16 18:08:07 +03:00
Sergei Petrunia
c886689261 MDEV-32320: Server crashes at TABLE::add_tmp_key
The code inside Item_subselect::fix_fields() could fail to check
that left expression had an Item_row, like this:

  (('x', 1.0) ,1) IN (SELECT 'x', 1.23 FROM ... UNION ...)

In order to hit the failure, the first SELECT of the subquery had
to be a degenerate no-tables select. In this case, execution will
not enter into Item_in_subselect::create_row_in_to_exists_cond()
and will not check if left_expr is composed of scalars.

But the subquery is a UNION so as a whole it is not degenerate.
We try to create an expression cache for the subquery.
We create a temp.table from left_expr columns. No field is created
for the Item_row. Then, we crash when trying to add an index over a
non-existent field.

Fixed by moving the left_expr cardinality check to a point in
check_and_do_in_subquery_rewrites() which gets executed for all
cases.
It's better to make the check early so we don't have to care about
subquery rewrite code hitting Item_row in left_expr.
2023-10-15 18:11:15 +03:00
Oleksandr Byelkin
d594f1e531 Removing MDEV-27871 because it is not a bug
Part 1
2023-10-13 14:09:22 +02:00
Lena Startseva
0c7af6a2a1 MDEV-32023 main.secure_file_priv_win fails with 2nd execution PS protocol
Fixed tests:
main.secure_file_priv_win - disabled ps2-protocol for queries like
"SELECT ... INTO OUTFILE ..."
2023-10-09 11:35:32 +07:00
Sergei Petrunia
422774b40a MDEV-10683: main.order_by_optimizer_innodb fails in buildbot
Fix order_by_optimizer_innodb and order_by_innodb tests.

The problem was that the query could be ran before InnoDB was
ready to provide a realistic statistic for #records in the table.

It provided a number that was too low, which caused the optimizer
to decide that range access plan wasn't advantageous and discard it.
2023-10-05 16:59:13 +03:00
Alexander Barkov
e4ce61ac0f MDEV-32226 UBSAN shift exponent X is too large for 64-bit type 'long long int' in sql/field.cc 2023-10-05 09:49:25 +04:00
Alexander Barkov
534a2bf1c6 MDEV-32275 getting error 'Illegal parameter data types row and bigint for operation '+' ' when using ITERATE in a FOR..DO
An "ITERATE innerLoop" did not work properly inside
a WHILE loop, which itself is inside an outer FOR loop:

outerLoop:
  FOR
   ...
   innerLoop:
    WHILE
      ...
      ITERATE innerLoop;
      ...
    END WHILE;
    ...
  END FOR;

It erroneously generated an integer increment code for the outer FOR loop.
There were two problems:
1. "ITERATE innerLoop" worked like "ITERATE outerLoop"
2. It was always integer increment, even in case of FOR cursor loops.

Background:
- A FOR loop automatically creates a dedicated sp_pcontext stack entry,
  to put the iteration and bound variables on it.

- Other loop types (LOOP, WHILE, REPEAT), do not generate a dedicated
  slack entry.

  The old code erroneously assumed that sp_pcontext::m_for_loop
  either describes the most inner loop (in case the inner loop is FOR),
  or is empty (in case the inner loop is not FOR).

  But in fact, sp_pcontext::m_for_loop is never empty inside a FOR loop:
  it describes the closest FOR loop, even if this FOR loop has nested
  non-FOR loops inside.

  So when we're near the ITERATE statement in the above script,
  sp_pcontext::m_for_loop is not empty - it stores information about
  the FOR loop labeled as "outrLoop:".

Fix:
- Adding a new member sp_pcontext::Lex_for_loop::m_start_label,
  to remember the explicit or the auto-generated label correspoding
  to the start of the FOR body. It's used during generation
  of "ITERATE loop_label" code to check if "loop_label" belongs
  to the current FOR loop pointed by sp_pcontext::m_for_loop,
  or belongs to a non-FOR nested loop.

- Adding LEX methods sp_for_loop_intrange_iterate() and
  sp_for_loop_cursor_iterate() to reuse the code between
  methods handling:
  * ITERATE
  * END FOR

- Adding a test for Lex_for_loop::is_for_loop_cursor()
  and generate a code either a cursor fetch, or for an integer increment.
  Before this change, it always erroneously generated an integer increment
  version.

- Cleanup: Initialize Lex_for_loop_st::m_cursor_offset inside
  Lex_for_loop_st::init(), to avoid not initialized members.

- Cleanup: Removing a redundant method:
    Lex_for_loop_st::init(const Lex_for_loop_st &other)
  Using Lex_for_loop_st::operator(const Lex_for_loop_st &other) instead.
2023-10-04 16:06:59 +04:00
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
Sergei Petrunia
3626379d42 MDEV-20168: main.innodb_icp fails in BB with various wrong execution plans
Add FORCE INDEX and ANALYZE TABLE PERSISTENT FOR ALL to make the plans
stable.
2023-10-03 18:14:18 +03:00
Oleksandr Byelkin
554aa1e2b4 Disable view protocol for the MDEV-31742 test because it make statistics differ or wrong (without service connection) 2023-09-27 07:54:33 +02:00
Lena Startseva
fec93e7155 MDEV-31465: main.sum_distinct-big and main.merge-big fail with timeout with view-protocol
MDEV-31455: main.events_stress or events.events_stress fails with view-protocol
MDEV-31457: main.delete_use_source fails (hangs) with view-protocol

Fixed tests:
main.sum_distinct-big, main.delete_use_source - disabled view-protocol
for some cases because they use transactions without autocommit
main.events_stress, main.merge-big - disabled service connection
for some queries since it is necessary that the query SELECT pass
in the same session
2023-09-27 10:28:00 +07:00
Oleksandr Byelkin
50a2e8b189 MDEV-32140: Valgrind/MSAN warnings in dynamic_column_update_move_left
Do not manipulate empty dynamic column, just better return empty dynamic column from the begining.
(it is also optimisation)
2023-09-26 13:56:05 +02:00
Vlad Lesin
275f434392 MDEV-25163 Rowid filter does not process storage engine error correctly.
The fix is to return 3-state value from Range_rowid_filter::build()
call:
1. The filter was built successfully;
2. The filter was not built, but the error was not fatal, i.e. there is
no need to rollback transaction. For example, if the size of container to
storevrow ids is not enough;
3. The filter was not built because of fatal error, for example,
deadlock or lock wait timeout from storage engine. In this case we
should stop query plan execution and roll back transaction.

Reviewed by: Sergey Petrunya
2023-09-25 15:13:07 +03:00
Oleksandr Byelkin
89a493d64c MDEV-31742 incorrect examined rows in case of stored function usage
The counter is global so we do not need add backup to it
if we do not zero it after taking the backup.
2023-09-22 13:58:35 +02:00
Oleksandr Byelkin
2bf291ba59 MDEV-30820 slow log Rows_examined out of range
Fix row counters to be able to get any possible value.
2023-09-22 12:10:38 +02:00
Oleg Smirnov
73ef86d4ef MDEV-29731 Assertion failure when HAVING in a correlated subquery references columns in the outer query
When resolving a column from the HAVING clause, a new Item_field
object may be created inside Item_ref::fix_fields().
But the object is created with an empty name resolution context,
which then leads to debug assertion failure during
Item_field::fix_fields().

The solution is to pass the correct name resolution context
when creating the Item_field object.

Reviewer: Oleksandr Byelkin (sanja@mariadb.com)
2023-09-20 11:05:34 +07:00
Dmitry Shulga
68353dc92a MDEV-23902: MariaDB crash on calling function
On creation of a VIEW that depends on a stored routine an instance of
the class Item_func_sp is allocated on a memory root of SP statement.
It happens since mysql_make_view() calls the method
  THD::activate_stmt_arena_if_needed()
before parsing definition of the view.
On the other hand, when sp_head's rcontext is created an instance of
the class Field referenced by the data member
  Item_func_sp::result_field
is allocated on the Item_func_sp's Query_arena (call arena) that set up
inside the method
  Item_sp::execute_impl
just before calling the method
  sp_head::execute_function()

On return from the method sp_head::execute_function() all items allocated
on the Item_func_sp's Query_arena are released and its memory root is freed
(see implementation of the method Item_sp::execute_impl). As a consequence,
the pointer
  Item_func_sp::result_field
references to the deallocated memory. Later, when the method
  sp_head::execute
cleans up items allocated for just executed SP instruction the method
  Item_func_sp::cleanup is invoked and tries to delete an object referenced
by data member Item_func_sp::result_field that points to already deallocated
memory, that results in a server abnormal termination.

To fix the issue the current active arena shouldn't be switched to
a statement arena inside the function mysql_make_view() that invoked indirectly
by the method sp_head::rcontext_create. It is implemented by introducing
the new Query_arena's state STMT_SP_QUERY_ARGUMENTS that is set when explicit
Query_arena is created for placing SP arguments and other caller's side items
used during SP execution. Then the method THD::activate_stmt_arena_if_needed()
checks Query_arena's state and returns immediately without switching to
statement's arena.
2023-09-19 08:57:36 +07:00
Daniel Black
1831f8e4d7 MDEV-31369 Disable TLS v1.0 and 1.1 for MariaDB
Remove TLSv1.1 from the default tls_version system variable.

Output a warning if TLSv1.0 or TLSv1.1 are selected.

Thanks Tingyao Nian for the feature request.
2023-09-13 20:17:29 +10:00
Sergei Golubchik
d890aca6b5 "un-skip" more skipped tests
* version_compile_os can be "linux-systemd", not equal to "Linux"
* main.no-threads forces no-threads scheduler, a check whether it
  has one_thread_per_connection is guaranteed to fail.
2023-09-11 11:23:26 +02:00
Sergei Golubchik
d762e9d943 MDEV-32093 long uniques break old->new replication
recalculate long unique hash in Write_rows_log_event
and Update_rows_log_event.

normally generated columns (stored and indexed virtual)
are deterministic and their values don't need to be recalculated
on the slave as they're already present in the row image.
but the long unique hash function was changed in MDEV-27653,
so a row event from the old master will have the old hash,
but a table created on the new slave will need a new hash.
2023-09-06 22:38:41 +02:00
Sachin
c53cb718b7 MDEV-22722 Assertion "inited==NONE" failed in handler::ha_index_init on the slave during UPDATE
test case only
2023-09-06 22:38:41 +02:00
Sergei Golubchik
65b3c89430 MDEV-32015 insert into an empty table fails with hash unique
don't enable bulk insert when table->s->long_unique_table
2023-09-06 22:38:41 +02:00
Sergei Golubchik
382c543f53 MDEV-32012 hash unique corrupts index on virtual blobs
as always when copying record[0] aside one needs to detach
Field_blob::value's from it, and restore them when record[0]
is restored from a backup.
2023-09-06 22:38:41 +02:00
Sergei Golubchik
e78ce63291 MDEV-17711 Assertion `arena_for_set_stmt== 0' failed in LEX::set_arena_for_set_stmt upon SET STATEMENT
restore SET STATEMENT variables between statements in a multi-statement
2023-09-06 22:38:41 +02:00
Alexander Barkov
9c8ae6dca5 MDEV-24797 Column Compression - ERROR 1265 (01000): Data truncated for column
Fix issue was earlier fixed by MDEV-31724. Only adding MTR tests.
2023-08-15 09:36:38 +04:00
Alexander Barkov
1fa7c9a3cd MDEV-31724 Compressed varchar values lost on joins when sorting on columns from joined table(s)
Field_varstring::get_copy_func() did not take into account
that functions do_varstring1[_mb], do_varstring2[_mb] do not support
compressed data.

Changing the return value of Field_varstring::get_copy_func()
to `do_field_string` if there is a compresion and truncation
at the same time. This fixes the problem, so now it works as follows:
- val_str() uncompresses the data
- The prefix is then calculated on the uncompressed data

Additionally, introducing two new copying functions
- do_varstring1_no_truncation()
- do_varstring2_no_truncation()

Using new copying functions in cases when:
- a Field_varstring with length_bytes==1 is changing to a longer
    Field_varstring with length_bytes==1
- a Field_varstring with length_bytes==2 is changing to a longer
    Field_varstring with length_bytes==2

In these cases we don't care neither of compression nor
of multi-byte prefixes: the entire data gets fully copied
from the source column to the target column as is.

This is a kind of new optimization, but this also was needed
to preserve existing MTR test results.
2023-08-15 07:00:17 +04:00
Monty
e9333ff03c MDEV-31893 Valgrind reports issues in main.join_cache_notasan
This is also related to
MDEV-31348 Assertion `last_key_entry >= end_pos' failed in virtual bool
           JOIN_CACHE_HASHED::put_record()

Valgrind exposed a problem with the join_cache for hash joins:
=25636== Conditional jump or move depends on uninitialised value(s)
==25636== at 0xA8FF4E: JOIN_CACHE_HASHED::init_hash_table()
          (sql_join_cache.cc:2901)

The reason for this was that avg_record_length contained a random value
if one had used SET optimizer_switch='optimize_join_buffer_size=off'.

This causes either 'random size' memory to be allocated (up to
join_buffer_size) which can increase memory usage or, if avg_record_length
is less than the row size, memory overwrites in thd->mem_root, which is
bad.

Fixed by setting avg_record_length in JOIN_CACHE_HASHED::init()
before it's used.

There is no test case for MDEV-31893 as valgrind of join_cache_notasan
checks that.
I added a test case for MDEV-31348.
2023-08-10 17:35:37 +03:00
Sergei Golubchik
ab10a675ac MDEV-31092 mysqldump --force doesn't ignore error as it should
failed SHOW CREATE FUNCTION means we don't dump this function,
but should still try to dump all other functions
2023-07-31 22:46:47 +02:00
Sergei Golubchik
4dd38f9f39 MDEV-31800 Problem with open ranges on prefix blobs keys
don't construct open ranges from prefix blob keys for < (less than)
just as it's already done for > (greater than)

because prefix KEY_PART doesn't create prefix Field for blobs
(see open_table_from_share() near "Create a new field for the key part"),
so stored_field_cmp_to_item() will compare the original field to the
value not taking the prefix length into account.
2023-07-31 22:46:47 +02:00
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
Lena Startseva
515ba857ba MDEV-31407: Add aliases in opt_trace.test for long column name for removing "--disable-view-protocol"
Change tests:
	opt_trace.test
	opt_trace_index_merge.test
	opt_trace_ucs2.test
2023-07-26 10:23:03 +07:00
Oleksandr Byelkin
cf50379b91 MDEV-25237 crash after setting global session_track_system_variables to an invalid value
Fix of typo in checking variable list corectness.

Fix of error handling in case of variable list parse error
2023-07-20 10:42:30 +02:00
Alexander Barkov
03c2157dd6 MDEV-28384 UBSAN: null pointer passed as argument 1, which is declared to never be null in my_strnncoll_binary on SELECT ... COUNT or GROUP_CONCAT
Also fixes:
  MDEV-30982 UBSAN: runtime error: null pointer passed as argument 2, which is declared to never be null in my_strnncoll_binary on DELETE

Calling memcmp() with a NULL pointer is undefined behaviour
according to the C standard, even if the length argument is 0.

Adding tests for length==0 before calling memcmp() into:
- my_strnncoll_binary()
- my_strnncoll_8bit_bin
2023-07-20 11:56:19 +04:00
Alexander Barkov
a79f4f6ec9 MDEV-22856 Assertion !str || str != Ptr' and Assertion !str || str != Ptr || !is_alloced()' failed in String::copy
The problem was earlier fixed by MDEV-26953.
Adding MTR tests only.
2023-07-20 11:06:30 +04:00
Alexander Barkov
30f3db3cf1 MDEV-29019 Assertion `(length % 4) == 0' failed in my_lengthsp_utf32 on SELECT
Problem:

Item_func_conv::val_str() copied the ASCII string with the numeric base
conversion result directly to the function result string. In case of a
tricky character set (e.g. utf32) it produced an illformed string.

Fix:

Copy the base conversion result to the function result as is only if
the function character set is ASCII compatible, go through a
character set conversion otherwise.
2023-07-19 11:18:16 +04:00
Alexander Barkov
9e5c1fb5d3 MDEV-23838 Possibly wrong result or Assertion `0' failed in Item_func_round::native_op
Change history in the affected code:

- Since 10.4.8 (MDEV-20397 and MDEV-23311), functions ROUND(), CEILING(),
  FLOOR() return a TIME value for a TIME input.
- Since 10.4.14 (MDEV-23525), MIN() and MAX() calculate a result for a TIME
  input using val_native() rather than val_str().

Problem:

The patch for MDEV-23525 did not take into account combinations like
MIN(ROUND(time)), MAX(FLOOR(time)), etc.

MIN() and MAX() with ROUND(time), CEILING(time), FLOOR(time) as an argument
call the method val_native() of the undelying classes Item_func_round and
Item_func_int_val. However these classes implemented the method val_native()
as DBUG_ASSERT(0).

Fix:

This patch adds a TIME-specific code inside:
- Item_func_round::val_native()
- Item_func_int_val::val_native()
still with DBUG_ASSERT(0) for all other data types,
as other data types do not call val_native() of these classes.

We'll need a more generic solition eventualy, e.g.
turn Item_func_round and Item_func_int_val into Item_handled_func.
However, this change would be too risky for 10.4 at this point.
2023-07-19 09:07:12 +04:00
Oleksandr Byelkin
b884216be7 MDEV-28017 Illegal mix of collations (cp1251_general_ci,IMPLICIT), (latin1_swedish_ci,COERCIBLE), (latin1_swedish_ci,COERCIBLE) for operation 'between'
Correct test fix is to disable service connection to create views in connection with correct charset settings.
2023-07-14 10:13:17 +02:00
Monty
7a5c984fa3 MDEV-20010 Equal on two RANK window functions create wrong result
The problematic query outlined a bug in window functions sorting
optimization. When multiple window functions are present in a query,
we sort the sorting key (as defined by PARTITION BY and ORDER BY) from
generic to specific.

SELECT RANK() OVER (ORDER BY const_col) as r1,
       RANK() OVER (ORDER BY const_col, a) as r2,
       RANK() OVER (PARTITION BY c) as r3,
       RANK() OVER (PARTITION BY c ORDER BY b) as r4
FROM table;

For these functions, the sorting we need to do for window function
computations are: [(const_col), (const_col, a)] and [(c), (c, b)].

Instead of doing 4 different sort order, the sorts grouped within [] are
compatible and we can use the most *specific* sort to cover both window
functions.

The bug was caused by an incorrect flagging of which sort is most
specific for a compatible group of functions. In our specific test case,
instead of picking (const_col, a) as the most specific sort, it would
only sort by (const_col), which lead to wrong results for rank function.
By ensuring that we pick the last sort key before an "incompatible sort"
flag is met in our "ordered array of sorting specifications", we
guarantee correct results.
2023-07-10 18:43:56 +03:00