Files
MariaDB-open-code/mysql-test
Aleksey Midenkov 0b2434d2e9 MDEV-25158 Segfault on INTERSECT ALL with UNION in Oracle mode
Oracle mode has different set operator precedence and handling (not by
standard). In Oracle mode the below test case is handled as-is, in
plain order from left to right. In MariaDB default mode follows SQL
standard and makes INTERSECT prioritized, so UNION is taken from
derived table which is INTERSECT result (here and below the same
applies for EXCEPT).

Non-distinct set operator (UNION ALL/INTERSECT ALL) works via unique
key release but it can be done only once. We cannot add index to
non-empty heap table (see heap_enable_indexes()). So every UNION ALL
before rightmost UNION DISTINCT works as UNION DISTINCT. That is
common syntax, MySQL, MSSQL and Oracle work that way.

There is union_distinct property which indicates the rightmost
distinct UNION (at least, so the algorithm works simple: it releases
the unique key after union_distinct in the loop
(st_select_lex_unit::exec()).

INTERSECT ALL code (implemented by MDEV-18844 in a896beb) does not
know about Oracle mode and treats union_distinct as the last
operation, that's why it releases unique key on union_distinct
operation. INTERSECT ALL requires unique key for it to work, so before
any INTERSECT ALL unique key must not be released (see
select_unit_ext::send_data()).

The patch tweaks INTERSECT ALL code for Oracle mode. In
disable_index_if_needed() it does not allow unique key release before
the last operation and it allows unfold on the last operation. Test
case with UNION DISTINCT following INTERSECT ALL at least does not
include invalid data, but in fact the whole INTERSECT ALL code could
be refactored for better semantical triggers.

The patch fixes typo in st_select_lex_unit::prepare() where
have_except_all_or_intersect_all masked eponymous data member which
wrongly triggered unique key release in st_select_lex_unit::prepare().

The patch fixes unknown error in case ha_disable_indexes() fails.

Note: optimize_bag_operation() does some operator substitutions, but
it does not run under PS. So if there is difference in test with --ps
that means non-optimized (have_except_all_or_intersect_all == true)
code path is not good.

Note 2: VIEW is stored and executed in normal mode (see
Sql_mode_save_for_frm_handling) hence when SELECT order is different
in Oracle mode (defined by parsed_select_expr_cont()) it must be
covered by --disable_view_protocol.
2025-05-29 12:34:06 +03:00
..

This directory contains test suites for the MariaDB server. To run
currently existing test cases, execute ./mysql-test-run in this directory.

Some tests are known to fail on some platforms or be otherwise unreliable.
In the file collections/smoke_test there is a list of tests that are
expected to be stable.

In general you do not have to have to do "make install", and you can have
a co-existing MariaDB installation, the tests will not conflict with it.
To run the tests in a source directory, you must do "make" first.

In Red Hat distributions, you should run the script as user "mysql".
The user is created with nologin shell, so the best bet is something like
  # su -
  # cd /usr/share/mysql-test
  # su -s /bin/bash mysql -c ./mysql-test-run

This will use the installed MariaDB executables, but will run a private
copy of the server process (using data files within /usr/share/mysql-test),
so you need not start the mysqld service beforehand.

You can omit --skip-test-list option if you want to check whether
the listed failures occur for you.

To clean up afterwards, remove the created "var" subdirectory, e.g.
  # su -s /bin/bash - mysql -c "rm -rf /usr/share/mysql-test/var"

If tests fail on your system, please read the following manual section
for instructions on how to report the problem:

https://mariadb.com/kb/en/reporting-bugs

If you want to use an already running MySQL server for specific tests,
use the --extern option to mysql-test-run. Please note that in this mode,
you are expected to provide names of the tests to run.

For example, here is the command to run the "alias" and "analyze" tests
with an external server:

  # mysql-test-run --extern socket=/tmp/mysql.sock alias analyze

To match your setup, you might need to provide other relevant options.

With no test names on the command line, mysql-test-run will attempt
to execute the default set of tests, which will certainly fail, because
many tests cannot run with an external server (they need to control the
options with which the server is started, restart the server during
execution, etc.)

You can create your own test cases. To create a test case, create a new
file in the main subdirectory using a text editor. The file should have a .test
extension. For example:

  # xemacs t/test_case_name.test

In the file, put a set of SQL statements that create some tables,
load test data, and run some queries to manipulate it.

Your test should begin by dropping the tables you are going to create and
end by dropping them again. This ensures that you can run the test over
and over again.

If you are using mysqltest commands in your test case, you should create
the result file as follows:

  # mysql-test-run --record test_case_name

  or

  # mysqltest --record < t/test_case_name.test

If you only have a simple test case consisting of SQL statements and
comments, you can create the result file in one of the following ways:

  # mysql-test-run --record test_case_name

  # mysql test < t/test_case_name.test > r/test_case_name.result

  # mysqltest --record --database test --result-file=r/test_case_name.result < t/test_case_name.test

When this is done, take a look at r/test_case_name.result.
If the result is incorrect, you have found a bug. In this case, you should
edit the test result to the correct results so that we can verify that
the bug is corrected in future releases.

If you want to submit your test case you can send it
to developers@lists.mariadb.org or attach it to a bug report on
http://mariadb.org/jira/.

If the test case is really big or if it contains 'not public' data,
then put your .test file and .result file(s) into a tar.gz archive,
add a README that explains the problem, ftp the archive to
ftp://ftp.mariadb.org/private and submit a report to
https://mariadb.org/jira about it.

The latest information about mysql-test-run can be found at:
https://mariadb.com/kb/en/mariadb/mysqltest/

If you want to create .rdiff files, check
https://mariadb.com/kb/en/mariadb/mysql-test-auxiliary-files/