Analysis:
Constant table optimization of the outer query finds that
the right side of the equality is a constant that can
be used for an eq_ref access to fetch one row from t1,
and substitute t1 with a constant. Thus constant optimization
triggers evaluation of the subquery during the optimize
phase of the outer query.
The innermost subquery requires a plan with a temporary
table because with InnoDB tables the exact count of rows
is not known, and the empty tables cannot be optimzied
way. JOIN::exec for the innermost subquery substitutes
the subquery tables with a temporary table.
When EXPLAIN gets to print the tables in the innermost
subquery, EXPLAIN needs to print the name of each table
through the corresponding TABLE_LIST object. However,
the temporary table created during execution doesn't
have a corresponding TABLE_LIST, so we get a null
pointer exception.
Solution:
The solution is to forbid using expensive constant
expressions for eq_ref access for contant table
optimization. Notice that eq_ref with a subquery
providing the value is still possible during regular
execution.
The patch also adjusts several instable test results
to order the result.
Analysis:
The function prev_record_reads() may skip (jump over)
some query plan nodes where record_count < 1. At the
same time, even though get_partial_join_cost() uses
all first N plan nodes after the last constant table,
it may produce a smaller record_count than
prev_record_reads(), because the record count for
some plan nodes may be < 1, and these nodes may not
participate in prev_record_reads.
Solution:
The current solution is to treat the result of
get_partial_join_cost() as the upper bound for the
total number of unique lookup keys.
mysql-test/suite/pbxt/r/func_group.result:
Result file update.
mysql-test/suite/pbxt/r/grant.result:
Use --sorted_result
mysql-test/suite/pbxt/r/group_min_max.result:
Result file update.
mysql-test/suite/pbxt/r/join_nested.result:
Result file update.
mysql-test/suite/pbxt/r/negation_elimination.result:
Result file update.
mysql-test/suite/pbxt/r/ps_grant.result:
Use --sorted_result
mysql-test/suite/pbxt/r/skip_grants.result:
Result file update.
mysql-test/suite/pbxt/r/subselect.result:
Adjust test case following error message change due to fix of Bug#48293
mysql-test/suite/pbxt/r/view_grant.result:
Result file update.
mysql-test/suite/pbxt/t/grant.test:
Use --sorted_result
mysql-test/suite/pbxt/t/ps_grant.test:
Use --sorted_result
mysql-test/suite/pbxt/t/subselect.test:
Adjust test case following error message change due to fix of Bug#48293
- Added checking of return value for system(), freopen(), fgets() and chown()
- Ensure that calls that require a format strings gets a format string
- Other trivial things
Updated test suite results (especially for pbxt and embedded server)
Removed warning for "Invalid (old?) table or database name 'mysqld.1'" from pbxt tests
Speed up some pbxt tests by inserting begin ; commit; around "while loops with inserts"
Added mysqld startup option '--debug-flush'
Create maria_recovery.trace in data directory instead of current directory
client/mysql.cc:
Check return value from system()
client/mysql_upgrade.c:
Check return value from fgets()
client/mysqladmin.cc:
Check return value from fgets()
client/mysqlslap.c:
Check return value from system() (but ignore it, as it's not critical)
extra/yassl/src/crypto_wrapper.cpp:
Check return value from fgets() (but ignore it, as it's internal file)
extra/yassl/taocrypt/src/aes.cpp:
Added extra {} to remove compiler warning
extra/yassl/taocrypt/src/blowfish.cpp:
Added extra {} to remove compiler warning
extra/yassl/taocrypt/src/misc.cpp:
Ifdef not used code
include/mysys_err.h:
Added error message for failing chown()
mysql-test/mysql-test-run.pl:
Don't give warning for skipping ndbcluster (never enabled in MariaDB)
mysql-test/suite/funcs_1/r/is_columns_is_embedded.result:
Update with new information schema information
mysql-test/suite/funcs_1/r/is_tables_is_embedded.result:
New test
mysql-test/suite/funcs_1/r/is_tables_myisam_embedded.result:
Update test results (has not been tested for a long time)
mysql-test/suite/funcs_1/r/is_tables_mysql_embedded.result:
Update test results (has not been tested for a long time)
mysql-test/suite/funcs_1/t/is_tables_is.test:
Don't run with embedded server (as results differ)
I added a new test for embedded server
mysql-test/suite/funcs_1/t/is_tables_is_embedded.test:
New test
mysql-test/suite/pbxt/my.cnf:
Allow one to run pbxt tests without having to specify --mysqld=--default-storage-engine=pbxt
mysql-test/suite/pbxt/t/count_distinct3.test:
Speed up test by inserting begin; ... commit;
mysql-test/suite/pbxt/t/subselect.test:
Speed up test by inserting begin; ... commit;
mysys/errors.c:
Added error message for failing chown()
mysys/my_copy.c:
Added error message for failing chown()
mysys/my_redel.c:
Added error message for failing chown()
mysys/safemalloc.c:
Added cast to get rid of compiler warning
sql/ha_partition.cc:
Fixed wrong argument to sql_print_error() (it requires a format string)
sql/log.cc:
Test return value of freopen()
sql/mysqld.cc:
Test return value of freopen()
Added startup option '--debug-flush' to be used when one gets a core dump (easy to explain to people on IRC)
sql/rpl_rli.cc:
Fixed wrong argument to sql_print_error() (it requires a format string)
sql/set_var.cc:
Added {} to get rid of compiler warnings
sql/slave.cc:
Fixed wrong argument to mi->report() and sql_print...() (they require a format string)
sql/sql_cache.cc:
Fixed wrong argument to sql_printinformation() (it requires a format string)
sql/sql_parse.cc:
Test return value of fgets()
sql/sql_plugin.cc:
Fixed wrong argument to sql_print_error() (it requires a format string)
sql/sql_select.cc:
Use unique table name for internal temp tables instead of full path
(Simple speed & space optimization)
sql/udf_example.c:
Removed compiler warning about not used variable
storage/maria/ha_maria.cc:
Fixed wrong argument to sql_print_error() and ma_check_print_error() (they require a format string)
storage/maria/ma_recovery.c:
Create maria_recovery.trace in data directory instead of current directory
storage/maria/unittest/ma_test_loghandler-t.c:
Fixed wrong argument to ok(); Requires a format string
storage/pbxt/src/strutil_xt.cc:
Detect temporary tables by checking if that path for the table is in the mysql data directory.
The database for temporary tables is after this patch, from PBXT point of view, ""
This is needed to stop PBXT from calling filename_to_tablename() with the base directory as an argument, which caused
ERROR: Invalid (old?) table or database name 'mysqld.1'" in the log when running the test suite.
tests/mysql_client_test.c:
Fixed compiler warnings
unittest/mysys/base64-t.c:
Fixed wrong argument to diag() (it requires a format string)
Added a comment that the current 'print' of differing buffers doesn't print the right thing,
but didn't fix this as it's not important (unless we find a bug in the real code)
