The bug could cause choosing a sub-optimal execution plan for
a single-table query if a unique index with many null keys were
defined for the table.
It happened because the code of the check_quick_keys function
made an assumption that any key may occur in an unique index
only once. Yet this is not true for keys with nulls that may
have multiple occurrences in the index.
Thirty five seconds is entirely too short of a period to wait for a server
to exit. Instead, make a valliant effort to make sure it exits, and only
give up after a very long period (arbitrarily chosen as 15 minutes).
In addition, if we're being asked to restart the server, then don't try
to start again if trying to stop the server failed.
---
Return zero by default, when the script exits.
---
Set return-/exit-value based on whether we successfully dealt with the
PID-file.
---
Don't wait that long if the program we're waiting on exits. It
should only exit if the server is not going to be started.
Its root cause is a difference between the "readline" and "libedit" (header files)
definitions of "rl_completion_entry_function", where the "libedit" one is wrong anyway:
This variable is used as a pointer to a function returning "char *",
but "libedit" declares it as returning "int" and then adds casts on usage.
Change it to "CPFunction *" and get rid of the casts.
Two problems here:
Problem 1:
While constructing the join columns list the optimizer does as follows:
1. Sets the join_using_fields/natural_join members of the right JOIN
operand.
2. Makes a "table reference" (TABLE_LIST) to parent the two tables.
3. Assigns the join_using_fields/is_natural_join of the wrapper table
using join_using_fields/natural_join of the rightmost table
4. Sets join_using_fields to NULL for the right JOIN operand.
5. Passes the parent table up to the same procedure on the upper
level.
Step 1 overrides the the join_using_fields that are set for a nested
join wrapping table in step 4.
Fixed by making a designated variable SELECT_LEX::prev_join_using to
pass the data from step 1 to step 4 without destroying the wrapping
table data.
Problem 2:
The optimizer checks for ambiguous columns while transforming
NATURAL JOIN/JOIN USING to JOIN ON. While doing that there was no
distinction between columns that are used in the generated join
condition (where ambiguity can be checked) and the other columns
(where ambiguity can be checked only when resolving references
coming from outside the JOIN construct itself).
Fixed by allowing the non-USING columns to be present in multiple
copies in both sides of the join and moving the ambiguity check
to the place where unqualified references to the join columns are
resolved (find_field_in_natural_join()).
When a merge table is opened compare column and key definition of
underlying tables against column and key definition of merge table.
If any of underlying tables have different column/key definition
refuse to open merge table.
The optimizer takes away columns from GROUP BY/DISTINCT if they constitute
all the parts of an unique index.
However if some of the columns can contain NULLs this cannot be done
(because an UNIQUE index can have multiple rows with NULL values).
Fixed by not using UNIQUE indexes with nullable columns to remove
grouping columns from GROUP BY/DISTINCT.
Depending on the queries we use different data processing methods
and can lose some data in case of double (and decimal in 4.1) fields.
The fix consists of two parts:
1. double comparison changed, now double a is equal to double b
if (a-b) is less than 5*0.1^(1 + max(a->decimals, b->decimals)).
For example, if a->decimals==1, b->decimals==2, a==b if (a-b)<0.005
2. if we use a temporary table, store double values there as is
to avoid any data conversion (rounding).
If inserting a GPL header, include a complete one
Makefile.am, mysql.dsw, mysql.sln:
Removed C version of mysql-test-run
mysql.spec.sh:
Specify GPL license only in GPL sources
.del-my_manage.h:
Delete: mysql-test/my_manage.h
mysql.spec.sh:
Added GPL header
.del-mysql_test_run_new.c:
Delete: mysql-test/mysql_test_run_new.c
.del-mysql_test_run_new.dsp:
Delete: VC++Files/mysql-test/mysql_test_run_new.dsp
.del-my_create_tables.c:
Delete: mysql-test/my_create_tables.c
.del-mysql_test_run_new_ia64.dsp:
Delete: VC++Files/mysql-test/mysql_test_run_new_ia64.dsp
msql2mysql.sh:
Use up-to-date GPL header
.del-mysql_test_run_new.vcproj:
Delete: VC++Files/mysql-test/mysql_test_run_new.vcproj
.del-my_manage.c:
Delete: mysql-test/my_manage.c
