to string conversions and vice versa"
Initial import of the dtoa.c code and custom wrappers around it
to allow its usage from the server code.
Conversion of FLOAT/DOUBLE values to DECIMAL ones or strings
and vice versa has been significantly reworked. As the new
algoritms are more precise than the older ones, results of such
conversions may not always match those obtained from older
server versions. This in turn may break compatibility for some
applications.
This patch also fixes the following bugs:
- bug #12860 "Difference in zero padding of exponent between
Unix and Windows"
- bug #21497 "DOUBLE truncated to unusable value"
- bug #26788 "mysqld (debug) aborts when inserting specific
numbers into char fields"
- bug #24541 "Data truncated..." on decimal type columns
without any good reason"
The test allowed random coincidence of connection ids for two concurrent
sessions performing CREATE/DROP temp tables.
Fixed with correcting the test. The sessions connection ids are not changed
from their defaults anymore.
When compressed myisam files are opened, they are always memory mapped
sometimes causing memory swapping problems.
When we mmap the myisam compressed tables of size greater than the memory
available, the kswapd0 process utilization is very high consuming 30-40% of
the cpu. This happens only with linux kernels older than 2.6.9
With newer linux kernels, we don't have this problem of high cpu consumption
and this option may not be required.
The option 'myisam_mmap_size' is added to limit the amount of memory used for
memory mapping of myisam files. This option is not dynamic.
The default value on 32 bit system is 4294967295 bytes and on 64 bit system it
is 18446744073709547520 bytes.
Note: Testcase only tests the option variable. The actual bug has be to
tested manually.
returns incorrect results with where
An outer join of a const table (outer) and a normal table
(inner) with GROUP BY on a field from the outer table would
optimize away GROUP BY, and thus trigger the optimization to
do away with a temporary table if grouping was performed on
columns from the const table, hence executing the query with
filesort without temporary table. But this should not be
done if there is a non-indexed access to the inner table,
since filesort does not handle joins. It expects either ref
access, range ditto or table scan. The join condition will
thus not be applied.
Fixed by always forcing execution with temporary table in
the case of ROLLUP with a query involving an outer join. This
is a slightly broader class of queries than need fixing, but
it is hard to ascertain the position of a ROLLUP field wrt
outer join with current query representation.
Problem: inserting a record we don't set unused null bits in the
record buffer if no default field values used.
That may lead to wrong live checksum calculation.
Fix: set unused null bits in the record buffer in such cases.
The bug is caused by a race condition between the
INSERT DELAYED thread and the client thread's FLUSH TABLE. The
FLUSH TABLE does not guarantee (as is (wrongly) suggested in the
test case) that the INSERT DELAYED is ever executed. The
execution of the test case will thus not be deterministic.
The fix has been to do a deterministic verification that both
threads are complete by checking the content of the table.
This test case tests a circular replication of four hosts.
A--->B--->C--->D--->A
The replicate is slow and needs more time to replicate all data in the circle.
The time it spends to replicate, sometimes, is longer than the time that
wait_condition.inc spends to wait that all data has been replicated. This
cause sporadical failure of this test case.
This patch uses sync_slave_with_master to ensure that all data can be replicated
successfully in the circle.
int join_read_key(JOIN_TAB*)
The eq_ref access method TABLE_REF (accessed through
JOIN_TAB) to save state and to track if this is the
first row it finds or not.
This state was not reset on subquery re-execution
causing an assert.
Fixed by resetting the state before the subquery
re-execution.
NULLable BIGINT and INT columns in comparison
Problem: a consequence of the fix for 43668.
Some Arg_comparator inner initialization missed,
that may lead to unpredictable (wrong) comparison
results.
Fix: always properly initialize Arg_comparator
before its usage.
int join_read_key(JOIN_TAB*)
The eq_ref access method TABLE_REF (accessed through
JOIN_TAB) to save state and to track if this is the
first row it finds or not.
This state was not reset on subquery re-execution
causing an assert.
Fixed by resetting the state before the subquery
re-execution.
Problem: add_collation did not check that cs->number is smaller
than the number of elements in the array all_charsets[],
so server could crash when loading an Index.xml file with
a collation ID greater the number of elements
(for example when downgrading from 5.5).
Fix: adding a condition to check that cs->number is not out of valid range.
'LOAD DATA CONCURRENT [LOCAL] INFILE ...' statment only is binlogged as
'LOAD DATA [LOCAL] INFILE ...' in SBR and MBR. As a result, if replication is on,
queries on slaves will be blocked by the replication SQL thread.
This patch write code to write 'CONCURRENT' into the log event if 'CONCURRENT' option
is in the original statement in SBR and MBR.
timestamp primary key
Since TIMESTAMP values are adjusted by the current time zone
settings in both numeric and string contexts, using any
expressions involving TIMESTAMP values as a
(sub)partitioning function leads to undeterministic behavior of
partitioned tables. The effect may vary depending on a storage
engine, it can be either incorrect data being retrieved or
stored, or an assertion failure. The root cause of this is the
fact that the calculated partition ID may differ from a
previously calculated ID for the same data due to timezone
adjustments of the partitioning expression value.
Fixed by disabling any expressions involving TIMESTAMP values
to be used in partitioning functions with the follwing two
exceptions:
1. Creating or altering into a partitioned table that violates
the above rule is not allowed, but opening existing such tables
results in a warning rather than an error so that such tables
could be fixed.
2. UNIX_TIMESTAMP() is the only way to get a
timezone-independent value from a TIMESTAMP column, because it
returns the internal representation (a time_t value) of a
TIMESTAMP argument verbatim. So UNIX_TIMESTAMP(timestamp_column)
is allowed and should be used to fix existing tables if one
wants to use TIMESTAMP columns with partitioning.
