column types TIMESTAMP is NOT NULL by default, so in order to have
TIMESTAMP column holding NULL valaues you have to specify NULL as
one of its attributes (this needed for backward compatibility).
Main changes:
Replaced TABLE::timestamp_default_now/on_update_now members with
TABLE::timestamp_auto_set_type flag which is used everywhere
for determining if we should auto-set value of TIMESTAMP field
during this operation or not. We are also use Field_timestamp::set_time()
instead of handler::update_timestamp() in handlers.
identical to another in result"
According to SQL standard queries like
"select t1.a as col from t1, t2 order by a" should return an error if
both tables contain field a.
using GROUP BY"
Now we are setting Field_timestamp::field_length to 19 in open_table()
if we are in new mode (and we are restoring it back when we are coming
back to normal mode). This also should solve potential problems with
some of LOAD DATA INFILE and SELECT * INTO in this mode.
BUG#4335 - one name can be handler open'ed many times.
Reworked the HANDLER functions and interface.
Using a HASH to store information on open tables that
survives FLUSH TABLE.
HANDLER tables alias names must now be unique, though it
is allowed in 4.0 to qualify them with the database name
of the base table.
Use 'mysqltest' as test database instead of test_$1 or test1,test2 to not accidently delete an important database
Safety fix for mailformed MERGE files
a second time". The bug was caused by incompatibility of
negations elimination algorithm and PS: during first statement
execute a subtree with negation was replaced with equivalent
subtree without NOTs.
The problem was that although this transformation was permanent,
items of the new subtree were created in execute-local memory.
The patch adds means to check if it is the first execute of a
prepared statement, and if this is the case, to allocate items
in memory of the prepared statement.
The implementation:
- backports Item_arena from 5.0
- adds Item_arena::is_stmt_prepare(),
Item_arena::is_first_stmt_execute().
- deletes THD::allocate_temporary_pool_for_ps_preparing(),
THD::free_temporary_pool_for_ps_preparing(); they
were redundant.
and adds a few invariants:
- thd->free_list never contains junk (= freed items)
- thd->current_arena is never null. If there is no
prepared statement, it points at the thd.
The rest of the patch contains mainly mechanical changes and
cleanups.
When in find_item_in_list() we are looking for item we should take into account unaliased
names of the fields but only if item with such aliased name is not found.
Also we should ignore aliases when looking for fully specified field.
Instead of trying to open time zone tables during calculation of CONVERT_TZ() function
or setting of @@time_zone variable we should open and lock them with the rest of
statement's table (so we should add them to global table list) and after that use such
pre-opened tables for loading info about time zones.
Added basic per-thread time zone functionality (based on public
domain elsie-code). Now user can select current time zone
(from the list of time zones described in system tables).
All NOW-like functions honor this time zone, values of TIMESTAMP
type are interpreted as values in this time zone, so now
our TIMESTAMP type behaves similar to Oracle's TIMESTAMP WITH
LOCAL TIME ZONE (or proper PostgresSQL type).
WL#1266 "CONVERT_TZ() - basic time with time zone conversion
function".
Fixed problems described in Bug #2336 (Different number of warnings
when inserting bad datetime as string or as number). This required
reworking of datetime realted warning hadling (they now generated
at Field object level not in conversion functions).
Optimization: Now Field class descendants use table->in_use member
instead of current_thd macro.
