Added test cases for bug #7351.
item_cmpfunc.cc:
Fixed bug #7351: incorrect result for a query with a
subquery returning empty set.
If in the predicate v IN (SELECT a FROM t WHERE cond)
v is null, then the result of the predicate is either
INKNOWN or FALSE. It is FALSE if the subquery returns
an empty set.
item_subselect.cc:
Fixed bug #7351: incorrect result for a query with a
subquery returning empty set.
The problem was due to not a quite legal transformation
for 'IN' subqueries. A subquery containing a predicate
of the form
v IN (SELECT a FROM t WHERE cond)
was transformed into
EXISTS(SELECT a FROM t WHERE cond AND (a=v OR a IS NULL)).
Yet, this transformation is valid only if v is not null.
If v is null, then, in the case when
(SELECT a FROM t WHERE cond) returns an empty set the value
of the predicate is FALSE, otherwise the result of the
predicate is INKNOWN.
The fix resolves this problem by changing the result
of the transformation to
EXISTS(SELECT a FROM t WHERE cond AND (v IS NULL OR (a=v OR a IS NULL)))
in the case when v is nullable.
The new transformation prevents applying the lookup
optimization for IN subqueries. To make it still
applicable we have to introduce guarded access methods.
Fix InnoDB bug: on HP-UX, with a 32-bit binary, InnoDB was only able to read or write <= 2 GB files; the reason was that InnoDB treated the return value of lseek() as a 32-bit integer; lseek was used on HP-UX-11 as a replacement for pread() and pwrite() because HAVE_BROKEN_PREAD was defined on that platform
added missing copyright text
moved ndb_init things to separate header file
removed ndb_global include
documented cluster connection class
moved internal constants to NdbImpl.hpp class
changed wait_until_ready behaviour somewhat
moved NdbWaiter, m_ndb_cluster_connection, to impl class
moved node selection things to cluster connection
moved all private things to impl class
added opts for shared memory and node selection
changed opts handling somewhat; introduced enum for options and common handling of option variables
added checks for transporter support
automatic addition of shared mem transporters
moved wait_until_ready code to cluster connection
added control of usage of new node selection method
I fixed the typos in the transaction-isolation comments.
I fixed the spelling mistakes in the comment. It had tripped up a support
customer as they couldn't start the server with transaction-isolation=
read-commited
(back to behaviour of 4.1.7). Warning was not fatal: mysqldump continued. And the good thing is that it helped spot that starting from 4.1.7,
SHOW CREATE DATABASE failed (if --single-transaction and first db has non-empty InnoDB table and there is a second db) and thus mysqldump
produced CREATE DATABASE statements missing the CHARACTER SET clause. Removing the bug which was in the server, and the warning reporting in
mysqldump (compatibility with old servers).
