With ibmdb2i_create_index_option set to 1, creating an IBMDB2I table
with a primary key should produce an additional index that uses EBCDIC
hexadecimal sorting. However, this does not work. Adding indexes that
are not primary keys does work. The ibmdb2i_create_index_option should
be honoured when creating a table with a primary key.
This patch adds code to the create() function to check for the value
of the ibmdb2i_create_index_option variable and, when appropriate, to
generate a *HEX-based shadow index in DB2 for the primary key. Previously
this behavior was limited to secondary indexes.
Additionally, this patch restricts the creation of shadow indexes to
cases in which a non-*HEX sort sequence is used, as the documentation
for ibmdb2i_create_index_option describes. Previously, the shadow index
would in some cases be created even when the MySQL-specific index used
*HEX sorting, leading to redundant indexes.
Finally, the code used to generate the list of fields for indexes
and the code used to generate the SQL statement for the shadow
indexes has been refactored into individual functions.
Some collations were causing IBMDB2I to report
inaccurate key range estimations to the optimizer
for LIKE clauses that select substrings. This can
be seen by running EXPLAIN. This problem primarily
affects multi-byte and unicode character sets.
This patch involves substantial changes to several
modules. There are a number of problems with the
character set and collation handling. These problems
have been or are being fixed, and a comprehensive
test has been included which should provide much
better coverage than there was before. This test
is enabled only for IBM i 6.1, because that version
has support for the greatest number of collations.
Creating an IBMDB2I table with the macce character set
is successful, but any attempt to insert data into the
table was failing.
This was happening because the character set name "macce"
is not a valid iconv descriptor for IBM i PASE. This patch
adds an override to convertTextDesc to use the equivalent
valid iconv descriptor "IBM-1282" instead.
Some collations--including cp1250_czech_cs,latin2_czech_cs,
ucs2/utf8_czech_ci, ucs2/utf8_danish_ci--are not being
sorted correctly by the IBMDB2I storage engine. This
was being caused because the sort order used by DB2 is
incompatible with the order expected by MySQL.
This patch removes support for the cp1250_czech_cs and
latin2_czech_cs collations because it has been determined
that the sort order used by DB2 is incompatible with the
order expected by MySQL. Users needing a czech collation
with IBMDB2I are encouraged to use a Unicode-based collation
instead of these single-byte collations. This patch also
modifies the DB2 sort sequence used for ucs2/utf8_czech_ci
and ucs2/utf8_danish_ci collations to better match the
sorting expected by MySQL. This will only affect indexes
or tables that are newly created through the IBMDB2I storage
engine. Existing IBMDB2I tables will retain the old sort
sequence until recreated.
Running a SELECT query over an IBMDB2I table with a cp1250 character set
was producing an error 2027 (ibmdb2i error 2027: Error converting single-byte
sort sequence to UCS-2).
The QMY_DESCRIBE_RANGE API was returning error 2027 to the storage engine
because the CCSID used for a cp1250 column (870) does not match the CCSID
used by the DB2 sort sequences associated with cp1250_* collations (1153).
This was because the storage engine relies on a set of system APIs to
determine which CCSID value most closely matches a particular MySQL
character set. However, in the case of cp1250, the system is returning
CCSID 870, which does not have a codepoint for the euro symbol, making it
an incorrect match.
This patch overrides the selection of a compatible CCSID to always return
1153 for cp1250.
wmemset was being used to fill the row buffers.
wmemset was intended to fill the buffer with
16-bit UCS2 pad values. However, the 64-bit
version of wmemset uses 32-bit wide characters
and thus filled the buffer incorrectly. In some
cases, the null byte map would be overwritten,
causing ctype_utf8.test and ibmdb2i_rir.test to
fail, giving the error message CPF5035.
This patch eliminates the use of wmemset to fill
the row buffer. wmemset has been replaced with
memset16, which always fills memory with 16-bit
values.
Occasionally, if both the partition_pruning
and partition_range tests are run sequentially
against the IBMDB2I engine, the partition_range
test will fail.
Compiler padding on a 64-bit build allowed
garbage data in the hash key used for
caching open iconv descriptors. As a
result, cached descriptors were not found,
and multiple duplicate iconv descriptors
were opened for a single character set.
Eventually, the maximum number of open
iconv descriptors was reached, and further
iconv_open() calls would fail, leading the
storage engine to report incorrectly that
the character set was not supported.
This patch widens the 16-bit members of the
hash key to 32 bits to eliminate compiler
padding. The entire length of the hash key
is now initialized correctly on both 32-bit
and 64-bit builds.
In order to better support the usage of
IBMDB2I tables from within RPG programs,
the storage engine should ensure that the
RCDFMT name is consistent and predictable
for DB2 tables.
This patch appends a "RCDFMT <name>"
clause to the CREATE TABLE statement
that is passed to DB2. <name> is
generated from the original name of
the table itself. This ensures a
consistent and deterministic mapping
from the original table.
For the sake of simplicity only
the alpha-numeric characters are
preserved when generating the new
name, and these are upper-cased;
other characters are replaced with
an underscore (_). Following DB2
system identifier rules, the name
always begins with an alpha-character
and has a maximum of ten characters.
If no usable characters are found in
the table name, the name X is used.
When a user selected an unsupported character set for an
IBMDB2I table, error 2501 or 2511 may have been returned,
giving the appearance of an internal programming error.
This patch consolidates these errors into a single descriptive
error message for the common case of an unsupported character
set.
The new error number is 2504 and indicates a user error.
The errors 2501 and 2511 remain to indicate cases of internal
programming errors.
The storage engine was not correctly handling the case in
which rnd_pos is executed for a handler without a preceding
rnd_next or index read operation. As a result, an unitialized
file handle was sometimes being passed to the QMY_READ API.
The fix clears the rrnAssocHandle at the beginning of each
read operation and then checks to see whether it has been
set to a valid handle value before attempting to use it
in rnd_pos. If rrnAssocHandle has not been set by a previous
read operation, rnd_pos instead falls back to the use of the
currently active handle.
On IBM i 5.4, schemas with names that are longer
than 8 characters and contain digits or an underscore
cannot contain IBMDB2I tables, even though this should
theoritically be possible if all alpha characters
are uppercase.
THe current patch fixes the IBMDB2I engine to
allow digits and the underscore(_) to be used in
schema names longer than 8 characters on IBM i 5.4.
In some circumstances, when a table is created with
the IBMDB2I engine, the CREATE TABLE statement will
return successfully but the table will not exist.
The current patch addresses the above issue and causes
CREATE to fail and report and error to the user.
The utf8_swedish_ci and ucs2_swedish_ci
collations do not work with indexes on
IBMDB2I tables.
The current patch adds the mapping for
ucs2_swedish collation and removes the
ucs2_spanish2 mapping which is not
supported by any version of the operating
system.
Modify plugins.m4 configuration framework so that plugins which are
not built still get added to the source distribution during make dist.
This came up now because we can only build ibmdb2i on i5/OS, and we
can't bootstrap our source dist on that platform. The solution is to
specify DIST_SUBDIRS containing all plugins, separate from SUBDIRS
which contains the plugins which are actually built.
This ibmdb2i code is from the ibmdb2i-ga3-src.zip file, with a patch
to plug.in to disable the plugin if the PASE environment isn't available.
