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.
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.
