Replication Agent for Informix processes transactions and stored
procedure invocations and passes data to the primary Replication
Server.
The primary Replication Server uses the datatype formats specified
in the replication definition to receive the data from Replication Agent for
Informix.
The following table describes the default conversions of Informix
datatypes to Sybase datatypes.
Table 2-3: Informix to Sybase default datatype
mapping
Informix
datatype
|
Informix length/range
|
Sybase datatype
|
Sybase length/range
|
Notes
|
|---|
byte
|
231 bytes,
binary data
|
image
|
2GB
|
|
blob
|
4 terabytes (4*240),
binary data
|
image
|
2GB
|
|
boolean
|
1 byte
|
char(1)
|
1 byte
|
Values are replicated
as literal characters t or f.
|
char(n)
|
32,767 bytes
|
char, varchar
|
32K
|
|
clob
|
4 terabytes (4*240),
text data
|
text
|
2GB
|
|
date
|
Number of
days since 12/31/1899
|
date or datetime
|
01/01/1753
to 12/31/9999
|
No special effort is required
to format the value for either Replication Server or Adaptive Server.
If the Informix value falls outside the Replication Server
supported range, Replication Server will not accept it.
Options for handling this situation include:
|
datetime largest_qualifier to smallest_qualifier
|
YEAR: 1 - 9999
MONTH: 1 - 12
DAY: 1 - 31
HOUR: 0 - 23
MINUTE: 0 - 59
SECOND: 0 - 59
FRACTION:
0 - 99999
|
char(n) or datetime
|
If datetime is
used, 01/01/1753 to 12/31/9999
|
If char is used,
the value of n depends on the date elements defined
for the column. For example, datetime year to fraction(5) requires n to
be 25, datetime month to day requires n to be
5.
If datetime is used, set the value of the pdb_convert_datetime parameter
to true before marking the table, then deal with
the range issue as described for the Informix date datatype.
|
decimal(p) or dec(p)
|
10-130 to
10124, up to 32 significant digits
|
decimal or float
|
When decimal is used,
10-38 to 1038,
38 significant digits.
float precision and range corresponds to
a C double datatype, approximately 16 significant
digits.
|
Using the decimal datatype
allows precision at the expense of range.
Using the float datatype allows range
(to the extent that the Replication Server platform supports range)
at the expense of precision.
However, extremely small values get truncated at log time
to 16 digits to the right of the decimal. For example, with the
primary column datatype of decimal(32), the
number 1.2345678901234567890123456789012e-10 is logged as 0.0000000001234567.
Extremely large values retain precision.
|
decimal(p,s) or dec(p,s) or numeric(p,s)
|
Range without error
is 0 to 10p-s - 10-s,
up to 32 significant digits
|
decimal
|
10-38 to
1038, 38 significant digits.
|
|
float(n) or double precision
|
Corresponds to a C double datatype on
the given system, approximately 16 significant digits.
|
float
|
Corresponds to a C double datatype on
the given system, approximately 16 significant digits.
|
Errors can be introduced if the Informix
platform and Replication Server platform handle the C double datatype
differently.
Extremely large values may lose significant digits at log
time. For example, with primary column datatype of float,
the number 1.234567890123456e125 is logged as 1.234568e+125.
However, extremely small values retain all digits.)
|
integer or int
|
-2,147,483,647
to 2,147,483,647.
|
int
|
-2,147,483,648
to 2,147,483,647.
|
|
int8
|
-9,223,372,036,
854,775,807 to 9,223,372,036,
854,775,807
|
decimal
|
10-38 to
1038, 38 significant digits.
|
|
interval largest_qualifier(n) to smallest_qualifier(n)
|
1 <= n <= 9
for largest_qualifier. If the type
of smallest_qualifier is fraction,
1 <= n <= 5. (n on smallest_qualifier only
valid if smallest_qualifier is a
fraction.)
|
char(n)
|
32K
|
The value of the char n depends
on the interval elements defined for the column. For example, interval year(5)
to month requires n to be 9, interval
day(9) to fraction(5) requires n to
be 25.
By modifying the script that builds the shadow table and associated primary
table triggers and stored procedures, you can break the interval value
into separate integer values. Or you can use
a function string to do this breakdown for each replicate.
|
lvarchar
|
4 GB
|
text
|
2GB
|
|
money(p,s)
|
Range without error is 0
to 10p-s - 10-s,
up to 32 significant digits
|
money or small-money
|
The money range is
-922,337,203,
685,477.5808 to
922,337,203,
685,477.5807.
The smallmoney range is
-214,748.3648 to 214,748.3647.
|
Both money and smallmoney datatypes
are accurate to one ten-thousandth of a monetary unit. This results
in truncation if the primary column allows accuracy beyond that
level.
|
nchar(n)
|
Up to 32,767 bytes of multi-byte
character data
|
unichar or char
|
32K
|
|
nvarchar(m,r)
|
Up to 255 bytes of multibyte character
data
|
univarchar or varchar
|
32K
|
|
real
|
See smallfloat.
|
|
|
|
serial
|
-2,147,483,647 to 2,147,483,647.
|
identity or integer
|
-2,147,483,648 to 2,147,483,647.
|
If identity is used,
the following command is applied to the replicated table before
an insert command:
set identity_insert table_name on
The following command is applied to the replicated table after
an insert command:
set identity_insert table_name off
 Columns with the identity datatype
are never updated by the update command.
|
serial8
|
-9,223,372,036,
854,775,807 to 9,223,372,036,
854,775,807
|
identity or numeric
|
1 to 1038 -
1
|
If identity is used,
the following command is applied to the replicated table before
an insert command:
set identity_insert table_name on
The following command is applied to the replicated table after
an insert command:
set identity_insert table_name off
Columns with the identity datatype
are never updated by the update command.
|
smallfloat
|
Corresponds to a C float datatype, approximately
8 significant digits.
|
real
|
Corresponds to a C float datatype, approximately
6 significant digits.
|
Errors may be introduced if the Informix
platform and Replication Server platform handle the C float datatype
differently.
|
smallint
|
-32,767 to 32,767
|
smallint
|
-32,768 to 32,767
|
|
text
|
2GB, text data.
|
text
|
2GB
|
|
varchar(m [,r])
|
255 bytes
|
char or varchar
|
32K
|
|
