Limits and Ranges

The following limits exist for the Informix-SE file system:

Maximum indexed key size: 120 bytes
Maximum number of fields per key: 8

The following limits exist for the Informix-OnLine file system:

Maximum indexed key size: 256 bytes
Maximum number of fields per key: 16

With the Acu4GL product for Informix, only one database can be open at a time. Within this one database, a maximum of 100 tables can be open at the same time. You can set this table maximum to a lower number via the runtime configuration variable MAX_CURSORS.

The following Informix data types are not currently supported:

INTERVAL
BLOB
FLOAT
SMALLFLOAT

Acu4GL for Informix supports the following data types; conversions between COBOL and database formats are as shown:

COBOL to	INFORMIX
PIC X PIC X(`n`) (`n`<=255) PIC X(`n`) (255 < `n` <=32739)	CHAR VARCHAR LVARCHAR
PIC 9 PIC 99X PIC 999 PIC 9999	SMALLINT
PIC 9(5) PIC 9(6) PIC 9(7)X PIC 9(8) PIC 9(9)	INTEGER
All other PIC 9’s	DECIMAL

INFORMIX to	COBOL
INTERGERX	PIC S9(10) or PIC S9(9) COMP-4
SMALLINT	PIC S9(5) or PIC S9(4) COMP-4
DECIMAL (6,2)	PIC (4)V99
MONEY(4)	PIC (2)V99
SERIAL	PIC 9(9)
DATE	PIC 9(6) or PIC 9(8)
DATETIME	PIC 9(12) or PIC 9(14)
VARCHAR (max, min)	PIC X(max)
LVARCHAR (max, min)	PIC X(max)

When the VAR_LENGTH directive is applied to a field, it is converted to a VARCHAR data type if the field is up to 255 bytes in size, or the LVARCHAR data type if the field is larger than 255 bytes, up to a maximum of 32,739 bytes, in size.

Opening a file I-O exclusive doesn’t hold lock on Informix. This is a limitation on the way the Informix Acu4GL product works. Since we do not do any actual operations on the table except to get information about it, Informix does not tell us the file is locked. Users should get a lock condition when they do a read with lock.

Performing error handling on the read/write will yield a 99 record locked on any read operation performed — even if the file is open for input.

Other limits are described in Limits and Ranges of the ACUCOBOL-GT documentation.