For the most part, files used in the 32-bit mode can be used in the 64-bit mode. However, the following types of files created in the 32-bit mode are incompatible with and cannot be used in the 64-bit-mode HiRDB:

• Backup files
• HiRDB files comprising the master directory RDAREA and data directory RDAREA

Changing HiRDB from the 32-bit mode to the 64-bit mode results in changes in the default values for the HiRDB system definition operands shown in Table 11-5.

Table 11-5 Operands with different default values

Operand	Specification item	Default in 32-bit mode	Default in 64-bit mode
pd_work_buff_size	Work table buffer size	HiRDB/Single Server: 384* HiRDB/Parallel Server: 1024*	5120*
pd_fes_lck_pool_size	Lock pool size for front-end servers	(Value of pd_max_users + 3) (value of pd_max_access_tables + 4) 6	(Value of pd_max_users + 3) (value of pd_max_access_tables + 4) 4
SHMMAX	Maximum shared memory segment size	200 megabytes	1024 megabytes

^* Value if the pd_work_buff_mode operand is omitted, or the default value if pool is specified. The default value does not change if each is specified in pd_work_buff_mode.

Changing from the 32-bit mode to the 64-bit mode increases HiRDB's memory requirements. For details on the memory requirement calculations, see the HiRDB Version 8 Installation and Design Guide.

Changing to the 64-bit mode requires changes in the UOC interface for the database load utility (pdload), with the result that the UOC must be re-created. For details on the UOC interface, see the section on the database load utility (pdload) in the HiRDB Version 8 Command Reference.

Changing to the 64-bit mode changes the configuration and sizes of the SQL linkage areas shown in Table 11-6. For details on the SQL linkage areas, see the HiRDB Version 8 UAP Development Guide.

Table 11-6 Changes in linkage areas

Linkage area	Size (bytes)
	32-bit mode	64-bit mode
SQLCA	336	368
SQLCABC	4	8
SQLCODE	4	8
SQLERRD	46	86

Changing to the 64-bit mode changes the configuration of the SQL descriptor areas, as well as the sizes and data types of the linkage descriptor areas, as shown in Table 11-7. For details on the SQL descriptor areas, see the HiRDB Version 8 UAP Development Guide.

Table 11-7 Changes in descriptor areas

Descriptor area	32-bit mode		64-bit mode
	Size (bytes)	Data type	Size (bytes)	Data type
SQLDA	16 + 16n		24 + 24n
SQLDABC	4		8
SQLVAR	16n		24n
SQLVAR_LOB	16n		24n
SQLLOBLEN		long		int
SQLDATA	4		8
SQLIND	4		8
SQLLOBIND	4	long	8	int

n: Number of SQLVAR variables specified in the SQLN descriptor area.

: No change in size or data type.

Because in UAPs written in C that support the 64-bit mode, the long-type is 8-byte long, the embedded variables that had used long will use int instead, and the C-language data descriptions listed in Table 11-8 will be changed. For details on the C-language data descriptions, see the HiRDB Version 8 UAP Development Guide.

Table 11-8 Changed C-language data descriptions

Data type of SQL		Data description in C	Data structure	Remarks
INTEGER	Simple type	int variable-name;	Variable
	Array type	int variable-name [n];	Array	1n4096
BLOB indicator variable		int indicator-variable-name;
SQL statement		struct{ int len; char str[n]; } variable-name;	Structure

: Cannot be coded.

Following is the procedure for converting a 32-bit-mode UAP into a 64-bit-mode UAP.

1. In the declarations of embedded variables, replace all occurrences of the long type with the int type.
2. Execute UAP preprocessing, specifying the /h64 option, which generates a 64-bit-mode post-source.
3. Compile the UAP, specifying the option that generates 64-bit-mode object code.
4. Link the UAP, specifying the 64-bit-mode HiRDB client library as the library to be linked.