IOBLOCKSIZE= Table Option

Specifies the number of rows in a block to be stored in or read from an SPD Server table.

Valid in:	SPD Server
Default:	8K compressed
Default:	32K encrypted (uncompressed)
Interaction:	Use IOBLOCKSIZE= in conjunction with the COMPRESS= or ENCRYPT= table option.

Syntax

Required Argument

Details

Example

Syntax

IOBLOCKSIZE=n

Required Argument

n

the size of the block.

Details

The software reads and stores a server table in blocks. IOBLOCKSIZE= is useful on compressed or encrypted tables. The server software does not use IOBLOCKSIZE= on server tables that are not compressed or encrypted.

For tables that are compressed or encrypted, the IOBLOCKSIZE= specification determines the number of rows to include in the block. The specification applies to block compression as well as data I/O to and from disk. The IOBLOCKSIZE= value affects the table's organization on disk.

When using server table compression or encryption, specify an IOBLOCKSIZE= value that complements how the data is to be accessed, sequentially or randomly. Sequential access or operations requiring full table scans favor a large block size (for example, 64K). In contrast, random access favors a smaller block size. Values smaller than 32K are ignored when encrypting data.

Example

A huge company mailing list is processed sequentially. Specify a block size for compression that is optimal for sequential access.

/* IOblocksize set to 64K */
data sport.maillist(ioblocksize=65536 compress=yes);
   input name $ 1-20
     address $ 21-57
     phoneno $ 58-69
     sex $71;

  datalines;

Douglas, Mike       3256 Main St., Cary, NC 27511        919-444-5555 M
Walters, Ann Marie  256 Evans Dr., Durham, NC 27707      919-324-6786 F
Turner, Julia       709 Cedar Rd., Cary, NC 27513        919-555-9045 F
Cashwell, Jack      567 Scott Ln., Chapel Hill, NC 27514 919-533-3845 M
Clark, John         9 Church St.,  Durham, NC 27705      919-324-0390 M
;
run;

IOBLOCKSIZE= Table Option

Syntax

Required Argument

n

Details

Example

See Also