This COBOL system supports more than one type of indexed file. The tables below illustrate the different types available and the features that they support. 
	 
 
	  
	 
Table 1. Indexed Files - Features Supported  
	  
	  
	  
	  
	  
	  
	  
		 
		  |  | Supports Files Logically >4 Gb | Fast Updates on Files with Multiple Duplicate Keys | Maximum Occurrences of Duplicate Key Value | Support for Variable Length Records and Compression | Separate Index File | 
 
	 
 
	  
		 
		  | IDXFORMAT"1" | No | No | 65535 | No | Yes | 
 
		 
		  | IDXFORMAT"2" | No | No | 65535 | No | Yes | 
 
		 
		  | IDXFORMAT"3" | No | No | 65535 | Yes | Yes | 
 
		 
		  | IDXFORMAT"4" | No | Yes | 4 G | Yes | Yes | 
 
		 
		  | IDXFORMAT"8" | Yes | Yes | 4 G | Yes | No | 
 
		 
		  | IDXFORMAT"12" | Yes | Yes | 4 G | Yes | Yes | 
 
	 
 
  
 
 
   
  
Table 2. Indexed Files - Physical Characteristics  
	  
	  
	  
	  
	  
	  
	  
		 
		  |  | Duplicate Occurrence Records | Data Record Alignment | File Pointer Size (bytes) | Residue Length Field | Index Node Includes Record Header | 
 
	 
 
	  
		 
		  | IDXFORMAT"1" | No | 1 | 4 | n/a | No | 
 
		 
		  | IDXFORMAT"2" | No | 1 | 4 | n/a | No | 
 
		 
		  | IDXFORMAT"3" | No | 4 | 4 | 2 | No | 
 
		 
		  | IDXFORMAT"4" | Yes | 4 | 4 | 2 | No | 
 
		 
		  | IDXFORMAT"8" | Yes | 8 | 6 | 4 | Yes | 
 
		 
		  | IDXFORMAT"12" | Yes | 8 | 6 | 4 | Yes |