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NbrOfKeyEntries
Number of entries in index file.
Short Name
IDXENT()
Type
Low-Level index file function
Declaration
LONG NbrOfKeyEntries(FILNO keyno)
Description
In V12 the file number typedef was formally changed from COUNT, a two-byte value to FILNO, a four-byte value. Refer to this link for compatibility details. Four Byte File Numbering
NbrOfKeyEntries() returns the number of entries in index file number keyno.
Note: A huge file may return values greater than 4 GB. This function returns the low-order 4-byte word of the 8-byte number of keys. To get the high-order 4-byte word, call ctGETHGH(). A return of zero is not necessarily an error if there are exactly a multiple 4 GB worth of key values.
Return
If an error occurs or the index file is empty, NbrOfKeyEntries() returns zero. Otherwise, NbrOfKeyEntries() returns the number of entries in the index file. When NbrOfKeyEntries() returns a zero, check uerr_cod: if uerr_cod is non-zero, an error condition was detected; otherwise, no key values are in the index. See c-tree Error Codes in the c-tree Programmer’s Reference Guide for a complete listing of valid c-tree error values.
Example
FILNO keyno;
scanf("%d",&keyno);
printf("\nThere are %ld entries in index #%d.",
NbrOfKeyEntries(keyno),keyno);
Limitations
With Standalone Multi-user systems, or when updates are immediately forced to disk, the time to add or delete an index entry can be reduced if the number of index entries is not maintained. By default, c-tree maintains this information. To disable this feature, add #define NO_IDXENT to the bottom of ctoptn.h/ctree.mak. By adding this define, multi-user, non-server applications may experience a performance gain. Therefore, we suggest you only use this function if it is very important to quickly determine the number of index entries.
