n_getindexcount() - Hit information

SYNOPSIS

#include <sys/types.h>
#include "tstone.h"
int n_getindexcount(SERVER *se);


DESCRIPTION
This function will return the count of rows to be read from the index for the most recently prepared statement, if available.


CAVEATS
The return from this function is only valid under certain circumstances, which are when the index has been scanned to get a list of potentially matching records. In a join, the return value will be the number of matches in the inner table corresponding to the current outer row, not the number of outer table matches. The actual number of records returned may be significantly less if post processing is done to resolve some of the where clause.

The default behaviour of Texis with a single relational operator and an index on the field is to walk the index as the rows are returned, which is faster at getting the initial rows out. Since it does not get all the matching rows from the index first, n_getindexcount() will return 0. This behaviour can be changed with the bubble property.


EXAMPLE


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