fn:count() or xdmp:estimate().
cts:search operation. If you specify the first item
from a cts:search expression,
then cts:remainder will return an estimate of the number
of fragments that match that expression.
This function makes it efficient to estimate the size of a search result
and execute that search in the same query. If you only need an estimate of
the size of a search but do not need to run the search, then
xdmp.estimate
is more efficient.
To return the estimated size of a search with
cts.remainder,
use the first item of a
cts.search
result sequence as the
parameter to
cts.remainder. For example, the following
query returns the estimated number of fragments that contain the word
"dog":
cts.remainder(fn.subsequence(cts.search("dog"), 1, 1))
When you take a subsequence of the
cts.search result ValueIterator,
MarkLogic Server will filter all of the false-positive results
up to the specified position, but not the false-positive results beyond
the specified
position. Because of this, when you
increase the the number of results in the
subsequence, the result from cts.remainder
might decrease
by a larger number than the increase in position number, or it might not
decrease at all. For example, if
the query above returned 10, then the following query might return 9, it
might return 10, or it might return less than 9, depending on how the
results are dispersed throughout different fragments:
cts.remainder(fn.subsequence(cts.search("dog"), 2, 2))
If you run
cts.remainder on a constructed node, it always
returns 0; it is primarily intended to run on nodes that are the retrieved
from the database (an item from a search result or an
item from the result of an XPath expression that searches through the
database).
var s = cts.search("dog");
var results = new Array();
var clone = s.clone();
for (var x of fn.subsequence(s, 1, 1) ) {
results.push(cts.remainder(x));
};
results.push(clone);
results;
=> Returns the estimated number of items in the search
for "dog" followed by the results of the search.
// Assume a document exist as follows:
// declareUpdate();
// xdmp.documentInsert("/test.json", {"a":"my test"});
for (var x of fn.subsequence(cts.search("my test"), 1, 1) ) {
cts.remainder(x);
};
=> 1
for (var a of cts.search("my test")) {
if (cts.remainder(a) == 1) {
xdmp.nodeUri(a);
};
};
=> /test.json