joinCount<JK extends SdbKey, JV extends SdbValue> method

Future<int> joinCount<JK extends SdbKey, JV extends SdbValue>(SdbClient client, { required SdbJoinTarget<JK, JV> target, SdbFindOptions<SK>? options, SdbJoinFindOptions? joinOptions, })

The number of rows joinIterate would hand out.

Without distinct nor inner, and joining on a store (at most one match per record), every record of the source gives one row, so this is the record count. Otherwise rows are added or dropped in a way only a scan can tell, so the join is run, reading as little as it can (neither side is handed out).

Implementation

Future<int> joinCount<JK extends SdbKey, JV extends SdbValue>(
  SdbClient client, {
  required SdbJoinTarget<JK, JV> target,
  SdbFindOptions<SK>? options,
  SdbJoinFindOptions? joinOptions,
}) async {
  var joinOpts = sdbJoinFindOptionsOrDefault(joinOptions);
  if (!joinOpts.distinct &&
      !joinOpts.inner &&
      target.index == null &&
      options?.offset == null &&
      options?.limit == null) {
    return countRecords(client, options);
  }
  var rowCount = 0;
  await _joinRun<JK, JV>(
    client,
    target: target,
    mode: null,
    options: options,
    joinOptions: joinOptions,
    emit: SdbJoinEmit.none,
    onEmit: (row) {
      rowCount++;
      return true;
    },
  );
  return rowCount;
}