Close the cursor.
MCO_RET mco_cursor_close( /*IN*/ mco_trans_h t, /*INOUT*/ mco_cursor_h c);
|
t |
The |
|
c |
A cursor handle returned from a cursor or index search function |
This function allows applications to explicitly close a cursor. High priority transactions (those set with priority
MCO_TRANS_HIGHand higher) optimize access to the index (if of type B-Tree) using a technique that we refer to as “smart locking”. Normally, we lock the page with a spinlock before getting access to a page and release the spinlock (unlock) before leaving the page. When smart locking is used, the database runtime does not release the lock while traversing (searching through) the B-Tree until we either reach the end of the result set, or the functionmco_cursor_close()is called.
| MCO_S_OK | Cursor closed successfully |
|
MCO_E_CURSOR_CLOSED |
Cursor already closed |
Application snippet:
const char * dbname = "SimpleDb";
int main(int argc, char* argv[])
{
mco_db_h db;
MCO_RET rc;
mco_device_t dev;
mco_db_params_t db_params;
mco_trans_h t;
mco_cursor_t c;
MCO_CURSOR_TYPE ctype;
...
rc = mco_db_open_dev( dbname, simple_get_dictionary(), &dev, 1, &db_params );
if ( MCO_S_OK != rc )
{
rc = mco_db_connect( dbname, &db );
...
rc = mco_trans_start(db, MCO_READ_ONLY, MCO_TRANS_FOREGROUND, &t);
if ( MCO_S_OK == rc )
{
...
A_list_cursor( t, &c);
...
rc = mco_cursor_close( t, &c );
...
}
}
...
}