fast search + QThread

[solook]

Hi All,
i want to search in large libraries with sql
about 20000 books;
each book is in one table and all book names stored in table named books;

my code for search is :

void MyThread::run()
{
    QStringList bookTables =db->getList("Select booktable From books;");
    QStringList bookNames =db->getList("Select bookNames From books;");
    int rowBook=0;
    int totalResultBooks=0;
    int totalResult=0;
    int allBookCount=bookTables.size();
    emit sendMaxProgress(allBookCount-1);
    while(rowBook<allBookCount )
    {
        QString query = QString("Select count(id) From b%1 Where text LIKE '%%2%'  Limit 0,1 ; ").arg(bookTables.at(rowBook)).arg(searchPatterned);
        QString resultBook =db->getStr(query);
        if(resultBook.toInt()>0)
       {
            totalResult+= resultBook.toInt();
            totalResultBooks++;
            QListWidgetItem *item = new QListWidgetItem;
            item->setText(bookNames.at(rowBook)+" ("+resultBook+") ");
            item->setData(12,bookTables.at(rowBook));
            QString str = "found "+QString::number(totalResult)+"at"+QString::number(totalResultBooks)+"Books";
            emit sendResult(item,str,rowBook);
       }
        msleep(40);
        rowBook++;
    }
 
}

void MyThread::run()
{
    QStringList bookTables =db->getList("Select booktable From books;");
    QStringList bookNames =db->getList("Select bookNames From books;");
    int rowBook=0;
    int totalResultBooks=0;
    int totalResult=0;
    int allBookCount=bookTables.size();
    emit sendMaxProgress(allBookCount-1);
    while(rowBook<allBookCount )
    {
        QString query = QString("Select count(id) From b%1 Where text LIKE '%%2%'  Limit 0,1 ; ").arg(bookTables.at(rowBook)).arg(searchPatterned);
        QString resultBook =db->getStr(query);
        if(resultBook.toInt()>0)
       {
            totalResult+= resultBook.toInt();
            totalResultBooks++;
            QListWidgetItem *item = new QListWidgetItem;
            item->setText(bookNames.at(rowBook)+" ("+resultBook+") ");
            item->setData(12,bookTables.at(rowBook));
            QString str = "found "+QString::number(totalResult)+"at"+QString::number(totalResultBooks)+"Books";
            emit sendResult(item,str,rowBook);
       }
        msleep(40);
        rowBook++;
    }

}

To copy to clipboard, switch view to plain text mode 

my question is :
i used :

msleep(40);

msleep(40);

To copy to clipboard, switch view to plain text mode 

to free 20% of cpu ..

is this way right?
is there any better way ?