How many accounts have an owner disposition and request for a statement to be generated upon a transaction?
Frequency = 'POPLATEK PO OBRATU' stands for issuance after transaction
SELECT COUNT(T1.account_id) FROM account AS T1 INNER JOIN disp AS T2 ON T1.account_id = T2.account_id WHERE T2.type = 'OWNER' AND T1.frequency = 'POPLATEK PO OBRATU'