[SQL] pobierz, plaintext 
SELECT tabelaA.nr AS numer, SUM(tabelaA.ilosc*tabelaB.cena) AS koszt FROM tabelaA LEFT JOIN tabelaB ON tabelaA.text=tabelaB.text WHERE tabelaA.kolor='zielony' AND tabelaA.rozmiar='maly' AND tabelaA.ilosc>0 GROUP BY tabelaA.nr
 
ponizsze kolumny maja INDEX FULLTEXT
tabelaA.text
tabelaB.text
[SQL] pobierz, plaintext 

id     select_type     table     type     possible_keys     key     key_len     ref     rows     Extra     
1     SIMPLE     tabelaA     ALL     NULL    NULL    NULL    NULL    29577     Using where; Using temporary; Using filesort
1     SIMPLE     tabelaB     ALL     text     NULL    NULL    NULL    92877     Using where