Informix Corp sees the growth rate of sales in its major geographical markets remaining constant in the second quarter but improving later this year with the introduction of new products: sales are growing at 25% to 26% in North America, 22% in Europe and 31% elsewhere, chief executive Phillip White said; he declined to comment on the growth rate for overall revenues in the second quarter and for 1994, but said the company plans an advertising and marketing campaign in conjunction with Microsoft Corp for the Informix SE database that will run on Windows NT beginning May 16; he also said that because Informix is convinced that parallel processing technology is the format for mainframes of the future, the company is preparing new products to serve that market; Informix OnLine 8.0 will be demonstrated later this year, he told the assembly: it will also demonstrate a new version of its tools, 4GL-Plus-Plus, in July.