crucial problem about two tables in a database!!!!!!!!!!!!11

I have two tables that stores company information in a database. Since retrieving data from the tables is too slow, the structure need to be improved. The current structure of the tables is as follows: First table contains table1 companyNo : unique field that is created by sequence companyTaxNumber:have a unique index companyName : have an index, but not unique companyAddress companyCountry timestamp trigger on table1: if insertion occurs: timestamp:0 if update occurs : increment timestamp by 1 Second Table Contains table2 Up_companyNo2 : unique field that is created by sequence Up_companyTaxNumber2:have a unique index Up_companyName2 : have an index, but not unique Up_companyAddress2 Up_companyCountry2 timestamp trigger on table2: if insertion occurs: timestamp:0 if update occurs : increment timestamp by 1 update table1 where table1.companyTaxNumber=table2.Up_companyTaxNumber2 and timestamp=1 the problem is the application uses table1 details, and give reference to "companyTaxNumber" in forms. When the company information is updated (rows are not updated, inserted with a new companyNo via sequence) and inserted into table1 from table2, the new forms will use the updated information. However, old forms cannot use updated ones, since reports cannot be changed. in conclusion, table2 contains last updated company information, the initial information before updates are not stored in table2 table 1 contains all the updates as new entries since forms that use these entries cannot change the references. So, table1 gets bigger and datas retrieved slowly. Can you give me clear advices about the improvement techniques about indexes and triggers? How can I handle this situation?