HP 3000 Manuals HP 3000 Manuals
HP ALLBASE/SQL and HP ALLBASE/BRW Modifying the DBEnvironment The BRW programs BRWCOMP and BRWEXEC work on the current data definitions in the SQL System Catalog. This is also true when a new report is specified with BRWXL. If the specifications of an existing report are modified by the user, the specifications already done are not automatically checked against the current System Catalog entries. So, if the DBE has been modified, answer 'yes' to the prompt: "Do you want to check the SQL DBEnvironment for changes?". The results of the check done during this upgrade are listed on the Select Report screen. The messages can be used to establish whether changes must be made manually to the report specifications. Example Suppose BRWCOMP aborts with an error because an item type changed from numeric to string. In order to correct the situation, you have to enter BRWXL and answer 'yes' to the prompt: "Do you want to check the SQL DBEnvironment for chanages?". In this instance, you must manually change the calculation formula (or formulae) in which the item occurs, and recompile the report. Performance Considerations If HP ALLBASE/SQL tables have different access sequence numbers, a query is sent to HP ALLBASE/SQL for each table. HP ALLBASE/SQL tables with the same access sequence number are combined to one HP ALLBASE/SQL query. [REV BEG] In general, it is more efficient to combine all HP ALLBASE/SQL tables from a single DBEnvironment into a single query by giving them all the same access sequence number in the Tune Access screen. This allows HP ALLBASE/SQL to apply internal optimization and internal SQL indexes to join the tables in the most efficient way. If separate queries are given for each HP ALLBASE/SQL table, HP ALLBASE/BRW will have to save the results of these queries into temporary files and sort these temporary files on the common relation items before combining the tables.[REV END] Names and Datatypes The following table compares the HP ALLBASE/SQL names and datatypes with the HP ALLBASE/BRW names and data types. It also identifies any limits HP ALLBASE/BRW places on HP ALLBASE/SQL. ------------------------------------------------------------------------------------------- - HP ALLBASE/SQL HP ALLBASE/BRW - ------------------------------------------------------------------------------------------- | Names Names in double quotation marks are not | | supported | - - | Names containing native language characters | | are not supported. | ------------------------------------------------------------------------------------------- | NULL value A NULL value is sorted as the highest | | value. Two NULL items are compared as | | unequal. | ------------------------------------------------------------------------------------------- | NO_VALUE NO_VALUE is sorted as the highest value. | | Two NO_VALUE items are compared as equal. | ------------------------------------------------------------------------------------------- | CHAR (1 to 3996) String Accepts any length, but truncates to 255 | | characters. | ------------------------------------------------------------------------------------------- | VARCHAR (1 to 3996) String Accepts any length, but truncates to 255 | | characters. | ------------------------------------------------------------------------------------------- | DECIMAL Precision 1 to 15 (number of digits) Scale | | from 0 to 15 (number of digits to the right | | of the decimal) | ------------------------------------------------------------------------------------------- | NUMERIC Allows up to 13 digits to the left of the | | decimal point, up to 6 digits to the right | | of the decimal point. If values to the | | left of the decimal are greater than 13 | | digits the exception condition OVERFLOW is | | set. Scales greater than 6 are truncated. | | Note that this could cause a loss of | | accurracy. | ------------------------------------------------------------------------------------------- - FLOAT Real - ------------------------------------------------------------------------------------------- - INTEGER Integer - ------------------------------------------------------------------------------------------- - SMALLINT Integer - ------------------------------------------------------------------------------------------- - DATE DATE - ------------------------------------------------------------------------------------------- - TIME TIME - ------------------------------------------------------------------------------------------- - DATETIME (Not supported) - ------------------------------------------------------------------------------------------- - INTERVAL (Not supported in first release) - ------------------------------------------------------------------------------------------- - NULL NO_VALUE - -------------------------------------------------------------------------------------------