In the past I have written about nesting data structures, a way to contain data structure(s) within another data structure. And there are times I have wanted to define a new data structure to be identical to another using the LIKEDS keyword.
01 dcl-ds One qualified ; 02 OneSF1 char(1) ; 03 dcl-ds Two ; 04 TwoSF char(5) ; 05 end-ds ; 06 OneSF2 char(1) ; 07 end-ds ; 08 dcl-ds Test1DS likeds(One) ; |
Ever since timestamps were introduction to RPG I have always felt aggrieved that they never contained the entire timestamp. Timestamps have six decimal places following the seconds and only the first three positions, milliseconds, were filled. The last three positions were always zero. Occasionally I have found in timestamp fields in two records with same value. I would unable to determine which record is older, without using other fields or the file's relative record number.
The latest round of new Technology Refreshes, IBM i 7.4 TR2 and 7.3 TR8, brought improvements to the way RPG does timestamps.
Some of what I am going to describe here may have been available in earlier releases or TRs.
I do not use the Keyed data structure, but I can appreciate this change that occurred as part of the latest new Technology Refreshes, IBM i 7.4 TR2 and 7.3 TR8, was significant.
Before the latest TRs the second parameter of the %KDS built function had to be a number to denote how many of the key fields were to be used. The change in the new TRs now allows for that second parameter to also allow a variable.
The old way would look something like this:
01 if (NbrKeyFlds = 1) ; 02 chain %kds(FileKeys:1) TESTFILER ; 03 elseif (NbrKeyFlds = 2) ; 04 chain %kds(FileKeys:2) TESTFILER ; 06 endif ; |
As part of the new Technology Refreshes, 7.4 TR2 and 7.3 TR8, came a table function to return information about a single library. I have to admit that I don't really care about some of the information returned in the results, but there are three columns I am going to find very useful.
The new table function LIBRARY_INFO is found in the library QSYS2. It combines data elements from the RTVLIBD and DSPOBJD commands. When calling this table function there are two parameters, one mandatory and the other is optional:
In these examples I am not going to use the second parameter.
Right, let's jump right in and see what information we can retrieve about one of my libraries:
Today is the day the PTFs for the latest Technology Refreshes are available for download, IBM i 7.4 TR2 and 7.3 TR8.
The relevant PTFs are:
You can find links to what are in these Technology Refreshes here.
I am now going to generate a support ticket asking RZKH to load these TRs on their partitions. When they have I can start sharing how to use these enhancements.
Every so often I stumble across something in Db2 for i that I may not have a practical use for, but I find interesting. The SQL table SQL_SIZING is a good example of this. It contains one row for each limit of the IBM i Db2 database manager.
The table contains just four columns:
This feature was brought to my attention by someone who was converting a fixed format SQLRPGLE program to modern all free RPG code, and wondered the purpose of this code snippet.
01 C/EXEC SQL 02 C+ SET OPTION COMMIT = *NONE, 03 C+ COMPILEOPT = 'DBGVIEW(*ALL)' 04 C/END-EXEC |
She understood the purpose of line 2. It was line 3 she had not seen before. Neither had I, and was intrigued as to what its purpose was and how else could it be used.
The latest updated version of IBM's "IBM i on Power – Performance FAQ" was published at the beginning of this month, May 1.
While it includes the usual system information, in the latter half it contains advice for:
To view the guide, which is a PDF, click here.