$increment is (or used to be) unique in that it was the only function that changed its argument. It reminded me of learning about "destructive functions" in LISP a long time ago. No matter where/how you use it, it increments. So "set a = $increment(a)" is redundant, but still OK to use. As you saw, developers started to use "if $increment(a)" alone, because that was shorter but also works fine, even thought it looks strange. I wasn't aware of "do $increment(a)" being allowed, which does look nicer, so I also learned something new from this thread, thanks.

And let's not forget to mention the popular and useful "set a($increment(a)) =  something"

Oh, and one more little tidbit about the 2nd argument to %ExecDirect(), the one containing the SQL text. Instead of being a single long string, it can be an array of strings, passed by reference with a leading dot (not variadic). So the first few lines of GetTransactions() could look like the example below. This approach has the nice benefit of adding spaces between each line; notice I removed the extra spaces at the end of each line of SQL.

    set sql = 1
    set sql(1) = "select Product->Name, Outlet->City, AmountOfSale, UnitsSold "_
        "from HoleFoods.SalesTransaction where Actual = 1"
    if (product '= "") {
        set sql($increment(sql)) = "and Product = ?"
        set args($increment(args)) = product
    }
    if (channel '= "") {
        set sql($increment(sql)) = "and Channel %INLIST ?"
        set args($increment(args)) = channel
    // ...and so on...and eventually...
    set result = ##class(%SQL.Statement).%ExecDirect(, .sql, args...)

It's a leading dot and trailing dots festival.

A few thoughts on this lovely post:

  • I think "Bad Solution #1" is really "Terrible, Awful, Never Ever Do This And I'm Not Kidding Solution #1."
  • I think "Bad Solution #2: Spaghetti Code" is really "OK Solution #1: Complex ObjectScript".
  • I think the alternative solution with the multiple "OR ? is null" statements could be "OK Solution #2: Complex SQL" but only if Runtime Plan Choice is available in your version and only if it allows the optimizer to pick a good plan in all cases (still to be verified by someone 🧐). Update 5/7/24: I have verified that in v2024.1, Runtime Plan Choice generates different good plans based on presence or absence of values for ? placeholders!
  • Performance options for the WHERE clause on channels. I haven't tested which of these options is better as the list of channels gets larger (although I don't think it would get really large).
    • Supplying a $listbuild of the channels and using %INLIST on that uses $listfind to test the condition for each row.
    • Looping through the $listbuild (as in Bad Solution #1), using either the "not-so-good $listlength style" or the "better $listnext style," and building a series of ORs uses $data on the subscripts of an array to test the condition for each row. Looping through the $listbuild and building a simpler IN instead of the series of ORs also uses $data on an array.
  • I think "Variadic" is my new favorite word!

Some more thoughts on this:

  • If the 3rd party system claims that they're not starting a transaction, but you have evidence that a transaction is starting, it would be good to try to work together to get to the bottom of that. Of course that's up to you. It's best to get the WRC involved.
  • Transactions are an application thing, not a user-oriented thing. There is no way to say "prevent user X or role Y from starting a transaction."
  • There is a potential reason for the 3rd party system to be using transactions even when simply reading data with SELECT, known as Isolation Level. Read about it here. To establish Isolation Level, you can use SET TRANSACTION (which doesn't start a transaction), or START TRANSACTION (which obviously does start a transaction). By default, a SELECT shows you all the matching rows, even rows that are uncommitted (changes to those rows could be rolled back). ISOLATION LEVEL READ COMMITTED is used when you want to guarantee that a SELECT shows you only committed data, although this may result in the SELECT failing to complete when it reaches a row that has not been committed yet. So maybe the 3rd party system is using START TRANSACTION for that. Maybe they could switch to SET TRANSACTION instead. Edit: Unfortunately, IRIS does not provide the ability to GRANT or REVOKE the ability to use SET/START TRANSACTION.
  • You wrote "If they have a process that is starting a transaction, i want it to fail/return an error to them." But wouldn't that prevent any of their queries from running? In other words, since the 3rd party system always starts a transaction, and that behavior can't be turned off, IRIS would return an error every time, and the query wouldn't run.

I edited this post and made some corrections below.

I think the Community needs more information in order to help you. Data for %Persistent classes is stored in globals. Data for %SerialObject classes is also stored in globals. Properties of %Persistent classes can reference %SerialObject classes, and when the %Persistent data is saved, the referenced %SerialObject data is also stored in globals.

The decision about whether to create %Persistent or %SerialObject classes for storing data is an object modeling decision, unrelated to the need to purge data on some schedule. Changing classes from %Persistent to %SerialObject (or vice versa) for an existing application is a major design change which would probably require plenty of code rewrites. I don't think anyone would do that work just for the sake of purging. There must be something else going on.

Semi-educated guess: Maybe when you say "purging" you're talking about purging messages in interoperability productions. These messages have message headers, message bodies, and the bodies may have properties that reference %Persistent or %SerialObject objects. When you purge those messages, you have the option to purge message bodies, but if the bodies reference %Persistent objects, the referenced objects are not purged. Maybe that's what you're seeing, and maybe that's why you're thinking of switching storage definitions. There is certainly a way to make sure that any referenced objects get purged when messages are purged, documented (briefly) here. The WRC can also offer assistance.

Please tell us if my semi-educated guess is correct, or if not, please give us more information. Happy New Year!

Very interesting question! In case anyone is wondering, in Studio you can access this info in the Workspace View on the Namespace tab or the Project tab. Right-click on the package name, and click Package Information. The information entered here is stored in the ^oddPKG global, subscripted by package name.


There doesn't appear to be a way to access this information in VS Code. I think it's worth creating an issue for this here (VS Code ObjectScript issues) and see what happens.

I'm not exactly sure what fast shutdown is so I don't know the answer. I'm also not sure if "iris force" is the same as fast shutdown. I suppose they could be similar. When you do "iris force" IRIS runs an irisstat to capture the pre-force state and writes it to messages.log; fast shutdown doesn't do that.

Edit: I also learned that fast shutdown waits for our system daemons to quiesce whereas iris force doesn't wait. @Eduard Lebedyuk: despite that behavior, maybe iris force takes longer because it runs irisstat.

It is ideal to stop IRIS before stopping the OS. However, if you stop the OS while IRIS is still running, IRIS can handle it. Check the IRIS messages.log after you shut down the OS, and you'll see lines like these:

10/16/23-18:11:04.649 (5940) 1 [Generic.Event] Operating System shutdown! InterSystems IRIS performing fast shutdown.
10/16/23-18:11:06.001 (5940) 1 [Generic.Event] Fast shutdown complete

If your plan is to stop the OS and change the machine name, then definitely shut down IRIS in advance of stopping the OS.

Thanks Mihoko!

Also note: the argument with ... after its name doesn't have to be the only argument to the method; it must be the last argument to the method. So NewMethod1()'s signature could be:
​​​​

ClassMethod NewMethod1(a as %String, b as %String, c... as %String)
{
    kill ^a, ^b, ^c
    set ^a = a, ^b = b
    merge ^c = c
}

Running it like this:

USER>DO ##class(TEST.ARGTEST1).NewMethod1(1,2,3,4,5,6,7)
USER>ZWRITE ^a, ^b, ^c
^a=1
^b=2
^c=5
^c(1)=3
^c(2)=4
^c(3)=5
^c(4)=6
^c(5)=7

Does this example make it clear? Does this meet your needs?

USER>set human = ##class(Simple.Human).%OpenId(1)

USER>zw human
human=20@Simple.Human  ; <OREF>
+----------------- general information ---------------
|      oref value: 20
|      class name: Simple.Human
|           %%OID: $lb("1","Simple.Human")
| reference count: 2
+----------------- attribute values ------------------
|       %Concurrency = 1  <Set>
|            Company = "GlobaDyne Inc."
|               Name = "Smith,John"
|              Phone = "265-288-5681"
|            Version = 2
+----------------- swizzled references ---------------
|             i%Home = $lb("6489 Clinton Street","Denver","NJ",26882)  <Set>
|             r%Home = ""  <Set>
|             i%Work = $lb("9353 Main Drive","Hialeah","MI",72997)  <Set>
|             r%Work = ""  <Set>
+-----------------------------------------------------

USER>write human.%IsModified()
0
USER>write human.PhoneIsModified()
0
USER>set human.Phone = "111-222-3333"

USER>write human.%IsModified()       
1
USER>write human.PhoneIsModified()   
1
USER>write human.Home.Street
6489 Clinton Street
USER>write human.Home.StreetIsModified()
0
USER>set human.Home.Street = "111 High Street"

USER>write human.Home.StreetIsModified()      
1
USER>

After reading through this thread, it seems like there are two questions:

  1. What is the correct syntax for calling a method? That question has been answered by several posts. It's either using ..method2() if method2() is in the same class as method1(), or ##class(package.class).method2() if method2() is in a different package.class. Use "do" to call the method, or "set retval = " to call the method and capture the returned value.
  2. Why when I run method1() I get data, but when I add a call to method2() from inside method1() I get no data? As Davide suggested, using "adm" as an embedded SQL cursor in the GetDataExecute() method and the GetSphereJauh() method is probably causing the problem, so try changing the cursor name to "juah" in the declare, open, fetch and close statements in GetSphereJauh(). If that doesn't help, you should probably contact TrakCare Support and get their help.