Index ZipIDX On ZipCode [ Data = (City, State) ];

Here, the index is built on the ZipCode field, and the City and State fields are included in the Data portion of the index structure (i.e., stored as part of the index global). When a query retrieves only City and State based on a ZipCode filter, the SQL engine can perform an index-only scan and avoid accessing the main "Master map". This behavior is similar to a covering index in SQL databases because the requested data is fully available within the index itself.

SELECT City, State FROM Sample.Person WHERE ZipCode = 19904;

In this case, the index global might look like:

^gblI("ZipIDX", ZipCode, ID) = $LB("", City, State)

The query will be satisfied using just the index, avoiding a full table (master map) access.

However, this index does not provide any benefit when the query uses City or State as filter conditions, since those fields are not part of the index key. So, It will search on the "Master map"

Now, consider another index:

Index CityStateIDX On (City, State);

This is a composite index (or multi-column index), where both City and State are stored as part of the index key (subscripts), not as index data. The global would look like:

^gblI("CityStateIDX", City, State, ID) = "

SELECT state FROM SAMPLE.PERSON1 WHERE city ='Newton'

When a query uses City or State in the WHERE clause, the index is used to locate the matching IDs, but the SQL engine must then perform a lookup in the master map to fetch any other columns, even if you're selecting only indexed fields like City or State.

So, composite indexes help filter rows efficiently, but they don't function like covering indexes unless the query involves only index keys and you don't need to retrieve other columns.

Here is the Index types documentation

Thank you, @Dmitry Maslennikov, for your incredible journey and inspiring contributions to the community. Wishing you continued success and endless learning ahead!

Here is the simplified version of the LIKE operator with SQL Procedure

Stored procedure

/// add multiple parameters depends on needs
Query NAMEINLIKE(p1 As %String = "", p2 As %String = "") As %Library.SQLQuery [ SqlProc ]
{
    SELECT  Name,Age FROM Sample.Person 
    WHERE Name like :p1 or Name like :p2
}

 SQL query

select * FROM SAMPLE.PERSON_NAMEINLIKE('%Eisenstien%','Xenia%')

ClassMethod INLIKE(pSQLColumnValue, pSearchValues...) As %Boolean [ SqlProc ]
{
    Set rtn=0
    For i=1:1:$O(pSearchValues(""),-1) {
        Set data = pSearchValues(i)
        If $E(data,1)="%"&&($E(data,*)="%") {
            Set data = $TR(data,"%")
            If pSQLColumnValue[data s rtn=1
        }
        ElseIf $E(data)="%" {
            Set data = $TR(data,"%")
            Set pat = ".ANPC1"""_data_""".ANPC"
            If pSQLColumnValue?@pat Set rtn = 1
        }
        ElseIf $E(data,*)="%" {
            Set data = $TR(data,"%")
            Set pat = "1"""_data_""".ANPC"
            If pSQLColumnValue?@pat Set rtn = 1
        } 
    }
    quit rtn
}

SQL Query

SELECT * FROM SAMPLE.PERSON
WHERE 1=SAMPLE.PERSON_INLIKE(FirstName,'%vid','Zelda%') 

Welcome to the DC, @DC AI Bot  

Hello @Evgeny Shvarov 

We can define the global name using either a compile-time class parameter or a runtime expression (COSEXPRESSION):

• Compile-time:
  Parameter GlobalName = {$NA(^AGlobal)};
• Runtime (COSEXPRESSION):
  Parameter GlobalName As COSEXPRESSION = "$NA(^AGlobal)";

Instead of assigning just the global name to the parameter and then later generating the full reference using $NAME, you can directly assign the full $NA(^AGlobal) expression to the parameter.

This eliminates the need to do something like:
set gn = $name(..#GlobalName)

Parameter GlobalName As COSEXPRESSION = "$NA(^AGlobal)";

Parameter GlobalName1 = {$NA(^AGlobal)};

ClassMethod SetGbl()
{
	Set @..#GlobalName1("test")=112
	zw @..#GlobalName
}

Yeah, that's true. the date should be in MM/DD/YYYY format. I updated the code.

Kudos to all the winners! 👏

As always there is a possibility to get <INVALID OREF> while direct access of objects. So, we can use responseData.items.%Get(0).titles.%Get(0).value.%Get("en_US") with some additional checks like below.

If $IsObject(responseData.items) && (responseData.items.%Size()) {
    dao1 =responseData.items.%Get(0) 
    If $IsObject(dao1.titles) {
        dao1.titles.%Get(0).value.%Get("en_US")
    }
}

Hello @Jonathan Perry

The rules for routine name /Class name is "If you start a routine name with %, use z or Z as the next character after that" So, You have to create routine in the name of %zTest/%ZTest