Hi Community!
Please welcome a new video on InterSystems YouTube Channel:
InterSystems and Python QuickStart
Globals
In the previous parts (1, 2) we talked about globals as trees. In this article, we will look at them as sparse arrays.
A sparse array - is a type of array where most values assume an identical value.
In practice, you will often see sparse arrays so huge that there is no point in occupying memory with identical elements. Therefore, it makes sense to organize sparse arrays in such a way that memory is not wasted on storing duplicate values.
In some programming languages, sparse arrays are part of the language - for example, in J, MATLAB. In other languages, there are special libraries that let you use them. For C++, those would be Eigen and the like.
Globals are good candidates for implementing sparse arrays for the following reasons:
Last comment 23 May 2019
In my earlier article on Adopting Bitmaps I described the technique already.
Now you can find a code example also on Open Exchange.
Suppose we need to store millions of values temporarily, that means, we don't care about them if we lose them but our application use them to get realtime information. Should I use Cachetemp or whatever other DB without journaling enabled? If answer is Cachetemp, shouldn't be a problem if we decide to scale using App Server + ECP? I'm not sure what would happen with the app logic in such architecture as I guess I couldn't map and share cachetemp...
Any idea/suggestion?
Last answer 13 February 2019 Last comment 13 February 2019
The Art of Mapping Globals to Classes 1 of 3
Looking to breathe new life into an old MUMPS application? Follow these steps to map your existing globals to classes and expose all that beautiful data to Objects and SQL.
Last comment 1 February 2019
Hi,
Most of my classes are mapped from Globals. I want to access Cache classes from a BI software through ODBC connection.
'Last update' information does not exist in most of the classes. My question is whether there is a 'last update' timestamp that is automatically generated for each line in classes I can extract to external systems?
Thanks
Last answer 10 November 2018 Last comment 12 November 2018
It's well-known that namespace global mapping helps us to write code independent on database storage details (Caché instance name, directory path). But sometimes we can face problems accessing an unsubscripted global which has subscript level mapping (SLM) defined. Most of such cases are evident and associated with administrative tasks that should be done on database level, but some of them can confuse even an experienced developer. Just to start:
Last comment 13 October 2018
Hi,
I've read into console.log that there is some problems writing the global Task History
09/13/18-09:33:00:109 (9052) 0 Error al escribir en global de historial de tareas - Error (ERROR #5002: Error de cache: <DATABASE>%SaveData+20^%SYS.Task.History.1 ^SYS("Task","HistoryD",66179),c:\intersystems\healthshare\mgr\)
Last answer 14 September 2018 Last comment 14 September 2018
I have a global that defines the instance that Ensemble is running under. I want to use this as part of another Global so I don't have to hard code a path.
For Example
^OSUWMCInstance = "TestClin"
^OSUMCLDAP("LDAPKey") = "/ensemble/^OSUWMCInstance/mgr/LDAPKeyStore/"
Is this possible?
Thanks
Scott
Last answer 31 July 2018
I am still working on a generic task where I need to apply journal file records to another database. Initially I didn't want to use Journal.Restore class methods as I need to perform some data transformation, and it seemed that the clearest way to achieve it was to read journal file record by record using %SYS.Journal.Record API.
Last answer 16 June 2018 Last comment 16 June 2018
The Art of Mapping Globals to Classes (4 of 3)
The forth in the trilogy, anyone a Hitchhikers Guide to the Galaxy fan?
If you are looking to breathe new life into an old MUMPS application follow these steps to map your globals to classes and expose all that beautiful data to Objects and SQL.
If the above does not sound familiar to you please start at the beginning with the following:
Last comment 12 June 2018
I'm working on a task where I need to apply journal file records to another database. I can't use Journal.Restore class methods as I need to perform some data transformation, therefore I'm reading journal file record by record using %SYS.Journal.Record API.
It seems that there are only few journal records that I need to process, namely:
Last answer 7 June 2018 Last comment 7 June 2018
Hi,
I wonder if you could help me with a problem with persistent globals and journals.
We have a few interfaces using a persistent global just to translate some codes. The use of that global is like a lookup table...an interface calls a method that search for a field (in the message) in the global. If found, the code is translated with another field from the global.
The format of the global is something like:
Last answer 10 May 2018 Last comment 11 May 2018
Hi,
I'm trying to export a global with this library %Library.Global with this call:
Last answer 3 May 2018 Last comment 3 May 2018
Hi! I have a local project written on Cache and Atelier on my PC. I need to move it to notebook. Tried to export globals, classes, MAC-programms and csp with frontend stuff, but after I created my apps on notebook and imported my set, it just didn't work. I think it's because I have some settings on Management Portal, so how can I export portal settings and what I should export to have my working apps on another computer?
Last answer 29 April 2018 Last comment 29 April 2018
Hi:
I'm looking for some help with JSON notation for a global structure. I need a way to represent a global structure in JSON where the global structure both has a value at a given node as well as sub-nodes.
Last answer 28 April 2018 Last comment 28 April 2018
Is there a way to reduce the size of a CACHE.DAT file after a major reduction in global content has been performed?
Thx... Larry.
Last answer 13 April 2018
Deployment, Globals, Microsoft Windows Server, System Administration, Web Development, Web Services, Ensemble
Hi.
The message is received a few times a day.
On documentation, this ^ISCSOAP^is log to service SOAP, but why send to cconsole.log?
04/04/18-01:00:00:597 (10608) 2 ^ISCSOAP in Namespace %SYS has been active for 348 day(s).
04/04/18-01:00:00:598 (10608) 2 ^ISCSOAP in Namespace X has been active for 165 day(s).
Help-me.
Tks
Last answer 5 April 2018 Last comment 5 April 2018
I have a simple app which tries to establish a connection with a Cache database instance via Global API for Java:
import com.intersys.globals.Connection;
import com.intersys.globals.ConnectionContext;
public class Assignment {
public static void main(String[] args) {
Connection connection = ConnectionContext.getConnection();
connection.connect("SAMPLES", "_SYSTEM", "SYS");
}
}
The expection I am getting:
Last answer 27 February 2018 Last comment 25 March 2018
Is there something in Cache that is equivalent to partitioning a table in Oracle? I'm trying to break some big tables into groups so that the most frequently accessed data is faster to retrieve.
Here is some information on this concept from Oracle.
https://docs.oracle.com/cd/B28359_01/server.111/b32024/partition.htm
Last answer 28 April 2016 Last comment 23 March 2018
Is there a way to pull a user name and password from the Credentials list that is kept in Ensemble? Right now I have a LDAP user that I have hard coded into my ZAUTHENTICATE, which I would like to get away from. I am not to familiar with settings Global, or calling them at least.
Thanks
Scott
Last answer 24 February 2018 Last comment 1 March 2018
Hi Guys,
I would like to know, how to setup a global structure in Cache classes storage type.
I want to set a global like below in Cache classes using Storage methods.
^A("ID1")="Name\Abb\Map"
^A("ID2")="Name\Abb\Map"
^A("ID3")="Name\Abb\Map"
...
If any lead it would be appreciated.
Thanks,
Arun Kumar Durairaj.
Last answer 1 February 2018
Some of our interfaces use globals for lookups, but we are currently looking at putting a groups of (document) interfaces in a separate production with a shared ‘Default Database for Routines’ to reduce code duplication.
Last answer 15 January 2018 Last comment 11 October 2017
Hi, Community!
Consider you move data from one server to another or make a deployment with persistent data. What do you do with index globals?
Is it always better to rebuild them or there are some cases when it worth to take them too?
Last answer 30 November 2017 Last comment 1 December 2017
The Art of Mapping Globals to Classes (3 of 3)
If you are looking to breathe new life into an old MUMPS application follow these steps to map your globals to classes and expose all that beautiful data to Objects and SQL.
If the above does not sound familiar to you please start at the beginning with the following:
Last comment 2 November 2017
I have a classname and a property name. I want to know, when I get object value directly from a global, which property corresponds to which position in the $lb structure.
Here's what I got so far:
Last answer 27 October 2017 Last comment 27 October 2017
I have two databases, and both of them have a global ^Data with subscripts going from 1 to 10 000 000.
I want to get one database with global ^Data but with subscripts going from 1 to 20 000 000.
Since each db is around 100 Gb and they are on a different hosts, what's the best way to merge them?
Last answer 25 October 2017 Last comment 25 October 2017
Hi,
I have a class with around 400k lines and 60 columns. Class storage is Cache SQL storage (Mapped from a global).
I want to create multiple indices on certain fields.
I am familiar with two approaches:
1. Create a new map (Index type) on a pointer global.
2. Create a bitmap index
Which approach is more recommended to be used in the case I described? If there are any other approaches, I will be happy to hear.
Thanks :)
Last answer 11 October 2017 Last comment 19 October 2017
Is there a way to omit or skip rollback of some data changes during a transaction rollback? Maybe some sort of "autonomous transaction"?
The issue is with error logging in transaction. For example we may have in nested calls the following structure:
TS
<some code>
<error happens>
TRO 1
<error log to database>
but if this code is in another transaction, and that rolls back we lose error data.
Last answer 28 August 2017 Last comment 25 August 2017