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#Caché

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InterSystems Caché is a multi-model DBMS and application server. See more details here.

Documentation.

Question
· Jul 16, 2017
How to index a class

Hi

I have two persistent classes defined. Lets call it Parent and Child.

Child class is one of the property of Parent Class.

I would like to define a index on Child class.

So what is the default behaviour I defined a index on a non simple data type member?

Any possibility that I could customized the behaviour ? For example. Child class has three properties.

Could I configure the index to index any combinations of these three properties?

Thanks for your help.

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I'm trying to recreate a smaller copy of our DEV machine on a sandbox instance. I installed a new instance, and thought it would be a good idea to copy over a few cache.dat files from the critical namespaces (but not all of them), and start from there.

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Hi all,

We faced a problem where we would like to map a $lb object to its corresponding data model structure in order to later on export it as JSON.

So imagin that we have something like this that actually maps to a persistent table with its structure. 

$lb("",,,,,"",,,"BOOLEAN","0",2,2,"1",,"bla",$lb(,,"bla","20050502123400"),"",1,"bla",,0)

Is there a way to transform this $lb (without the need of openig the object itself) to a JSON object with the proper table fields as properties?

Many thanks

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Hy.

I set up cache in container, which is working fine. But when accessing managment portal the default user was alway Unknown user and no username or password were required. So i disabled the Unknow user in the Security section, but now i keep getting an error access denid.

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Question
· Jul 12, 2017
Database Wildcards

Greetings,

How do I organize a wildcard search with respect to a database search?

Example of what I am trying to do: s x=$o(^G("ABC","A*",x))

Trying to navigate through the ^G global for all occurrences of "ABC", and "A*" ("A"+wildcard) but I am new to M and don't know positively how to do this. Perhaps I don't use an "*" at all, rather; another convention altogether.

Please advise.

Thanks in advance for everyone's assistance.

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Hi, Community!

And so I continue with publishing of the tasks for the Final round of InterSystems Contest on InterSystems Caché and DeepSee as a part of IT Planet Student Championship in Sochi. This year we had about 2 000 participants in InterSystems Contest.

One of the tasks for the finals was to crack the black box and another to output 9876543210!

Here's the next task: gravity!

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I am working with Caché Relationships.

I know how to iterate through the One side of the relationship and for each One iterate through all the various Manys.

What I have been trying to figure out, is the code (I can put into a Class) that will start at the top of the Manys, iterate down and for each of the Manys, pull the associated One.

I can do this with SQL or Globals, but I want to use only Class type code.

Is that clear? Any help?

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You might find it useful or not. It depends on what you can imagine it to be used with, like I had to.

Either way, I created a lib that can fetch environment variables from a file or from the OS where Caché is running.

Mostly know as dotenv. Many languages have it, so why not Caché?

The usage is pretty simple:

If you want to use OS env vars exclusively, just use the method:

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Article
· Jul 7, 2017 19m read
Indexing of non-atomic attributes

Quotes (1NF/2NF/3NF)ru:

Every row-and-column intersection contains exactly one value from the applicable domain (and nothing else).
The same value can be atomic or non-atomic depending on the purpose of this value. For example, “4286” can be
  • atomic, if its denotes “a credit card’s PIN code” (if it’s broken down or reshuffled, it is of no use any longer)
  • non-atomic, if it’s just a “sequence of numbers” (the value still makes sense if broken down into several parts or reshuffled)

This article explores the standard methods of increasing the performance of SQL queries involving the following types of fields: string, date, simple list (in the $LB format), "list of <...>" and "array of <...>".

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Hello,

I'm currently exploring alternatives to CSP/services and ODBC/Sql Maps for access to Caché. I'm not seeing a library which would interest me, so am considering creating one myself.

Does 'CacheConnection' in C# use RPC of some sort, or a defined protocol to communicate with Caché, or does it do so over telnet with scripted commands? I would assume the former. If so, is this a publicly documented protocol that can be implemented by library developers?

Any guidance in this area would be appreciated.

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hi

I restored one database on Server B with EXTSELCT^DBREST command from backup file (this backup file is taken from Server A).

When I execute select some rows from one table, it return error like this,

the same select sql can return correct data in server A

But when I select other rows from same table on Server B, it return correct data.

Why? maybe the backup file corrupted?

Thanks

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"SELECT %SYSTEM.SQL_TableExists('table name') "could work as expected under SQL shell,

but for "CALL %SYSTEM.SQL_TableExists('table name')" does not work (not any error reported, it just show nothing).

Is there any reason why CALL could not be applied to a stored procedure?

Thanks.

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Question
· Nov 28, 2016
spatial data

Hello. I am a student from Syktyvakar Forest Institute(Russia).

I need to make Research : "Databases for working with spatial data
Consider MySQL, PostgreSQL and 1 to choose from". I want to explore Cache with subject library of spatial data.

Help.

Does Someone from the developers write the libraries of spatial data?

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Good day, I would like to find out the size of Caché ObjectScript variable in order to guarantee that my program will not leak, equally in terminal and Caché globals. For example how huge number I can store in that variable ? And what happen in Caché when variable will leak ? How is this behavior treated? (how much memory is reserved for common variable?)

Thanks in advance for your answers.

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