Question
· Mar 29, 2019
Ensemble as a Data lake

We have been storing raw messages in a MySQL database for DR and ad hoc purposes. We are thinking of using an Ensemble instance as our data lake instead. We could segregate the source data by namespace or by global. But either way we'll want a custom global to index the data for data retrieval performance purposes.

Anyone else taking this approach? Any feedback?

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Hello Fellow Cache Developers:

Has anyone ever created an index on values of a list property? If so, would you be willing to share an example?

Also, feel free to offer input and suggestions regarding use of indexes on List values.

Here is my database scenario:

Parent Class:

PropertyA - %String

PropertyB - %Integer

Child Class:

PropertyC - %Integer

PropertyD - list of %Integer

Data illustration:

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I have a class which defines a property as array of %String. Is it possible to index values of this property and use this property in SQL?

I have tried 'Index idx On prop(ELEMENTS)' and then a select from the generated collection table, but this is still orders of magnitude slower than queries to the containing class.

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Question
· Apr 15, 2018
Indexes in Cache Objects

Hi-

I have the following objects

Class A

Property P1 As B

Property P2 As %String

Property P3 As %String

Class B

Property P1 As %String

Can I create an index in Class A based on P1.P1. Basically I want an index of class A by property P1 in class B

I tried creating the following but got a compile error

Index I1 On P1.P1

Thanks

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I have a persistent class that represents cities across the United States. It is below, but basically has a City Id, Name, Lat, Lon and a few other unimportant fields for this issue. Anytime I attempt to query on the Latitude or Longitude it immediately returns no results. My first thought was that it was a casting issue so I tried casting both sides to floats, ints, even strings and in all cases it immediately comes back with no results. I then decided to cast it to a string and attempt a like statement thinking it might be something about how floats are handled, but still no joy. Any

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Article
· Jul 8, 2023 2m read
Character-Slice Index

A recent question from @Vivian Lee reminded me of a rather ancient example.
It was the time when DeepSee's first version was released.
We got Bitmap Index.
And we got BitSlice Index: mapping a numeric value by its binary parts.
So my idea: Why not indexing strings by their characters?
The result of this idea was presented first in June 2008.
IKnow wasn't publicly available at that time.

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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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Hello, community!

I've stumbled on some unexpected behavior, and decided to check with you if this is normal. Basically, I'm rebuilding indices and the result is not journaling (which leads to missing indices at shadow server).

The $ZV is "Cache for UNIX (Red Hat Enterprise Linux for x86-64) 2015.2.1 (Build 705U) Mon Aug 31 2015 16:53:38 EDT"

I have an example class

Class tmp.A As %Persistent;

Index IP1 On P1;

Property P1 As %String;

for example there is one object which have P1 = 1, so

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The object and relational data models of the Caché database support three types of indexes, which are standard, bitmap, and bitslice. In addition to these three native types, developers can declare their own custom types of indexes and use them in any classes since version 2013.1. For example, iFind text indexes use that mechanism.

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Earlier in this series, we've presented four different demo applications for iKnow, illustrating how its unique bottom-up approach allows users to explore the concepts and context of their unstructured data and then leverage these insights to implement real-world use cases. We started small and simple with core exploration through the Knowledge Portal, then organized our records according to content with the Set Analysis Demo, organized our domain knowledge using the Dictionary Builder Demo and finally build complex rules to extract nontrivial patterns from text with the Rules Builder Demo.

This time, we'll dive into a different area of the iKnow feature set: iFind. Where iKnow's core APIs are all about exploration and leveraging those results programmatically in applications and analytics, iFind is focused specifically on search scenarios in a pure SQL context. We'll be presenting a simple search portal implemented in Zen that showcases iFind's main features.

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Hi all,

I'm working on a requirement to loop through all encounter streamlets(SDA) to identify specific encounters based on an encounter extension property for a patient fetch request. However, this current process is time-consuming, and we need to create indexes for that property to quickly retrieve the expected results without going through all the encounter streamlets of a patient.

I would appreciate help on how to achieve this, as I couldn't find any documentation explaining how to create indexes on a SDA element.

Thanks in advance.

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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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High-Performance Message Searching in Health Connect

The Problem

Have you ever tried to do a search in Message Viewer on a busy interface and had the query time out? This can become quite a problem as the amount of data increases. For context, the instance of Health Connect I am working with does roughly 155 million Message Headers per day with 21 day message retention. To try and help with search performance, we extended the built-in SearchTable with commonly used fields in hopes that indexing these fields would result in faster query times. Despite this, we still couldn't get some of these queries to finish at all.

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Article
· Feb 2, 2021 12m read
A custom SQL index with Python features

Image search like Google's is a nice feature that wonder me - as almost anything related to image processing.

A few months ago, InterSystems released a preview for Python Embedded. As Python has a lot of libs for deal with image processing, I decided to start my own attemptive to play with a sort of image search - a much more modest version in deed :-)

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Hey Community,

Enjoy the new video on InterSystems Developers YouTube:

A better way of buidling index for IRIS

https://www.youtube.com/embed/Ly-1hukmh8Y
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Hi Community,

Enjoy the new video on InterSystems Developers YouTube from our Tech Video Challenge:

Using Character Slice Index in InterSystems IRIS

https://www.youtube.com/embed/_aYpLVZfiCA
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InterSystems FAQ rubric

For volatile tables (tables with many INSERTs and DELETEs), storage for bitmap indexes can become inefficient over time.

For example, suppose that there are thousands of data with the following definition, and the operation of bulk deletion with TRUNCATE TABLE after being retained for a certain period of time is repeatedly performed.

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