I have a production system that has a large dataset of about 2 million rows. I need to create an index on a property but don't want it available to queries until the index is fully populated. Is there a way I can create the indexed, fire off the build, then "activate" the index so queries can use it.
By specifying the start and end values of the IDs for which you want to rebuild indexes in the arguments of the %BuildIndices() method provided in the persistent class (=table) definition, you can rebuild only the indexes within that range.
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
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 :-)
I know of the existance of (ELEMENTS) to create an index from a list, but I actually would like to index the content of an element of a list. Is it possible?
My scenario:
Class: Property Test As list of TestList;
Test.List: Property Name As %String; Property Surname As %String;
I would like to have an index based on the TestList.Name. If I try using
Index NewIndex On Test(ELEMENTS)
it will create an index with Name and Surname in it, but I just want to have an index with the name. Is it possible?
I'd like to know if there are any issues if an index is inserted into a table without running the %BuildIndices() method.
It's important to note that data inserted before the index is not important for retrieval, so it's not a problem data inserted before the index don't show up in queries.
The reason why I'm asking this is that I'd like to avoid index reconstruction on big tables which I need to inser such index.
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
Suppose you have an application that allows users to write posts and comment on them. (Wait... that sounds familiar...)
For a given user, you want to be able to list all of the published posts with which that user has interacted - that is, either authored or commented on. How do you make this as fast as possible?
Here's what our %Persistent class definitions might look like as a starting point (storage definitions are important, but omitted for brevity):
I just have introduced new tag Indexing which relates to articles and questions on how to introduce, manage and increase performance with Indexing on Caché Objects.
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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