There are three things most important to any SQL performance conversation: Indices, TuneTable, and Show Plan. The attached PDFs includes historical presentations on these topics that cover the basics of these 3 things in one place. Our documentation provides more detail on these and other SQL Performance topics in the links below. The eLearning options reinforces several of these topics. In addition, there are several Developer Community articles which touch on SQL performance, and those relevant links are also listed.
There is a fair amount of repetition in the information listed below. The most important aspects of SQL performance to consider are:
The types of indices available
Using one index type over another
The information TuneTable gathers for a table and what it means to the Optimizer
How to read a Show Plan to better understand if a query is good or bad
A good writer is supposed to draw you in with the title and bury the answer somewhere in the article. I suppose this makes me a bad writer – don’t think less of me, my whole feeling of self-worth comes from the opinions of internet strangers!
Continuing on with providing some examples of various storage technologies and their performance profiles, this time we looked at the growing trend of leveraging internal commodity-based server storage, specifically the new HPE Cloudline 3150 Gen10 AMD processor-based single socket servers with two 3.2TB Samsung PM1725a NVMe drives.
Often InterSystems technology architect team is asked about recommended storage arrays or storage technologies. To provide this information to a wider audience as reference, a new series is started to provide some of the results we have encountered with various storage technologies. As a general recommendation, all-flash storage is highly recommended with all InterSystems products to provide the lowest latency and predictable IOPS capabilities.
The first in the series was the most recently tested Netapp AFF A300 storage array. This is middle-tier type storage array with several higher models above it. This specific A300 model is capable of supporting a minimal configuration of only a few drives to hundreds of drives per HA pair, and also capable of being clustered with multiple controller pairs for tens of PB's of disk capacity and hundreds of thousands of IOPS or higher.
In the last post we scheduled 24-hour collections of performance metrics using pButtons. In this post we are going to be looking at a few of the key metrics that are being collected and how they relate to the underlying system hardware. We will also start to explore the relationship between Caché (or any of the InterSystems Data Platforms) metrics and system metrics. And how you can use these metrics to understand the daily beat rate of your systems and diagnose performance problems.
As I was going though and trying to figure out why our CACHE.dat has increased in size over the past 18 days, I found that EnsLib_HL7.Message is still retaining messages dating back to 2014 even though we have our
APM normally focuses on the activity of the application but gathering information about system usage gives you important background information that helps understand and manage the performance of your application
We have 1lakh records in table and while using sql select statement , it is taking more than 9mins to 12 mins to get the records. could you please how to optimize this performance issue if we have more records.