IT Career Guides & Free Resources
Expert roadmaps, tutorials, salary guides and interview prep across Data Science, Generative AI, Python, Cloud & Analytics — written by GloryTecks trainers in Hyderabad.
All articles
Power BI Performance Tuning: Make Reports Faster
A method for making Power BI reports faster: measure first with Performance Analyzer and read its DAX query, visual display and other timings, then shrink the import model, reduce column cardinality on a real retail dataset, write lighter DAX, filter and simplify pages, and check capacity and gateways.
Spark Performance Interview Questions
Spark performance questions ask what you would change, and how you would know it helped. Five tuning levers are tested on 3.5 million real taxi trips with evidence that does not depend on the machine: pushed-down filters in the plan, task counts, partition sizes before and after salting, join types, and cache hits.
Spark Performance Tuning: Shuffles, Joins and Caching
A practical guide to Spark performance: reading the physical plan, why 200 shuffle partitions became one under adaptive query execution, how Spark chooses broadcast or sort-merge joins and how hints change it, what skew looks like in real partition sizes, when caching pays, and a tuning checklist.
Partitioning Data in S3 for Athena Performance
A practical guide to partitioning S3 data for Athena: what a partition is, how to choose keys, and how partitions are registered. A real month of taxi trips is partitioned by day and by hour to show pruning, a filter that prunes nothing, stray partitions from bad timestamps, and the small-file cost of going too fine.
Redshift Performance Tuning: Distribution and Sort Keys
Redshift performance tuning starts with two table properties: how rows are distributed across slices and how they are sorted on disk. This guide explains the four distribution styles and the sort key options, simulates block skipping and slice skew on 2.96 million real rows, and shows when AUTO is the right answer.
ADF Performance Tuning: DIUs and Parallelism
Raising DIUs is the reflex when a Copy activity is slow, and it is often the wrong move. This guide explains what Data Integration Units and parallel copies control, their documented defaults and limits, how billing responds, when staged copy helps, and how to read the monitoring view to find the real bottleneck.